Artcraft Urban Group Pty Ltd v Streetworx Pty Ltd

1. The appellant be granted leave to appeal.
2. The appeal be dismissed.
3. The appellant pay the respondent's costs of and incidental to the appeal. Note: Entry of orders is dealt with in Rule 39.32 of the Federal Court Rules 2011.

Background 1 These proceedings are concerned with an application for leave to appeal from orders of the Court made by the primary judge on 2 February 2015. Although the application for leave to appeal (and supporting affidavit material) recites the making of Orders 3, 4, 5 and 16 on 30 January 2015 and the draft notice of appeal also recites the making of declarations and orders on 30 January 2015, the declarations and orders from which the application and appeal lies were made on 2 February 2015. 2 On 25 February 2015, the Court ordered that the application for leave to appeal be heard at the time of hearing any appeal. 3 In substance and effect, the parties conducted these proceedings before the Full Court on the footing of a hearing of all grounds of appeal on the merits. 4 I have had the benefit of reading what I would describe as the final draft reasons for judgment of Justice Jessup on this appeal. I have elected to formulate these reasons in support of the orders I propose and in doing so I note that Jessup J has reproduced at [170] images of the "Modified Artcraft luminaire" reproduced in the reasons of the primary judge at [41] and extracted from Annexure "B" to the amended statement of claim. 5 In the principal proceeding the respondent to the appeal, Streetworx Pty Ltd ("Streetworx"), sought relief against the appellant, Artcraft Urban Group Pty Ltd ("Artcraft"), and Murray John Saint ("Mr Saint"), a director and general manager of Artcraft, arising out of contended infringements by Artcraft (and authorisation of those infringements by Mr Saint) of two Australian innovation patents of which Streetworx is the registered proprietor under the Patents Act 1990 (Cth) (the "Act" or "Patents Act"). Those innovation patents are numbered 2009101103 (the "103 Patent") and 2009101104 (the "104 Patent"). Streetworx sought declarations as to infringement, injunctions restraining further infringements of the patents, damages or an account of profits, and other relief. 6 The trial of the action dealt only with issues of liability and an order was made that issues of liability be heard and determined separately from and prior to issues of relief: see Streetworx Pty Ltd v Artcraft Urban Group Pty Ltd [2014] FCA 1366; (2014) 110 IPR 82 at [3] (the "principal proceeding"). Because the issues were split in this way, an application for leave to appeal was necessary. 7 In the principal proceeding, the primary judge made a declaration that Artcraft had infringed each of claims 1 to 4 of the 103 Patent and each of claims 1 to 4 of the 104 Patent by exploiting in Australia without the licence or authority of Streetworx the "Artcraft luminaire as defined in the Amended Statement of Claim": Declaration 1. The "Artcraft luminaire" is described at para 2(c)(i) and (ii) of the amended statement of claim as a lighting assembly bearing, at least before May 2013, the name "Artcraft" and model number "AUGT5" as depicted in Annexure "A". 8 The primary judge also made a declaration that Artcraft had infringed each of claims 1 to 4 of the 103 Patent and each of claims 1, 2 and 4 of the 104 Patent by exploiting in Australia, without the licence or authority of Streetworx, the "Windowless Artcraft luminaire as defined in the Amended Statement of Claim": Declaration 2. The "Windowless Artcraft luminaire" is described at para 2(e)(i) and (ii) of the amended statement of claim as a lighting assembly bearing, at the latest January 2012, the name "Artcraft" and model number "AUGT5" as depicted in Annexure "C". 9 Of immediate relevance to these proceedings, the primary judge also made a declaration that Artcraft had infringed each of claims 1 to 4 of the 103 Patent by exploiting in Australia, without the licence or authority of Streetworx, the "Modified Artcraft luminaire as defined in the Amended Statement of Claim": Declaration 3. The "Modified Artcraft luminaire" is described at para 2(d)(i) and (ii) of the amended statement of claim as a lighting assembly bearing, at the latest January 2014, the name "Artcraft" and model number "AUGT5" as depicted in Annexure "B". The photographs reproduced by the primary judge in his reasons for judgment at [41] are described as "picture 2" and "picture 4" of Annexure "B" to the amended statement of claim. Justice Jessup has also reproduced these images at [170] of his Honour's reasons in this appeal. There is no need for me to reproduce the images in these reasons. 10 In the principal proceedings, Artcraft cross-claimed for revocation of the patents on a number of grounds. By Order 4 of the orders made on 2 February 2015, the primary judge dismissed the cross-claim of the respondents. 11 By Order 5(a), Artcraft was permanently restrained from infringing either of the patents and, in particular, from making or, put simply, exploiting a lighting assembly as claimed in any of claims 1 to 4 of either of the patents, without the licence or authority of Streetworx. Artcraft was also permanently restrained from authorising other persons to do anything the subject of the principal restraint at Order 5(a), without the licence or authority of Streetworx: Order 5(b). 12 By Order 16, the Court certified that pursuant to s 19 of the Patents Act, "the validity of claims 1 to 4 of the 103 Patent was questioned unsuccessfully in this proceeding". 13 By these appeal proceedings, Artcraft appeals from Declaration 3 (that is to say, the declaration of infringement by Artcraft of claims 1 to 4 of the 103 Patent in respect of the "Modified Artcraft luminaire") and Orders 4, 5 and 16 made and given on 2 February 2015. Although Order 5 is framed in terms of a permanent injunction restraining infringement of either of the patents, Artcraft confines its appeal in relation to the infringement finding to an appeal from a finding that the Modified Artcraft luminaire infringed the 103 Patent. 14 The ground upon which Artcraft challenges the declaration and Order 5 goes to a question of construction of claim 1 of the 103 Patent. Put simply, the contention is that, properly construed, the relevant section of a plastic visor forming part of the Modified Artcraft luminaire does not satisfy a requirement of claim 1, that is, an integer of the claim, that the "termination chamber" of the "lighting assembly" contemplated by claim 1 be "visible through the visor". 15 Artcraft contends that if there is no error of construction of claim 1 with the result that the phrase "visible through the visor", in context, is broad enough to comprehend the features of the Modified Artcraft luminaire, then the primary judge erred in concluding that claim 1 of the 103 Patent (and each of its dependent claims) is fairly based as required by s 40(3) of the Act as it stood at the material time and is useful as required by s 18(1A)(c) of the Act.

The 103 Patent 16 The invention the subject of the 103 Patent bears the title "Lighting Assembly". A complete specification for an invention must describe the invention fully including the best method known to the applicant of performing the invention and where it relates to an application for an innovation patent, the complete specification must end with at least one and no more than five claims defining the invention: s 40(2)(a) and (c) of the Act. The claim or claims must be clear and succinct and fairly based on matter described in the specification: s 40(3) of the Act. 17 By the complete specification, the author of the document tells the reader the things described at [18] to [55] of these reasons. 18 The present invention relates to the field of lighting, particularly lighting assemblies and fixtures of the type known as "exterior luminaire". 19 In one particular aspect, the present invention relates to a light assembly, that is, an electrical device used to create artificial illumination and in one particular aspect the present invention is suitable for use as outdoor lighting of the type found in public areas such as parks and gardens, sports and leisure areas and thoroughfares such as roads, streets and tunnels. Where used in the complete specification, the term "light assembly" includes luminaire within its scope. The term "luminaire" is a term of the art that includes a lighting assembly comprising a light source (lamp), a reflector for directing the light, an aperture covered by a lens, an outer casing for lamp alignment and protection, an electrical ballast and connection to a power source. 20 The use of electric street lighting dates back to the 19th Century when carbon arc lamps employing alternating current were used to ensure the electrodes burned down at the same rate. However, due to constant maintenance and other factors they had been replaced by incandescent light bulbs which remained in use until replaced by high-intensity discharge lamps. Before the invention of photoelectric controls ("PE cells"), a single switch or clock would be used to regulate turning on or turning off all artificial light in an entire district. Street lighting today typically uses high intensity discharge lamps or high pressure sodium lamps. The use of compact fluorescent lamps is also becoming common as their quality improves. 21 As to orientation and fixing, the specification says that street lights are located at the top of poles in order to maximise the amount of light they cast onto the thoroughfare below. Since the 19th Century, street lighting has progressed from the use of straight, vertical poles three to four metres in height to include much taller structures of up to 10 metres in height often curved at the top or including a bracket to locate the light closer to the centre of the thoroughfare. 22 In terms of the prior art, the specification recites that many of these types of street lights are produced including those sold under the registered Australian trade mark "Greenstreet" by Pierlite Pty Ltd and the street light described in Pierlite's patent application AU 2004205200. 23 As to these prior art lighting assemblies, the specification says this: In lighting assemblies such as the Greenstreet® apparatus there is often multiple parts for entry to internal portions of the lens/visor, the component area may not be locked and could vibrate loose. Also the fixture may not be attached with lanyard. [emphasis added] 24 As to the perceived difficulties of these types of street lights, the specification says this: These issues [as described in the quoted passage at [23]] may contribute to warranting increased ongoing maintenance. With the additional part(s) included by having a separate cover arrangement, there is an opportunity for the apparatus to be loose, moving and a potential for falling parts, which can be a serious OHS issue. These arrangements allow a point of entry for vermin, spiders (webs), insects/pests to enter the light and allows weather/pollution exposure and effects (e.g. salt in coastal areas). Risk introduced because of the above include that of fire, electrocution and general OHS hazards. [emphasis added] 25 The issue of ongoing maintenance generally is taken up in the next paragraph of the specification in these terms: Service and maintenance of street lighting incurs significant cost for the organisation responsible, such councils or power companies, who may have to ensure that linesman [linesmen] tend to many thousands of street lights over a large area. For example, visual inspections of lighting assemblies may be carried out at 24 month intervals or more frequently if environmental conditions are severe and they are typically automatically replaced when they have achieved their rated life because their output gradually deteriorates over time. [emphasis added] 26 The elevated position of a light has particular significance in this way: The elevated position of each light contributes to the time, cost and difficulties associated with servicing and maintaining the lighting system. In order to save time and avoid interruption to service, street light systems are not usually turned off during maintenance or servicing and the lighting system is left "live" while the linesmen are at work. Typically they manually handle cables operating at 196-254V AC or 176-254V DC. Accordingly, in addition to routine occupational safety and health hazards for an electrician, linesmen must also face the hazards of working at elevated heights with live electricity cables. [emphasis added] 27 As to the problems presented by street lights of the prior art, the specification says this: One of the problems with street lights of the prior art is that they are not sufficiently robust to withstand exposure to the external environment (including adverse weather conditions, pollution, sunlight, ingress of insect and other pests and/or their nests/webs etc) or the internal environment created by normal use (such as build up of heat leading to shortened life of components). This leads to parts becoming brittle, corroded or otherwise worn out so that they cease working. This increases the need for servicing and maintenance. [emphasis added] 28 There are two other problems presented by street lights of the prior art, the first of which is put this way: Another problem with street lights of the prior art is that they are time consuming to maintain. Because the street lights are serviced "live", linesmen must wear several thick protective gloves which limit their manual dexterity, making even simple manipulations quite difficult and time consuming. This problem can be made worse if the linesman has to replace components of the street light that break easily because they are brittle or corroded. Another factor that makes street lights time consuming to maintain is the comparatively small size of the components and their housing. Because linesman [linesmen] must work at elevated heights, a component that is dropped may plummet many metres to the ground, potentially injuring those below or causing lost time when the linesman goes to retrieve the part. [emphasis added] 29 The second identified further problem is put this way: A further problem with street lights of the prior art is the malfunctioning of the photoelectric (PE) cell. A PE cell is typically present in each individual street light and controls the activation and deactivation of the street light based on the ambient light level. "Day burners" (lights that emit 24 hours a day) are often caused when PC [PE] cells fail to turn off, shortening the lifespan of the light components and concomitantly increasing maintenance needs. PC [PE] cells typically fail to turn off when something blocks them from sensing ambient light. Furthermore, a PC [PE] cell may fail to activate if impinged upon by stray light, such as reflected light or illumination from an adjacent street light. [emphasis added] 30 The specification then sets out a summary of the invention by reference to a sequence of objects to be achieved by particular embodiments of the invention. Those objects are put this way: SUMMARY OF INVENTION An object of the embodiments of the present invention is to reduce the maintenance and servicing required for lighting assemblies. A further object of the embodiments of the present invention is to improve the ease and speed with which lighting assemblies can be serviced or maintained. It is an object of the embodiments described herein to overcome or alleviate at least one of the above noted drawbacks of related art systems or to at least provide a useful alternative to related art systems. [emphasis added] 31 Having identified the objects of the embodiments, the specification then identifies an aspect of the embodiments in this way, at p 5, lns 19-25: In a first aspect of embodiments described herein there is provided a lighting assembly having a casing comprising a main body defining a port for receiving a mains cable, and a visor, the casing enclosing; - a reflector assembly for receiving at least one lamp, and - a termination chamber, wherein the visor is of unitary construction for covering both the reflector assembly and the termination chamber. [emphasis added] 32 In formulating this first aspect of the embodiments, there is no reference to the notion of the termination chamber (or a part of it) and the reflector assembly (or a part of it) being visible through the visor covering the reflector assembly and the termination chamber. 