The Equitable Doctrine of Assignor Estoppel Does Not Prevent PTAB from Instituting an IPR, PTAB Litigation Blog
On July 25, 2016, the United States Court of Appeals for the Federal Circuit issued a decision in In re: Magnum Tools Int’l, Ltd., No. 2015-1300 (Fed. Cir. Jul. 25, 2016) confirming that the burden of proving invalidity lies with the petitioner throughout the entire IPR proceeding and never shifts to the patent owner. In Magnum Tools, the court disagreed with the PTAB’s view that institution of an IPR upon a finding of a reasonable likelihood of success operates to shift the burden of producing evidence of non-obviousness to the patent owner.