Patent of improvement

An improvement patent is a patent that protects an improvement made to an already patented invention. The improvement must itself meet the conditions of patentability, that is, be new, involve an inventive step and be susceptible of industrial application. The improvement patent is not a distinct legal category in French law. The former certificate of addition, which allowed a holder to protect its own improvements at lower cost, has been abolished. An improvement is therefore protected by an ordinary patent.

Improvement patent and dependent patent

Where the improvement cannot be exploited without reproducing the features of the earlier patent, the improvement patent is said to be dependent. Its holder cannot exploit its invention without the authorisation of the holder of the dominant patent. Conversely, the holder of the dominant patent cannot exploit the improvement without the agreement of the holder of the second patent. This situation of mutual blockage often leads to a cross licence.

The compulsory dependency licence

To prevent a useful improvement from remaining unexploited, Article L. 613-15 of the French Intellectual Property Code organises a compulsory dependency licence. The holder of the improvement patent may ask the judicial court for a licence over the earlier patent, provided its invention represents an important technical advance and a considerable economic interest compared with the dominant invention. The holder of the earlier patent may then obtain a reciprocal licence. The provision is available on Légifrance.

Key points

In practice, the improvement patent is a patent portfolio management tool. It allows a competitor to secure a negotiating position against the holder of a basic patent. It also allows the original holder to prolong the protection of its technology by patenting its own improvements, within the limits of novelty and inventive step. The firm advises on these filing and negotiation strategies, presented on the page patent commercialisation.