Is the Essentiality of a Claim Element a Question of Fact?

Hollick Solar Systems Ltd v Matrix Energy Inc 2012 FCA 174 Létourneau JA: Blais CJ, Pelletier JA aff’g 2011 FC 1213 Scott J (blogged here)

Hollick brought an action alleging that Matrix infringed its patent in a solar air heating system. Matrix defended on the basis that its system did not infringe, as the patent specified that the heated air is removed into the building through a plenum at “the top” of the panels, while the defendant’s device placed the air intake at the bottom of the panel. Since a patent may be infringed despite a substitution of a non-essential element of the invention (Free World Trust 2000 SCC 66 [55]), the question was whether the location of the air intake at the top of the panel was an essential element. Scott J’s opinion is one of the very few decisions to actually apply the three-step Improver test for essentiality that was approved in Free World Trust at [55]-[56]. The first step in that test is to ask whether the “variant” – the defendant’s device – has “a material effect on the way the invention works.” But what is meant by “the invention”? The inventive concept, or the invention as claimed? This question was raised directly on the facts (though it was not addressed specifically in the decision), as it appears that the defendant’s system was less efficient, and the placement of the intake at the bottom was intended to avoid the claims. Scott J at trial held that it was essential, and therefore the defendant’s system did not infringe, as the placement had a material effect on the way the invention worked: “The criteria is not whether the variant improves the performance of the invention but rather does it have a significant effect on how the device functions, be it positive or negative” [59]. Because Scott J considered only the claims, and not the inventive concept in coming to this conclusion, it is implicit that he took “the invention” in the Improver test to mean the invention as claimed.

The only question dealt with on appeal was whether Scott J erred in holding that the placement of the intake was an essential element. The FCA affirmed, noting that the determination of whether there was a material effect depended on the testimony of expert witnesses, and “[w]e are in effect asked to second-guess the judge on his appreciation of expert evidence on factual issues and issues of credibility, and then substitute our own appreciation” [17]. The FCA stated that it was not persuaded that Scott J had made an error of law or an overriding and palpable error on a question of fact or mixed law and fact.

This holding has two interesting implications. First, it indirectly affirms that “the invention” in the Improver test means the invention as claimed, not the inventive concept. However, it is not particularly strong authority on this point, as the question of the correct interpretation of the Improver questions point was not raised specifically either at trial or on appeal. As I noted in my post on Scott J’s decision, my own view is that the better interpretation of the Improver questions is that “the invention” means the inventive concept. With that said, the answer is certainly not easy to extract from the “mangle” of the Improver decision.

Second, the standard of review applied by the FCA implies that the question of whether an element is material is a question of fact, or at least mixed fact and law, and is therefore entitled to deference. Does this also mean that the question of whether an element is essential is a question of fact? Are the three different questions in the Improver test to be assessed on different standards? This question is not easy to answer, given that the Improver test is not consistently used. The FCA’s point that evaluation of technical evidence was required is certainly compelling on the facts in Hollick, but its approach may be contrasted with that taken by the FCA in Easton Sports Canada Inc. v Bauer Hockey Corp 2011 FCA 83, (blogged here). In Bauer the FCA affirmed the trial decision that the element was essential only after a detailed consideration of the evidence, and rather than affirming on the basis of lack of error, the FCA held affirmatively that the element in question “is an essential feature of the claim” [54]. With that said, it is not clear whether this reflects any difference in principle, or simply reflects differences in the way the cases were argued.