The U.S. Court of Appeals for the Federal Circuit ruled on Jan. 14, 2025, in Lynk Labs, Inc. v. Samsung Electronics Co., Ltd., that published U.S. patent applications may continue to be used as prior art in inter partes review (IPR) proceedings as of the date the application was filed with the U.S. Patent and Trademark Office (USPTO). The ruling is consistent with established practice and is a win for IPR petitioners.
In November 2021, Samsung Electronics Co. filed a petition challenging certain claims of U.S. Patent No. 10,687,400 (the ’400 patent), owned by Lynk Labs. On June 26, 2023, the Patent Trial and Appeal Board (PTAB) found all challenged claims to be unpatentable. In part, Samsung’s petition relied upon a published U.S. patent application, referred to as Martin, as prior art. Lynk Labs argued that Martin did not qualify as “prior art consisting of … [a] printed publication,” as 35 U.S.C. § 311(b) required to form the basis of an IPR, because it published on Oct. 21, 2004, after the Feb. 25, 2004, priority date of the ’400 patent. The Martin publication was abandoned by the applicant, and never issued as a patent.
The PTAB rejected this argument, relying on 35 U.S.C. § 102(e)(1). Pre-AIA[1] section 102(e)(1) identified as prior art those inventions described in “an application for patent, published under section 122(b), by another filed in the United States before the invention by the applicant for patent.” The PTAB agreed with Samsung that Martin was prior art because it was filed on April 16, 2003, before the Feb. 25, 2004, priority date of the ’400 patent even though Martin’s publication was after the ’400 patent’s priority date. In support of this conclusion, the PTAB relied upon past nonprecedential PTAB and Federal Circuit cases, as well as a contrast from the statute governing the PTAB’s now-sunset covered business method proceedings, which explicitly limited challenges to those based on “prior art that is described by [pre-AIA] section 102(a).”
The Federal Circuit heard argument on Oct. 10, 2024, and considered whether the court should deviate from well-established USPTO practice, which it described as “plausible” and “rational.” During the argument, the parties agreed that a published application for a U.S. patent is a “printed publication” under § 311(b). But the dispute turned on what date — the application’s filing date or the application’s publication date — controlled the application’s availability as prior art.
Lynk Labs urged the court to hold that an application becomes prior art once it is publicly accessible, i.e., upon the application’s publication, consistent with how the court analyzes nonpatent publications, such as an article, user manual or thesis. Samsung and the USPTO, however, argued that the court should maintain existing practice and that the public accessibility test advanced by Lynk Labs applies only to nonpatent publications and not to published U.S. patent applications, which are governed by § 102(e)(1).
The court agreed with Samsung and the USPTO and held that “[t]he main problem with Lynk Labs’ argument is that, unlike § 102(a) or (b), and unlike books, articles, or other types of printed publications, Congress created — in § 102(e)(1) — a special rule for published patent applications. … [U]nder § 102(e)(1), even if a patent application was published after a claimed invention, it may serve as prior art to the invention if the application was filed before the invention.”
As a result, IPR petitioners may continue to rely upon published U.S. patent applications as prior art as of the application’s filing date. This keeps within a petitioner’s arsenal a swath of applications filed before a challenged patent’s priority date but published thereafter.
[1] The America Invents Act (AIA) passed in 2011 and changed the text of 35 U.S.C. § 102.