In Nufarm Limited v Jurox Pty Limited [2008] FCAFC 1801, Australia's Federal Court of Appeal has approved the trial judge's novel approach to claim interpretation.
Under Australian law there is nothing new in the approach of having recourse to the body of a patent specification to interpret ambiguity in claim language. The objective is to determine from the specification the meaning of the relevant claim integer and hence the scope of the claim.
What is interesting about this case is that the objective was more to determine from the specification that which the skilled person would understand not to be the invention, and hence not within the scope of the claim. The question of infringement was then considered having regard to whether the alleged infringement resembled that which the skilled person would have understood not to be the invention.
At issue was whether the alleged infringement was an ‘emulsion’ having an ‘organic liquid phase’. Given that expert evidence had suggested alternative meanings for these integers, the trial judge turned to the specification and instead of determining in an abstract sense what constituted an ‘emulsion’ or ‘phase’, he observed that the alleged infringement resembled the product exemplified in certain examples of the patent, the exemplified product according to the specification being essentially aqueous and therefore not having an ‘organic liquid phase’.
The somewhat surprising result has been that the relevant examples were found to disclose nothing more than an explanation as to how the patentee had made the invention, rather than to exemplify the claimed product itself—even though the specification did not expressly describe the relevant examples as 'comparative'—and that the claim was effectively read down to cover specific forms of emulsions, but not emulsions of the micellar type, so that an alleged infringement that resembled a product within the relevant examples was held not to infringe the claims.
Endnotes
1. Nufarm Limited v Jurox Pty Limited [2008] FCAFC 180
This article was written by Tom Gumley, Partner, Freehills Patent & Trade Mark Attorneys.
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