PTAB challenges

The USPTO's Open Data Portal API did not return any AIA trial proceedings for US Patent 11,121,222 during the most recent ingest, as stated in the "PTAB proceedings on file" section. However, the "Litigation summary" section of the provided patent analysis explicitly lists multiple inter partes review (IPR) proceedings. This analysis will proceed using the detailed IPR information from the "Litigation summary," as it appears to be more current and comprehensive.

Proceedings overview

There have been a total of twelve identified AIA trial proceedings challenging US Patent 11,121,222. Four of these IPRs (IPR2023-00324, IPR2023-00420, IPR2023-00509, IPR2023-00552, IPR2024-00021) were terminated due to settlement. One IPR (IPR2024-00020) resulted in a Final Written Decision finding claim 44 unpatentable, though it also appears to have settled. Two IPRs (IPR2023-01242, IPR2023-01244) had Final Written Decisions that were subsequently vacated by the Director and remanded for further proceedings. Two IPRs (IPR2024-00470, IPR2024-00552) are pending after institution. The remaining two IPRs (IPR2024-00673, IPR2024-00674) are ongoing, with institution decisions pending or recently made. The defensive posture for a defendant is mixed: claim 44 has been found unpatentable in one proceeding (though settled), and the status of claims in the vacated FWDs is uncertain. Several claims remain untested or are currently subject to ongoing PTAB review.

IPR2024-00020 — Cirrus Logic, Inc., Omnivision Technologies, Inc., AMS Sensors USA, Inc., et al. v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2023-10-27
• Status: Final Written Decision issued finding claim 44 unpatentable. The broader case appears to have resulted in a settlement.
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: Not publicly available from provided text.
• Final Written Decision: The Final Written Decision found claim 44 unpatentable.
• Settlement / termination: The broader case appears to have resulted in a settlement, and Patent Owner indicated it would file for Director Review of the FWD.
• Appeal: Not publicly available from provided text.
• Defensive value: Claim 44, a CMOS-specific claim, was found unpatentable by the PTAB. While the case settled, this FWD provides a strong indicator of invalidity for claim 44, potentially rendering infringement theories built solely on this claim vulnerable.

IPR2023-01242 — Semiconductor Components Industries, LLC, d/b/a onsemi, and ON Semiconductor Corporation. Texas Instruments Inc. joined. v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2023-07-27
• Status: A Final Written Decision was issued, but this was subsequently vacated by the Director, and the case was remanded to the Board for further proceedings as of April 2025. A request for rehearing of the Director's review was denied in May 2025.
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: Not publicly available from provided text.
• Final Written Decision: An FWD was issued, but its contents regarding specific claims are not detailed in the provided text. This FWD was subsequently vacated by the Director.
• Settlement / termination: The proceeding was remanded after the Director vacated the FWD.
• Appeal: Not publicly available from provided text.
• Defensive value: The vacating of the FWD by the Director means that the prior determination of patentability/unpatentability for claims challenged in this IPR is no longer valid. The outcome of this proceeding is uncertain until the remanded proceedings conclude.

IPR2023-01244 — Semiconductor Components Industries, LLC, d/b/a onsemi, and ON Semiconductor Corporation. Texas Instruments Inc. joined. v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2023-07-27
• Status: A Final Written Decision was issued, but this was subsequently vacated by the Director, and the case was remanded to the Board for further proceedings as of April 2025. A request for rehearing of the Director's review was denied in May 2025.
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: Not publicly available from provided text.
• Final Written Decision: An FWD was issued, but its contents regarding specific claims are not detailed in the provided text. This FWD was subsequently vacated by the Director.
• Settlement / termination: The proceeding was remanded after the Director vacated the FWD.
• Appeal: Not publicly available from provided text.
• Defensive value: Similar to IPR2023-01242, the vacating of the FWD means the prior determination of patentability/unpatentability for claims challenged in this IPR is no longer valid. The outcome is uncertain until the remanded proceedings conclude.

IPR2024-00470 — Monolithic Power Systems Inc. v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2024-02-03
• Status: Pending - Instituted.
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: The petition was instituted. Specific details on the claims challenged and grounds are not publicly available from provided text.
• Final Written Decision: Not yet issued.
• Settlement / termination: Not terminated.
• Appeal: Not applicable at this stage.
• Defensive value: This proceeding is active and could potentially lead to the invalidation of claims. Its outcome will impact the patent's strength.

IPR2024-00552 — Monolithic Power Systems, Inc. v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2024-03-18
• Status: Pending - Instituted.
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: The petition was instituted. Specific details on the claims challenged and grounds are not publicly available from provided text.
• Final Written Decision: Not yet issued.
• Settlement / termination: Not terminated.
• Appeal: Not applicable at this stage.
• Defensive value: This is an active proceeding that could lead to claim invalidation. Its eventual decision will be crucial for assessing the patent's scope and validity.

IPR2023-00324 — Sony Group Corporation, Dell, Inc., et al. v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2022-12-12
• Status: Terminated - Settlement.
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: Not publicly available from provided text.
• Final Written Decision: Not issued due to settlement.
• Settlement / termination: Terminated due to settlement.
• Appeal: Not applicable.
• Defensive value: The settlement means no final determination of patentability was reached, so the challenged claims remain patentable as far as this IPR is concerned.

IPR2023-00420 — Intel Corporation v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2022-12-28
• Status: Terminated - Settlement.
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: Not publicly available from provided text.
• Final Written Decision: Not issued due to settlement.
• Settlement / termination: Terminated due to settlement.
• Appeal: Not applicable.
• Defensive value: The settlement means no final determination of patentability was reached, so the challenged claims remain patentable as far as this IPR is concerned.

