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Lynk Labs, Inc. v. Samsung Electronics Co., Ltd., (Fed. Cir. 2025) Appeal No. 2023-2346

2.3.25

Lynk Labs, Inc. (“Lynk”) appealed a final written decision from the Patent Trial and Appeal Board (“PTAB”) in an inter partes review (“IPR”) that found claims 7–13 and 15–17 of U.S. Patent No. 10,687,400 (the “’400 Patent”) unpatentable. The Federal Circuit affirmed the PTAB’s decision, and Judge Prost prepared the opinion. Particularly, the Court affirmed that a patent publication is prior art under 35 U.S.C. §§ 102 and 311(b) in an IPR even where the publication published after the challenged patent’s priority date.

The ’400 Patent generally relates to AC driven LEDs, LED circuits, and AC drive circuits and methods. Samsung Electronics Co., Ltd. (“Samsung”) filed a petition for IPR of the ’400 Patent challenging claims 7–20 as unpatentable for obviousness under 35 U.S.C. § 103. Six of Samsung’s grounds of unpatentability relied on U.S. Patent Application Publication No. 2004/0206970 (“Martin”). Importantly for this discussion, Martin was filed before the ’400 Patent’s priority date but was published after the ’400 Patent’s priority date.

Lynk raised three main arguments on appeal: (1) Martin could not serve as prior art to the ’400 Patent in an IPR because, although Martin was filed before the ’400 Patent’s priority date, it was published (and thus became publicly accessible) only thereafter; (2) the PTAB erred in construing a portion of claim 7; and (3) the PTAB erred in construing a different portion of claim 7. For purposes of this discussion, only argument (1) is addressed.

In addressing Lynk’s argument that Martin cannot serve as prior art, the Federal Circuit began with the plain language of the statute: an IPR petitioner may challenge a patent “only on a ground that could be raised under [35 U.S.C. §§] 102 or 103 and only on the basis of prior art consisting of patents or printed publications.” The parties agreed that Martin is a printed publication; however, Lynk argued that Martin is not prior art because it was not publicly accessible before the priority date of the ’400 Patent.

In support of its holding that Martin is prior art, the Federal Circuit pointed to the fact that Congress created a special rule for published patent applications in 35 U.S.C. § 102(e)(1), unlike books, articles, or other types of printed publications that Lynk seeks to rely on.

A person shall be entitled to a patent unless—

   …

(e) the invention was described in—

(1) an application for patent, published under [35 U.S.C. § 122(b)], by another filed in the United States before the invention by the applicant for patent ….

35 U.S.C. § 102(e) (emphasis added). Therefore, interpreting the statute and aligning it with the legislative intent, the Federal Circuit held that a U.S.-filed patent application serves as prior art to a claimed invention if the application was filed before the claimed invention even if the U.S.-filed patent application was published after the claimed invention.

John Willis Stevens | Associate Attorney