Opinions — Monday, March 9, 2026

The Federal Circuit affirmed the Patent Trial and Appeal Board's final written decisions holding all challenged claims of U.S. Patent Nos. 7,391,791 and 8,942,252, owned by Implicit, LLC, unpatentable as anticipated or obvious over the Janevski prior art reference. Following the Board's initial decisions in September 2019, Implicit sought and obtained certificates of correction under 35 U.S.C. § 256 in August 2022 to add Guy Carpenter as a co-inventor. Implicit argued that with Carpenter named as an inventor, his earlier work would inure to the inventors' benefit and antedate Janevski, thereby removing it as prior art. On remand limited to addressing the impact of the inventorship corrections, the Board held that Implicit had forfeited (and alternatively waived, and was judicially estopped from raising) any new antedating theory based on Carpenter's involvement, despite § 256's generally retroactive effect. The Federal Circuit held that forfeiture can apply to § 256 corrections and that the Board did not abuse its discretion in finding forfeiture where Implicit possessed the inventorship evidence from the outset but waited until after final written decisions to seek correction without sufficient justification.

This decision clarifies that the retroactive effect of § 256 inventorship corrections does not immunize parties from procedural doctrines like forfeiture when they fail to assert inventorship arguments with adequate diligence during IPR proceedings. The court distinguished Egenera, Inc. v. Cisco Systems, Inc., where mid-litigation inventorship correction was permitted after a claim construction changed claim scope, emphasizing that no such scope change occurred here to justify Implicit's delayed assertion. The holding imports principles from Stark v. Advanced Magnetics, Inc. requiring diligent action during interference proceedings into the IPR context, establishing that parties cannot strategically withhold inventorship theories and raise them post-final decision based on later-obtained corrections. The court's rejection of Implicit's justifications—that it believed its initial position correct and that the proposed co-inventor resided abroad—signals skepticism toward strategic sandbagging and reinforces that parties bear the burden of presenting complete inventorship theories when antedating arguments are initially raised, particularly where the evidence was within the patent owner's sole possession throughout.

In Chien-Min Sung v. Samsung Electronics Co., Ltd., et al., the Federal Circuit dismissed the appeal from a Patent Trial and Appeal Board decision in IPR2024-00533 pursuant to the parties' agreement under Federal Rule of Appellate Procedure 42(b), with each side to bear its own costs.

The Federal Circuit affirmed the district court's judgment that claims 1–8 and 11 of U.S. Patent No. 6,879,040, asserted by DSS, Inc. against Nichia Corporation and Nichia America Corporation, are invalid as indefinite under 35 U.S.C. § 112. The court issued a per curiam opinion disposing of the appeal on indefiniteness grounds alone.

The court's summary disposition reflects the panel's agreement that the indefiniteness determination was straightforward enough to warrant affirmance without extended analysis. By disposing of the case solely on § 112 grounds, the court declined to reach any other validity or infringement issues that may have been presented, suggesting that the claim language failed to meet the reasonable-certainty standard required to inform a person of ordinary skill in the art about the scope of the invention with reasonable certainty. The brevity of the ruling indicates the panel found no reversible error in the district court's construction or application of the definiteness requirement.