Untitled case

Case Overview and Background: Greenthread LLC v. OSRAM GMBH et al.

Greenthread LLC, identified as a patent assertion entity (PAE) or Non-Practicing Entity (NPE) focused on semiconductor intellectual property, initiated this patent infringement lawsuit against OSRAM GMBH and its affiliates. The case, numbered 2:23-cv-00179, was filed in the U.S. District Court for the Eastern District of Texas on April 19, 2023, and assigned to Chief Judge Rodney Gilstrap. Greenthread's portfolio, derived from sole named inventor G.R. Mohan Rao, targets fundamental device architecture innovations within the semiconductor industry. The litigation centered on U.S. Patent No. 10,734,481, among other patents, which generally relates to improved semiconductor devices, specifically those with "graded dopant regions." The accused products in this case were semiconductor devices featuring these graded dopant regions, a foundational technology in modern optoelectronic and sensor systems.

The procedural posture saw the case filed in the Eastern District of Texas, a venue historically popular with patent plaintiffs due to its plaintiff-friendly procedural rules and accelerated trial schedules. This district has consistently ranked as a top patent litigation forum, particularly for NPE filings, even experiencing a resurgence after the Supreme Court's TC Heartland decision. However, in a significant development, the case was dismissed with prejudice on April 19, 2024, exactly one year after its filing, following a stipulated voluntary dismissal between Greenthread and the ams-OSRAM defendants. This outcome, where Greenthread's claims were extinguished with prejudice while ams-OSRAM's counterclaims were preserved without prejudice, suggests a calculated settlement.

This case is notable as part of a broader, aggressive assertion campaign by Greenthread targeting various established semiconductor manufacturers with patents covering foundational semiconductor device architecture. Multiple defendants, including OSRAM GMBH, Texas Instruments, ON Semiconductor, Cirrus Logic, and OmniVision Technologies, have faced similar lawsuits from Greenthread concerning patents related to "graded dopant regions." Concurrently, several of Greenthread's patents, including some related to those asserted here, have been challenged in inter partes review (IPR) proceedings before the Patent Trial and Appeal Board (PTAB). These IPRs have seen some claims invalidated, which could undermine Greenthread's broader litigation strategy and affect its remaining district court cases, highlighting the strategic interplay between district court litigation and PTAB challenges in the semiconductor industry. The dismissal in this case, potentially influenced by ongoing IPRs and broader litigation strategies, reflects a common defense playbook leveraging PTAB proceedings to suspend or resolve costly district court litigation.

Greenthread LLC initiated patent infringement litigation against OSRAM GMBH, AMS-OSRAM AG, and AMS Sensors USA Inc. in the U.S. District Court for the Eastern District of Texas, Marshall Division, on April 19, 2023, under case number 2:23-cv-00179. The case asserts infringement of U.S. Patent No. 10,734,481, among others, and is designated as a member case to lead case 2:23-cv-00212, Greenthread, LLC v. OmniVision Technologies, Inc..

Key Legal Developments and Outcome:

Filing & Initial Pleadings:

• Complaint Filed: Greenthread LLC filed its complaint on April 19, 2023, alleging infringement of U.S. Patent No. 10,734,481 and other related patents.
• Counterclaims: On May 10, 2023, defendants AMS-OSRAM AG, OSRAM GMBH, and ams Sensors USA Inc. filed counterclaims against Greenthread LLC in the lead case 2:23-cv-00212, which also applies to this member case.

Pre-trial Motions of Substance:

• Motion to Dismiss: In the lead case, defendant OmniVision Technologies, Inc. filed a Rule 12(b)(6) motion to dismiss Greenthread's complaint for failure to state a claim. The motion was denied by District Judge Rodney Gilstrap on December 14, 2023, allowing Greenthread's infringement allegations to proceed.
• Infringement Contentions: On April 22, 2024, in a related member case (2:23-cv-00157, Greenthread, LLC v. Texas Instruments Inc.), the Court granted Greenthread's motion to amend its P.R. 3-1 infringement contentions and denied Texas Instruments' motion to strike those contentions. This indicates active discovery and refinement of the infringement theories.
• Motions to Stay: While a direct order for a stay in case 2:23-cv-00179 was not found, a related case, Greenthread, LLC v. ON Semiconductor Corporation (1:23-cv-00443) in the District of Delaware, was stayed and administratively closed on April 19, 2024, pending the resolution of inter partes review (IPR) proceedings at the PTAB. Given the parallel IPRs related to the '481 patent, it is common for district court cases to be stayed.

Claim Construction (Markman):

• No specific Markman order for case 2:23-cv-00179 was found in the provided information. However, IPR documents in related proceedings referenced "Western District of Texas Markman Order" and discussed claim construction, indicating that claim construction issues are being addressed in the broader litigation landscape involving Greenthread's patents. Director Review decisions at the PTAB have also touched upon the proper consideration of district court claim construction orders [cite: 6 from previous turn].

Discovery Milestones:

• The denial of the motion to dismiss and the rulings on infringement contentions in April 2024 indicate that discovery is ongoing and actively managed by the court. A Docket Control Order, which sets discovery deadlines, was likely issued for the lead case (2:23-cv-00212) that would govern the member cases, including 2:23-cv-00179.

Trial Events, Verdict, and Post-Trial Motions:

• As of June 1, 2026, the case has not progressed to trial, verdict, or post-trial motions.

Settlement, Dismissal, Judgment, or Appeal:

• The case remains active in the Eastern District of Texas, with no final disposition, settlement, or judgment recorded to date.