33 The specification then identifies a preference in relation to the casing which is said to avoid problems associated with prior art lighting assemblies. The specification puts it this way: Preferably the casing includes at least one integral hinge that permits movement of the visor from a first, closed position to a second, open position permitting full access to the reflector assembly and termination chamber, without the visor disengaging from the main body. This avoids the problem associated with prior art lighting assemblies which have a hinge separate to the casing and a plurality of parts that are prone to coming apart and disengaging from the casing. Further, the integral hinge portion prevents excess freedom of movement of the visor/lens with respect to the casing, which can result in misalignment of the two parts upon closing up of the light assembly at the end of maintenance and/or service. [emphasis added] 34 The specification recites another preference in the form of an interface between the visor and the main body of the light assembly, in these terms: Preferably a gasket of silicon or neoprene or other suitable material is provided along at least part of the interface between the visor and the main body. In addition the edge of the visor or main body includes a lip to form a hermetic seal against ingress of dirt, insects or moisture. Moisture ingress in lighting assemblies of the prior art contributes to corrosion or shorting out of components, requiring a linesman to open up the lighting assembly to dry it out and replace the damaged components. Build up of insect nests and dirt on the visor tend to reduce the transparency of the lens and diminish the output and effectiveness of the light so that a linesman must open up the assembly and clean the lens with detergent. [emphasis added] 35 The specification then describes a second aspect of the embodiments in these terms, at p 8, lns 1-9: In a second aspect of embodiments described herein there is provided a lighting assembly having a casing comprising a main body defining a port for receiving a mains cable, and a polymer visor, the casing enclosing, - a reflector assembly for receiving at least one lamp, and - a termination chamber, the termination chamber being at least 20-25% of the volume of the casing wherein the visor is of unitary construction and is adapted to cover both the reflector assembly and the termination chamber. [emphasis added] 36 In the second aspect of the embodiments, there is no reference to the notion of the termination chamber (or a part of it) and the reflector assembly (or a part of it) being visible through the visor covering the reflector assembly and the termination chamber. 37 In the preferred embodiments, the termination chamber is to be between 23-25% of the volume of the casing. 38 The advantage of the increased volume of the termination chamber over the prior art is put this way: The increased volume of the termination chamber compared to equivalent structures of the prior art allows easier manual handling of the mains cable and easier manipulation of other parts and components within the casing such as the PE cell and the terminal block, without the use of tools. … Preferably, … the termination chamber is 200-220 mm in width, 120-140 mm deep (60-65mm excluding the visor) and 200-300 mm in length. The larger volume of the termination chamber thus permits an improved layout of components. [emphasis added] 39 The increase in volume of the termination chamber is also said to assist in dissipating heat and reducing the operating temperature. In particular, the increased volume keeps the "control gear" cooler by locating it further away from the casing surface. 40 The specification then describes a third aspect of the embodiments in these terms, at p 9, lns 30-33; p 10, lns 1-4: In yet a third aspect of embodiments described herein there is provided a lighting assembly having a casing comprising a main body defining a port for receiving a mains cable, and a visor, the casing enclosing; - a reflector assembly for receiving at least one lamp, and - a termination chamber for location of a PE cell, wherein the visor is of unitary construction for covering both the reflector assembly and the termination chamber, and at least the detector portion of the PE cell is entirely enclosed within the casing. [emphasis added] 41 The specification then addresses the advantage of enclosing at least the detector portion of the PE cell entirely within the casing as a solution to the problems identified in the prior art, in these terms: Lighting assemblies of the prior art typically comprised PE cells seated in the termination chamber, but projecting through an opening in the casing so that at least part of the PE cell is external to the casing. Over time the opening would typically fill with dirt or insect nests, enshrouding the PE cell to block it from the ambient light and cause it to malfunction. Accordingly, inclusion of the PE cell within the casing such that the detector portion of the PE cell is enclosed so as to avoid any opening or breach in the casing proximate [to] the PE cell avoids these problems. [emphasis added] 42 In the third aspect of the embodiments, there is no reference to the notion of the termination chamber (or a part of it) and the reflector assembly (or a part of it) being visible through the visor covering the reflector assembly and the termination chamber. 43 However, the specification then identifies a preference in this way at p 10, lns 13-29: Preferably the components located within the termination chamber as well as the components of the reflector assembly are visible through the visor. For example, this part of the visor may be clear or lightly frosted compared to the remainder of the visor. Similar light fittings of the prior art have included a two part visor - a first part comprising a clear lens for the lamp and a second part comprising an opaque cover for the termination chamber. A preferred embodiment of the present invention allows a linesman to carry out a visual inspection of the components without having to remove any covers. Typically the part of the visor in the vicinity of the PE cell is clear so that the PE cell correctly detects the level of ambient light. Using frosting in other parts of the visor however may provide the advantage of preventing reflected or early ambient light impinging on the PE cell and causing it to prematurely deactivate. In particular, the use of frosting as in this preferred embodiment can avoid "day burners" (lights that are emitting 24 hours per day or at least into periods of the day not requiring artificial lighting). In related art systems, the avoidance of "day burners" was achieved by the addition of or attachment of a shield to the casing to shield the sensor or PE Cell. These shields were not attached to the lens/visor. [emphasis added] 44 The specification then immediately identifies a problem presented by frosting of the visor/lens and the solution to that problem, in these terms, at p 10, lns 30-34; p 11, lns 1-3: Moreover, initial prototyping of a preferred embodiment of the present invention identified that by frosting the visor/lens to eliminate ambient light entry; light was also being reduced to the sensor/PE Cell. This was solved by a preferable arrangement whereby a non-frosted region of visor/lens/casing enables sensor/PE Cell to receive the correct lighting entering the apparatus. This has shown that this embodiment provides a saving in maintenance costs hence a saving in the likelihood of "day burners". [emphasis added] 45 The specification then identifies these matters: Lighting assembly and apparatus in accordance with embodiments as described herein are suitable for use with existing public lighting assemblies and can be used by (but not limited to) power authorities, councils, sport and leisure areas, parks and gardens, ports authorities and developers. … 46 The embodiments of the invention are said to stem from a particular realisation, in this way: In essence, embodiments of the present invention stem from the realization that improving the construction of the lighting assembly is fundamental to reducing the time and costs associated with service and maintenance. [emphasis added] 47 The advantages provided by the lighting assembly of preferred embodiments are said to include these advantages among others, at p 11, lns 24-31; p 12, lns 1-4: • requires less time for installation and routine maintenance, … • provides better access to components for repair and replacement, • easier to maintain and service, • lower occupational health and safety risks during installation, servicing and maintenance, … [emphasis added] 48 The specification recites that further disclosure, objects, advantages and aspects of preferred and other embodiments may be better understood by those skilled in the relevant art "by reference to the following description of embodiments taken in conjunction with the accompanying drawings". Figure 1 is an exploded view of a preferred embodiment of the lighting assembly illustrating the major components. In that figure, the visor is of unitary construction and at least in the vicinity of the lamp it is conformed to act as a prismatic lens. The specification says that the visor is typically made of acrylic, polycarbonate or other hard-wearing polymer that can be made clear or translucent although other suitable materials may be used as would be understood by a person skilled in the art. The specification says that in Figure 1, the "components located within the termination chamber (13) as well as the components of the reflector assembly (11) are visible through the visor (7)". 49 What are the components of the reflector assembly? 50 The specification says that they include, by reference to Figure 2: … a gear tray (17) having lamp holders (19a, 19b) for securing either ends of the lamps (21a, 21b), a reflector tray (23), an electronic ballast (25), a 3-way terminal socket (27) with two MOVs connected to supply terminals and a lanyard (29). An electronic ballast (also known as control gear) is a solid state electronic device that limits the amount of current in an electronic circuit particularly when the load does not regulate its own current consumption well enough. … In the embodiment illustrated in this drawing [Figure 2] the reflector assembly is adapted to support the electronic ballast and two lamps, preferably two 14 watt lamps which are equivalent to an 80 watt mercury vapour lamp but with 66% less energy use and reduced greenhouse emissions. However the reflector assembly (11) may alternatively be adapted to receive a single or compact lamp. The reflector assembly (11) is held at one end to the main body (1), and at the other end to the termination chamber (13) by two pairs of fasteners (31a, 31b) such as stainless steel 1/4 turn single throw screws. … A quick release lanyard (29) and plug socket are installed to assist component replacement. 51 What are the components of the termination chamber? 52 The specification says this, by reference to Figure 2: The termination chamber (13) includes a terminal tray (33), a terminal block (35) of plastic or other suitable material and is adapted to hold a PE cell (37). The termination chamber is at least 25% of the volume of the casing. This is combined with improved layout of the components within the termination chamber (13). For example, the port (3) is elongated to provide additional stability for the light fitting when located on the support (5), and in addition, this makes it easier for the linesman to thread the live main cable into the light fitting. Furthermore, the terminal block (35) is of increased size to make it easier for the linesman to connect the mains cable, which is typically a twin cable of large gauge (6mm2) and is relatively inflexible and resistant to bending. The PE cell (37) is seated in the terminal tray (35) and can be completely enclosed within the casing, with no part projecting through the visor (7). The part of the visor (7) in the vicinity of the PE cell (37) is clear so that the PE cell (37) correctly detects the level of ambient light. Using frosting in other parts of the visor (7) however may provide the advantage of preventing reflected or early ambient light impinging on the PE cell (37) and causing it to prematurely deactivate. 53 What is a termination chamber? 54 At [104], the primary judge says this: In summary, in my view a skilled addressee would construe "termination chamber" such that: (a) it needed to be an enclosed area; (b) it is an area separate from the reflector assembly; (c) it is enclosed on one side by the casing and on the other side by the visor; (d) it does not include the control gear; (e) it contains the terminal block; and (f) it may include the PE cell (I note that this is expressly stipulated in claim 1 of the 104 Patent). 55 Claim 1 of the 103 Patent is in these terms: 1. A lighting assembly having a casing comprising a main body defining a port for receiving a mains cable, and a visor, the casing enclosing; - a reflector assembly for receiving at least one lamp, and - a termination chamber located laterally in relation to the reflector assembly, wherein the visor is of unitary construction for covering both the reflector assembly and the termination chamber, at least part of the termination chamber and at least part of the reflector assembly being visible through the visor. [emphasis added] 56 Claims 2, 3, 4 and 5 of the 103 Patent are dependent claims.

