PTAB challenges

Proceedings overview

There is one AIA trial proceeding on file for US Patent 11026088. This proceeding, IPR2025-01307, is currently in the "Trial Instituted" stage, meaning a trial has been authorized by the PTAB. No claims have been invalidated or sustained by a Final Written Decision yet, nor has the petition been denied. The patent is currently undergoing inter partes review, indicating that its claims are being challenged.

IPR2025-01307 — Samsung Electronic Co. Ltd. et al. v. Maxell Ltd.

• Type: Inter Partes Review
• Filed: 2025-07-25
• Status: Trial Instituted. The PTAB has determined that there is a reasonable likelihood that at least one challenged claim is unpatentable, and a trial has been formally commenced.
• Judge panel: The judge panel for IPR2025-01307 includes Administrative Patent Judges Kalpana J. Srinivasan, Michael P. Tierney, and Christopher R. Gherardini.
• Petition grounds: Samsung Electronic Co. Ltd. et al. challenged claims 1-19 of U.S. Patent No. 11,026,088 as unpatentable under 35 U.S.C. § 103 over combinations of various prior art references including US 2008/0172421 A1 (Hayashi) and US 2012/0324021 A1 (Mochizuki).
• Institution decision: Instituted on 2026-04-08. The PTAB instituted review of claims 1-19, finding that the Petitioner demonstrated a reasonable likelihood of prevailing with respect to claims 1-19 being unpatentable under 35 U.S.C. § 103.
• Final Written Decision (if issued): A Final Written Decision has not yet been issued, as the proceeding is currently in the trial stage.
• Settlement / termination: No settlement or termination has been publicly reported.
• Appeal: Not applicable yet, as no Final Written Decision has been issued.
• Defensive value: This proceeding indicates that claims 1-19 are currently being challenged and are at risk of being invalidated. Any assertion of these claims should be viewed with caution, as their patentability is actively under review by the PTAB. The institution decision suggests that the Petitioner has presented strong arguments against these claims.

Strategic summary

All of the patent's claims, specifically claims 1-19 of US11026088, are currently undergoing an active Inter Partes Review in IPR2025-01307. No claims have been definitively canceled or sustained by a Final Written Decision. The institution of the IPR means the PTAB found a reasonable likelihood that these claims are unpatentable, putting all currently asserted claims in a precarious position.

Regarding the estoppel landscape, if a defendant is being asserted against by Maxell Ltd. on US11026088, the specific prior art grounds raised by Samsung Electronic Co. Ltd. et al. in IPR2025-01307 are unavailable to Samsung and its privies in future PTAB challenges against claims 1-19. However, other defendants are not estopped from raising these same grounds or new grounds, particularly if they are not in privity with Samsung. New prior art or different combinations of the existing art could still be used to challenge these claims in future proceedings or district court litigation.

There is only one active IPR on this patent, filed by Samsung Electronic Co. Ltd. et al. The fact that a major technology company like Samsung is challenging the patent is a significant signal, indicating potential impact on the industry. The proceeding is still in its early stages following institution.

Recommended next steps

As IPR2025-01307 is an active proceeding with a "Trial Instituted" status, it is critical to monitor its progress closely. The PTAB has a statutory deadline of one year from the institution date (April 8, 2026) to issue a Final Written Decision. Therefore, a Final Written Decision is anticipated by April 8, 2027. Key upcoming milestones typically include potential oral hearings and the eventual Final Written Decision. The institution decision for IPR2025-01307, which details the specific claims challenged and the prior art cited, is publicly available on the USPTO PTAB Decisions portal. This document should be reviewed immediately to understand the specifics of the challenge.