On July 2, 2026, the United States Court of Appeals for the Federal Circuit (“CAFC”) issued a precedential opinion vacating and remanding a decision of the U.S. District Court for the District of Delaware holding claims of U.S. Patent No. 8,862,978 invalid for indefiniteness under 35 U.S.C. § 112(f).  TrackTime, LLC v. Amazon.com Services LLC, No. 2024-1102 (Fed. Cir. July 2, 2026).  In reaching its decision, the CAFC held that the district court failed to adequately consider whether the challenged software claim limitations, read in context, would have conveyed sufficient structure to a person of ordinary skill in the art before treating those limitations as means-plus-function limitations governed by Section 112(f).  The Federal Circuit separately affirmed the judgment regarding U.S. Patent No. 8,856,638, which had been found invalid and not infringed.

On February 19, 2026, the U.S. Court of Appeals for the Federal Circuit affirmed the District of Delaware’s grant of summary judgment of non infringement in favor of defendants in Genuine Enabling Tech. LLC v. Sony Corp., No. 17-CV-135, 2024 WL 1255513 (D. Del. Mar. 25, 2024). The Federal Circuit held that patentee failed to present sufficient evidence that the accused components were structurally equivalent to the disclosed structure of a means plus function limitation under 35 U.S.C. § 112(f). 

On September 10, 2021, Judge Richard G. Andrews of the U.S. District Court for the District of Delaware issued a Memorandum Opinion on claim construction.  Peloton Interactive, Inc. v. ICON Health & Fitness, Inc., No. 20-662-RGA, slip. op. (D. Del. Sept. 10, 2021).  Judge Andrews held that certain claims of the asserted patent containing “translator device…” limitations were invalid as indefinite under 35 U.S.C. § 112 ¶ 6 because they failed to disclose corresponding structure for the claimed function.

On September 9, 2021, the Court of Appeals for the Federal Circuit (CAFC) affirmed the decision of the Patent Trial and Appeal Board in a post-grant review proceeding construing the claim term “pressure control assembly” as a means-plus-function limitation and finding the challenged claims indefinite for lack of corresponding structure.  Team Worldwide Corp. v. Intex Recreation Corp., __ F.3d __ (Fed. Cir. Sept. 9, 2021)

On March 2, 2021, the Court of Appeals for the Federal Circuit (CAFC) issued an opinion reversing the district court’s conclusion that a claim was not invalid as indefinite.  Rain Computing, Inc. v. Samsung Elecs., Am., Inc., __ F.3d __ (Fed. Cir. Mar. 2, 2021).  The CAFC held that the claim term, “user identification module,” was a means-plus-function limitation under 35 U.S.C. § 112 ¶ 6, and invalid as indefinite for failure to disclose corresponding structure (here, an algorithm).
 

On August 12, 2019, the Court of Appeals for the Federal Circuit (“CAFC”) issued an opinion vacating and remanding the obviousness finding of the U.S. Patent and Trademark Office’s Patent Trial and Appeal Board (“PTAB”).  MTD Products Inc. v. Iancu, __ F.3d __ (Fed. Cir. Aug. 12, 2019).  The CAFC ruled that the PTAB’s claim construction on which its obviousness finding was premised was incorrect because the construction conflated corresponding structure in the patent’s specification with a structural definition for the term, instead of construing the term as a means-plus-function term under 35 U.S.C. § 112, ¶ 6.