Reasons for judgment of the primary judge 57 At [38], the primary judge observes that, apparently, due to commercial concerns about the potential impact of the litigation commenced by Streetworx, Artcraft introduced its Modified Artcraft luminaire with modifications that were designed with the intention of avoiding any patent infringement. At [39], the primary judge says this: The key modification was to the design of the visor, being the acrylic/polycarbonate/polymer outer casing of the luminaire, with respect to coverage of the visor over the termination chamber, being the internal portion of the luminaire where the mains cable terminated, housing inter alia the PE cell (cf with the reflector assembly being the internal portion of the luminaire, housing inter alia the lamps which reflect emitted light). [emphasis added] 58 At [40], the primary judge explained the changes, by way of comparison with the Artcraft luminaire in this way: In the Artcraft Luminaire, the PE cell was located in the termination chamber, completely enclosed within the visor with no part projecting through the visor. The portion of the visor located directly above the PE cell was a fully transparent oval shape of approximately 5 cms in diameter, allowing the PE cell and most of the termination chamber to be visible through the transparent portion. The remaining portion of the visor above the termination chamber was lightly frosted. Contrastingly, in the Modified Artcraft Luminaire the detector portion of the PE cell (approximately 1 cm at the tip of the PE cell) projected through an opening in the visor located over the termination chamber. The visor was designed so that the tip of the PE cell protruded through an aperture or sleeve in the visor in the shape of a circular cavity, which fitted closely around the PE cell (although there was approximately a 2 mm gap between the edge of the aperture and the PE cell). An insert in the visor, a semi-circle shape depression, surrounded the aperture. There was no fully transparent portion of the visor above the termination chamber; the entirety of the visor in that region was frosted, in a slightly heavier opacity when compared to the Artcraft Luminaire. [emphasis added] 59 The question to be determined, as a matter of construction, is the proper meaning to be attributed to the integer "at least part of the termination chamber being visible through the visor" and having decided that question, whether the Modified Artcraft luminaire exhibits the integer as construed. 60 At [75], the primary judge observes that the "word 'visible' just looking at the language of claim 1" does not provide any "express content or context". Also at [75], the primary judge poses a series of questions about the possible content and context of the term ultimately asking: "How clearly visible is a part of the termination chamber to be?" It will be necessary to say something later in these reasons about the principles to be applied in answering the construction question. 61 The primary judge understood the term "visible" to be a "relative term". 62 At [82], the primary judge said this: Streetworx has contended that in the context of the specification, the integer "at least part of the termination chamber … being visible through the visor" means that one can see through the visor the presence of components located within the termination chamber, but not necessarily the components in detail. So, one can discern that there are components, but that one might not necessarily see or need to see what they are. So, parts of each of the termination chamber and reflector must be visibly discernible, without necessarily being able to see components in detail. Streetworx contends that the need to see what the components are is encapsulated in the preferred embodiment of being able to conduct a visual inspection of the components. [emphasis added] 63 At [65], the primary judge observes that a claim of a patent is to be construed from the perspective of how a person skilled in the art would have understood the patentee to be using the words selected in the language of the claim, informed by the notional skilled addressee's general knowledge and that which has been disclosed in the specification. At [67], the primary judge observes that the Court is to place itself in the position of a person acquainted with the state of the art at the priority date and in order to identify the characteristics of the skilled addressee, the Court must identify the field of the art to which the invention relates. 64 At [73], the primary judge observes that the person skilled in the art for the purposes of the issues in the case is: … one who possesses the general skills of a designer of street lights, with practical knowledge and experience of the way in which street lights are repaired and maintained and the issues which can arise in the course of such maintenance and associated service. This hypothetical person may comprise a team, for example a designer of street lights, a maintenance person and a linesman. In what I discuss below and in my statements and conclusions on questions of construction, such statements and conclusions are expressed from the perspective of how such a skilled addressee would construe the claims. [emphasis added] 65 At [83], the primary judge observes that Mr Sylvan Sherwood Browne, an experienced patent practitioner in engineering related fields and who holds a degree in electrical engineering, (and who is a partner in the intellectual property firm, FB Rice) described the quality of visibility required by claim 1 as that set out at [82] of the primary judge's reasons as contended for by Streetworx. Mr Browne was an expert called by Streetworx. 66 Artcraft at trial relied upon the expert evidence of Mr John Robert Rogers, a consulting engineer with qualifications in illumination engineering and 56 years' experience "in the area of lighting" including having worked at GEC from 1957 to 2010 primarily in the manufacture of commercial lighting including discharging management and technical roles. Mr Rogers is described as a "life fellow" of the "Illuminating Engineering Society of Australia and New Zealand". At [84], the primary judge observes that Mr Rogers questioned the reason (as contended for by Streetworx and Mr Browne) for a requirement that the relevant integer means that one can see, through the visor, the presence of components located within the termination chamber but not necessarily the components in detail. 67 At [84], the primary judge said this: Although Rogers for [Artcraft] questioned the reason for this requirement, he did not have any difficulty in understanding the meaning of "visible". Further, when considering the construction of claim 1 of the 104 Patent, Rogers described differing levels of visibility required by the two expressions in the same manner as set out in the evidence of Browne. Rogers revealed under cross-examination (in the context of being asked about whether the solid control gear chamber in the Boronia met the visibility requirement of claim 1 of the 103 Patent) that he had originally construed the term alone, without reference to the body of the specification. That was not appropriate. When asked to consider what the term meant in light of the body of the specification, he agreed that claim 1 was directed to the language on p 10, lines 13-16 of the Patents which required visibility of the components but not necessarily needing to be able to discern what they were. That is a lesser requirement than the visibility required to perform a visual inspection of components as set out in claim 1 of the 104 Patent. [emphasis added] 68 At [85], the primary judge observes that Artcraft fixed upon the preferred embodiment of the claimed invention of enabling "a linesman to carry out a visual inspection of the components of the termination chamber [without having to remove any covers]". Also at [85], the primary judge observes that, for the purposes of construction of claim 1, all features of the claim must be considered not just those which relate to features identified in a preferred embodiment of the invention. At [86], the primary judge notes Artcraft's contention that Streetworx's construction to the effect that the visor reveal the presence of components within the termination chamber but not necessarily the components in detail, was inconsistent with the purpose explained by the author of the patent at p 10, lns 13-20 commencing with the word "preferably" and ending with the phrase "remove any covers": see [43] of these reasons. 69 In addressing Artcraft's contention of inconsistency, the primary judge makes this observation at [87]: But [Artcraft has] paid little attention to the words "[in] a preferred embodiment" in the last sentence of [the passage relied upon by Artcraft at p 10, lns 13-20], which described the level of visibility required in claim 1 of the 104 Patent not claim 1 of the 103 Patent. A "preferred embodiment" of an invention is a narrower form of the invention described. 70 The sentence given emphasis by the primary judge to which Artcraft was said to have paid little attention was this: "A preferred embodiment of the present invention allows a linesman to carry out a visual inspection of the components without having to remove any covers". That sentence forms part of the complete specification said to be a preferred embodiment of the "present invention", namely, the invention the subject of the 103 Patent. The language of claim 1 of the 103 Patent makes no reference to adaptation of the visor to allow "visual inspection of components within the termination chamber". 71 The conclusions of the primary judge are set out at [88], [89] and [90] in these terms: 88 [Artcraft submits] that the word "visible" must be understood in the context of the specification as a whole, and in a purposive sense, as involving visibility assessed by reference to there being a practical level of visibility into the termination chamber, sufficient to allow an inspection of the internal components by persons, such as linesmen, maintaining the luminaire. 89 I accept that the word "visible" must be understood in the context of the specification as a whole as involving visibility assessed by reference to there being a practical level of visibility into the termination chamber. But I do not accept that the level of visibility must be sufficient to allow an inspection of the internal components by persons, such as linesmen, maintaining the luminaire. 90 In my view, the construction advanced by Streetworx is correct when seen through the perspective of a skilled addressee. Although there must be a practical level of visibility into the termination chamber, particularly from an EPV, it is not required that there be sufficient visibility to allow an inspection of the internal components. The wording of the integer does not stipulate for such a requirement. Further, it is incorrect to take the meaning from a preferred embodiment. Further, Streetworx's construction conformably fits with the specification as a whole. In terms of a purposive construction, it is consistent with making the invention work. [emphasis added]

Approaches to construction 72 As already mentioned, s 40 of the Act provides that a complete specification for an invention must describe the invention fully including the best method known to the applicant of performing the invention and, so far as an application for an innovation patent is concerned, it must end with at least one claim (and no more than five claims) defining the invention. 73 In order to ascertain the invention "described and claimed", it is necessary to refer to the specification as a whole. That was the course Menzies J took in Welch Perrin & Co Pty Ltd v Worrel (1961) 106 CLR 588 at p 593 ("Welch Perrin v Worrel"). On appeal, Dixon CJ, Kitto and Windeyer JJ also observed at p 610 that the specification must be read as a whole and further observed that "[i]f it is impossible to ascertain what the invention is from a fair reading of the specification as a whole that, of course, is an end of the matter". 74 The complete specification, which includes both the body and the claims (see Kimberley-Clark Australia Pty Limited v Arico Trading International Pty Limited and Others (2001) 207 CLR 1 at [14], per Gleeson CJ, McHugh, Gummow, Hayne and Callinan JJ), must be construed in the light of the common knowledge in the art before the priority date and must not be read in the abstract. The Court must place itself in the position of some person acquainted with the surrounding circumstances as to the state of the art and manufacture at the relevant time: Kimberley-Clark Australia Pty Limited v Arico Trading International Pty Limited and Others at [24], per Gleeson CJ, McHugh, Gummow, Hayne and Callinan JJ. 75 Because the patent instrument is not a document operating inter-parties, but rather a public instrument, it must define the monopoly in such a way that it is not reasonably capable of being misunderstood. Even though the specification must be read as a whole, it is necessarily made up of parts which have different functions. It is not legitimate to narrow or expand the boundaries of the monopoly, as defined by the claims, by adding to the language of the claims, glosses drawn from other parts of the specification. Further, if the language of a claim is clear, it is not to be rendered obscure simply because obscurities can be found in particular sentences in parts of the specification: Welch Perrin v Worrel at p 610, Dixon CJ, Kitto and Windeyer JJ. 76 A proper analysis of the specification may show that references to a particular embodiment are by way of "illustration and explanation of the invention" rather than a "definition of it": Welch Perrin v Worrel at p 612, Dixon CJ, Kitto and Windeyer JJ. 77 In Interlego A.G. v Toltoys Pty Ltd (1973) 130 CLR 461 at p 477, Barwick CJ and Mason J approached the construction of the claims and identification of the invention by reading the specification as a whole. Their Honours observed at p 478, in the circumstances of the questions in issue in that case, that it would be unlikely that anyone would conclude on reading the specification as a whole that the invention "as described makes claim to a method of assembly" of a particular kind. Their Honours observed, however, adopting the propositions derived from Welch Perrin v Worrel (described at [75] of these reasons) that the settled rule is that in ascertaining the width of a particular claim (that is, the construction to be attributed to the words defining the monopoly), it is not permissible to vary or qualify the "plain and unambiguous meaning of the claim" by reference to the body of the specification. 78 However, the rational starting point is not to simply turn to the language of the claims and seek to attribute meaning to those words in the abstract. The body of the specification and the claims must be read together as a whole in an attempt to identify the invention and determine whether the meaning of the words used in the claim (that is, the construction of the claim in question) is truly "plain and unambiguous". If, having examined the s 40(2)(a) description of the invention in the body of the specification and the s 40(2)(b) definition of the claims, an expression used in the claims is not clear, it is then permissible to return to the body of the specification to either "define or clarify" the meaning of words used in the claim (see Interlego A.G. v Toltoys Pty Ltd, p 479 per Barwick CJ and Mason J) without infringing the rule that clear and unambiguous words in the claim cannot be varied or qualified by reference to the body of the specification. See also, to the same effect, Kimberley-Clark Australia Pty Limited v Arico Trading International Pty Limited and Others at [15], per Gleeson CJ, McHugh, Gummow, Hayne and Callinan JJ. 79 In Kirin-Amgen Inc v Hoechst Marion Roussel Ltd [2004] UKHL 46; [2005] R.P.C. 169, Lord Hoffmann made a number of observations about approaches to construction of patent specifications and patent claims derived from principles applied by the English courts. Lord Hoffmann did so in the context of examining the application of the European Patent Convention (the "Convention") and the Protocol on the Interpretation of Article 69 of the Convention (the "Protocol"). Although a consideration of the Convention and the Protocol provides the context in which other questions were examined, Lord Hoffmann's observations about the history of the development of the principles of construction have relevance in construing patent specifications and patent claims in Australia. Lord Hoffmann explained the principles in this way: 27 [The] … [principles] applied (at any rate in theory) by an English court construing a legal document … required the words and grammar of a sentence to be given their "natural and ordinary meaning", that is to say, the meanings assigned to the words by a dictionary and to the syntax by a grammar. This meaning was to be adopted regardless of the context or background against which the words were used, unless they were "ambiguous", that is to say, capable of having more than one meaning. As Lord Porter said in Electric & Musical Industries Ltd v Lissen Ltd (1938) 56 R.P.C. 23, 57: "If the Claims have a plain meaning in themselves [emphasis supplied], then advantage cannot be taken of the language used in the body of the Specification to make them mean something different." 28 On the other hand, if the language of the claim "in itself" was ambiguous, capable of having more than one meaning, the court could have regard to the context provided by the specification and drawings. If that was insufficient to resolve the ambiguity, the court could have regard to the background, or what was called the "extrinsic evidence" of facts which an intended reader would reasonably have expected to have been within the knowledge of the author when he wrote the document. 29 These rules, if remorselessly applied, meant that unless the court could find some ambiguity in the language, it might be obliged to construe the document in a sense which a reasonable reader, aware of its context and background, would not have thought the author intended. Such a rule, adopted in the interests of certainty at an early stage in the development of English law, was capable of causing considerable injustice and occasionally did so. The fact that it did not do so more often was because judges were generally astute to find the necessary "ambiguity" which enabled them to interpret the document in its proper context. Indeed, the attempt to treat the words of the claim as having meanings "in themselves" and without regard to the context in which, or the purpose for which, they were used was always a highly artificial exercise. 30 … As it happens, though, by the time the Protocol was signed, the English courts had already begun to abandon them [the principles Lord Hoffmann had earlier described], not only for patent claims, but for commercial documents generally. … It came to be recognised that the author of a document such as a contract or a patent specification is using language to make a communication for a practical purpose and that a rule of construction which gives his [or her] language a meaning different from the way in which it would have been understood by the people to whom it was actually addressed is liable to defeat his [or her] intentions. It is against that background that one must read the well known passage in the speech of Lord Diplock in Catnic Components Ltd v Hill & Smith Ltd [1982] R.P.C. 183, 243 when he said that the new approach should also be applied to the construction of patent claims: "A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge." 31 This was all of a piece with Lord Diplock's approach a few years later in the Antaios case [1985] A.C. 191, 201 to the construction of a charterparty: "I take this opportunity of re-stating that if detailed semantic and syntactical analysis of words in a commercial contract is going to lead to a conclusion that flouts business commonsense, it must be made to yield to business commonsense." 32 Construction, whether of a patent or any other document, is of course not directly concerned with what the author meant to say. There is no window into the mind of the patentee or the author of any other document. Construction is objective in the sense that it is concerned with what a reasonable person to whom the utterance was addressed would have understood the author to be using the words to mean. Notice, however, that it is not, as is sometimes said, "the meaning of the words the author used", but rather what the notional addressee would have understood the author to mean by using those words. The meaning of words is a matter of convention, governed by rules, which can be found in dictionaries and grammars. What the author would have been understood to mean by using those words is not simply a matter of rules. It is highly sensitive to the context of, and background to, the particular utterance. It depends not only upon the words the author has chosen but also upon the identity of the audience he is taken to have been addressing and the knowledge and assumptions which one attributes to that audience. … 33 In the case of a patent specification, the notional addressee is the person skilled in the art. He (or, I say once and for all, she) comes to a reading of the specification with common general knowledge of the art. And he reads the specification on the assumption that its purpose is to both to describe and to demarcate an invention - a practical idea which the patentee has had for a new product or process - and not to be a textbook in mathematics or chemistry or a shopping list of chemicals or hardware. … The purpose of a patent specification, as I have said, is no more nor less than to communicate the idea of an invention. An appreciation of that purpose is part of the material which one uses to ascertain the meaning. But purpose and meaning are different. If, when speaking of the widest purpose, Jacob L.J. [in Rockwater Ltd v Technip France SA [2004] R.P.C. 46, CA. at 41] meant the widest meaning, I would respectfully disagree. There is no presumption about the width of claims. A patent may, for one reason or another, claim less than it teaches or enables. 