Very often in patent infringement lawsuits, the defendant files a cancellation action against the allegedly infringed patent as a counterclaim, even before trying and demonstrating he did not infringe the patent.
But however frequent such counterclaims may be, they are not to be filed with haste or casualness.
A recent case judged by the Court of Appeals of Lyon provides a good example.
One of the two co-owners of a patent had been exclusively authorized by the other to initiate and conduct all by himself any patent infringement action he deemed necessary or appropriate. And that is exactly what he did.
Considering a third party was manufacturing and distributing several products reproducing several claims of the co-owned patent, the authorized co-owner filed a patent infringement action.
The alleged infringer intended to argue back that the patent was invalid but his counterclaim was found inadmissible because he omitted to serve a third-party notice to the second co-owner of the patent. The Court logically considered that a counterclaim which aims at cancelling a patent cannot be decided upon without all the owners of the patent being part of the proceedings.
This decision provides an opportunity to remind that joint ownership agreements, either related to patents or to other IP rights such as trademarks or registered designs, must be very carefully drafted and/or looked into. If such agreements are intended to make IP management easier by clearly defining each co-owner’s rights and responsibilities, some provisions may have very serious consequences and repercussions.
In the present case for example, should the defendant had duly served a third-party notice to the other co-owner of the patent, the latter would have been faced with defending the validity of his patent whereas he had not even been consulted by his partner before the lawsuit was initiated. He should really trust him.