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Federal Circuit Affirms That Published Patent Applications Are Prior Art in IPRs As Of Their Filing Dates, Not Their Publication Dates
01/31/2025
On January 14, 2025, the United States Court of Appeals for the Federal Circuit (“CAFC”) issued a precedential opinion affirming a final written decision from the U.S. Patent Trial and Appeal Board (“PTAB”) finding the challenged claims of U.S. Patent No. 10,687,400 unpatentable. Lynk Labs, Inc. v. Samsung Elecs. Co., Ltd., (Fed. Cir. January 14, 2025). In its decision, the CAFC considered the question of when a published patent application is deemed prior art in an inter partes review (“IPR”) and concluded, as did the PTAB, that they are prior art as of their filing date.
The ’400 patent is owned by Lynk Labs and “generally relates to light emitting diodes (‘LEDs’) and LED drivers.” It more “specifically relates to alternating current (‘AC’) driven LEDs, LED circuits, and AC drive circuits and methods.” The claims recite lighting systems with various LED circuit configurations.
In November 2021, Samsung filed a petition for IPR of the ’400 patent. The first six grounds of unpatentability presented in Samsung’s petition relied on prior art combinations that each included U.S. Patent Application Publication No. 2004/0206970 (“Martin”). The Martin application was filed before the ’400 patent’s priority date but was published only after that date. After rejecting Lynk Labs’ argument that Martin could not serve as prior art to the ’400 patent in an IPR, the PTAB determined that each of the claims at issue on appeal would have been obvious in view of Martin and at least one other reference.
On appeal, Lynk Labs argued that the PTAB wrongly relied on Martin as prior art to the ’400 patent because, although Martin was filed before the ’400 patent’s priority date, it was published (and thus became publicly accessible) only after the priority date.
In addressing this argument, the CAFC first turned to the statute governing IPR petitions, which states that 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.” 35 U.S.C. § 311(b) (emphasis added by CAFC). Regarding “printed publications,” the CAFC stated that “[t]he touchstone of whether a reference constitutes a printed publication is public accessibility.” The CAFC then noted that there was no dispute that Martin, a published patent application, is publicly accessible, and therefore constitutes a “printed publication.”
Lynk Labs agreed that Martin is a “printed publication,” but argued that Martin is not a “prior art…printed publication[]” as to the ’400 patent. In support, Lynk Labs pointed to cases—contemplating books, articles, or the like—that analyzed prior-art status under § 102(a) or (b).
The CAFC acknowledged that the cases Lynk Labs cited stand for the proposition that, to be a prior art printed publication as to a given patent under one of these subsections, the reference at issue must have been publicly accessible before the critical dates indicated in those sub-sections, e.g., the date of invention for § 102(a). The main problem with Lynk Labs’ argument, according to the CAFC, was 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. Specifically, § 102(e) states (in relevant part) that a U.S.-filed patent application “published under [§] 122(b)” serves as prior art to a claimed invention if the application was “filed . . . before the [claimed] invention.” Id. § 102(e)(1) (emphasis added by CAFC). The CAFC then concluded that because published patent applications, like Martin, are deemed prior art as of their filing date under § 102(e)(1), Martin is a prior art printed publication as to the ’400 patent under the plain language of § 311(b).
The CAFC further noted that Lynk Labs did not dispute that, due to § 102(e)(2), an IPR challenge under § 311(b) can include as a “prior art . . . patent[]” a patent that did not become a patent until after the challenged patent’s priority date. Given the context of § 102(e), the CAFC found no satisfactory explanation as to why patent applications that are later published (and thus become printed publications) should have a prior-art status different from patent applications that later become patents.
The CAFC found that Lynk Labs’ remaining arguments based on the historical context behind § 311(b) only added further support for the plain-language interpretation set forth above. Last, the CAFC noted that treating published patent applications (with the special prior-art rule of § 102(e)(1) applied) as available prior art under § 311(b) is fully consistent with the “congressional purpose in restricting reexamination”—and later, IPRs—to printed documents. Accordingly, the CAFC affirmed the PTAB’s decision finding the claims on appeal unpatentable as obvious based on Martin in combination with other art.