34 "Purposive construction" does not mean that one is extending or going beyond the definition of the technical matter for which the patentee seeks protection in the claims. The question is always what the person skilled in the art would have understood the patentee to be using the language of the claim to mean. And for this purpose, the language he has chosen is usually of critical importance. The conventions of word meaning and syntax enable us to express our meanings with great accuracy and subtlety and the skilled man will ordinarily assume that the patentee has chosen his language accordingly. As a number of judges have pointed out, the specification is a unilateral document in words of the patentee's own choosing. Furthermore, the words will usually have been chosen upon skilled advice. The specification is not a document inter rusticos for which broad allowances must be made. … [emphasis added but for inter rusticos] 80 It follows from a consideration of the authorities at [72] to [79] of these reasons that the questions to be answered can be framed in this way. 81 First, having regard to the complete specification as a whole, comprising both the body of the document and the claims defining the invention, and then having considered the language of claim 1, would the skilled addressee have understood, objectively viewed, the author of the patent, by using the language of the integer "at least part of the termination chamber being visible through the visor", to have conveyed a particular identified "plain and unambiguous" meaning? 82 Second, if the meaning of the integer is not plain and unambiguous, what assistance might then be gained in ascertaining the meaning of the integer by properly having regard to the body of the complete specification? 83 The language of the integer selected by the patentee is "at least part of the termination chamber being visible through the visor". The appeal proceeded on the footing that no point of distinction is made about the phrase "at least part of". The question is whether the termination chamber is "visible through the visor". 84 The primary judge at [75] identified a number of possible difficulties in attributing meaning to the phrase "visible through the visor". The term "visible" has a number of meanings. The Oxford English Dictionary identifies these meanings. 85 First, as an adjective "visible" means "capable of being seen; that by its nature is an object of sight; perceptible by the sense of sight". 86 Second, as an adjective, "that may be mentally perceived or observed; clearly or readily evident or perceptible; apparent, manifest, obvious". 87 Third, as an adjective, "that can be seen under certain conditions, at a certain time, or by a particular person; in sight; open or exposed to sight or view". 88 As a noun, "visible" might mean "a visible thing or entity" or "that which is visible, esp. the visible world". 89 What understanding was conveyed to the skilled addressee by the use of the phrase "visible through the visor"? 90 Mr Browne for Streetworx understood the integer to mean that one can see, through the visor, the presence of components within the termination chamber but not necessarily the components in detail, that is, one can discern the presence of components but not necessarily "see or need to see what they are". However, Mr Browne did not derive that meaning from the language of the claim as such. In that sense, a reading of the body of the specification together with the claim did not enable a plain and unambiguous meaning. Thus, Mr Browne had recourse to particular parts of the specification to derive an understanding that the patentee was conveying, by the words of the claim, the notion that the integer meant one could see, through the visor, the presence of components within the termination chamber but not a requirement of seeing the components "in detail" or indeed a need to see the components in detail. 91 That construction was, in part, based upon recognising that the language of the claim did not extend into the language of lns 19 and 20 at p 10 concerning enabling a linesman to "carry out a visual inspection of the components without having to remove any covers". 92 Mr Rogers for Artcraft conceded in cross-examination that he had sought to understand the language of the integer without any regard to the body of the specification. Having been taken to the specification, he seemed to accept that the integer was seeking to convey a meaning drawn from lns 13 to 16 on p 10 of the specification. 93 Artcraft, however, as a matter of construction, put simply, took the position that although the language of the integer had direct reference to the preference expressed at lns 13 to 16 of p 10, the language of the integer needed to be construed and understood in the context of the wider, necessarily related, language of that part of the complete specification at lns 16 to 20 and, in particular, lns 18 to 20. 94 On that footing, the language of the claim ought to be understood as meaning that the termination chamber is visible through the visor so as to enable the components of the termination chamber to be seen but also sufficiently visible to allow a linesman to carry out a visual inspection of the components without removing any covers. Thus, that notion of visibility would be consistent with the Oxford English Dictionary meaning of "clearly or readily evident or perceptible; apparent, manifest, obvious". 95 The immediate difficulty with that construction is that the patentee, by the language selected for the relevant integer of claim 1, seems to have expressly confined the language defining the claim to language in terms of the preference reflected at only lns 13 to 16 of p 10 of the complete specification without incorporating what might be described as the limitation at lns 18 to 20. To the extent that the language of the integer might be rendered clear and unambiguous by reference to the relevant section of the complete specification, the language used in claim 1 is limited to the statement of the preference at lns 13 to 16. 96 The constructional difficulty, however, lies in seeking to understand, in a practical way, the meaning the author of claim 1 intended to convey by using the language selected for the relevant integer if the meaning is understood as limited to enabling a person to see, through the visor, the presence of components within the termination chamber but not necessarily the components in detail. In a practical sense, what would be the point of enabling a person to see components without being able to see them in detail? This would seem to be especially so if being able to see components through the visor of the light assembly invention is related to advantages in servicing and maintenance. 97 In many parts of the specification, emphasis is given by the author to the advantages of ease of service and maintenance by reason of the invention and the elimination, within prior art articles, of increased ongoing maintenance associated with those prior art articles. Much is said in the specification about the time, cost and difficulties associated with servicing and maintaining lighting systems of the prior art. Much is said on this topic as the identified objects of the invention and those objects are translated into aspects of the embodiments and, in particular, the third aspect of the embodiment which has the closest relationship to the language of the integer. The specification gives emphasis to advantages in installation, servicing and maintenance of the lighting system the subject of the invention. See [24] - [28], [30], [40], [43] and [47] of these reasons. 98 I accept the force of the observations of Jessup J that there is a necessary relationship between the preference expressed at lns 13 to 16 of p 10 and the reference at lns 18 to 20 of enabling a linesman to carry out a visual inspection of the components without having to remove any covers. I also accept that those individuals who would be carrying out maintenance and servicing of light assemblies the subject of the invention would necessarily be familiar with the constructional features of the assembly, the layout of the termination chamber (and the reflector assembly) and the components within the termination chamber. In terms of seeking to ascertain, objectively, what a person skilled in the art would have understood the patentee to mean by using the language of the claim, it seems unlikely that the patentee meant, by the visibility integer, that a linesman would be able to see the presence of components that he or she already knew to be located within the termination chamber but not necessarily the components in detail. That construction seems unlikely to confer any identifiable practical advantage. 99 However, at [89] and [90] of the principal judgment, the primary judge accepted that the word "visible" must be understood in the context of the specification as a whole as involving visibility assessed by reference to a practical level of visibility into the termination chamber at a level less than sufficient to allow an inspection of the internal components. The primary judge observed that the wording of the visibility integer did not stipulate for a visibility requirement sufficient to allow an inspection of the internal components of the termination chamber. 100 It is one thing for a linesman to have a sufficient level of visibility such that the components within the termination chamber are "capable of being seen" in the sense of being "an object of sight" perceptible to the linesman by the "sense of sight" and understood by a skilled addressee as enabling a linesman to see the presence of components, in that sense. It is yet another thing for a linesman to have a sufficient level of visibility as would render the components within the termination chamber "clearly or readily evident" or "apparent, manifest, obvious" in the sense of enabling a sufficient level of visibility to allow a linesman to conduct an inspection of the internal components without having to remove any covers. Those two postulates represent very different things. 101 What is the practical advantage of the first level of visibility as compared with the second? 102 I generally accept that the complete specification does not establish with real precision an articulated relationship between the first level of visibility and a particular advantage. However, it may well be that there are real and practical advantages in a linesman, in the field, being able to look through the visor in a way which enables him or her to see the components without necessarily being able to see them in sufficient clarity to conduct an inspection of those components. One advantage of the termination chamber being visible to a linesman, through the visor, in a way less than that required to enable the linesman to conduct an inspection of the internal components is that such a degree of visibility enables the linesman to detect whether the components are, apparently, affected by environmental contaminants such as moisture ingress which may reveal corrosion of components of the termination chamber to a person skilled in the art, the build-up of insect nests, evidence of spiders or spider webs and other contaminants which might lead a linesman to conclude that the particular assembly needs to be opened and inspected in the performance of a maintenance protocol. 103 The capacity to see components within the termination chamber, through the visor (as opposed to seeing those components, through the visor, with the necessary clarity to enable inspection to occur), might well confer a practical level of visibility into the termination chamber as contemplated by the primary judge at [89] and [90] of his Honour's reasons from the perspective of the skilled addressee as found by his Honour at [73] of his Honour's reasons. The practical level of visibility so found is consistent with the meaning of "visible" as: "that can be seen under certain conditions, at a certain time, or by a particular person; in sight; open or exposed to sight or view". 104 Although minds might differ about the question of construction of the visibility integer, I am not satisfied that the primary judge has fallen into error in the construction reflected at [89] and [90] of his Honour's reasons. Moreover, it needs to be remembered that the patentee adopted language in claim 1 which bears a relationship to a particular part of the specification that is, lns 13 to 16 of p 10 of the complete specification. The patentee chose not to include within the language of the integer, the additional defining feature of visibility through the visor sufficient to allow a linesman to carry out a visual inspection of the components without having to remove any covers.

The principles 105 Section 40(3) of the Patents Act provides that the "claim or claims must be clear and succinct and fairly based on the matter described in the specification". 106 Section 40(3), obviously enough, has a relationship with s 40(2). 107 Section 40(2)(a) provides that a complete specification must describe the invention fully, including the best method known to the applicant of performing the invention and s 40(2)(b) provides that where the complete specification relates to an application for a standard patent it must end with a claim or claims "defining the invention". Although s 40(3) does not use the word "invention", the requirement in s 40(3) that the claims be fairly based on the matter "described" in the specification, is a requirement that the claims "be fairly based on the matter in it that discusses the 'invention'" [emphasis added]: Lockwood Security Products Pty Limited v Doric Products Pty Limited (2004) 217 CLR 274 at 293 [53] (Lockwood Security v Doric Products") by the Court, Gleeson CJ, McHugh, Gummow, Hayne and Heydon JJ. 108 The term "invention", for this purpose, includes the alleged invention: Lockwood Security v Doric Products at [53]. In s 40(1), "invention" means "the embodiment which is described, and around which the claims are drawn": AMP Inc v Utilux Pty Ltd (1971) 45 ALJR 123 at 127, per McTiernan J, adopted and approved in Kimberly-Clark Australia Pty Ltd v Arico Trading International Pty Ltd (2001) 207 CLR 1 at 14-15 [19] to [21], ("Kimberly-Clark v Arico Trading") by the Court, Gleeson CJ, McHugh, Gummow, Hayne and Callinan JJ, for the purposes of the Patents Act. The term "invention" has the same meaning in s 40(2) and, so far as s 40(3) "implicitly" refers to an invention, it must necessarily "bear the same meaning there": Lockwood Security v Doric Products at [53]. 109 In Olin Corporation v Super Cartridge Co Pty Ltd (1977) 180 CLR 236 at 239-240, Barwick CJ said this: The critical question which in my opinion remains is whether the product claims in question are fairly based on the disclosure of the specification and do not exceed it, or, as it is put, are not too wide, having regard to the terms of the application. … The question whether the claim is fairly based is not to be resolved, in my opinion, by considering whether a monopoly in the product would be an undue reward for the disclosure. Rather, the question is a narrow one, namely whether the claim to the product being new, useful and inventive, that is to say, the claim as expressed, travels beyond the matter disclosed in the specification. [emphasis added] 110 That formulation of the question to be addressed, when the issue is one of "fair basing" of a claim under s 40(3) of the Patents Act was approved and adopted in Kimberly-Clark v Arico Trading at [15]. In answering that question, the Patents Act "requires a comparison between the matter described in the specification and the claim which defines the scope of the monopoly: Kimberly-Clark v Arico Trading at [15]; Lockwood Security v Doric Products [49]. In Lockwood Security v Doric Products at [69], the Court also observed that s 40(3) requires "a real and reasonably clear disclosure", adopting the formulation of Fullagar J, in Société Des Usines Chimiques Rhône-Poulenc v Commissioner of Patents (1958) 100 CLR 5 at 11: see also CCOM Pty Ltd v Jiejing Pty Ltd (1994) 51 FCR 260 at 281(G) to 282(A) ("CCOM v Jiejing") per Spender, Gummow and Heerey JJ. 111 As to the correct method to be adopted, the Court observed at [68] in Lockwood Security v Doric Products that in making the relevant comparison, it would be "wrong to seek to isolate in the body of the specification 'essential integers' or 'essential features' of an alleged invention and to ask whether they correspond with the essential integers of the claim in question" [emphasis added]. That view is also consistent with the view expressed by the Full Court in CCOM v Jiejing at 281(G). 112 In Lockwood Security v Doric Products, the Court also observed at [68], as to method, that it would be wrong to employ "an over meticulous verbal analysis" in undertaking the required statutory comparison, adopting the formulation of the Full Court in CCOM v Jiejing at 281(B) based on an approach adopted by Buckley LJ in Stauffer Chemical Company's Application [1977] R.P.C. 33 at 54, lns 9-17. 113 In examining the content of the notion of a "real and reasonably clear disclosure", the Court in Lockwood Security v Doric Products observed that these words, when used in connection with s 40(3), "do not limit disclosures to preferred embodiments". The Court observed at [69] that Fullagar J's formulation "serves the function of compelling attention to the construction of the specification as a whole, putting aside particular parts which, although in isolation they might appear to point against the 'real' disclosure, are in truth only loose or stray remarks" [emphasis added]. 114 The Court at [69] embraced the observations of Gummow J in Rehm Pty Ltd v Websters Security Systems (International) Pty Ltd (1988) 81 ALR 79 at 95. His Honour there said this: The circumstance that something is a requirement for the best method of performing an invention does not make it necessarily a requirement for all claims; likewise, the circumstance that material is part of the description of the invention does not mean that it must be included as an integer of each claim. Rather, the question is whether there is a real and reasonably clear disclosure in the body of the specification of what is then claimed, so that the alleged invention as claimed is broadly, that is to say in a general sense, described in the body of the specification. [emphasis added] 115 Artcraft contends that the disclosure in the specification, as to visibility, is confined to a linesman being able to carry out a visual inspection of the components without having to remove any covers (see [43] of these reasons and p 10, lns 13-29 of the specification) with the result, as to the visibility integer, that a construction of Claim 1 of the 103 Patent that comprehends a "practical level" of visibility into the termination chamber (particularly from an Elevated Platform Vehicle) which is less than "sufficient visibility" to allow an inspection of the internal components without having to remove any covers (such as enabling a linesman to discern the ingress of insect and other pests and/or their nests/webs or a build-up of insect nests and dirt on the visor), "travels beyond" the "real and reasonably clear" disclosures in the specification. 116 Having regard to the principles just discussed, I do not accept that Claim 1, by reason of the visibility integer, travels beyond the real and reasonably clear disclosures in the specification. The specification must be considered as a whole. The specification recognises that lighting assemblies of the prior art often allowed multiple parts for entry to internal portions of the lens/visor and the component area. The specification recognises that this problem contributed to the significant cost associated with service and maintenance and that one of the specific problems of prior art street lights was that they were not sufficiently robust to withstand environmental conditions and the ingress of insect and other pests and/or their nests/webs. The specification says that an object of the embodiments is to reduce the maintenance and servicing required for lighting assemblies and to improve the ease and speed with which they can be serviced or maintained. In reciting the preferences for a series of interfaces between the visor and the main body of the light assembly, a particular seal of silicone or neoprene is provided between the visor and the main body so as to address reduction in the transparency of the lens and diminished output and effectiveness of the light due to the build-up of insect nests and dirt on the visor. In the section at p 10, lns 13-29 of the specification, a preference is expressed that the components located within the termination chamber as well as the components of the reflector assembly are visible through the visor. The specification also describes as a preferred embodiment of the invention allowing a linesman to carry out a visual inspection of the components without having to remove any covers. 117 The construction of the integer "visible through the visor" as described at [102] of these reasons is entirely consistent with the notion of visibility in the specification having regard to the preferences expressed at p 10 of the specification against the background of the objects sought to be achieved taking account of the problems of the prior art sought to be solved by the invention, as described. The specification reflects a real and reasonably clear disclosure and the claims do not travel beyond the disclosures in the specification, taken as a whole.