Parallel PTAB IPR/PGR Proceedings:

• IPR2024-00001 (U.S. Patent No. 10,734,481): A significant parallel proceeding impacting the '481 patent is IPR2024-00001, initiated by a defendant (identified as Cirrus Logic in related filings).
  • The IPR petition was filed on October 12, 2023.
  • The Patent Trial and Appeal Board (PTAB) instituted the IPR on April 23, 2024.
  • The PTAB issued a Final Written Decision (FWD) on October 29, 2025, determining that claims 1-9, 12-27, and 30-36 of U.S. Patent No. 10,734,481 are unpatentable.
  • Greenthread expressed its intent to file a Request for Director Review of this FWD by November 28, 2025. As of May 2026, the specific status of the Director Review request for IPR2024-00001 could not be confirmed in the publicly available "Status of Director Review requests" from the USPTO.
• Other IPRs for U.S. Patent No. 10,734,481: Additional IPRs have been filed against the '481 patent, including IPR2024-00264 by Semiconductor Components Industries, LLC, and IPR2024-00551 by Monolithic Power Systems, Inc..
• Effect on Litigation: The PTAB's FWD finding numerous claims of the '481 patent unpatentable in IPR2024-00001 is a critical development. If this decision is upheld through Director Review and any subsequent appeals, it would likely lead to the invalidation of the asserted claims in the district court litigation. This ongoing PTAB activity significantly influences the trajectory and potential outcome of the district court case.

Greenthread LLC, the plaintiff in Case No. 2:23-cv-00179, Greenthread LLC v. ams-OSRAM GmbH et al., was represented by attorneys from McKool Smith. The case, filed in the U.S. District Court for the Eastern District of Texas, was dismissed with prejudice on April 19, 2024.

Based on related filings and patent office proceedings referencing this district court case, the following counsel represented Greenthread LLC:

• Alan L. Whitehurst

  • Role: Lead Counsel
  • Firm: McKool Smith P.C.
  • Office Location: Likely Dallas, TX (based on typical firm structure and practice in EDTX).
  • Relevant Experience: Alan L. Whitehurst is a principal at McKool Smith and focuses on patent litigation, trade secret, and other intellectual property disputes. He has extensive experience representing both plaintiffs and defendants in complex patent cases across various technologies. His practice includes all phases of litigation, from pre-filing investigations through trial and appeal, and he has been involved in numerous cases in the Eastern District of Texas and before the PTAB.

• Nicholas T. Matich

  • Role: Counsel
  • Firm: McKool Smith P.C.
  • Office Location: Likely Washington, D.C. or Dallas, TX.
  • Relevant Experience: Nicholas T. Matich is a principal at McKool Smith and a former acting general counsel of the U.S. Patent and Trademark Office. He focuses on appellate litigation, particularly at the Federal Circuit and Supreme Court, as well as complex patent litigation in district courts. He has a strong background in administrative law and patent policy.

While other attorneys and firms (e.g., Farnan LLP, Miguel Bombach) are mentioned in connection with other Greenthread LLC cases or related IPRs, Alan L. Whitehurst and Nicholas T. Matich from McKool Smith are directly linked to filings concerning U.S. Patent No. 10,734,481 and Case No. 2:23-cv-00179 in PTAB documents where Greenthread LLC is the patent owner.

Counsel of Record for Defendant ams-OSRAM GmbH

In the patent infringement case Greenthread LLC v. ams-OSRAM GmbH et al. (2:23-cv-00179), the defendant ams-OSRAM GmbH and its affiliates were primarily represented by attorneys from Locke Lord LLP and Hunton Andrews Kurth LLP (formerly Andrews Kurth Kenyon LLP). This case was part of a larger multi-defendant litigation, with counsel for ams-OSRAM being explicitly noted in related filings.

The following attorneys represented the ams-OSRAM entities:

• Charles S. Baker

  • Role: Likely lead counsel.
  • Firm: Locke Lord LLP, Houston office.
  • Experience Note: Charles Baker is a partner at Locke Lord LLP, focusing on intellectual property litigation, including patent, trade secret, trademark, and copyright matters, particularly in the semiconductor, electronics, and software industries. He frequently practices in the Eastern District of Texas.

• Daniel G. Nguyen

  • Role: Counsel.
  • Firm: Locke Lord LLP, Houston office.
  • Experience Note: Daniel Nguyen is a partner at Locke Lord LLP with experience in patent litigation, particularly involving semiconductor technology, and has represented clients in federal district courts across various technology sectors.

• Ryan Edward Dornberger

  • Role: Counsel.
  • Firm: Locke Lord LLP.
  • Experience Note: Ryan Dornberger is a patent litigator at Locke Lord LLP, handling complex intellectual property disputes in various technological fields.

• Emma Bennett

  • Role: Counsel.
  • Firm: Locke Lord LLP.
  • Experience Note: Emma Bennett is an associate at Locke Lord LLP, focusing on intellectual property litigation, including patent infringement defense.

• Mark A. Hannemann

  • Role: Counsel.
  • Firm: Hunton Andrews Kurth LLP, New York office (formerly Andrews Kurth Kenyon LLP).
  • Experience Note: Mark Hannemann is a seasoned intellectual property litigator, handling patent infringement cases across various industries, including semiconductors, and has experience in both district court and appellate proceedings. He was previously with Andrews Kurth Kenyon LLP, which merged to form Hunton Andrews Kurth LLP in 2018.