In patent law, opposition is a procedure that allows a person or entity to challenge the validity of a granted patent. This procedure is generally open for a specified period after the patent is granted, providing an opportunity to challenge its validity before it becomes final.
Oppositions to European and French patents must be filed based on at least one of the following grounds:
- Lack of novelty: the invention is not new; it has already been disclosed to the public before the filing date of the patent.
- Lack of inventive step: the invention does not involve an inventive step, i.e. it is merely a combination of elements already known to a person skilled in the art.
- The invention is not patentable: it concerns a discovery, a scientific theory, an aesthetic creation, an economic method, a computer program, or a therapeutic or surgical method. This ground may also be invoked where the invention is contrary to public order or morality.
- Insufficient description of the invention: the invention is insufficiently described to the extent that it cannot be reproduced based on the information provided in the patent alone.
In France and Europe, opposition proceedings must be initiated within nine months of the grant of the patent. This procedure allows interested parties to submit written arguments and evidence challenging the validity of the patent. The opponent may be a competitor, a third party, or any person wishing to challenge the validity of a patent.
Depending on the outcome of the opposition proceedings, the Patent Office may decide to:
- maintain the patent as granted
- maintain the patent in amended form
- revoke the patent.
Opposition is therefore an important step in the patent-granting process to ensure that only valid and genuinely innovative patents remain in force.