The principles 118 Section 18(1A)(c) of the Act provides, relevantly for the purposes of this topic, that an invention is a patentable invention for the purposes of an innovation patent if the invention, so far as claimed in any claim, is useful. If the invention, so far as claimed in any claim of an innovation patent is not useful, the invention is not a "patentable invention" under s 18(1A)(c) and is thus susceptible of revocation under s 138(3)(b) of the Act. 119 It is "no objection" to the validity of an innovation patent granted under the Act that it is "commercially impracticable". The utility of the patent depends upon whether, by following the teaching of the specification, the result claimed is produced: Advanced Building Systems Pty Ltd v Ramset Fasteners (Aust) Pty Ltd (1998) 194 CLR 171 at 187 [24], Brennan CJ, Gaudron, McHugh and Gummow JJ adopting and citing Lane Fox v Kensington & Knightsbridge Electric Lighting Co [1892] 3 Ch 424 at 430-431. 120 The "basic principle" of inutility is that if an invention "does what it is intended by the patentee to do, and the end attained is itself useful, the invention is a useful invention": Fawcett v Homan (1896) 13 RPC 398, Lindley LJ at 405, adopted by Gummow J as a correct statement of principle in Rehm Pty Ltd v Websters Security Systems (International) Pty Ltd (1988) 81 ALR 79 at 96 ("Rehm"). What the invention is "intended" to do is a matter to be gathered from "title and the whole of the specification": Rehm, Gummow J at 96. 121 Put another way, the two questions are: first, what is the promise of the invention derived from the whole of the specification?; second, by following the teaching of the specification, does the invention, as claimed in the patent, attain the result promised for it by the patentee?: Décor Corporation Pty Ltd v Dart Industries Inc (1988) 13 IPR 385 at 394 ("Décor v Dart"), Lockhart J (in the Full Court); Welcome Real-Time SA v Catuity Inc (2001) 113 FCR 110 at 144 [160], Heerey J; H Lundbeck A/S v Alphapharm Pty Ltd [2009] FCAFC 70; (2009) 177 FCR 151 at 198 [217] ("Lundbeck"), Bennett J; Ranbaxy Australia Pty Ltd v Warner-Lanbert Co LLC (2008) 77 IPR 449 at 479 [141], Emmett, Weinberg and Bennett JJ. Further, "everything" that is within the scope of a claim must be useful, that is, attain the result promised for the invention by the patentee: Lundbeck at 172 [81], Emmett J. 122 Artcraft's contention, put simply, is that if the integer of Claim 1 "at least part of the termination chamber … being visible through the visor" means (or as Artcraft would have it "extends" to) a practical level of visibility into the termination chamber such that one can see through the visor the presence of components located within the termination chamber but not necessarily the components in detail, then, the claim "goes beyond" the "promise" of the specification because the "invention as claimed does not attain the result promised for it by the patentee", to use the language of Lockhart J in Décor v Dart. In examining the specification to understand and identify the result promised by the patentee so as to determine whether the claim attains the promised result, a distinction must be drawn between the "result promised" for the invention by the specification and only or mere "references" to a "statement" of the promise of a "preferred embodiment" of the invention: Décor v Dart, Lockhart J at 394. 123 What then is the result promised for the invention by the patentee? The primary judge found that Artcraft had incorrectly identified that promise. 124 At [343], the primary judge made this observation: For the reasons advanced earlier, [Artcraft's] contentions should be rejected. First, they do not accurately describe the promise (see at [20], [82], [89]-[90], [248]-[255], [319]-[320] and [346]). Second, the promise of the invention, as accurately stated (see earlier) has been adequately met. 125 At [346], the primary judge said this: Generally, in the case of each impugned claim [of the 103 Patent] the respondents [Artcraft] mischaracterised the result promised by the patentee by casting the "promise" in an overly narrow way. For example, regarding claim 1 of the 103 Patent, the purported "promise" referred to by the respondents is in fact a description of an advantage of a preferred embodiment of the invention. Similarly with claim 4 of the 103 Patent, the purported "promise" regarding corrosion is merely given as an example in the Patents of a way in which the locking system may seize. But the result promised by the patentee can be any one of the objects of the invention identified earlier. That is what the patentee has promised the invention will do. Each of the impugned claims achieves one or more of those promises. Further, as I have earlier explained, such promises are useful. 126 As already identified in these reasons, the patentee identifies a number of problems presented by lighting assemblies of the prior art. 127 One problem was that prior art assemblies often exhibited multiple points for entry to internal portions of the lens/visor with the result that the "component area" may not be locked. Vibration was also perceived to be a problem. These issues of multiple points of entry were thought to contribute to increased ongoing maintenance of the assembly. In part, at least, the perceived problem provided a point of entry for vermin, spiders (webs), insects and pests to enter the assembly and gave rise to "increased ongoing maintenance". Such service and maintenance gave rise to "significant cost" for the organisation responsible for servicing the lighting assemblies. Moreover, the elevated position of each light contributed to the time, cost and difficulties associated with servicing and maintaining the lighting system. 128 Another problem was that lighting assemblies of the prior art were not sufficiently robust to withstand exposure to the external environment including weather conditions and the ingress of insects and other pests and/or their nests/webs. Another problem was the malfunctioning of the photoelectric cell in lighting assemblies of prior art. The invention sought to address these problems by identifying a series of objects to be achieved by embodiments of the invention. One object of the invention is to reduce maintenance and servicing of lighting assemblies. Another object of the embodiments is to improve the ease and speed with which lighting assemblies can be serviced or maintained. The specification recites that it is an object of the embodiments described in the specification to either overcome or alleviate at least one of the problems or "noted drawbacks" of related art systems or at least to provide a "useful alternative" to the related art systems. 129 This description represents the identified objects of the embodiments. The specification then identifies three "aspects" of embodiments. The first aspect is concerned with providing an assembly having a casing comprising a main body and a visor enclosing a reflector assembly and a termination chamber in which the visor is of unitary construction for covering both the reflector assembly and the termination chamber. The specification then identifies "a preference" in relation to the casing. The specification then identifies "another preference" in the form of a particular interface between the visor and the main body of the assembly. That preference is designed to inhibit moisture ingress and inhibit the build-up of insect nests and dirt on the visor which tends to reduce the transparency of the lens and diminish the output and effectiveness of the light so that a linesman, in respect of an assembly exhibiting those characteristics, "must open up the assembly and clean the lens with detergent". 130 A second aspect of the embodiments also goes to a casing comprising a main body and, this time, a polymer visor encasing the reflector assembly and the termination chamber in which the visor is of unitary construction and adapted to cover both the reflector assembly and the termination chamber. In this aspect, however, the termination chamber is at least 20% to 25% of the volume of the casing. The advantage of the increased volume is that it enables an improved layout of the components. 131 A third aspect of the embodiments contemplates a lighting assembly having a casing comprising a main body of the assembly enclosing a reflector assembly and a termination chamber for location of the PE cell, and a visor, in which the visor is of unitary construction for covering the reflector assembly and the termination chamber, and at least the detector portion of the PE cell is entirely enclosed within the casing. 132 Having addressed those three aspects of the embodiments serving the identified "objects", the specification recites a preference. The preference recited by the patentee is that the components located in the termination chamber as well as the components of the reflector assembly are "visible through the visor" (which, of course, is of unitary construction and covers both the reflector assembly and the termination chamber). The specification then explains, by way of example, a means by which the components might be rendered visible through the visor by particular treatment of the visor: it might be clear or lightly frosted compared to the remainder of the visor. 133 Having identified the preference and having given an example of how the preference might be achieved, the specification then describes a "preferred embodiment" of the invention which seems to be treated by the patentee as something entirely different from a disclosure and discussion of aspects of embodiments which serve the objects of the present invention. The particular preferred embodiment set out at this point in the specification is one which "allows", enables, a linesman to carry out a visual inspection of the components without having to remove any covers. 134 The specification then describes typical aspects of the relationship between a clear visor and a photoelectric cell which serve the interests of detecting the level of ambient light. Problems associated with that relationship are then discussed. 135 The embodiments of the invention are said to stem from a realisation on the part of the patentee that improving the construction of the lighting assembly is fundamental to solving the problem of the time and costs associated with service and maintenance of lighting assemblies of the prior art and serves the object of the present invention by reducing the time and costs associated with service and maintenance. 136 Claim 1 of the patent by defining the invention (as required by s 40(2)(b) of the Act) in terms which comprehend a visor of unitary construction for covering both the reflector assembly and the termination chamber with at least part of the termination chamber and at least part of the reflector assembly "being visible through the visor", expressly reflects the patentee's description of the preference for the relevant components of the termination chamber as well as the components of the reflector assembly to be "visible through the visor" as set out at p 10, lns 13-14 of the specification. The additional notion that a preferred embodiment of the present invention is one which allows a linesman to "carry out a visual inspection of the components without having to remove any covers" does not find expression in the language of claim 1 of the patent. 137 It can be seen from this review that the result promised for the invention by the patentee is that some, at least, of the problems of the prior art are to be solved by the "objects", "aspects" and "preferences" described for the invention in the specification by providing for and promising a lighting assembly that has a casing comprising a main body (identifying a point or port for a mains cable) which encloses a reflector assembly (containing particular components) and a termination chamber (also containing particular components) and a visor of single or unitary construction which encloses both the reflector assembly and the termination chamber in such a way that the components within each chamber are visible through the visor. The "result promised" by the patentee for the invention does not include a promise that the invention will allow a linesman to look, see and visually inspect the components of each chamber enclosed by the unitary visor without having to remove the enclosing cover (that is to say, by tilting the visor back on its hinge so as to open each chamber to visual inspection). 138 The patentee apparently thinks and certainly says in the specification that the particular facility of the invention of allowing or enabling a linesman to look, see and visually inspect the components of each chamber enclosed by the visor without having to remove the visor, is truly a "preferred embodiment" but the expression of that preferred embodiment is only, as a matter of orthodoxy, a reference to or statement of the promise of a preferred embodiment not a statement of the result promised for the invention. 139 The result promised for the invention is that the components of each chamber will be "visible through the visor" in the sense discussed at [100] to [104] of these reasons. Had the specification "taught" otherwise of the invention, it would have taught the promise of the invention as enabling a linesman to see the components of each chamber with sufficient clarity to enable him or her to visually inspect the components, through the visor, in the discharge of the maintenance function, without the linesperson needing to open or remove the visor from its extant position enclosing the chambers and covering the components. That was no part of the result promised by the patentee for the invention. 140 By following the teaching of the specification, it can be seen that the invention, as claimed, attains the result promised for it by the patentee in the specification and thus the invention is useful in the s 18(1A)(c) sense. 141 It follows that I would grant leave to appeal and dismiss the appeal with costs. I certify that the preceding one hundred and forty-one (141) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Greenwood.

