PLG v Ardon International Ltd [1995] FSR 116

Section 1(1) of the PA 1977 stipulates the essential prerequisites for a patent claim to be valid: novelty, industrial application and inventive application. Only if these conditions are satisfied may a patent be granted. Of these requirements, the inventive step – the essence of making an invention in the popular mind – has generated the greatest divergence in judicial approach and hence uncertainty in patent law. ‘Invention’ is not defined by the PA 1977, but under s 3, an invention shall be taken to involve an inventive step if it is not obvious to persons skilled in the art, having regard to any matter which forms part of the state of the art. The state of the art comprises all matter before the priority date made available to the public by written or oral description, by use or in any other way (see s 2(3)).