Claim interpretation

Claim interpretation is the operation by which the office or the court determines the meaning and scope of the claims of a patent, a necessary preliminary to any assessment of validity or infringement. Under Article 69 of the European Patent Convention (EPC) and Article L. 613-2 of the French Intellectual Property Code, the extent of protection is determined by the claims, the description and drawings being used to interpret them. The Protocol on the Interpretation of Article 69 sets out the spirit of that interpretation.

Principles of interpretation

The claims are read by the person skilled in the art, in light of the common general knowledge at the filing or priority date, and not according to their literal or grammatical meaning alone. The description and drawings serve to shed light on the terms used, and the description may act as a dictionary where the proprietor has defined a term in a particular sense. Interpretation does not, however, allow a feature appearing only in the description to be added to the claims, nor a feature to be removed on the ground that it does not appear essential.

Convergence of European approaches

The Enlarged Board of Appeal of the European Patent Office recently held that the claims are the starting point for assessing patentability and that the description and drawings must always be consulted to interpret them, and not only where the claims appear unclear. The Court of Appeal of the Unified Patent Court (UPC) laid down similar principles in its very first decisions, holding that the claim is the decisive basis for protection and is to be interpreted in light of the description and drawings, from the standpoint of the person skilled in the art. French case law likewise allows the description and drawings to be used to shed light on the claims, while refusing to let them alter their scope.

Uniform interpretation in litigation

The same interpretation must in principle prevail when assessing validity and infringement, so as to prevent the proprietor from arguing a narrow reading to escape the prior art and a broad one to catch the accused product. This requirement is particularly acute before the UPC, where the counterclaim for invalidity may be heard together with the infringement action, as before the Paris Judicial Court, which rules on both issues. Statements made by the proprietor during the grant procedure may be relied upon, but their weight remains debated.

Key points

Claim interpretation decides the outcome of most patent disputes, since both validity and infringement depend on it. European courts are converging on a reading by the person skilled in the art, informed by the description, without rewriting the claims. A consistent interpretation should be settled very early in the dispute, valid both in defending validity and in supporting infringement, and the definitions given in the description should be checked.

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This glossary entry is general in scope and does not constitute legal advice.

Dhenne Avocats litigates patent disputes before the Paris Judicial Court, the Paris Court of Appeal and the Unified Patent Court. Where the question arises in a real case, the useful moment is almost always before proceedings are issued.

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