Addressing the type of prior art that may form the basis of an inter partes review (IPR) proceeding, the US Court of Appeals for the Federal Circuit vacated an unpatentability finding based on “applicant admitted prior art” in the challenged patent. Qualcomm Inc. v. Apple Inc., Case Nos. 20-1558, -1559 (Fed. Cir. Feb. 1, 2022) (Taranto, Bryson, Chen, JJ.)

Qualcomm owns a patent directed to integrated circuit devices having power detection circuits for systems with multiple supply voltages. The patent seeks to solve problems associated with stray currents causing level shifters in integrated circuits to trigger input/output devices for transmission, which results in erroneous output signals from the circuit. The patent describes various prior art methods for solving the stray current problem.

Apple filed IPR petitions based on two grounds. The first was based on the combination of four prior art references. In its final written decision, the Patent Trial & Appeal Board (Board) found that the combination of these four references did not render the challenged claims invalid. The second ground relied on the applicant admitted prior art disclosed in the specification of the challenged patent in combination with another prior art reference (Majcherczak). During the IPR proceedings, Qualcomm admitted that the combination of the applicant admitted prior art and Majcherczak taught every element of the challenged claims but argued that Apple’s use of the applicant admitted prior art as the basis for an invalidity ground is barred in an IPR proceeding. The Board disagreed with Qualcomm and found the challenged claims unpatentable based on Apple’s second ground. Qualcomm appealed.

Qualcomm argued on appeal that IPR proceedings may only be based on “prior art patents or prior art printed publications” and that 35 U.S.C. § 311(b), which governs IPR proceedings, does not allow for the use of “a patent owner’s admissions” that is contained in non-prior art documents. Apple countered, arguing that any prior art that is contained in “any patent or printed publication, regardless of whether the document itself is prior art, can be used as a basis for [an invalidity] challenge.”

The Federal Circuit agreed with Qualcomm, finding that applicant admitted prior art in a challenged patent may not form the “basis” for an invalidity claim in an IPR proceeding. The Court explained that invalidity grounds advanced in an IPR must be based on patents or printed publications that are themselves prior art to the challenged patent. In reaching this conclusion, the Court relied on the 2019 Supreme Court opinion in Return Mail, Inc. v. U.S. Postal Serv., which referred to “patents and printed publications” in the context of § 311(b) as “existing at the time of the patent application.” The Court also looked to its own interpretations of “prior art consisting of patents or printed publications” in the context of ex parte reexamination proceedings under 35 U.S.C. §§ 301 and 303, which “permits the Director to institute a reexamination after ‘consideration of other patents or printed publications.’” Accordingly, the Court vacated the unpatentability finding and remanded the proceeding for a determination of whether the applicant admitted prior art relied upon by Apple formed the “basis” of its invalidity challenge.

Practice Note: Despite finding that applicant admitted prior art cannot be used to form the “basis” of an invalidity grounds in an IPR proceeding, the Federal Circuit noted various other instances where applicant admitted prior art is allowed in such a proceeding. For example, the Court indicated that applicant admitted prior art is helpful when assessing whether a patent’s claims would have been obvious, including determination of a skilled artisan’s knowledge or skill level or furnishing a motivation to combine various references.