In Power Integrations, Inc. v. Lee, [2014-1123], (August 12, 2015), the Federal Circuit reversed the PTAB’s decision affirming the rejection of claims of U.S. Patent No. 6,249,876, in a reexamination proceeding.

The Federal Circuit found that the PTAB erred in failing to consider the previous construction of the claims in District Court litigation.  While acknowledging that the PTAB is generally not bound by a prior judicial construction of a claim term, and that in reexaminations the PTAB applies a different claim construction standard than applied by the district court, the Federal Circuit found that the PTAB still had an obligation to “acknowledge” the interpretation, and “assess” whether it is consistent with the broadest reasonable construction of the term.  The Federal Circuit said that het PTAB declined to address or even acknowledged the district court’s prior determination, and because the patent owner’s construction was “tied” to the district courts’ construction, the Federal Circuit thought that the PTAB had an obligation to evaluate that construction and determine whether it was consistent with the broadest reasonable interpretation.