Better to curse the darkness – infringement of street lighting assembly patent upheld
Note: Where any of the barristers were involved in a case reported below and the matter is still running, or potentially so, the other correspondents have taken the role of reporting that case
Artcraft Urban Group Pty Ltd v Streetworx Pty Ltd  FCAFC 29
Patents – innovation patent – construction – “preferred embodiments” in specification – fair basis – utility
In the principal proceedings, the respondent (Streetworx) was successful in its infringement claims against the first appellant (AUG) and its director and general manager Mr Saint, in respect of two innovation patents for outdoor overhead lighting assemblies known as luminaires. AUG was unsuccessful in its cross-claim for revocation.
According to the relevant specification, Streetworx’s luminaires are designed to overcome a variety of problems with existing street lighting assemblies. Servicing lighting assemblies generally is difficult, due to the need for visual inspection and servicing while the lighting is “live”, and their elevated position. The other problems cited in the specification relate to added difficulties in servicing and maintenance, such as: degradation due to exposure to the elements; infestation by insects or other pests due to entry points occurring through vibration; and general malfunction.
Streetworx’s products are said to overcome these issues through various means that effectively result in a lighting assembly that consists of fewer parts, is more robust, and is easier to service. According to the specification, “Preferably the components located within the termination chamber as well as the components of the reflector assembly are visible through the visor“. A second part of the specification implies that that aspect of the lighting assembly enables inspection without the removal of any covers (and avoids certain other issues with having the photoelectric sensor (PE cell) projecting through an opening in the casing, as is the case with prior art street lights).
AUG appealed against the trial judge’s findings to the effect that a particular AUG product that had been modified in an attempt to avoid infringing Streetworx’s patents nevertheless infringed one of the patents in suit. The relevant question was whether a plastic visor incorporated into AUG’s modified luminaire satisfied the requirement in claim 1 of the patent that the “termination chamber” of the “lighting assembly” be “visible through the visor”. The part of the visor of AUG’s modified product that sat over the “termination chamber” (which houses, among other things, the PE cell and the end of the mains cables) was frosted, and the PE cell protruded through the visor. AUG contended that its visor did not meet the requirements set out in claim 1, alternatively even if it did, its revocation action ought to have succeeded on the basis of lack of fair basis and lack of utility of that particular claim.
On the construction point, the key issue was whether the “visibility” element was satisfied if the presence of components in the termination chamber was merely discernible (with the language of “visibility” in the claim mirroring the extract from the specification set out above) or whether those components also had to be sufficiently clear so as to allow a linesman to inspect the components without removing the cover (a benefit of “visibility” identified in the same paragraph of the specification). As Jessup J noted, the case was unusual because the “preferred embodiment” of Streetworx’s invention corresponded to the primary claim, rather than one of the independent claims.
The majority of the Full Court (Greenwood J, with whom Rares J agreed) held that the trial judge did not err in finding that the broader construction would still convey a practical level of “visibility” from the perspective of the skilled addressee, although Greenwood J conceded that minds might differ on the point. Justice Rares also observed that the specification contemplated the possibility of a “lightly frosted” visor over the termination chamber, and held that a skilled addressee would construe the term “visible” in claim 1 in the context of that possibility. Both Greenwood and Rares JJ observed that, if nothing else, the linesman would still be able to detect the intrusion of pests, dirt or moisture through a frosted visor.
In contrast, Jessup J would have upheld the appeal, as the only benefit identified in the specification for the visibility element was to allow inspection without the removal of covers; in context, that reference was to be understood as part of the same “preferred embodiment”. Further, the skilled addressee (i.e. a linesman) would already know that there were components present in the termination chamber, and would conclude that inspection was the relevant benefit. That being the case, the Court was entitled to have recourse to that passage of the specification as a constructional tool for the claim, and the narrower interpretation of the visibility element would be warranted. Justice Jessup’s findings on construction also meant that AUG’s complaints of lack of fair basis or utility would fall away.
In light of the comments of Greenwood and Rares JJ concerning the benefits conveyed by even the broader approach to “visibility”, it is unsurprising that AUG’s assertions as to lack of fair basis and lack of utility were unsuccessful. As to the former, Greenwood J (with whom Rares J agreed) did not accept that claim 1 “travels beyond the real and reasonably clear disclosures in the specification“, when the specification was read as a whole. As to the latter, the task was to identify the “result promised for the invention” by the patentee, and to then determine whether the invention, as claimed, would achieve that result. The result promised was that the components in the termination chamber would be “visible” in the broader sense which, in light of their Honours’ conclusions as to construction above, was what claim 1 taught.
The matter has been remitted to the trial judge for a determination of quantum. No application for special leave was filed in the High Court from the Full Court’s decision.