Patents are presumed valid (C. Cass. com., 20 October 1964); however, they may be revoked if contrary evidence is provided by the party invoking such invalidity (« actori incumbit probatio« ).

Grounds for Invalidity of a French Patent

Principle

The possible grounds for invalidity of a French patent are listed in Article L613-25 CPI.

The list of grounds for invalidity is exhaustive (C. Cass. com., 2 June 1992, No. 90-21629 contra C. Cass. com., 8 December 1992, No. 91-14234, which adds a rule of ineffectiveness of a claim (where the claim is not based on the description or is contradicted by the description, a condition that is now a ground for invalidity)).

Grounds for Invalidity

The grounds for invalidity of a French patent are:

  • The subject matter of the French patent is not patentable under the provisions of: Article L611-10 CPI (non-invention, novelty, inventive step, industrial application); Article L611-11 CPI (novelty); Article L611-13 CPI (cases of non-prejudicial disclosure); Article L611-14 CPI (inventive step); Article L611-15 CPI (industrial application); Article L611-16 CPI, L611-17 CPI, L611-18 CPI, or L611-19 CPI (exclusions from patentability). The patent does not disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art; the subject matter of the patent extends beyond the content of the application as filed or, where the patent has been granted on the basis of a divisional application, if its subject matter extends beyond the content of the initial application as filed;
  • after limitation, the scope of protection conferred by the patent has been broadened.

Partial Invalidity

A patent may also be partially invalidated (Article L613-27 CPI, which mentions this possibility).

Possibility of Limitation

To strengthen their patent, the proprietor may limit it in the context of invalidity proceedings (Article L613-25 CPI).

Absolute or Relative Invalidity?

The grounds for invalidity listed in Article L613-25 CPI are absolute: any interested party may request the invalidation of the patent.

Grounds for Invalidity of the French Part of a European Patent

Principle

The possible grounds for invalidity of a French patent are listed in Article L614-12 CPI together with Article 138(1) EPC.

Grounds for Invalidity

The grounds for invalidity of a European patent are:

  • The subject matter of the European patent is not patentable under the provisions of: Article 52 EPC (invention); Article 53 EPC (exclusions from patentability); Article 52 EPC and Article 54 EPC (novelty); Article 55 EPC (non-prejudicial disclosures); Article 52 EPC and Article 56 EPC (inventive step); Article 52 EPC and Article 57 EPC (industrial application); the European patent does not disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art (within the meaning of Article 83 EPC); the subject matter of the European patent extends beyond the content of the application as filed (Article 123(2) EPC) or, where the patent has been granted on the basis of a divisional application or a new application filed under Article 61, if the subject matter of the patent extends beyond the content of the earlier application as filed (Article 76(1) EPC); the protection conferred by the European patent has been extended (Article 123(3) EPC); or
  • the proprietor of the European patent was not entitled to obtain it (Article 60(1) EPC).

Partial Invalidity

Partial invalidity of a patent is possible (Article 138(2) EPC and Article L613-27 CPI, which mentions this possibility) and must be declared as an amendment to the claims. Thus, partial invalidity may not involve merely amending the description or drawings.

Possibility of Limitation

In national proceedings, the proprietor of the patent must be given the opportunity to limit the patent by amending the claims (Article 138(3) EPC and Article L613-25 CPI) to address the objections raised. This limitation then serves as the basis for the proceedings. The limitation, of course, has retroactive effect (Article 68 EPC).

Absolute or Relative Invalidity?

The grounds for invalidity are, in principle, absolute.

However, regarding the last ground for invalidity (i.e., if the patent was obtained by an unauthorized person), the Cour de cassation has ruled that this ground for invalidity under Article 138(1)(e) EPC is relative in France (C. Cass. com, 14 February 2012 No. 11-14288).