The Federal Circuit’s recent decision last week in Inland Diamond Prods. Co. v. Cherry Optical Inc., offers an important reminder for patent litigators: a PTAB’s factual finding in an inter partes review (IPR) does not automatically bind a district court. The case underscores that issue preclusion has clear boundaries when different forums apply different standards of proof.
Background of the Dispute
The dispute arose after the PTAB found certain independent claims of two lens-related patents unpatentable as obvious while upholding several other dependent claims. Later, in district court litigation over the same…
