Federal Circuit Affirms PTAB Rejection of Lock Manufacturer’s Bid to Invalidate Biometric Access Patents

The U.S. Court of Appeals for the Federal Circuit (CAFC) issued a decision today in ASSA ABLOY AB v. CPC Patent Technologies Pty Ltd., affirming Patent Trial and Appeal Board (PTAB) final written decisions that upheld the validity of several claims covering a biometric access control system. ASSA ABLOY AB and its affiliates, including HID Global Corp., ASSA ABLOY Global Solutions, Inc., and Master Lock Company LLC, argued the Board misconstrued a key claim term and ignored one of its unpatentability theories, but the CAFC found neither argument persuasive.

CPC Patent Technologies Pty Ltd. owns U.S. Patent Nos. 9,665,705 and 9,269,208, which share a common specification and describe a system for granting secure access to a locking mechanism through biometric authentication. Under the disclosed system, a user seeking entry presents a biometric signal, such as a fingerprint, to a sensor, which compares the input against a database of authorized signatures before granting or denying access. The patents also describe a separate enrollment process in which an administrator authorizes new users by entering a sequence of finger presses with varying durations, such as the “dit, dit, dit, dah” pattern described in the specification.

ASSA filed three inter partes review (IPR) petitions challenging the two patents, each asserting the same obviousness combination of Bianco and Mathiassen, and the Board instituted all three. It initially construed “biometric signal” to require a functional element, but on Director review, that construction was vacated and remanded for further briefing. On remand, the Board revised its construction to “a physical or behavioral biometric attribute,” dropping the functional requirement while rejecting ASSA’s proposed alternative, “the input and output of the biometric sensor,” as too broad since it would sweep in any type of input. Under the revised construction, the Board again found the challenged claims not unpatentable. It concluded that Mathiassen’s finger tap navigation feature did not disclose the claimed enrollment steps because, in that mode, the touch pad was no longer functioning as a fingerprint sensor.

On appeal, it contended that the Board’s construction of “biometric signal” improperly excluded the patents’ only disclosed enrollment embodiment, because an administrator’s finger presses could be entered without any biometric reading. Additionally, ASSA argued the Board never addressed its position that Bianco alone, without Mathiassen, disclosed or rendered obvious the enrollment limitations.

The Federal Circuit reviewed claim construction de novo and sided with the Board on both points. Since the claim language connects the “biometric signal” used during enrollment back to the same biometric signal earlier defined as one received by a sensor and matched against a database, the court rejected ASSA’s broader reading. The court also found the Board’s construction consistent with the specification, since the administrator’s finger presses remain biometric attributes that the sensor reads even during enrollment. The specification explains that when a legitimate sequence isn’t entered within the required time, the system instead treats the presses as attempts to gain access rather than as enrollment. The court wrote that ASSA “provides no persuasive reason for its view that the biometric sensor’s ability to read a fingerprint is effectively turned off during the enrollment process.”

The CAFC additionally noted the Board’s construction tracked its earlier ruling in a separate set of IPRs brought by Apple against the same patents, in which several challenged claims were found unpatentable and affirmed on appeal, while other claims remained valid.

Furthermore, the court found ASSA’s petitions did not raise a Bianco-only ground as a standalone theory, pointing to petition language in which ASSA relied on Mathiassen to satisfy the claimed step of mapping finger-press entries into an instruction. The court stated that “it is of the utmost importance that petitioners in the IPR proceedings adhere to the requirement that the initial petition identify ‘with particularity’ the ‘evidence that supports the grounds for the challenge to each claim.’” The Federal Circuit further explained that “[a] petitioner may not rely on a vague, generic, and/or meandering petition and later fault the Board for failing to understand what the petition really meant.” The CAFC noted ASSA raised the Bianco-only theory for the first time in supplemental briefing following Director review, making it untimely under existing Federal Circuit precedent barring new obviousness rationales introduced after the initial petition.

The CAFC affirmed the Board’s final written decisions in both proceedings, concluding ASSA had not shown the Board’s claim construction was incorrect or that the Board failed to address any of ASSA’s petitioned-for unpatentability grounds.