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Date Published

Examiners must give consideration to the teachings of the prior art, i.e. what would the skilled addressee have done on reading the citation?

"if carrying out the directions contained in the prior inventor's publication will inevitably result in something being made or done which, if the patentee's patent were valid, would constitute an infringement of the patentee's claim, this circumstance demonstrates that the patentee’s claim has in fact been anticipated.”

General Tire & Rubber Co v Firestone Tyre & Rubber Co Ltd [1972] RPC 457 at pages 485-486.


"To anticipate the patentee's claim, the prior publication must contain clear and unmistakable directions to do what the patentee claims to have invented ... A signpost, however clear, upon the road to the patentee's invention will not suffice. The prior inventor must be clearly shown to have planted his flag at the precise destination before the patentee."

General Tire & Rubber Co (supra at page 486).

It therefore follows that a prior disclosure will only invalidate a claim if, after having read it, the skilled addressee would, rather than could, have produced all the essential features of the claim:

"Any information as to the alleged invention given by any prior publication must be for the purpose of practical utility, equal to that given by the subsequent patent. The latter invention must be described in the earlier publication that is held to anticipate it, in order to sustain the defences of anticipation. Where the question is solely one of prior publication, it is not enough to prove that an apparatus described in an earlier specification could have been used to produce this or that result. It must also be shown that the specifications contain clear and unmistakable directions so to use it. It must be shown that the public have been so presented with the invention that it is out of the power of any subsequent person to claim the invention as his own."

Canadian General Electric Co., Ltd v Fada Radio Ltd (1930) 47 RPC 69 at page 90.


"If ... the prior publication contains a direction which is capable of being carried out in a manner which would infringe the patentee's claim, but would be at least be as likely to be carried out in a way that would not do so, the patentee's claim will not be anticipated."

General Tire & Rubber Co (supra at page 486).

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