Conditions for the validity of a patent

Patents are presumed valid (C. Cass. com., 2 October 1964); nevertheless, they may be revoked if contrary evidence is provided by the party invoking such nullity (« actori incumbit probatio« ).

Grounds for revocation of a French patent

Principle

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

The list of grounds for revocation 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 inefficiency 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 revocation).

Grounds for revocation

The grounds for revocation of a French patent are:

• The subject matter of the French patent is not patentable under the following articles:
  • L611-10 CPI (non-invention, novelty, inventive step, industrial application);
  • L611-11 CPI (novelty);
  • L611-13 CPI (cases of non-prejudicial disclosure);
  • L611-14 CPI (inventive step);
  • L611-15 CPI (industrial application);
  • L611-16 CPI or L611-17 CPI or L611-18 CPI or L611-19 CPI (exclusion 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 increased.

Partial revocation

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

Possibility of limitation

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

Relative or absolute nullity?

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

Grounds for revocation of the French part of a European patent

Principle

The possible grounds for revocation of a French patent are listed in Article L614-12 CPI together with A138(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 following articles:
  • A52 EPC (invention);
  • A53 EPC (exclusions from patentability);
  • A52 EPC and A54 EPC (novelty);
  • A55 EPC (non-prejudicial disclosures);
  • A52 EPC and A56 EPC (inventive step);
  • A52 EPC and A57 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 A83 EPC);
• the subject-matter of the European patent extends beyond the content of the application as filed (A123(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 (A76(1) EPC);
• the protection conferred by the European patent has been extended (A123(3) EPC); or
• the proprietor of the European patent was not entitled to obtain it (A60(1) EPC).

Partial invalidity

Partial invalidity of a patent is possible (A138(2) EPC and L613-27 CPI, which mentions this possibility) and must be declared as an amendment of the claims. Thus, partial invalidity cannot merely involve modifying the description or the 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 (A138(3) EPC and L613-25 CPI) in order to address the objections raised. This limitation then serves as the basis for the proceedings. The limitation, of course, has retroactive effect (A68 EPC).

Relative or absolute 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 nevertheless ruled that this ground for invalidity under A138(1)(e) EPC was relative in France (C. Cass. com, 14 February 2012 n°11-14288).