Judge McMahon Rejects Estoppel Argument Based on Lack of Reasonableness and Diligence in Prior Art Searching | Patterson Belknap Webb & Tyler LLP
On December 21, 2023, Judge McMahon (S.D.N.Y.) denied GeigTech East Bay LLC’s (“GeigTech”) motion to preclude Lutron Electronics Co. (“Lutron”) from raising an affirmative defense of invalidity based on 35 U.S.C. § 325(e)(2), i.e., the Post-Grant Review (“PGR)” estoppel provision.
Specifically, GeigTech argued that Lutron is estopped from asserting: (1) grounds already raised in Lutron’s prior PGR petitions, and (2) grounds that Lutron could have reasonably raised during PGR, including invalidity based on prior art that a reasonable searcher would have (but didn’t) found and 35 U.S.C. § 101.
At the outset, the Court explained that although the Federal Circuit has not refined exactly what facts or circumstances are needed to show a skilled searcher has conducted a diligent search, district courts have concluded that a skilled searcher would have been able to find a particular reference when the moving party: (1) identifies the search string and search source that would locate the allegedly unavailable prior art and (2) presents evidence, likely expert testimony, why such a criterion would be part of a skilled searcher’s diligent search.
GeigTech presented the Court with URL links to two searches conducted on Google Patents that yield the Kirsch and Cid Quintas references. The Court found this sufficient to satisfy the first requirement. As for the second requirement, GeigTech’s evidence consisted solely of the search queries themselves and an admission from Lutron’s technical expert that it would be “reasonable for someone looking for prior art . . . to come across Kirsch.” The Court found such evidence wholly lacking. The Court explained that because the choice of GeigTech’s search queries was clearly the product of hindsight, one cannot infer that a skilled researcher would have found Kirsch and Cid Quintas merely because these particular searches yielded the patents. In fact, as the Court noted, the search queries identified by GeigTech included search terms that did not appear anywhere in the patent-in-suit—with no accompanying explanation from GeigTech. As for the admission by Lutron’s expert, the Court disregarded it because the expert was an engineering consultant, not a prior art search expert. The Court also held that estoppel did apply to other references that were either raised by Lutron, or could have been raised in the PGR because Lutron was aware of them. For the same reason, the Court also ruled that Lutron is estopped from challenging the validity of the patent-in-suit under 35 U.S.C. §§ 101 and 112.
Case: GeigTech East Bay LLC v. Lutron Elecs. Co., No. 18 Civ. 05290 (CM), Dkt. No. 362 (S.D.N.Y. Dec. 21, 2023)
