By Adam J. Cook and Michael Oblon

On appeal from an inter partes review (“IPR”), the Federal Circuit held that, under pre-America Invents Act (“pre-AIA”) law, a published patent application is prior art as of its filing date as opposed to its later date of publication.  The Court based its decision on a finding that the term “printed publications” as used in the IPR statute is temporally agnostic.  Specifically, whether a piece of prior art achieves printed publication status does not affect its section 102 effective prior art date.  See Lynk Labs, Inc. v. Samsung Elecs. Co., No. 2023-2346, 2025 WL 85559, at *8 (Fed. Cir. Jan. 14, 2025).

On November 12, 2021, Samsung Electronics (“Samsung”) filed a petition for IPR of U.S. Patent No. 10,687,400 (“’400 Patent”) owned by Lynk Labs (“Lynk”).  See Lynk Labs, Inc. v. Samsung Elecs. Co., No. IPR2022-00149, Paper 1 (P.T.A.B. Nov. 12, 2021).  The ’400 Patent discloses various LED circuits and drivers.  See U.S. Patent No. 10,687,400.  The PTAB granted institution based on Samsung’s assertions that claims of the ’400 Patent were unpatentable as obvious.  See Lynk Labs, Inc., No. IPR2022-00149, Paper 16.  To prove unpatentability, Samsung cited Martin, a published patent application, as prior art.  See id., Paper 1.

Two forms of prior art are permitted in an IPR:  “patents and printed publications[.]”  35 U.S.C. § 312.  Martin was a published patent application, not a granted patent, so it had to qualify as a printed publication.  See Lynk Labs, Inc., 2025 WL 85559, at *2.  To be a printed publication, Martin had to be publicly accessible, which the parties stipulated had occurred in October 2004 when Martin was published.  See id.

Moreover, Martin’s effective prior art date had to precede the ’400 patent’s priority date of February 25, 2004, to be valid prior art.  See id., at *1.  Martin was filed in April 2003 and published in October 2004.  See id.  The PTAB determined that Martin’s prior art date was its filing date, making Martin valid prior art.  See Lynk Labs, Inc., No. IPR2022-00149, Paper 33.  The Panel then relied on Martin to find the ’400 Patent unpatentable as obvious.  See id.  Lynk appealed to the Federal Circuit.  See id., Paper 34.

On appeal, Lynk argued that Martin’s prior art date was instead its publication date because of section 312’s printed publication requirement.  See Lynk Labs, Inc., 2025 WL 85559, at *2-3.  For support, Lynk turned to pre-AIA sections 102(a) and (b), which state that a printed publication’s prior art date is its publication date if it is published before invention or one year before a patent application is filed.  See id., at *3.  Essentially, Lynk argued that pre-AIA sections 102(a) and (b) for printed publications applied when calculating Martin’s effective prior art date because section 312 required Martin to qualify as a printed publication.  See id.

However, Lynk’s tallest hurdle was pre-AIA section 102(e)(1), a special rule for calculating the effective prior art date of published patent applications.  See id.  Pre-AIA section 102(e)(1) states that a published patent application is prior art when “filed in the United States[.]”  35 U.S.C. § 102(e)(1) (2010).  Lynk brushed off section 102(e)(1), arguing that if the IPR statute drafters meant for 102(e)(1) to apply, then section 312 would have separately included published patent applications as a valid form of prior art usable in an IPR.  See Lynk Labs, Inc., 2025 WL 85559, at *4.  Section 312 instead permits published patent applications only when they qualify as printed publications.  See id.  Thus, to Lynk, pre-AIA sections 102(a) and (b) applied when calculating a published patent application’s prior art date in an IPR, not special rule 102(e)(1).  See id.

The Court found that two things could be true at once:  (1) Martin can be a printed publication, and (2) Martin can be a published patent application.  See id.  To the Court, 102(e)(1) was merely a special rule that applied when calculating the prior art date of published patent applications, a special type of printed publication.  See id.  Moreover, the Court noted that Lynk’s argument would require section 312’s use of “printed publications” to include a hidden temporal requirement.  See id., at *6.  However, a hidden temporal requirement would fly in the face of each subsection of pre-AIA section 102 which already includes their own temporal rules for determining when a piece of prior art becomes effective.  See id.  The “‘when’ issue for prior-art status is dictated by the . . . temporal language from § 102—not the meaning of ‘printed publication’ itself, which is otherwise temporally agnostic.”  Id.

Thus, the Court held that certain printed publications (e.g., published patent applications) asserted in an IPR can have an effective prior art date that precedes their date of publication.  This holding is consistent with the PTAB’s longstanding treatment of published patent applications in IPRs.  In the Federal Circuit’s opinion, prior art is effective when section 102 states that it is, “secret” or not.

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Matt Johnson is one of the Firm's primary contacts on practice before the PTAB. Currently co-chairing the Firm's PTAB subpractice and involved in proceedings at the Board since the first day of their availability in September 2012, Matt regularly represents clients as both petitioners and patent owners at the Board. He further works as an advocate for clients in appeals from Board proceedings at the Federal Circuit.