2025 Federal Circuit IP Appeals: Lynk Labs, Inc. v. Samsung Elecs. Co., 125 F.4th 1120 (Fed. Cir. 2025) (Lourie, Prost, Stark)

Samsung filed an IPR petition challenging claims of Lynk Labs’ patent related to light emitting diode (LED) lighting systems used for general lighting and decoration. Six of the alleged grounds of unpatentability relied on a U.S. patent application to Martin, which was filed before the priority date of the challenged patent but published after the priority date. Lynk Labs appealed the Patent Trial and Appeal Board’s (PTAB) determination that the claims were unpatentable for obviousness and argued that Martin could not be used as prior art in the IPR.

The Federal Circuit rejected Lynk Labs’ argument and affirmed. 35 U.S.C. § 311(b) limits IPR challenges only to “a ground that could be raised under section 102 or 103 and only on the basis of prior art consisting of patents or printed publications.” The court observed that Lynk Labs’ argument that Martin is not a prior art printed publication relied on cases that analyzed books and articles under §§ 102(a) or (b). Prior art under those subsections must be publicly accessible before the relevant date — here the priority date of the challenged patent. However, the court found those cases inapposite because Congress created “a special rule” for published patent applications in § 102(e). Under that subsection, published patent applications — like Martin — are “deemed prior art as of their filing date.” Thus, the court concluded that “the plain language” of §§ 311(b) and 102(e) permit IPR challenges based upon published patent applications that were filed before the patent’s priority date because published patent applications are a specific type of printed publication deemed prior art as of their filing date (rather than their date of publication).

The court found this result supported by the historical context behind § 311(b). The phrase “patents or printed publications” first appeared in 1980 in the newly created procedures for ex parte reexamination. Congress limited those proceedings to “prior art consisting of patents or printed publications” — the same phrase used in § 311(b) — to provide a cheaper and faster alternative to challenge patent validity on grounds normally handled by patent examiners, while leaving challenges on other, more evidence-intensive grounds (e.g., public use or sale) to the courts. This same phrase also appeared in the 1999 statute that limited challenges of the newly created inter partes reexamination procedure on the same basis and also, for the first time, provided for the publication of patent applications.

With that context, the court was unpersuaded by Lynk Labs’ argument that a reference is a “prior art printed publication” only if it is published before the relevant date (which would exclude applications treated as prior art under § 102(e)). The court observed that much of the case law relied on by Lynk Labs predated the publication of patent applications and so did not inform the definition of “prior art printed publication” vis-à-vis published patent applications. The court determined that the term “printed publication” “does not have its own, baked in temporal requirement, and that instead whatever temporal requirement exists is drawn from the other [statutory] language” (i.e., §§ 102(a), (b), and (e)(1)). Thus, published patent applications are afforded “a prior-art effect,” under § 102(e)(1), different from the effect given to printed publications in §§ 102(a) and (b). The court found its interpretation consistent with the congressional purpose to limit IPRs to printed documents because they are the types of references “normally handled by patent examiners” and do not require substantial discovery or factfinding. Therefore, the court concluded the PTAB properly deemed Martin prior art.

Lynk Labs has petitioned the Supreme Court for certiorari. That petition remains pending as of the publication of this review.

Related:

In re Riggs, 131 F.4th, 1377 (Fed. Cir. 2025) (holding that a non-provisional application is prior art under § 102(e) as of its provisional application’s filing date, provided it is entitled to the priority date of the provisional application).

Merck Serono S.A. v. Hopewell Pharma Ventures, Inc., 159 F.4th 10 (Fed. Cir. 2025) (holding that any difference between the inventive entity between inventors of a prior art reference and inventors of a patent claim, regardless of whether inventors are added or subtracted, renders the prior disclosure by “another” and available as prior art under § 102(e)).

This article appeared in the 2025 Federal Circuit IP Appeals: Summaries of Key 2025 Decisions report.