PTAB challenges

Based on the information available for US Patent 9,402,120 B2, there has been one inter partes review (IPR) filed against the patent, which was denied institution.

Proceedings overview

One IPR has been filed against US Patent 9,402,120 B2, and the Patent Trial and Appeal Board (PTAB) denied institution of the trial. This means all claims of the patent remain valid and un-canceled. For a defendant, this outcome strengthens the patent's presumption of validity and makes a subsequent PTAB challenge more difficult, as the patent has already survived one attempt.

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IPR2025-00690 — Unified Patents, LLC v. Earin AB

• Type: Inter Partes Review
• Filed: 2025-02-12
• Status: Not Instituted - Merits. The PTAB panel reviewed the petition and determined that the petitioner did not establish a reasonable likelihood that it would prevail in showing any of the challenged claims were unpatentable.
• Judge panel: I am unable to identify the specific Administrative Patent Judges on this panel with high confidence from the available search results. This information is typically found on the cover page of the Institution Decision document.
• Petition grounds: Unified Patents challenged claims 1-3, 5-7, 9, 10, and 12-16 as unpatentable under 35 U.S.C. § 103 (obviousness) based on several prior art references.
• Institution decision: Institution was denied on 2025-08-20. The PTAB was not persuaded that the petitioner's combination of prior art references taught or suggested all the limitations of the challenged claims, particularly the specific successive arrangement of components along the earbud's longitudinal axis as recited in independent claim 1.
• Final Written Decision: No Final Written Decision was issued because the trial was never instituted.
• Settlement / termination: The proceeding was not terminated due to settlement; it concluded with the PTAB's decision to deny institution.
• Appeal: A petitioner cannot appeal a decision to deny institution to the Federal Circuit. Therefore, this proceeding is concluded.
• Defensive value: This proceeding hardens the patent, especially the challenged claims (1-3, 5-7, 9, 10, and 12-16). A defendant attempting a new IPR would be wise to use different prior art or arguments than those that failed in this petition. The denial signals that the examiner's original decision to grant the patent has been affirmed by a panel of PTAB judges in a preliminary review.

Strategic summary

All claims of US Patent 9,402,120 B2 remain valid and in force. No claims have been canceled or amended through a PTAB trial. The patent as a whole survived its only PTAB challenge when institution was denied in IPR2025-00690. The claims challenged in that proceeding (1-3, 5-7, 9, 10, and 12-16) can be considered "hardened" by the denial, while the remaining claims are untested.

The estoppel provisions of 35 U.S.C. § 315(e) now bar the petitioner, Unified Patents, LLC, and any real parties in interest or privies, from filing a subsequent IPR on any ground that was raised or reasonably could have been raised in the IPR2025-00690 petition. A new defendant not affiliated with Unified Patents is not estopped. However, any new petition would face a high bar, especially if relying on the same or similar prior art. A defendant should focus on finding prior art that was not considered during the original examination or in the denied IPR petition.

The involvement of Unified Patents, a defensive patent aggregator, indicates that this patent is likely being asserted against members of a particular technology sector. The patent owner's success in fending off the IPR at the institution stage demonstrates a capable defense and may signal a willingness to litigate rather than settle for a nuisance value.

Recommended next steps

For a defendant facing an assertion of US Patent 9,402,120 B2, the key takeaway is that a PTAB-based invalidity defense will be challenging.

• No claims have been invalidated. The patent remains fully intact.
• There are no active PTAB proceedings.
• The denial of institution in IPR2025-00690 suggests that obviousness arguments based on the art cited in that petition are unlikely to succeed. Any new PTAB strategy must be based on new, stronger prior art that was not previously before the USPTO.
• The absence of other PTAB challenges is also a data point. While not dispositive, it suggests that other potential defendants have not yet identified a clear path to invalidating the claims at the PTAB.