RARES J: 142 I have had the considerable advantage of reading the separate reasons of Greenwood J and Jessup J. I generally agree with what Greenwood J has written and his conclusion that the appeal fails but would add the following observations on claim 1, using Jessup J's nomenclature of the "page 10 passage" (see [166] of his reasons). 143 The page 10 passage commences by suggesting that 'preferably', the components in the termination chamber be visible through the visor, as well as those in the reflector assembly. The next sentence immediately offers alternatives for the visor over the termination chamber being either "clear or lightly frosted compared to the remainder of the visor". The passage then explains that "the use of frosting as in this preferred embodiment can avoid "day burners"". The skilled addressee would understand that the reference in the middle of the page 10 passage, to a preferred embodiment of the invention that "allows a linesman to carry out a visual inspection of the components without having to remove any covers", was to an embodiment with light frosting in the visor covering the termination chamber. 144 In light of the page 10 passage, the skilled addressee would understand that the ambiguous expression in claim 1, "at least part of the termination chamber … being visible through the visor", meant that at least some of the visible part of that chamber is, or could be, perceptible to the outside observer through the frosting on the visor. The preferred embodiment also contemplated that the PE cell portion of the termination chamber have a clear visor. Such a portion would also fall into the meaning of the ambiguous expression of visibility in claim 1. 145 Clear and unambiguous words in a claim in a patent must be construed without resort to other parts of the complete specification. Thus, the width of a claim expressed in clear and unambiguous language cannot be varied or qualified by reference to the body of the specification: Welch Perrin & Co Pty Ltd v Worrel (1961) 106 CLR 588 at 610 per Dixon CJ, Kitto and Windeyer JJ; Interlego AG v Toltoys Pty Ltd (1973) 130 CLR 461 at 478 per Barwick CJ and Mason J. However, if an expression in a claim is not clear, the claim can be construed by reference to the specification as a whole. In Interlego AG 130 CLR at 479, Barwick CJ and Mason J said: If the expression is not clear it is then permissible to resort to the body of the specification to define or clarify the meaning of words used in the claim without infringing the rule that clear and unambiguous words in the claim cannot be varied or qualified by reference to the body of the specification … 146 The specification and claims must be construed in light of the common general knowledge in the relevant art before the priority date. The specification must be read as a whole and construed according to the ordinary rules for construction of written documents: Welch Perrin 106 CLR at 610. 147 Visibility is often a question of degree. Something can be visible without its features being distinct or even clear to the viewer. The degree of visibility of what is being observed will vary depending on the distance between the viewer and the subject of his or her observation. For example, the degree of visibility of persons, the natural environment or objects will vary depending on the time of day, such as dawn, dusk or midday, and ambient weather conditions, such as fog, storm, dark covering cloud or bright sunlight. 148 Thus, the meaning of the expression "being visible through the visor" in claim 1 is not clear or unambiguous. That expression, in its context in claim 1 alone, does not convey in its ordinary meaning that "at least part of the termination chamber" be so exposed to an observer that its entire contents can be clearly seen without any obscurity. Moreover, the expression "at least part of the termination chamber" does not convey, of itself, how much of that chamber need be "visible through the visor" to meet the criterion it prescribes. 149 It follows that claim 1 must be read in the context of the complete specification as a whole, as a skilled addressee would have understood it, in light of the common general knowledge before the priority date. The page 10 passage provides the skilled addressee with context in which to understand what claim 1 means. That passage referred to a preferred embodiment in which the visor over the termination chamber could be either clear or lightly frosted "compared to the remainder of the visor" and that the components in the chamber be "visible" through such a visor. 150 A lightly frosted visor is translucent but not entirely transparent (cf: patent page 13 lines 9-15). The translucence allows the viewer to perceive, to a lesser degree than possible with a clear transparent visor, what the visor encases. The light frosting necessarily interferes with the clarity of an observer's view of what is on the other side of the visor. 151 The primary judge accepted the expert evidence of both Mr Browne and Mr Rogers that the visibility integer in claim 1 ought be construed to mean that the viewer can see through the visor that there were components or materials inside the termination chamber but that it was not necessary for the viewer to be able to discern what the components or materials were. That construction was justified having regard to the ordinary and natural meaning of claim 1, read as a skilled addressee would read it in light of the specification as a whole and the common general knowledge before the priority date. If, for example, there had been an intrusion by insects or spiders, or moisture had built up, inside the termination chamber, a linesman would be able immediately to see that there was some interference with the ordinary degree of visibility through a frosted visor, that he or she would expect, and, based on knowledge, experience and what the departure from the ordinary degree of visibility was, would be able to decide or consider whether he or she needed to open the visor to access the termination chamber (see patent page 4 lines 1-22, page 6 lines 14-20, page 11 lines 25-31). 152 The skilled addressee would understand that claim 1 did not require complete transparency of the visor covering the termination chamber. Rather, the skilled addressee would understand that the visibility integer required the visor to be sufficiently translucent so as to enable a linesman to perceive, from an external inspection, whether it appeared that the inside of the termination chamber was not in the state that he or she would expect. The degree of perceived difference may also assist the linesman in working out what preparatory steps might be needed before he or she ascended to examine the luminaire's contents. 153 Accordingly, I would grant leave to appeal, but dismiss the appeal with costs. I certify that the preceding twelve (12) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Rares .

JESSUP J: 154 This is an application for leave to appeal and, subject to the grant of leave, an appeal from certain orders made on 2 February 2015 by a single Judge of the court in a patent infringement action brought by the respondent, Streetworx Pty Ltd, against the applicant (for leave to appeal), Artcraft Urban Group Pty Ltd, and its general manager, Murray John Saint. In those orders, the primary Judge declared that the applicant had, by exploiting a lighting assembly bearing the model number "AUGT5", infringed Claims 1, 2, 3 and 4 of the respondent's Innovation Patent No 2009101103 ("the Patent"), made a corresponding injunction and dismissed the applicant's, and Mr Saint's, cross-claim challenging the validity of the Patent. 155 The necessity for the grant of leave to appeal arose because the trial before the primary Judge dealt only with what may loosely be described as issues of liability. The other aspects of the case, involving damages or an account of profits, remain to be dealt with. In point of substance, however, the applicant lost the case at first instance, and now seeks to reverse that outcome. Understandably in these circumstances, the respondent offered no resistance to the proposal that leave to appeal should be granted. The proceeding before the Full Court was conducted as an appeal on the merits. I would grant leave to appeal. In my reasons which follow below, I shall refer to Artcraft Urban Group Pty Ltd as "the appellant". 156 The field of technology with which the appeal is concerned is that of assemblies for outdoor overhead lighting in public places, most obviously streets and other thoroughfares, but also paths, parks, industrial sites, and any area in which illumination is required at night. In contemporary times, illumination of such areas is commonly provided by lights fixed to the extremities of poles which are generally vertical in their orientation, but which are curved at their uppermost sections such that beams of light are directed more or less downwards towards the area to be illuminated. At the general level, it will be appreciated that the wiring and operation of such a light requires the presence of components by which the power is brought to the light and the operation of the light controlled, and of a reflector to cause the beams of the light to travel in the desired direction. 157 The specification for the Patent commences by describing the shortcomings in the background art. It is said that, in lighting assemblies of the kind typically found, the chamber enclosing the electrical components was separate from that enclosing the lamp/reflector arrangement. Thus, "the component area may not be locked and could vibrate loose." This separation, and the presence of multiple points of entry, allowed for the ingress of vermin, such as spiders and insects, and exposed the apparatus to environmental hazards, such as water. It is said: One of the problems with street lights of the prior art is that they are not sufficiently robust to withstand exposure to the external environment (including adverse weather conditions, pollution, sunlight, ingress of insect and other pests and/or their nests/webs etc) or the internal environment created by normal use (such as build up of heat leading to shortened life of components). This leads to parts becoming brittle, corroded or otherwise worn out so that they cease working. This increases the need for servicing and maintenance. 158 The problems of maintaining light assemblies such as those under consideration are referred to. Taking street lights as the exemplar, it is pointed out that, because such lights are serviced "live", linesmen must wear several thick protective gloves which limit their manual dexterity, making even simple manipulations difficult and time consuming. Because of the comparatively small size of the components and their housing, and because linesmen must work at elevated heights, the risk arises that a component may be dropped from a height, thereby causing time to be lost when the linesman goes to retrieve it, and potentially injuring those below. 159 According to this part of the specification, a further problem with street lights in the prior art is the malfunctioning of the photoelectric ("PE") cell. A PE cell is typically present in each individual street light, and controls the activation and deactivation of the lamp based on the ambient light level. "Day burners", lights that emit 24 hours a day, are often caused when PE cells fail to turn off, such as when blocked by something that shuts out the ambient light, shortening the lifespan of the light components and increasing maintenance needs. Alternatively, a PE cell may fail to activate if impinged upon by stray light, such as reflected light or illumination from an adjacent street light. 160 The specification proceeds to lay out a "summary of the invention". The following are given as the objects of the invention: • An object of the embodiments of the present invention is to reduce the maintenance and servicing required for lighting assemblies. • A further object of the embodiments of the present invention is to improve the ease and speed with which lighting assemblies can be serviced or maintained. • It is an object of the embodiments described herein to overcome or alleviate at least one of the above noted drawbacks of related art systems or to at least provide a useful alternative to related art systems. 161 The "first aspect of embodiments" described in the specification is as follows: … a lighting assembly having a casing comprising a main body defining a port for receiving a mains cable, and a visor, the casing enclosing; • a reflector assembly for receiving at least one lamp, and • a termination chamber, wherein the visor is of unitary construction for covering both the reflector assembly and the termination chamber. Characteristics of that aspect of the invention which are not presently relevant are then described. 162 The "second aspect of embodiments" described in the specification is as follows: … a lighting assembly having a casing comprising a main body defining a port for receiving a mains cable, and a polymer visor, the casing enclosing; • a reflector assembly for receiving at least one lamp, and • a termination chamber, the termination chamber being at least 20-25% of the volume of the casing, wherein the visor is of unitary construction and is adapted to cover both the reflector assembly and the termination chamber. The differences between this aspect and the first aspect are, first, the requirement that the visor be polymer, and secondly, the specification that the size of the termination chamber be no less than a stated percentage of the volume of the whole. 163 The significance of the requirement that the visor be polymer is reflected in the text of the specification which follows, in which it is said that, typically, the lighting assembly, or at least its internal housing structure, is made entirely of non-conducting material such as a polymer to reduce the possibility of live surfaces when a linesman performs maintenance on the light fitting or in the event that the mains cabling becomes unfixed. That is said to provide, essentially, "a double insulating light assembly", and to involve a "non-conductive envelope … for service and maintenance". This envelope is said to comprise "one or a combination of" an entry to the light fixture/assembly, a terminal block, casing, control gear, globe holders, a PE cell receptacle and an earth connector. 164 The significance of the requirement that the size of the termination chamber be no less than a stated percentage of the volume of the entire casing is said to lie in the greater ease of the manual handling of the mains cable, and of the manipulation of other parts and components within the casing such as the PE cell and the terminal block, without the use of tools. The larger volume termination chamber also assists in dissipating heat, thereby reducing operating temperature. 165 Because of its significance in the resolution of the present appeal, I next set out a lengthy passage from the specification, still within the section described as a "summary", which deals with a "third aspect of embodiments" of the invention. The italicised portion is so rendered in these reasons because of its importance in the appellant's case on appeal. In submissions made on its behalf, this portion was referred to as "the page 10 passage" and, for the sake of convenience, I too shall employ that convention. 166 The third aspect is described as follows: In yet a third aspect of embodiments described herein there is provided a lighting assembly having a casing comprising a main body defining a port for receiving a mains cable, and a visor, the casing enclosing; • a reflector assembly for receiving at least one lamp, and • a termination chamber for location of a PE cell, wherein the visor is of unitary construction for covering both the reflector assembly and the termination chamber, and at least the detector portion of the PE cell is entirely enclosed within the casing. Lighting assemblies of the prior art typically comprised PE cells seated in the termination chamber, but projecting through an opening in the casing so that at least part of the PE cell is external to the casing. Over time the opening would typically fill with dirt or insect nests, enshrouding the PE cell to block it from the ambient light and cause it to malfunction. Accordingly, inclusion of the PE cell within the casing such that the detector portion of the PE cell is enclosed so as to avoid any opening or breach in the casing proximate the PE cell avoids these problems. Preferably the components located within the termination chamber as well as the components of the reflector assembly are visible through the visor. For example, this part of the visor may be clear or lightly frosted compared to the remainder of the visor. Similar light fittings of the prior art have included a two part visor - a first part comprising a clear lens for the lamp and a second part comprising an opaque cover for the termination chamber. A preferred embodiment of the present invention allows a linesman to carry out a visual inspection of the components without having to remove any covers. Typically the part of the visor in the vicinity of the PE cell is clear so that the PE cell correctly detects the level of ambient light. Using frosting in other parts of the visor however may provide the advantage of preventing reflected or early ambient light impinging on the PE cell and causing it to prematurely deactivate. In particular, the use of frosting as in this preferred embodiment can avoid "day burners" (lights that are emitting 24 hours per day or at least into periods of the day not requiring artificial lighting). In related art systems, the avoidance of "day burners" was achieved by the addition of or attachment of a shield to the casing to shield the sensor or PE Cell. These shields were not attached to the lens/visor. Moreover, initial prototyping of a preferred embodiment of the present invention identified that by frosting the visor/lens to eliminate ambient light entry; light was also being reduced to the sensor/PE Cell. This was solved by a preferable arrangement whereby a non-frosted region of visor/lens/casing enables sensor/PE Cell to receive the correct lighting entering the apparatus. This has shown that this embodiment provides a saving in maintenance costs hence a saving in the likelihood of 'day burners'. 