A recent Federal Circuit decision in Lynk Labs v. Samsung has important implications for what types of prior art can be used to challenge patents in inter partes review (IPR) proceedings. The court held that a published patent application can serve as prior art in an IPR as of its filing date, not just its later publication date.
Understanding Pre-AIA 35 U.S.C. § 102(e)(1)
To grasp the significance of the court’s ruling, it’s helpful to take a closer look at pre-AIA 35 U.S.C. § 102(e)(1). This section states:
“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…”
In other words, pre-AIA § 102(e)(1) creates a special prior art rule for published U.S. patent applications. It says that if another inventor files a U.S. application before the invention date of the patent at issue, that application becomes prior art as of its filing date, as long as it eventually gets published.
Notably, this means the application can be prior art before the public ever sees it. Contrast this with the typical rule for “printed publications” under § 102(a) or (b), which only become prior art as of their public accessibility date.
So why did Congress create this unique prior art rule for published applications? The Federal Circuit explained that it wanted to “afford published patent applications a prior-art effect different from the effect given to printed publications in § 102(a) and (b).” Congress likely recognized that patent applications go through examination and are more reliable than other printed publications.
How pre-AIA § 102(e)(1) Applies in IPRs
Section 311(b) allows IPR petitions only “on the basis of prior art consisting of patents or printed publications.” So are published applications usable in IPRs?
Lynk Labs argued no, contending that the case law definition of “printed publications”—references that were publicly accessible before the critical date—is implicitly baked into the IPR statute. Under that view, an application filed before but published after the challenged patent would be excluded.
But the Federal Circuit disagreed, finding that “the plain language of § 102(e)(1) supports our interpretation of § 311(b).” The court explained (emphasis added):
“Section 311(b) permits IPR challenges based upon ‘prior art consisting of patents or printed publications.’ A published patent application is, by its literal terms, a ‘printed publication.’ So, 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. And, by virtue of § 102(e)(1), a published patent application—this specific type of ‘printed publication’—is deemed prior art as of its filing date.”
The court found this plain-language interpretation fully consistent with Congress’s intent for IPRs—to allow validity challenges on the types of prior art that examiners normally handle, like patents and printed publications, as opposed to issues requiring more intensive discovery like public use or on-sale bars. Published applications fit squarely into the first category.
Implications for Patent Owners and Challengers
The Lynk Labs ruling provides important certainty for patent practitioners. For challengers, it green-lights the use of published applications in IPRs as of their filing dates, even if the application was not public at that time. For patent owners, it means being prepared to antedate such references.
Circuit Judge Sharon Prost authored the decision, joined by Circuit Judges Alan D. Lourie and Leonard P. Stark. Lynk Labs, Inc. v. Samsung Electronics Co., LTD., Case No. 2023-2346 (Fed. Cir. Jan. 14, 2025).
The authors of www.PatentLawyerBlog.com are patent trial lawyers at Jeffer Mangels Butler & Mitchell LLP. For more information about this case, contact Greg Cordrey at 949.623.7236 or GCordrey@jmbm.com.