Hamlet And The Patenting Of Parameters In Europe

As a general rule, an applicant is free to draft a patent claim in any desired claim language; the same is true for the accompanying description. However, when an invention manifests in particular parameters and the invention shall be protected by a European patent granted under the European Patent Convention, some particular issues may arise. Five of these issues are discussed in this paper. Contrary to Hamlet, we must ask not only one question in this context, but several.

Clarity Is it usual, or is it not usual: that is the question.

Although a product may be defined in a claim in various ways, the Guidelines for Examination in the European Patent Office (hereinafter: "the Guidelines") state that a product should only be exceptionally defined by its parameters. In this context, parameters are considered to be characteristic values, which may be values of directly measurable properties or may be defined as more or less complicated mathematical combinations of several variables in the form of formulae.

However, according to the Guidelines, such a characterization by parameters is in principle only allowable in those cases where the invention cannot be adequately defined in any other way. Additionally, it is required that the parameters can be clearly and reliably determined either by indications in the description or by objective procedures, which are usual in the art. Given that the definition of the invention should appear completely in the claim itself whenever reasonably practicable, and given that the method of measurement is necessary for the unambiguous definition of the parameter, the method should be mentioned in the claim.

There are only...