When is a Published Patent Application Deemed Prior Art in IPR?
The U.S. Court of Appeals for the Federal Circuit recently affirmed a Patent Trial and Appeal Board (PTAB) decision in Lynk Labs, Inc. v. Samsung Electronics Co., Ltd.,[1] holding that a published patent application can qualify as prior art from its filing date. The Federal Circuit decision answered the previously unanswered question whether a published patent application should be considered prior art as of its filing date or, instead, its publication date in Inter Partes Review (IPR) proceedings.
Samsung filed a petition for IPR in November 2021 challenging the validity of some claims of a Lynk Labs patent. The key prior art reference Samsung relied on was a U.S. Patent Application Publication which was filed before but published after the challenged patent’s priority date. Samsung argued that the Patent Application Publication, in combination with other references, rendered unpatentable the challenged claims of Lynk Labs’ patent for obviousness.
Lynk Labs argued that the Publication could not be used as prior art because it was not publicly accessible before the priority date of its patent. Specifically, Lynk Labs contended that under 35 U.S.C. § 102(a) and (b), a reference must be publicly accessible to qualify as a prior art printed publication. Since the Publication was only published after the priority date of the challenged patent, Lynk Labs claimed it could not be used in an IPR under 35 U.S.C. § 311(b). Further, Lynk Labs contended that Congress intentionally used different wording in § 102(e)(1) for published patent applications and §§ 102(a)-(b) for printed publications and argued that this distinction meant that published patent applications should not be treated as printed publications in IPR.
The Federal Circuit rejected Lynk Labs’ arguments that “printed publications” in § 311(b) must be publicly accessible before the priority date. The court specifically explained that Congress did not limit prior art in IPR to just §§ 102(a)-(b) prior art, but also included § 102(e)(1) prior art, which specifically allows earlier-filed but later-published patent applications to be used as prior art. Regarding Lynk Labs’ arguments that Congress intentionally used different language in §§ 102(e)(1) and 102(a) and (b), the court stated that “it simply does not follow that two different terms must mean completely distinct things” because “[o]ne could be a specific instance of a general term.” As such, the Federal Circuit ruled that a published patent application is, by its literal terms, a printed publication, and that a published patent application is considered prior art as of its filing date, not its publication date, under 35 U.S.C. § 102(e)(1). Since the Publication relied on by Samsung was filed before the priority date of the challenged Lynk Labs patent, the Federal Circuit affirmed the PTAB’s conclusion that it qualified as a valid prior art reference in the IPR.
In making its ruling, the court reviewed and considered the historical context of 35 U.S.C. § 311(b). The Federal Circuit noted that the phrase “patents or printed publications” first appeared to limit references that could be used in reexamination proceedings in § 301 of the 1980 Patent Act, a phrase which is still recited in 35 U.S.C. § 311(b). The purpose of that phrase was to allow the Patent and Trademark Office to evaluate “patents and printed materials” separate from prior art requiring a substantial discovery or fact-finding process—such as sales or public use. The court concluded that “[t]reating published patent applications (with the special prior-art rule of § 102(e)(1) applied) as available prior art under § 311(b) is thus fully consistent with Congress’s purpose in limiting the types of patentability challenges in IPRs.” The Federal Circuit further concluded that “§§ 311(b) and 102(e)(1) permit IPR challenges based upon published patent applications, and such published patent applications can be deemed prior art in IPRs as of their filing date.”
The Lynk Labs decision reinforces prior Federal Circuit decisions holding that patent applications can serve as valid prior art in IPR proceedings as of their filing dates, rather than their publication dates. In addition, the Federal Circuit considered that the legislative intent of the IPR process was to provide “a cheaper and less time-consuming alternative to challenge patent validity on certain issues.” Further, the court concluded that treating published patent applications as prior art is consistent with this purpose because patents and printed publications do not require “additional discovery or fact finding.”
The decision thus underscores the importance for applicants to file patent applications as early as possible in order to avoid the possibility of later validity challenges based upon prior art that was unpublished at the time of filing. Applicants should also be cognizant that parties challenging a patent application may be able to find prior art that was not published or known at least during the early stages of patent application preparation and prosecution.
For litigants, while the Lynk Labs decision expands the scope of prior art that may be available for challenging a patent during IPR proceedings, it also increases the potential scope of IPR estoppel. Patent challengers in IPRs should exercise caution to conduct a thorough search for patent applications filed, but not published, before the filing date of the challenged patent before filing an IPR petition. Such applications, if locatable in the usual course of a competent prior art search, may be barred from use in subsequent federal district court proceedings.
