What is the purpose of a reissue patent?

A reissue patent serves the specific purpose of correcting an error in a previously granted patent. This can include errors such as mistakes in the specification, drawings, or claims that might affect the patent's enforceability or scope. The reissue process allows the patent holder to fix these issues and potentially broaden or narrow the claims to better protect the invention as initially intended. This is crucial because it helps ensure that the patent accurately reflects the inventor's original work and intentions, maintaining the integrity of the patent system.

While extending the duration of a patent or changing its ownership are important concepts in patent law, those actions are not the goals of a reissue patent. Similarly, while it is possible for reissue patents to affect claims, the primary objective is to correct errors rather than to permanently change claims for strategic reasons.