Estoppel Limits: CAFC Clarifies USPTO Authority in Ex Parte Reexams Following IPR
In the high-stakes environment of patent litigation, defendants often employ a multi-front strategy to invalidate asserted claims. A common tactic involves filing both a petition for inter partes review (IPR) and a request for ex parte reexamination. This “belt and suspenders” approach raises complex questions regarding statutory estoppel, particularly when an IPR reaches a final decision while the reexamination remains pending. On December 1, 2025, the United States Court of Appeals for the Federal Circuit (Federal Circuit) addressed this precise intersection of administrative proceedings in In re: Gesture Technology Partners, LLC (Fed. Cir. 2025, 2025-1075).
The Federal Circuit affirmed a decision by the Patent Trial and Appeal Board (the Board), holding that the estoppel provisions of 35 U.S.C. § 315(e)(1) do not prevent the United States Patent and Trademark Office (USPTO) from continuing an ex parte reexamination, even after the petitioner (or their privy) is estopped from maintaining the proceeding.
The ruling underscores a key distinction between the role of a petitioner and the role of the USPTO: while a petitioner may be barred from “maintaining” a challenge, the agency itself is under no such restriction. This decision serves as a significant reminder of the independent momentum ex parte reexaminations possess once initiated.
Background of the Dispute
The dispute centers on U.S. Patent No. 7,933,431 (the ‘431 patent), owned by Gesture Technology Partners, LLC (Gesture). The ‘431 patent describes a method and apparatus designed “to enable rapid TV camera and computer based sensing” of objects and human input (p. 2). The technology is intended for various applications, including handheld devices, video games, and automotive systems (p. 2).
The procedural history of this case is notably tangled, involving parallel tracks of administrative review. Samsung Electronics Co. (Samsung) requested an ex parte reexamination of the ‘431 patent, which the USPTO granted (p. 2). While this reexamination was underway, two separate IPR petitions were filed against the same patent. One IPR was filed by Unified Patents LLC—an organization in which Samsung is a member—and another by Apple Inc. (p. 2).
Both IPR proceedings resulted in final written decisions invalidating the majority of the claims in the ‘431 patent. Specifically, the Board invalidated claims 7-9 and 12 in the Unified Patents IPR, and claims 1-10, 12, and 14-31 in the Apple IPR (p. 2). Following the Board’s decision in the Unified Patents IPR, Gesture petitioned the USPTO to terminate the pending ex parte reexamination.
Gesture argued that Samsung, as a member of Unified Patents, was estopped under 35 U.S.C. § 315(e)(1) from maintaining the reexamination on grounds it could have raised in the IPR (p. 3). The USPTO denied this petition, asserting that the estoppel provision did not apply to ongoing ex parte reexaminations (p. 3).
Ultimately, the Examiner in the reexamination rejected the remaining claims at issue—claims 11 and 13—as anticipated by U.S. Patent 5,982,853 (”Liebermann”) (p. 3). The Board affirmed this rejection, prompting Gesture’s appeal to the Federal Circuit.
The Court’s Analysis: Unpacking the Central Legal Issue
The Federal Circuit faced three distinct challenges from Gesture, but the primary legal question concerning the interaction between IPR estoppel and reexamination procedure stands out as the most consequential for patent practice.
1. The Scope of Estoppel in Ex Parte Reexaminations
Gesture contended that the USPTO erred by refusing to terminate the reexamination. The patent owner’s argument relied on the text of 35 U.S.C. § 315(e)(1), which states that a petitioner in an IPR “may not request or maintain a proceeding before the Office with respect to that claim on any ground that the petitioner raised or reasonably could have raised during that [IPR]” (p. 6). Gesture reasoned that because the reexamination is a “proceeding before the Office,” allowing it to continue violated the statute (p. 6).
The Federal Circuit rejected this interpretation. The court focused its analysis on the statutory definitions of the roles played by the parties involved. The court noted that while a petitioner initiates the request, the petitioner does not “maintain” an ex parte reexamination.
“The statute provides that ‘[t]he petitioner in an [IPR] of a claim of a patent ... may not request or maintain a proceeding before the Office’ on certain grounds after the IPR decision issues. ... A petitioner requests a reexamination ... and a petitioner may file a reply if the patent owner chooses to file a statement ... but the petitioner does not maintain the proceeding. Rather, the Patent Office does.” (p. 6).