167 The specification proceeds to describe the invention by reference to diagrams. It is not necessary to reproduce them here, but the following passage in the specification, which relates to one of the diagrams, may be of some importance: The visor (7) is of unitary construction and at least in the vicinity of the lamp it is conformed to act as a prismatic lens. The visor is typically made of acrylic, polycarbonate or other hard wearing polymer that can be made clear or translucent, however, other suitable materials may used as would be understood by the person skilled in the art. The components located within the termination chamber (13) as well as the components of the reflector assembly (11) are visible through the visor (7). 168 Turning next to the claims in the specification, Claim 1 reads as follows: A lighting assembly having a casing comprising a main body defining a port for receiving a mains cable, and a visor, the casing enclosing; • a reflector assembly for receiving at least one lamp, and • a termination chamber located laterally in relation to the reflector assembly, wherein the visor is of unitary construction for covering both the reflector assembly and the termination chamber, at least part of the termination chamber and at least part of the reflector assembly being visible through the visor. Claims 2, 3 and 4 are dependent on Claim 1. 169 The principal issue in the present appeal is whether, in the appellant's lighting assembly, at least part of the termination chamber is "visible through the visor" within the meaning of Claim 1. This aspect of Claim 1 may conveniently be referred to as the visibility integer. In other respects, and subject to its invalidity case, the appellant does not challenge the primary Judge's conclusion on infringement. The appellant's two remaining challenges to the validity of the Patent, those relating to fair basis and utility, are likewise linked to the visibility integer in Claim 1, in ways which I shall explain in due course below. 170 There is, of course, no uncertainty about the grammatical meaning of the word "visible". But a glance at the photographs of the appellant's assembly included in the reasons of the primary Judge demonstrates immediately why the connotation of this word has become problematic. In those photographs, reproduced below, the termination chamber lies beneath the frosted section to the left-hand end of the plastic visor, where the identifying letters and numbers may be seen. The white circular item which has the appearance of a button is the PE cell. 171 The question for consideration is: is the termination chamber on the appellant's assembly "visible through the visor"? When a motorist, driving his or her car on a foggy morning, notices a blurred shape approaching on what ought to be the other side of the road, is the presumed other vehicle "visible" at that stage? In the present case, the notional linesman would know that there were components in the termination chamber. The primary Judge held that those components would be visible through the visor if the linesman could see that components were present, notwithstanding that he or she could not make out what they were, much less inspect them to ascertain, at least as far as appearances go, their condition. That conclusion is challenged by the appellant. 172 We need not be concerned with whether only "part" of the termination chamber is so visible: the appeal was conducted on the footing that the chamber as such either is, or is not, visible within the meaning of Claim 1. 173 As to the visibility integer, the primary Judge said: The word "visible" just looking at the language of claim 1 itself does not provide any express content or context. Visible from what perspective? The ground? An elevated work platform? Visible under what conditions? Further, "visible" is a relative term. Is it good visibility, poor visibility or any visibility? In other words, how clearly is a person to see through the visor? How clearly visible is a part of the termination chamber to be? How clearly visible is a part of the reflector assembly to be? Does the visor need to be completely transparent? Can it be frosted? And if so, to what degree? Further, it is to be noted that claim 1 does not expressly refer to any visibility of any components within either the termination chamber or reflector assembly …. I agree with what is implicit in this passage from his Honour's reasons, namely, that it is necessary to find some purpose or context for the inclusion of this integer in order to understand, if possible, the contribution which it makes to the invention in a functional or practical sense. 174 Before the primary Judge, the respondent submitted that the meaning of the visibility integer was that - … one [could] see through the visor the presence of components located within the termination chamber, but not necessarily the components in detail. So, one [could] discern that there [were] components, but … might not necessarily see or need to see what they [were]. So, parts of each of the termination chamber and reflector must be visually discernible, without necessarily being able to see components in detail. His Honour accepted that submission. 175 The appellant's submission on the meaning of the visibility integer was substantially based on the presence in the specification of the page 10 passage. It was said that this passage demonstrated that the point of the termination chamber being "visible through the visor" was to enable the linesman to inspect the condition of the components within it, thereby dispensing with the need to open the covering of the chamber for purely inspectional purposes. 176 In resolving this controversy, the primary Judge referred to certain expert evidence which had been given before him. The respondent's expert, Sylvan Browne, was a registered patent attorney with approximately 16 years' experience as an international and domestic patent practitioner in engineering-related fields. According to his Honour, Mr Browne described the quality of visibility required in the terms employed by the respondent in its submission noted above, "including by comparison to the more prescriptive requirement of 'allowing visual inspection' discussed in the specification." 177 The appellant called John Robert Rogers, a consultant lighting engineer with qualifications in illuminating engineering and 56 years' experience in the area of lighting. The primary Judge dealt with his evidence in the following way: Rogers revealed under cross-examination (in the context of being asked about whether the solid control gear chamber in the Boronia met the visibility requirement of claim 1 of the 103 Patent) that he had originally construed the term alone, without reference to the body of the specification. That was not appropriate. When asked to consider what the term meant in light of the body of the specification, he agreed that claim 1 was directed to the language on p 10, lines 13-16 of the Patents which required visibility of the components but not necessarily needing to be able to discern what they were. That is a lesser requirement than the visibility required to perform a visual inspection of components as set out in claim 1 of the 104 Patent. The "104 Patent" was another patent that featured in the litigation before the primary Judge, in which Claim 1 contained the words "wherein … the portion of the visor covering the termination chamber is adapted to allow visual inspection of components within the termination chamber." 178 The primary Judge continued: The respondents [ie the appellant and Mr Saint] fixed upon a preferred embodiment (p 10) of the claimed invention (that the visor allows a linesman to carry out a visual inspection of the components of the termination chamber). But for construction purposes, all features of a claim must be considered, not just those which relate to what has been identified as a preferred embodiment. Having set out the page 10 passage, his Honour continued: But the respondents have paid little attention to the words "[in] a preferred embodiment" in the last sentence of the quote, which described the level of visibility required in claim 1 of the 104 Patent not claim 1 of the 103 Patent. A "preferred embodiment" of an invention is a narrower form of the invention described. 179 His Honour's conclusion in respect of the visibility integer was as follows: I accept that the word "visible" must be understood in the context of the specification as a whole as involving visibility assessed by reference to there being a practical level of visibility into the termination chamber. But I do not accept that the level of visibility must be sufficient to allow an inspection of the internal components by persons, such as linesmen, maintaining the luminaire. In my view, the construction advanced by [the respondent] is correct when seen through the perspective of a skilled addressee. Although there must be a practical level of visibility into the termination chamber, particularly from an EPV, it is not required that there be sufficient visibility to allow an inspection of the internal components. The wording of the integer does not stipulate for such a requirement. Further, it is incorrect to take the meaning from a preferred embodiment. Further, [the respondent's] construction conformably fits with the specification as a whole. In terms of a purposive construction, it is consistent with making the invention work. 180 On appeal, the appellant submitted that the primary Judge had dissected the page 10 passage by perceiving in it two separate embodiments of the invention so far as claimed in Claim 1, namely, that introduced by the adverb "preferably", and that described in the final sentence ("A preferred embodiment …). Thus his Honour implicitly acknowledged that the page 10 passage might be used to give content to the visibility integer to the extent that it required that the components in the termination chamber be visible, but so much thereof as proposed the purpose of enabling a linesman visually to inspect the components without having to remove any covers was a preferred embodiment only, and was not relevant to the construction of Claim 1. The respondent accepted that his Honour did read the page 10 passage in this way, and defended him for having done so. It was submitted on its behalf that - The use of the phrases "Preferably the components located within the termination chamber ... are visible through the visor" and "A preferred embodiment ... allows a linesman to carry out a visual inspection of the components without having to remove any covers" are consistent with there being two levels of visibility - the latter being a "preferred embodiment" which is distinct from the former, broader disclosure. 181 Before coming directly to this controversy, I should consider the legal basis of a submission made on behalf of the respondent, namely, that it was not "legitimate, in the absence of an express reference in the claim itself, to import into a claim features of a preferred embodiment so as to limit the scope of the claim." That proposition was a modified reflex of what had been said by Gummow J in Rehm Pty Ltd v Websters Security Systems (lnternational) Pty Ltd (1988) 81 ALR 79, 89: The settled rule is that in ascertaining the width of a particular claim, it is not permissible to vary or qualify the plain and unambiguous meaning of the claim by reference to the body of the specification; provided that if an expression in the claim is not clear, then it is permissible to resort to the body of the specification to define or clarify the meaning of the words used in the claim: Interlego AG v Toltoys Pty Ltd (1973) 130 CLR 461 at 478-9. …. Further, whilst resort may be had in the circumstances I have indicated to the body of the specification, it also must be remembered that it usually is not legitimate, in the absence of an express reference in the claim itself, to import into a claim features of the preferred embodiment. The preferred embodiment cannot properly be used to introduce into the definite words of a claim an additional definition or qualification of the patentee's invention: Erickson's Patent (1923) 40 RPC 477 at 491. 182 In the case referred to by Gummow J, Re Erickson's Patent (1923) 40 RPC 477, it was held that recourse to the specification was not permissible to introduce specific integers into an otherwise broadly-expressed claim with a view to saving it from invalidity for want of novelty. Although it was a construction case, it was not one in which the legitimacy of having recourse to a preferred embodiment as a means of understanding the invention claimed was in issue. Indeed, the Master of the Rolls cited (40 RPC at 486) what had been said by Lord Loreburn in Ingersoll Sergeant Drill Company v Consolidated Pneumatic Tool Company Ld. (1908) 25 RPC 61, 83: Obviously the rest of the specification may be considered in order to assist in comprehending and construing a claim, but the claim must state, ether by express words or by plain reference, what is the invention for which protection is demanded. The idea of allowing a patentee to use perfectly general language in the claim, and subsequently to restrict, or expand, or qualify what is therein expressed by borrowing this or that gloss from other parts of the specification is wholly inadmissible. Likewise, Sargant LJ said (25 RPC at 491) that the claim was - … the operative part of the document, and where the terms of that part of the document are in plain language any other parts of the documents are of little, if any, importance, but if the language of the Claim is doubtful, then the other parts of the document can properly be resorted to for the purpose of assisting in the interpretation of the language of the Claim. His Lordship also said (25 RPC at 491): [A]s to the preferred embodiment, although the Drawings show, and the letter-press describes, a combined atomizer and strainer, it, again, does not follow that the Patentee intended to claim as a necessary part of his invention every feature there shown described. To do so would introduce a very dangerous element into the construction of Specifications. A preferred embodiment as shown in Drawings and as described in words may illustrate and explain, but it cannot properly be used to introduce into the definite words of a Claim an additional definition or qualification of the Patentee's invention. 183 As noted in the respondent's outline, these authorities were amongst those collected by Cooper J in Bartlem Pty Ltd v CMMC Pty Ltd (2001) 53 IPR 124, 130 [16]. 184 With respect to the respondent's submission referred to at para 181 above, the authorities deal with a situation in which an unambiguous claim is sought to be enlarged, diminished or modified in some way by the importation of the features of a preferred embodiment. They do not qualify the conventional rule that recourse may be had to any clearly relevant part of the specification for the purpose either of understanding the character of the invention to which a claim relates or of resolving terms of the claim which may be ambiguous or of uncertain connotation, either textually or in their application to a particular situation. A "preferred embodiment" of an invention, as described in the specification, will commonly represent a limited form of the invention covered by a dependent claim. Indeed, a dependent claim of this kind may be referred to as a "preferred embodiment claim": see Lockwood Security Products Pty Ltd v Doric Products Pty Ltd (No 2) (2007) 235 CLR 173, 183 [23]. In such a case, the inappropriateness of deploying the preferred embodiment to construe down, or up, the meaning of the main, or independent, claim as a whole does not require emphasis. 185 But where it is clear that a particular claim was intended to reflect a corresponding preferred embodiment referred to in the specification, any recourse to the specification for such legitimate constructional purposes in relation to the claim as may be available would of necessity be to the passage in which that embodiment is described. Décor Corporation Pty Ltd v Dart Industries Inc (1988) 13 IPR 385 provides an example. There, all members of the Full Court commenced from the position that issues of infringement and fair basis were to be resolved by reference to the terms of the relevant claim, and that these were not to be enlarged, diminished or modified by what may have been said elsewhere in the specification. But, to varying degrees (Sheppard and Foster JJ more so than Lockhart J), each of their Honours cast an eye on the terms in which the preferred embodiment had been expressed for such assistance as they may have provided on the construction of the problematic aspect of the relevant claim. 