Claims under the European Patent Convention

Article 84 of the European Patent Convention (EPC) defines the function of the claims under the European Patent Convention, the function being to define the matter, i.e. the invention, for which patent protection is sought. This legal provision also imposes that the claims must be clear, concise as well as supported by the description of the European patent application or patent. The form and content of the claims are defined in Article 84, and supplemented by the Rule 43 EPC.

The wording of Article 84 is as follows:

The claims shall define the matter for which protection is sought. They shall be clear and concise and be supported by the description.

The EPC requires that the claims must be clear (i.e., for instance the claim wording cannot be obscure) and must define the matter for which protection is sought in terms of the technical features of the invention. The rationale behind this requirement is to ensure that the public is not left in any doubt as to which subject-matter is covered by a particular patent and which is not. The clarity requirement therefore plays an important role in providing legal certainty for third parties to determine whether they are infringing or could infringe a patent or not, so as in turn to be able to make the most informed economic decisions as possible (such as taking a license, designing around, refraining from entering a market, etc.).

According to the established case law of the EPO boards of appeal, the claims must be clear "in themselves when being read with the normal skills, but not including any knowledge derived from the description of the patent application ...". In other words, the wording of a claim must be clear in itself.

As mentioned above, a claim must define the matter for which the protection is sought in terms of the technical features of the invention. These technical features need not necessarily be structural however; they may also be functional. Structural features may for example consist in a nail, a screw or a rivet, whereas functional features define the suitability for performing certain functions, such as for example fastening means.

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