Client-Centered Intellectual Property Solutions

Published but not Public?  Federal Circuit Confirms Published Patent Applications Count as Prior Art from Filing Date in IPRs.

On Behalf of | Jan 31, 2025 | Firm News |

On January 14, 2025, the United States Court of Appeals for the Federal Circuit issued a precedential decision in Lynk Labs, Inc. v. Samsung Electronics Co., No. 23-2346 (Fed. Cir. Jan. 14, 2025), addressing whether a published patent application can serve as prior art in inter partes review (IPR) proceedings as of its filing date. The case arose from an IPR initiated by Samsung Electronics challenging claims of Lynk Labs’ U.S. Patent No. 8,410,400 (“the ’400 patent”), which covers LED-based lighting technology. The Patent Trial and Appeal Board (PTAB) ruled that ten claims of the ’400 patent were unpatentable as obvious over a prior-filed but later-published patent application, U.S. Patent Application Publication No. 2004/0206970 (“Martin”).

Lynk Labs appealed, arguing that the Martin application was not prior art under pre-AIA 35 U.S.C. § 102(e)(1) because it was not publicly available before the ’400 patent’s priority date. The Federal Circuit rejected this argument and affirmed the PTAB’s finding of unpatentability, holding that § 102(e)(1) “treats this type of printed publication as prior art as of a time before it became publicly accessible—i.e., as of its filing date.” Lynk Labs, Inc. v. Samsung Electronics Co., No. 23-2346, slip op. at 9 (Fed. Cir. Jan. 14, 2025). The Court reasoned that § 102(e)(1) operates as a “special rule” for published patent applications, distinct from the general requirements for printed publications under §§ 102(a) and 102(b). Id. at 8.

Relying on case law interpreting §§ 102(a) and 102(b), Lynk Labs contended that a reference must have been publicly accessible before the critical date to qualify as a prior art printed publication. Id. at 7. The Federal Circuit rejected this argument, explaining that § 102(e)(1) operates as a distinct provision that establishes prior art status for published patent applications based on their filing date, not their publication date. Unlike §§ 102(a) and 102(b), which impose a public accessibility requirement, § 102(e)(1) expressly allows a later-published patent application to serve as prior art if it was filed before the claimed invention. Id. at 8–9. The Court found that Lynk Labs failed to reconcile its interpretation with § 102(e)(2), which applies a similar filing-date rule to issued patents. Id. at 9. The Court also dismissed the argument that § 311(b)’s reference to “printed publications” excludes published patent applications treated as prior art under § 102(e)(1), because such applications are just a specific type of printed publication. Id. at 10. Thus, “when § 311(b) permits IPR challenges based upon ‘prior art . . . printed publications,’ it includes within its literal scope challenges based upon a published patent application.” Id.

Lynk Labs contended that Congress, by using the term “printed publications” in § 311(b), intended to carry forward historical judicial interpretations that require public accessibility before the priority date. It argued that, under the interpretive canon articulated in Taggart v. Lorenzen, 587 U.S. 554 (2019), Congress’ use of this established term should be presumed to bring “old soil” with it—meaning that § 311(b) should exclude published patent applications unless they were publicly accessible before the relevant date. Id. at 13.

The Federal Circuit found this argument unpersuasive, emphasizing that many of the cases cited by Lynk Labs predated the statutory change in 1999, when Congress first mandated the publication of patent applications and established § 102(e)(1) to govern their prior art status. Id. at 14. The Court explained that earlier cases addressed unpublished applications or traditional printed materials, such as books and journal articles, and did not speak to Congress’ later creation of a distinct prior art rule for published patent applications. Id.

The Court further reasoned that, while § 311(b) does incorporate the traditional public accessibility requirement for printed publications, this does not override the specific treatment of published patent applications under § 102(e)(1). Id. at 14–15. Accordingly, the Court rejected Lynk Labs’ attempt to read a public accessibility timing requirement into § 311(b) that would conflict with the statutory framework governing § 102(e)(1). Id. at 16–17.

Additionally, the Court noted that Congress deliberately structured § 102(e)(1) differently by setting the filing date—not the publication date—as the relevant date for determining prior art status. It reasoned that Congress’ decision to apply a distinct rule for published patent applications should not be overridden by prior case law interpreting different statutory provisions. Id. at 18–19. The Court further found that excluding § 102(e)(1) prior art from IPRs would create an unjustified distinction between district court litigation and IPR proceedings, undermining the consistency of the prior art framework. Id. at 19–20 n.10.

Ultimately, the Court affirmed that Martin was properly considered prior art under § 102(e)(1) and that its filing date—not its publication date—was the controlling factor in the IPR proceeding. Id. at 20.

The Federal Circuit’s decision reaffirms the longstanding principle that prior-filed but later-published patent applications qualify as prior art as of their filing date. This ruling has significant implications for patent owners, petitioners in IPR proceedings, and patent prosecutors alike. By clarifying that § 102(e)(1) establishes a “special rule” for patent applications, the Court eliminated any lingering uncertainty regarding their treatment as prior art under § 311(b).

For patent challengers, this decision strengthens the ability to rely on previously unpublished patent applications in IPRs, broadening the scope of available prior art. Petitioners can now cite such references with greater confidence, knowing that the Federal Circuit has definitively upheld their use under § 102(e)(1). This ruling also harmonizes the prior art framework across district court litigation and IPR proceedings, ensuring consistency in how pre-AIA law applies to unpublished patent applications.

On the other hand, patent owners must be more vigilant in assessing the full landscape of potential prior art. The ruling serves as a reminder that traditional prior art searches may not capture all references that could later be asserted against a patent in an IPR. Applicants may need to conduct more extensive prior art searches when filing continuation or divisional applications to account for the possibility that unpublished applications could later emerge as invalidating references.

Going forward, patent owners engaged in litigation or post-grant proceedings should account for the possibility of “hidden” prior art. As a practical matter, this ruling may incentivize early due diligence in identifying previously unpublished applications that could serve as prior art in future disputes. The decision also highlights the continued importance of understanding how pre-AIA prior art provisions operate in the context of IPRs and district court litigation.