Collingwood Lighting Ltd v Aurora Ltd

For anticipation, prior art must disclose subject-matter whose performance would necessarily infringe the patent. A possible or likely consequence is insufficient. An obviousness case based on common general knowledge must identify and establish that knowledge. The skilled person is not assumed to treat every prior-art document as equally relevant and the question is whether the invention would have been reached, not merely whether it could have been reached. Patent claims are construed purposively in context, but deliberate claim limitations remain effective. A claimed fire-resistant housing is not limited to one component or one material unless the claim requires that result. Thermal contact with part of the housing may suffice where the claim does not require contact with the whole housing.

Collingwood claimed that Aurora’s I-9 fire-resistant LED downlights infringed a patent for a lighting unit in which heat was conducted from the LED element through a fire-resistant housing to an external heat sink. Aurora challenged claim 1 for anticipation and obviousness and denied infringement. It also relied on a redesign incorporating an insulating silicone ring between housing components.

The central issues were whether the cited prior art disclosed or rendered obvious the claimed arrangement, whether the housing had to be a single component or made of one material, whether the redesign fell outside the claim, and whether Aurora had established the statutory defence to damages based on lack of knowledge or reasonable grounds for supposing that the patent existed.

1. Validity. Claim 1 was valid. Under the approach summarised in Synthon BV v SmithKline Beecham plc [2005] UKHL 59, [2006] RPC 10, anticipation requires disclosure which, if performed, would necessarily infringe. The Mondloch disclosure used an aluminium housing and did not necessarily disclose a fire-resistant housing. Its technical ambiguity also prevented a clear and unambiguous disclosure of the claimed invention.
2. An obviousness case based on common general knowledge must establish the alleged knowledge. The assertion that an external heat sink was common general knowledge was unsupported and contradicted the market evidence. The claimed arrangement therefore involved an inventive step over the common general knowledge.
3. In assessing documentary prior art, the skilled person is deemed to read and understand it, but does not approach every document with the expectation that it solves the relevant problem. Applying Inhale v Quadrant [2002] RPC 21 and the could/would approach explained in Actavis UK Ltd v Novartis AG [2010] EWCA 82, [2010] F.S.R. 18, the relevant question was whether the skilled person would have made the necessary modifications without hindsight. Mondloch, Ryan and the Aurora products did not make the claimed design obvious.
4. Construction and infringement. Section 125 of the Patents Act 1977, Article 69 of the European Patent Convention and the Protocol required purposive construction in context. A preferred embodiment does not delimit the claim. Claim 1 did not require a housing comprising one component or one material. The original I-9 products therefore infringed.
5. The redesign also infringed. The claim required thermal contact with the fire-resistant housing, not necessarily with every part of it. The brass disc remained part of the housing and conducted heat to the heat sink. In any event, the silicone ring would have been an immaterial variant on the approach discussed in Improver Corp v Remington Products Ltd [1990] FSR 181.
6. Damages. Under section 62(1) of the Patents Act 1977, Aurora bore the burden of proving that it neither knew nor had reasonable grounds for supposing that the patent existed. The second limb was objective, and belief that the patent was invalid or not infringed would not suffice. Applying the evidential principle referred to in Fairchild v Glenhaven Funeral Services Ltd [2002] UKHL 22, [2003] 1 AC 32, Aurora failed to discharge that burden. Claim 16 was not independently valid if claim 1 were invalid. The court ordered that consequential orders be addressed after judgment.