Submarine Patent Law and Legal Definition

A submarine patent is usually used as slang for a patent that is delayed in prosecution by the applicant. The patent is delayed in order to let an infringing user continue to develop its business, with the intention of taking in later-invented technology once the patent finally “surfaces” from the U.S. Patent and Trademark Office (PTO). The patent applicant is aware of the developments and purposely delays the PTO's issuance of a patent, so that the invention's unwitting users will be forced to pay license fees. From November 29, 2000, most patent applications have to be published within 18 months of filing; therefore submarine patents are considerably rare these days.