Supreme Court Retains Doctrine of Assignor Estoppel, But With Limits By Kevin E. Noonan and Joshua R. Rich — Patent law is replete with arcane (and often judge-made) doctrines, such as the doctrine of equivalence and obviousness-type double patenting. In addition, long having been considered a property right (Oil States to the recent contrary), patents have been bound to greater or lesser degrees with equitable considerations attendant on the transfer of property and proper limits thereof. These two strands of patent law and jurisprudence converge in the doctrine of assignor estoppel, the question before the Court in Minerva Surgical, Inc….
