assignor estoppel

Patents. Estoppel barring someone who has assigned the rights to a patent from later attacking the patent’s validity. Westinghouse Elec. & Mfg. Co. v. Formica Insulation Co., 266 U.S. 342, 45 S.Ct. 117 (1924). • The doctrine was narrowed by Diamond Scientific Co. v. Ambico, Inc., 848 F.2d 1220 (Fed. Cir. 1988), in which the […]