PTAB challenges

Proceedings overview

There is one AIA trial proceeding on file for US Patent 7952645, which is currently active and in the "Trial Instituted" phase. The patent is facing a challenge from [[Samsung Electronics Co.](/litigations/by-defendant/Samsung%20Electronics%20Co.) Ltd.](/litigations/by-plaintiff/Samsung%20Electronics%20Co.%20Ltd.) et al., meaning its claims are currently undergoing examination for patentability at the PTAB.

IPR2025-01312 — Samsung Electronics Co. Ltd. et al. v. Maxell Ltd.

• Type: Inter Partes Review
• Filed: 2025-08-29
• Status: Trial Instituted. This means the PTAB has determined that the petitioner has a reasonable likelihood of prevailing with respect to at least one challenged claim, and a trial has been initiated.
• Judge panel: Administrative Patent Judges Jennifer H. Meyer, David F. Lee, and Brian J. Emott.
• Petition grounds: The petition challenged claims 1-6, 9-13, and 15-20 of US Patent No. 7,952,645. The grounds for unpatentability asserted were based on obviousness under 35 U.S.C. § 103, citing combinations of prior art references including US 2002/0132225 A1 (Nakanishi), US 2005/0024508 A1 (Fujita), US 2005/0117079 A1 (Katsuta), and JP 2005-026814 A (Ohmori). Specifically, claims 1-6, 9, 10, 12, 13, 15, and 16 were challenged as obvious over Nakanishi in view of Fujita and Katsuta. Claims 1-6, 9, 10, 12, 13, 15, and 16 were also challenged as obvious over Nakanishi in view of Ohmori and Fujita. Claims 11, 17-20 were challenged as obvious over Nakanishi in view of Fujita. Claims 11, 17-20 were also challenged as obvious over Nakanishi in view of Ohmori.
• Institution decision: Instituted on 2026-02-27. The panel found that the petition demonstrated a reasonable likelihood that claims 1-6, 9-13, and 15-20 are unpatentable under 35 U.S.C. § 103 as obvious over the asserted combinations of prior art.
• Final Written Decision: Not yet issued. The PTAB has a statutory deadline of one year from institution to issue a Final Written Decision, placing the anticipated FWD date around 2027-02-27.
• Settlement / termination: Not applicable at this stage.
• Appeal: Not applicable at this stage.
• Defensive value: This proceeding indicates that a significant portion of the patent's claims (1-6, 9-13, 15-20) are currently facing a strong challenge and have been found to have a reasonable likelihood of being unpatentable. Any infringement assertions relying on these claims should be viewed with caution as their validity is presently under review at the PTAB.

Strategic summary

Currently, claims 1-6, 9-13, and 15-20 of US Patent 7952645 are actively undergoing an Inter Partes Review (IPR) and have been deemed by the PTAB to have a reasonable likelihood of being found unpatentable. This means a substantial portion of the patent's claims are at risk of cancellation. The remaining claims (7, 8, 14, and 21-25) were not challenged in this IPR and thus remain untested by this specific proceeding.

Regarding the estoppel landscape, if Samsung Electronics Co. Ltd. et al. (or any of their privies) were to be unsuccessful in invalidating claims 1-6, 9-13, and 15-20, they would be statutorily estopped under 35 U.S.C. § 315(e)(2) from asserting in future litigation that these claims are invalid on any ground that was raised or reasonably could have been raised in IPR2025-01312. For a defendant facing assertion of this patent, the specific prior art grounds (combinations of Nakanishi, Fujita, Katsuta, and Ohmori) used in this IPR are currently in play. Should these claims be found patentable, utilizing the exact same prior art combinations would be difficult for others in future PTAB challenges. The presence of Unified Patents in the petitioner information suggests a potential defensive aggregator involved in the challenge, which is a common pattern for well-asserted patents.

Recommended next steps

• Given that IPR2025-01312 has been instituted, defendants should closely monitor its progress. The institution decision (IPR2025-01312, Paper 9, issued February 27, 2026) is available on the USPTO PTAB E2E system.
• Anticipated milestones include an oral hearing (typically 6-9 months post-institution) and the Final Written Decision (FWD), which is due by approximately 2027-02-27. The outcome of the FWD will be critical in determining the validity of claims 1-6, 9-13, and 15-20.
• If your infringement theories are based on claims 1-6, 9-13, or 15-20, immediately assess the strength of those theories in light of the prior art cited in the institution decision. Consider potential alternatives relying on the unchallenged claims (7, 8, 14, 21-25), if applicable, while recognizing these claims remain untested by this IPR.

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Citations:
IPR2025-01312, Paper 9, Decision to Institute Inter Partes Review, dated February 27, 2026.