PTAB challenges

Proceedings overview

As of 2026-05-23, there is one AIA trial proceeding on file for US Patent 11812091. This Inter Partes Review (IPR) is currently active and in the "Trial Instituted" phase. For a defendant, this means that while the patent claims are currently being challenged, none have been invalidated or confirmed patentable by the PTAB yet, leaving the defensive posture fluid.

IPR2025-01311 — [[Samsung Electronics Co.](/litigations/by-defendant/Samsung%20Electronics%20Co.) Ltd.](/litigations/by-plaintiff/Samsung%20Electronics%20Co.%20Ltd.) et al. v. Maxell Ltd

• Type: Inter Partes Review
• Filed: 2025-09-05
• Status: Trial Instituted (The PTAB has decided to initiate a review of the challenged claims, and the trial is currently underway.)
• Judge panel: Administrative Patent Judges Jennifer B. Myers, David L. St. Jean, and Michelle M. Bordner.
• Petition grounds: Samsung Electronics Co. Ltd. and Unified Patents LLC challenged claims 1-20 of US Patent No. 11,812,091 under 35 U.S.C. § 102 and § 103, relying on prior art references including US 2005/0028204 A1 (Nakamura) and JP 2005-006144 A (Fujitsu).
• Institution decision: Instituted on 2026-03-05. The panel found that the Petition demonstrated a reasonable likelihood that claims 1-20 are unpatentable under 35 U.S.C. §§ 102 and 103.
• Final Written Decision: Not yet issued.
• Settlement / termination: No public record of settlement or termination.
• Appeal: No appeal has been filed, as no Final Written Decision has been issued.
• Defensive value: This active IPR means that all claims of the patent are under review for patentability. If the challenged claims are eventually invalidated, any assertion based on them would be significantly weakened. The involvement of Unified Patents as a co-petitioner indicates a coordinated defensive effort.

Strategic summary

Currently, all twenty claims (1-20) of US Patent 11812091 are UNTESTED in the sense that no Final Written Decision has been issued, but they are actively UNDER REVIEW for patentability in IPR2025-01311. None have been definitively canceled or sustained by the PTAB. The institution of the IPR signifies that the PTAB found a reasonable likelihood of unpatentability for all challenged claims (1-20) based on the presented prior art.

Regarding the estoppel landscape, if IPR2025-01311 proceeds to a Final Written Decision, the petitioners (Samsung Electronics Co. Ltd. and Unified Patents LLC) and their privies would be estopped under 35 U.S.C. § 315(e)(2) from asserting in future district court or ITC proceedings any invalidity grounds they raised or reasonably could have raised during the IPR. For a defendant currently being asserted against, the prior art grounds raised in this IPR (Nakamura, Fujitsu, etc., under §§ 102 and 103) are currently being litigated at the PTAB.

A pattern signal here is the involvement of Unified Patents LLC as a co-petitioner, which is a defensive aggregator that often challenges patents deemed problematic for its member companies. This suggests a strategic and organized effort to address the patent.

Recommended next steps

• Since IPR2025-01311 is in the "Trial Instituted" stage, the next significant milestones will be the Patent Owner's Response, Petitioner's Reply, and potentially an oral hearing. The Final Written Decision is typically due within one year of institution. The institution date was 2026-03-05, so the Final Written Decision is anticipated by approximately 2027-03-05.
• Monitor the progress of IPR2025-01311 closely on the USPTO PTAB E2E system to track all filings, arguments, and the eventual Final Written Decision. The institution decision is available at https://e2e.uspto.gov/e2e/.
• For any defendant facing assertion, the outcome of this IPR will be crucial, as it could result in the cancellation of all challenged claims (1-20).## Proceedings overview
  There is one AIA trial proceeding on file for US Patent 11812091, IPR2025-01311. This proceeding is active and in the "Trial Instituted" phase. For a defendant, this means that while the patent claims are currently being challenged, none have been invalidated or confirmed patentable by the PTAB yet, leaving the defensive posture fluid.

IPR2025-01311 — Samsung Electronics Co. Ltd. et al. v. Maxell Ltd

• Type: Inter Partes Review
• Filed: 2025-09-05
• Status: Trial Instituted. The Patent Trial and Appeal Board (PTAB) has decided to initiate a review of the challenged claims, and the trial is currently underway.
• Judge panel: Administrative Patent Judges Jennifer B. Myers, David L. St. Jean, and Michelle M. Bordner.
• Petition grounds: Samsung Electronics Co. Ltd. and Unified Patents LLC challenged claims 1-20 of US Patent No. 11,812,091 under 35 U.S.C. § 102 (anticipation) and § 103 (obviousness), relying on prior art references including US 2005/0028204 A1 (Nakamura) and JP 2005-006144 A (Fujitsu).
• Institution decision: Instituted on 2026-03-05. The PTAB found that the Petition demonstrated a reasonable likelihood that claims 1-20 are unpatentable under 35 U.S.C. §§ 102 and 103. The decision to institute followed a bifurcated review process where the Director first assesses discretionary considerations, then refers to a three-judge panel for a decision on the merits and other statutory considerations if discretionary denial is not appropriate.
• Final Written Decision: Not yet issued.
• Settlement / termination: No public record of settlement or termination.
• Appeal: No appeal has been filed, as no Final Written Decision has been issued.
• Defensive value: This active IPR means that all claims of the patent are under review for patentability. If the challenged claims are eventually invalidated, any assertion based on them would be significantly weakened. The involvement of Unified Patents as a co-petitioner indicates a coordinated defensive effort.

Strategic summary

Currently, all twenty claims (1-20) of US Patent 11812091 are UNTESTED in the sense that no Final Written Decision has been issued. However, they are actively UNDER REVIEW for patentability in IPR2025-01311. None have been definitively canceled or sustained by the PTAB. The institution of the IPR signifies that the PTAB found a reasonable likelihood of unpatentability for all challenged claims (1-20) based on the presented prior art, including Nakamura (US 2005/0028204 A1) and Fujitsu (JP 2005-006144 A).

Regarding the estoppel landscape, if IPR2025-01311 proceeds to a Final Written Decision, the petitioners (Samsung Electronics Co. Ltd. and Unified Patents LLC) and their privies would be estopped under 35 U.S.C. § 315(e)(2) from asserting in future district court or ITC proceedings any invalidity grounds they raised or reasonably could have raised during the IPR. For a defendant currently being asserted against, the prior art grounds raised in this IPR (Nakamura, Fujitsu, etc., under §§ 102 and 103) are currently being litigated at the PTAB.

A pattern signal here is the involvement of Unified Patents LLC as a co-petitioner, which is a defensive aggregator that often challenges patents deemed problematic for its member companies. This suggests a strategic and organized effort to address the patent. It is also notable that Samsung has filed multiple IPRs against Maxell patents, following a jury verdict in the Eastern District of Texas where Maxell was awarded damages, though Samsung later had that verdict overturned and some claims invalidated in that case. This indicates ongoing litigation between these parties and a strategy by Samsung to challenge Maxell's patents at the PTAB.

Recommended next steps

• Since IPR2025-01311 is in the "Trial Instituted" stage with an institution date of 2026-03-05, the Final Written Decision is typically due within one year of institution, meaning it is anticipated by approximately 2027-03-05.
• Monitor the progress of IPR2025-01311 closely on the USPTO PTAB E2E system to track all filings, arguments, and the eventual Final Written Decision. The institution decision is available at https://e2e.uspto.gov/e2e/.