Disclosure of the invention

The role of the skilled person

5.119 The specification is addressed to a non-inventive person of ordinary skill in the art. Therefore, objection should not be raised to any terminology that would be clear in meaning to the skilled person. Moreover, the specification is a technical document that is intended to instruct a skilled person on how to work the invention, and if the specification meets that purpose then no objection should be raised on the basis that it is possible to describe the invention more clearly in a different way (Schwarzkopf and Ors’ Application, 31 RPC 437).

5.120 The skilled person can include a group or team of such persons. The abilities of the skilled person were stated in Valensi and another v British Radio Corporation Ltd, [1973] RPC at page 377:

“We think the effect of these cases as a whole is to show that the hypothetical addressee is not a person of exceptional skill and knowledge that his is not to be expected to exercise any invention or any prolonged research, inquiry or experiment. He must, however, be prepared to display a reasonable degree of skill and common knowledge of the art in making trials and to correct obvious errors in the specification, if a means of correcting them may be found.”

5.121 If the skilled person comprises a team then different parts of the specification may be addressed to the different skilled addressees, who cooperate to work the invention (Osram Lamp Works Ltd v Pope’s Electric Lamp Co Ltd 34 RPC at page 391).

5.122 The description should enable the skilled person wishing to achieve success rather than failure to work the invention without an undue expenditure of time and effort and without undue experimentation (Mayne Pharma v Debiopharm and Sanofi Synthélabo [2006] EWHC 1123 (Pat) at [65]). The general principles relating to undue experimentation were stated by Aldous J in Mentor v Hollister [1993] RPC 7 as follows:

“The section requires the skilled man to be able to perform the invention but does not lay down the limits as to the time and energy that the skilled person must spend seeking to perform the invention before it is insufficient. Clearly there must be a limit. The sub-section by using the words, clearly enough and completely enough, contemplates that patent specifications need not set out every detail necessary for performance, but can leave the skilled man to use his skill to perform the invention. In doing so he must seek success. He should not be required to carry out any prolonged research, enquiry or experiment. He may need to carry out the ordinary methods of trial and error, which involve no inventive step and generally are necessary in applying the particular discovery to produce a practical result. In each case, it is a question of fact, depending on the nature of the invention, as to whether the steps needed to perform the invention are ordinary steps of trial and error which a skilled man would realise would be necessary and normal to produce a practical result.”

5.123 The Court in Institut Pasteur v Genelabs Diagnostics followed these principles in determining that sufficiency does not require minute, step-by step directions, and that the skilled person does not need to be told information that would be common general knowledge in the art.

5.124 Insufficiency will not arise merely on the basis that some difficulty is experienced in working the invention. Generally this will be according to acceptable levels of failure in the particular art. However, if the invention is not repeatable or if success is unpredictable then the specification may be insufficient. Nevertheless, it can be assumed that the skilled person should be trying to make the invention work (KirinAmgen Inc v Hoechst Marion Roussel [2005] RPC 9). Thus, if the skilled person would quickly realise that one method would work and another would fail, the specification is not insufficient because the claim is expressed in terms broad enough to include both methods. However, the specification must be sufficient to allow the invention to be performed without undue burden, having regard to the fact that the specification should explain to the skilled person how the invention can be performed. The question whether a burden is undue must be sensitive to the nature of the invention, the abilities of the skilled person and the art in which the invention has been made (Eli Lilly & Co. v Human Genome Sciences Inc [2008] EWHC 1903 (Pat) [2008] RPC 29).

5.125 The test for enablement of a prior disclosure for the purpose of anticipation is the same as the test of enablement of the patent itself for the purpose of sufficiency (SmithKline Beecham Plc’s (Paroxetine Methanesulfonate) Patent, [2006] RPC 10). However, the role of the person skilled in the art is different. In the case of disclosure, the skilled person is taken to be trying to understand what the author meant. His common general knowledge forms the background in construing the disclosure, with the patent being construed on similar principles. On the other hand, for enablement, the person skilled in the art is assumed to be willing to make trial and error experiments to get it to work, and the question is not what the skilled person would think the disclosure meant, but rather whether the skilled person would be able to work the disclosed invention.