477. Test of obviousness.

The statutory question is whether the invention is obvious to the notional person skilled in the art. A four-stage test for obviousness has been established by the courts1:


    (1)     identify the notional 'person skilled in the art'2 and identify the relevant common general knowledge3 of that person;


    (2)     identify the inventive concept of the claim in question or if that cannot readily be done, construe it;


    (3)     identify what, if any, differences exist between the matter cited as forming part of the 'state of the art' and the inventive concept of the claim or the claim as construed; and