The court relied on its precedent in Alarm.com Inc. v. Hirshfeld, emphasizing that the reexamination statute does not provide for requester involvement after the optional reply (p. 6). Consequently, estoppel operates to bar the petitioner from further filing or advocacy, but it does not act as an injunction against the USPTO itself. The agency retains the authority—and arguably the duty—to complete the examination of the patent’s validity once the process has been set in motion.
2. Anticipation by Liebermann
The court then turned to the substantive issue of patentability for claims 11 and 13. These claims depend on claim 7, which recites a handheld computer apparatus with a camera and “computer means ... for analyzing said image to determine information concerning a position or movement of said object” and “means for controlling a function of said apparatus using said information” (p. 5).
The Board interpreted the “means for controlling” limitation as a means-plus-function claim requiring the device to “(1) receive position information, (2) correlate the position information with a function of the apparatus, and (3) cause the apparatus to perform the function” (p. 7). Gesture argued that the prior art, Liebermann, failed to disclose the “correlating” function because it merely sent data in a fixed manner (p. 8).
Liebermann describes a communication system for the deaf that digitizes sign language motions (p. 3). The court found substantial evidence supporting the Board’s finding that Liebermann’s system did, in fact, correlate images to functions.
“Liebermann’s disclosures support the conclusion that its device ‘correlates [an] image with a transmission function by transforming the image into unique identifiers to be transmitted.’ ... Substantial evidence therefore supports the Board’s conclusion that Liebermann discloses correlating position information with a function of the apparatus.” (p. 8).
By transforming captured images into unique identifiers for transmission, the prior art device satisfied the functional requirement of “correlating” the input to an output function.
3. Jurisdiction Over Expired Patents
Finally, Gesture argued that the Board lacked jurisdiction to invalidate the ‘431 patent because it had expired. The Federal Circuit dismissed this argument summarily. Citing its recent decision in Apple Inc. v. Gesture Tech. Partners, LLC (a related appeal), the court reiterated that a patent owner maintains rights in an expired patent, specifically the right to sue for past damages (p. 9). This potential for damages creates a live case or controversy sufficient to confer jurisdiction upon the Board (p. 9).
Key Takeaways and Practical Implications
The Federal Circuit’s decision in In re: Gesture Technology Partners provides necessary clarity on the procedural mechanics of post-grant proceedings. For practitioners and stakeholders, several implications emerge:
The “Zombie” Reexamination: This decision confirms that an ex parte reexamination can survive the estoppel of the party that requested it. Once the USPTO grants the request, the proceeding takes on a life of its own. Defense counsel should view ex parte reexamination as a fire-and-forget missile: once launched, it cannot necessarily be recalled or stopped by estoppel attaching to the requester.
Strategic Redundancy: For challengers, this ruling validates the strategy of parallel filings. Even if an IPR results in a final written decision that triggers § 315(e)(1) estoppel, a previously instituted ex parte reexamination remains a viable threat to the patent. The requester may be barred from filing further papers, but the Examiner will continue the invalidity analysis based on the record.
Patent Owner Defense: Patent owners must recognize that defeating a challenger in an IPR—or obtaining an estoppel shield—does not automatically scrub pending reexaminations. The battle must continue against the Examiner. The focus shifts from adversarial litigation to persuading the Office, which requires a distinct advocacy style focused on technical distinctions rather than procedural bars.
Conclusion
In re: Gesture Technology Partners, LLC reinforces the USPTO’s independent authority to police patent validity. By distinguishing between the “maintenance” of a proceeding by a petitioner and the administration of that proceeding by the Office, the Federal Circuit has ensured that ex parte reexaminations function as intended: as an inquisitorial review rather than a purely adversarial dispute.
The decision affirms that statutory estoppel is a restriction on the litigant, not a shackle on the agency. For the patent community, this serves as a potent reminder that once a validity challenge is placed before the USPTO, the agency’s mandate to ensure only valid patents remain in force takes precedence over the procedural limitations of the private parties involved.
As the PTAB environment evolves, relying solely on procedural defenses like estoppel may prove insufficient; substantive technical distinction remains the surest path to preserving patent rights.
Disclaimer: This is provided for informational purposes only and does not constitute legal or financial advice. To the extent there are any opinions in this article, they are the author’s alone and do not represent the beliefs of his firm or clients. The strategies expressed are purely speculation based on publicly available information. The information expressed is subject to change at any time and should be checked for completeness, accuracy and current applicability. For advice, consult a suitably licensed attorney and/or patent professional.