Case: Kirin-Amgen Inc v Hoeschst Marion Roussel Ltd (2004) 64 IPR 444
Outcome: followed
A patent specification should be given a purposive rather than a purely literal construction: Catnic Components Ltd v Hill &amp; Smith Ltd [1982] RPC 183 (' Catnic ') at 242-243; D&eacute;cor at 400; Improver Corporation v Remington Consumer Products Ltd [1990] FSR 181 (' Improver '); Nicaro Holdings Pty Ltd v Martin Engineering Co (1989-1990) 16 IPR 545 at 560-561; Commonwealth Industrial Gases Ltd v M W A Holdings Pty Ltd (1970) 44 ALJR 385 at 388; Beltreco at [81]; Kirin-Amgen Inc v Hoeschst Marion Roussel Ltd (2004) 64 IPR 444 (' Kirin-Amgen '); Sachtler at [43]-[67]. It is inappropriate, however, to approach construction of the specification with a view to being 'fair' to the patentee; Kirin-Amgen at [33]; Sachtler at [60]. The fact that the monopoly is granted in consideration for the disclosure of the invention to the general knowledge base of society must be recognised: Beltreco at [70]. Indeed, the principles governing a definition of a monopoly operating over the public at large require a description of the claims that 'is not reasonably capable of misunderstanding': Martin at 59. The patentee must define the invention with sufficient precision to permit the monopoly to be determined and allow the general public to identify from the words of the claims the conduct prohibited: British United Shoe Machinery Co Ltd v A Fussell &amp; Sons Ltd (1908) 25 RPC 631 at 650-651. The public are entitled to be able to design around the monopoly claimed in a patent and therefore they must be able to determine reliably the scope of the claims: Beloit Technologies Inc v Valmat Paper Machinery Inc [1895] 24 RPC 705 at 720. 37 In my view, the evidence objected to by Clorox is admissible as relevant in the present proceedings in relation to the proper construction of the Patent's claims. While terms used in a claim are to be given their ordinary English meaning, the hypothetical addressee is the non-inventive person skilled in the art before the priority date: see [20] above. This is made plain by Lord Hoffman in Kirin-Amgen at [32] where his Lordship stated: '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. ' (emphasis added)