IPR2023-00509 — Dell Technologies, Inc., and Dell, Inc. v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2023-01-27
• Status: Terminated - Settlement.
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: Not publicly available from provided text.
• Final Written Decision: Not issued due to settlement.
• Settlement / termination: Terminated due to settlement.
• Appeal: Not applicable.
• Defensive value: The settlement means no final determination of patentability was reached, so the challenged claims remain patentable as far as this IPR is concerned.

IPR2023-00552 — Intel Corporation v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2023-02-01
• Status: Terminated - Settlement.
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: Not publicly available from provided text.
• Final Written Decision: Not issued due to settlement.
• Settlement / termination: Terminated due to settlement.
• Appeal: Not applicable.
• Defensive value: The settlement means no final determination of patentability was reached, so the challenged claims remain patentable as far as this IPR is concerned.

IPR2024-00021 — Cirrus Logic, Inc., Omnivision Technologies, Inc., AMS Sensors USA, Inc., et al. v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2023-10-27
• Status: Terminated - Settlement.
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: Not publicly available from provided text.
• Final Written Decision: Not issued due to settlement.
• Settlement / termination: Terminated due to settlement.
• Appeal: Not applicable.
• Defensive value: The settlement means no final determination of patentability was reached, so the challenged claims remain patentable as far as this IPR is concerned.

IPR2024-00673 — Texas Instruments Incorporated v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2024-03-12
• Status: Ongoing. Texas Instruments moved to be joined with pending IPRs filed by onsemi (IPR2023-01242 and IPR2023-01244).
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: Not publicly available from provided text.
• Final Written Decision: Not yet issued.
• Settlement / termination: Not terminated.
• Appeal: Not applicable at this stage.
• Defensive value: This proceeding is ongoing, with potential impact on the claims challenged. Its current status means no definitive validity determination has been made.

IPR2024-00674 — Texas Instruments Incorporated v. Greenthread, LLC

• Type: Inter Partes Review
• Filed: 2024-03-12
• Status: Ongoing. Texas Instruments moved to be joined with pending IPRs filed by onsemi (IPR2023-01242 and IPR2023-01244).
• Judge panel: Not publicly available from provided text.
• Petition grounds: Not publicly available from provided text.
• Institution decision: Not publicly available from provided text.
• Final Written Decision: Not yet issued.
• Settlement / termination: Not terminated.
• Appeal: Not applicable at this stage.
• Defensive value: This proceeding is ongoing, with potential impact on the claims challenged. Its current status means no definitive validity determination has been made.

Strategic summary

Of the independent claims, claim 44 was found unpatentable in IPR2024-00020. The status of claims challenged in IPR2023-01242 and IPR2023-01244 is currently uncertain due to the Director's decision to vacate the Final Written Decisions and remand the cases. The remaining independent claims (1, 21, 39, 41, 42, 43, and the dependent claims not tied to claim 44) have either been subject to IPRs that settled before a final decision, or they are currently being challenged in active, instituted IPRs (IPR2024-00470, IPR2024-00552) or pending IPRs (IPR2024-00673, IPR2024-00674). Therefore, while claim 44 faces a strong challenge to its validity, other claims are either presumed patentable (due to settlement) or their validity is still under review.

The estoppel landscape is complex due to the numerous settlements. For petitioners who settled (Sony, Dell, Intel, Cirrus Logic, Omnivision, AMS Sensors, et al.), 35 U.S.C. § 315(e)(2) bars them (and their privies) from raising any ground that was raised or reasonably could have been raised in their respective IPRs. This means these parties would face estoppel in subsequent litigation on those grounds. For a defendant not involved in these settlements, or not in privity with the petitioners, a wider range of prior-art grounds may still be available for challenges, provided they have not been litigated to a final judgment on the merits. Given the vacated FWDs in IPR2023-01242 and IPR2023-01244, the estoppel effect from those proceedings is also currently unclear.

A clear pattern signal is the high volume of IPR filings, particularly from major technology companies like Sony, Dell, Intel, onsemi, and Texas Instruments. This indicates that the patent is being widely asserted, leading to concerted efforts to challenge its validity at the PTAB. The repeated settlements suggest a strategy by Greenthread, LLC, to monetize the patent through licensing agreements, possibly using the threat of ongoing litigation, while avoiding a definitive PTAB decision on all claims. The Director's review and remand of the onsemi IPRs also highlights the active and often unpredictable nature of PTAB proceedings for this patent family.

Recommended next steps

• If you are a defendant facing assertion of US Patent 11,121,222, note that claim 44 has been found unpatentable in IPR2024-00020. Any infringement theory built on claim 44 is significantly weakened by this finding.
• For claims challenged in IPR2023-01242 and IPR2023-01244, monitor the remanded proceedings closely. The previous FWDs were vacated, so the patentability of those claims is once again in question.
• For claims challenged in IPR2024-00470 and IPR2024-00552, these proceedings are instituted and pending. Track their progress, including oral hearings and the statutory one-year deadline for Final Written Decisions (which would be around February 2025 and March 2025, respectively, from the institution dates).
• For claims challenged in IPR2024-00673 and IPR2024-00674, these are ongoing. Keep an eye on institution decisions and any subsequent trial stages.
• Given the history of settlements, consider the potential for settlement negotiations. However, the existing FWD against claim 44, and the ongoing/remanded proceedings, provide leverage for defendants.