Teleforum

Prosecution laches is an infrequently used equitable doctrine that bars enforcement of a patent when the patentee has unreasonably delayed prosecution in a way that prejudices others. It is most commonly used by accused infringers as a defense in patent litigation, although the USPTO can also use it as a basis for refusing allowance. Regardless, it is most often used against the backdrop of multiple continuation applications.Continuation applications are applications which all follow from (i.e., claim priority to) a single earlier application. Creating “families” of patent applications in this way is a very common practice and allows the patent owner to claim different embodiments of the original invention in response to changes in marketplace and/or technological evolution. In Sonos Inc. v. Google LLC, currently on appeal to the Federal Circuit, the district court, following a jury verdict in favor of the patentee, found Sonos’ patents unenforceable due to prosecution laches, despite Sonos