National and regional laws provide opposition and other administrative revocation and invalidation mechanisms that make it possible for third parties to intervene in the patent examination process before the grant of a patent, or to challenge a patent after its grant.
While the design of such mechanisms may differ from one country/region to another, the common objective is to provide a simple, quick and inexpensive means to increase patent quality by providing additional input to the process. These mechanisms also provide an alternative to potentially lengthy and costly judicial proceedings.
The most common mechanisms are:
Many countries provide opposition mechanisms in their patent systems. Opposition systems stricto sensu offer third parties an opportunity to oppose the grant of a patent within a certain period of time provided by the applicable law.
A re-examination is a proceeding conducted by the patent office after the grant of a patent in which the validity of a patent is re-examined at the request of the patentee or third party, as provided by the applicable law.
The administrative revocation and invalidation mechanisms provide for an inter partes review of the validity of a patent which is not limited to a certain period after the grant of the patent.
Many patent offices provide the opportunity for third parties to submit prior art documents, such as published patent applications and patents or other publications, which they believe are relevant to the determination of patentability of the claimed invention.