186 Notwithstanding the rather absolute terms in which the respondent's submission, referred to above, was expressed, I do not think there could be any real controversy as to the general approach to the construction of claims which I have outline above. The circumstance which makes the present case unusual is that the preferred embodiment which lies at the centre of the controversy corresponds not to one of the dependent claims but to the primary, or independent, claim itself. Save in the places mentioned in paras 166 and 167 above, there is no reference in the specification to the requirement for, or the advantages of, the termination chamber being visible through the visor. Being an integer of the primary claim, one would expect to find a corresponding reference in the consistory clause, but there is no such reference. 187 Moreover, there is nothing in the description of the background art in the specification that would shed any light on why, if it were the case, traditional forms of lighting assemblies, lacking this visibility integer, were regarded as deficient, suboptimal or in need of improvement because the termination chambers with which they were equipped were not visible through the visors. If the reader of the Patent had some inkling of the problem which the inventor sought to address by including this integer, he or she might be at least part of the way along the road to an appreciation of what it means in a practical setting. But the reader is not advantaged in this way. 188 But the primary Judge was able to discern a purpose of the visibility integer. In the passages which I have set out at para 179 above, that purpose seems to have been to facilitate "a practical level of visibility into the termination chamber", not involving "sufficient visibility to allow an inspection of the internal components". What might have been the purpose of being able to see into the termination chamber, but being unable to inspect the components therein, is not, with respect, evident from the specification. I can understand, from a purely textual viewpoint, the difference between a component being visible, on the one hand, and being susceptible of visual inspection - or what his Honour elsewhere, accepting the respondent's submission, described as being able to see what the components were - on the other hand, but the practical purpose of being able to do the former but not the latter is something which, I would have to say, cannot be affirmed on the basis of what is contained in the specification. 189 The only benefit, disclosed in the specification, of a state of affairs in which the termination chamber is visible through the visor is that described in the preferred embodiment upon which the appellant relies: it "allows a linesman to carry out a visual inspection of the components without having to remove any covers". 190 On appeal, the respondent pointed to a deal of evidence which had been led before the primary Judge in what was then the appellant's innovative step case (not pursued on appeal). The question there was whether the invention, so far as claimed in Claim 1, varied from prior art information of the kind referred to in subs (5) of s 7 of the Patents Act 1990 (Cth) ("the Act") only in ways that made no substantial contribution to the working of the invention within the meaning of subs (4). Relevantly to the matter presently under discussion, the question came down to this: did the inclusion of the visibility integer, as construed by his Honour, make such a contribution? 191 The respondent used this evidence on appeal as a counter to the appellant's constructional argument that the skilled addressee, reading the specification, would understand that the visibility integer delivered no greater benefit to what would otherwise have been an assembly conforming with Claim 1 than that referred to in para 189 above. The evidence referred to various respects in which the physical environment within the termination chamber might be problematic in ways that would not be visible to a linesman unless he or she could see through the visor into the chamber, to an extent at least. That evidence related to such things as the presence of spiders and spider webs, of insects (alive or dead), of pooled water and of soot-like blackened detritus (the result, so the linesman would infer, of the earlier burning or disintegration of plastic components). From the way the appeal was conducted on behalf of the appellant, I think we must accept that the skilled addressee would read the Patent with an appreciation that the linesman's ability to notice, even if not to see in detail, the presence of these things in the termination chamber would be one of the benefits of having that chamber visible through the visor, where the degree of visibility was at least that which conformed with the primary Judge's construction of the visibility integer. 192 But that is not to say that the skilled addressee would, himself or herself, have understood the construction of that integer as referable to, much less as dependent on, that appreciation. The controversy, it must be kept squarely in mind, was between visible in the sense of being able to undertake a visual inspection of the components in the termination chamber and visible in the sense of being able to discern the presence of the components, without being able to see what they were. There is nothing in the skilled addressee's presumed conception of the advantages that would be delivered to the linesman by his or her ability to see through the visor that would have pointed to the second of these senses, rather than to the first. 193 Neither is there anything in the specification that would link the visibility of the termination chamber through the visor with the insect/spider/water problem. Indeed, if anything, by its focus on the elimination of the physical means of ingress of these unwanted things, the specification teaches away from the perception of such a linkage. Where insects are mentioned in the specification, for instance, it is in the setting of eliminating points of ingress. Even in the text immediately preceding the page 10 passage, set out at para 166 above, the concern of the inventor is with the opening in a casing through which the PE cell would project in the prior art. 194 To date, I have concluded, first, that the fact that the last sentence in the page 10 passage is expressed, in terms, as a "preferred embodiment" does not categorically disqualify it as a source of assistance in the construction of the visibility integer in Claim 1, secondly, that it is in the page 10 passage itself, and in the corresponding explanation of one of the diagrams mentioned in para 167 above, that one finds the only references in the specification to the benefits of the termination chamber being visible through the visor, and thirdly, that, although the skilled addressee would recognise that an additional benefit would be some scope for the linesman to notice the presence of insects, spiders, water or other detritus inside the visor before opening it, he or she would not thereby understand that the inventor had included the visibility integer in Claim 1 to achieve that benefit. 195 In this state of things, it is necessary to return to the essence of the controversy which lies between the parties on the construction of the visibility integer: was the primary Judge correct to read the page 10 passage as propounding two discrete embodiments of the invention so far as claimed in Claim 1? In my respectful view, his Honour was not. Ultimately, I am driven to that conclusion by constructional considerations which relate to the relationship between the visibility integer and those parts of the specification to which it self-evidently corresponds, and which relate to the structure and sense of the specification as a whole. 196 There are three such considerations. The first is based upon an understanding of the place of the "third aspect" of the embodiments of the invention in the specification, and specifically upon how that aspect varies from the first. Where the third aspect departs from the first is in the requirement that "at least the detector portion of the PE cell is entirely enclosed within the casing". The skilled addressee would immediately see a problem here: if the visor were not translucent, then (1) the PE cell would not be in communication with ambient light and would not work as intended, and (2) the condition of the PE cell could not be visually inspected without opening the visor. The next paragraph explains the nature of the problems in the prior art that have arisen from the presence of some kind of aperture through which the PE cell projected. The next two paragraphs (those commencing, "Preferably …" and, "Moreover …") explain how the inventor overcame these problems. It is noteworthy that the requirement adopted by the inventor was not translucency but visibility, that is, the condition of a person notionally external to the termination chamber being able to see into it. Whatever may be the significance of that distinction, the explanations contained in the two paragraphs referred to must be seen as referrable to the third aspect of the invention, ie one in which the PE cell was located inside the visor covering the chamber. 197 Thus, although it is not directly the appellant's point, the skilled addressee would, in my view, understand the term "this preferred embodiment" as used in the passage following immediately after the page 10 passage as referring to the single embodiment with which the paragraph as a whole is concerned. The "frosting" there referred to is self-evidently the same frosting as is introduced in the second sentence of the page 10 passage. The message is that visibility is an advantage - permitting the linesman to carry out a visual inspection - but too much light must not be allowed into the termination chamber lest the PE cell be deactivated by "reflected or early ambient light". 198 The second consideration is that so much of the page 10 passage as refers to a "preferred embodiment" in terms does not describe a physical, structural or mechanical variant of the invention. In this respect, the passage does not conform to the pattern to be observed, with only one exception, elsewhere in the "summary" section of the specification. The following are the other uses of the term "preferred embodiment" in that section: • In a preferred embodiment, the casing comprises a clip that is capable of independently supporting the visor on the body of the casing, that is, without additional support from the hinge. • In a preferred embodiment large gauge fasteners mount the casing to the support. • In a preferred embodiment, the port is adapted to receive a grommet. • In preferred embodiments, the termination chamber is between 23-25% of the volume of the casing. • In a preferred embodiment, the non-conductive envelope comprises one or a combination of: Entry to the light fixture/assembly; Terminal block; Casing; Control gear; Globe holders; PE Cell receptacle; Earth connector. • Moreover, initial prototyping of a preferred embodiment of the present invention identified that by frosting the visor/lens to eliminate ambient light entry; • In a preferred embodiment, there is provided a light assembly adapted to accommodate two 14W environmentally friendly lamps which are the equivalent of an 80W mercury vapour lamp, which may reduce energy use by 66%. • Advantages provided by the lighting assembly of preferred embodiments of the present invention comprise the following: • can be installed as part of a new lighting structure or retrofitted to existing lighting assemblies, structures or supports, • requires less time for installation and routine maintenance, • malfunctions are reduced, • provides better access to components for repair and replacement, • easier to maintain and service, • lower occupational health and safety risks during installation, servicing and maintenance, • can operate using 'green' lamps adapted to reduce energy consumption. The exception to which I referred was the final usage of the term "preferred embodiment" in the list above. That was no more than a drawing together, towards the end of the "summary" section of the specification, of the advantages of all of the previously-mentioned preferred embodiments taken together. 199 By contrast, as used in the final sentence in the page 10 passage, the term refers to something which the linesman would be able to do if the assembly were configured in accordance with a preferred embodiment. Reading this sentence, the skilled addressee would, in my view, immediately ask himself or herself, what embodiment? He or she, knowing that the preferred embodiments were the inventor's way of describing the best known methods of performing the invention - something which the final sentence does not do - would readily appreciate that the embodiment was that described in the first sentence in the page 10 passage, namely, one in which the components located within the termination chamber were visible through the visor. He or she, in my view, would naturally read the page 10 passage as though the facilitation of a visual inspection of those components was an important, indeed a defining, attribute of that embodiment. He or she would not, in my view, read the last sentence as introducing yet another preferred embodiment, one which was narrower than that set out in the first sentence thereof. 200 The third consideration is that I cannot understand what practical benefit there would be in a linesman being able, by looking through the visor, to know only that there were components inside. Surely he or she would already know that much at least. As mentioned above, the respondent's attempts to portray his or her ability to see insects and other pests, and water if present, valid though such considerations may be at the general level, come to grips neither with the way the visibility question is dealt with in the specification nor with his Honour's own construction of the visibility integer, one which made a distinction between being able to note the presence of components (held to be a requirement of the integer) and being able to discern what the components were (held not to be a requirement). Approaching the matter in a practical way, I cannot, with respect, see the sense in that distinction. 201 The conclusion I reach is that, as a matter of construction, the page 10 passage refers not to two embodiments of the invention but to one only, that which is broadly described as requiring the components in the termination chamber to be visible through the visor, which requirement, in turn, is given purpose and thus content by reference to the ability of the linesman to carry out a visual inspection of those components without having to remove any covers. 202 This being the only point of the visibility integer in Claim 1, the court should not, in my view, be inhibited from having recourse to the page 10 passage, as so understood, as a constructional tool apropos that integer. I would limit the scope of that integer to an assembly in which the termination chamber was visible through the visor to the extent necessary to allow the linesman visually to inspect the components therewithin. 203 It is uncontroversial that the appellant's assembly does not meet that test. I would, therefore, uphold its challenge to the primary Judge's findings on infringement. 204 The appellant has two other grounds of appeal. The first relates to fair basis. Guarding against the prospect that it would fail on its construction case in relation to the visibility integer, the appellant submits that the broader understanding of that integer which attracted itself to the primary Judge was not fairly based in the specification because it was the page 10 passage only that might have provided the corresponding basis, and that passage justified only the narrower understanding for which the appellant contended. Because I would uphold the appellant's construction of the visibility integer, I would hold that its fair basis case falls away. Even were his Honour correct on the construction point, however, that case could not succeed in the way it was presented. His Honour's construction of the visibility integer did find a basis in the specification, namely, in the first sentence of the page 10 passage. It was his Honour's refusal to read the final sentence in that passage as confining apropos the first that led to the appellant's failure at first instance on the constructional point. 205 I would take the same approach to the other ground of appeal relied on by the appellant, want of utility. The pith of that ground was stated in the appellant's outline as follows: … [I]f the claim bears the construction given by the trial judge, it includes subject matter that does not give the advantage promised in the Page 10 Passage, viz sufficient visibility to allow a linesman to carry out a visual inspection of the components without having to remove any covers. On the basis of the construction which I would give to the visibility integer, the appellant's utility ground would fall away. On the other hand, if his Honour's conclusion, and the way he reached it, were to be upheld, the characteristic claimed in Claim 1 would be no more than what was promised in the first sentence of the page 10 passage. The final sentence in the page 10 passage would be read as a further embodiment to which no claim corresponded. On that view of things, this ground could not succeed. 206 For the reasons I have given, I would allow the appeal. I certify that the preceding fifty-three (53) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Jessup.