Patent owners attempting to enforce patents issued after years of delay in the U.S. Patent and Trademark Office (PTO) may begin to face more often the defense of prosecution laches. In Symbol Tech., Inc. v. Lemelson Medical, the Court of Appeals for the Federal Circuit recently revived this equitable defense, the validity of which had been uncertain for decades due in part to federal statutes and rules governing patent application practice in the PTO.[1]� The 2-1 decision of the Federal Circuit recognized a cause of action based upon prosecution laches and reversed the lower court’s dismissal of certain counts of a declaratory judgment complaint seeking to render unenforceable a number of patents that issued from a string of applications pending for decades in the PTO. The panel majority held that the doctrine of laches may be applied, as a matter of law, to bar enforcement of patents issued after an unreasonable and unexplained delay in prosecution even though the applicant complied with all pertinent statutes and rules.
‘Submarine’ Patenting
