Assignment history

Inventors

• Seiji Yamahira (Employer: Panasonic Corp)

Note: In the US, initial ownership of a patent typically vests in the inventor. However, employment agreements often assign these rights to the employer. Given Panasonic Corp was the original assignee, it is highly probable Seiji Yamahira was employed by Panasonic Corp at the time of filing.

Original assignee

The original assignee on the issued patent is Panasonic Corp.

Panasonic Holdings Corporation (formerly Panasonic Corporation) is a Japanese multinational electronics manufacturer, headquartered in Kadoma, Osaka, Japan. They produce a wide range of products and services, including consumer electronics, home appliances, automotive and avionic systems, industrial equipment, and rechargeable batteries. In 2019, Panasonic sold its semiconductor business.

Panasonic Holdings Corporation is currently operating.

Assignment timeline

• 2009-06-22 (executed) / recorded 2009-09-22 — Reel 023266/0680
  • Conveyance: Assignment
  • Assignor: YAMAHIRA, SEIJI
  • Assignee: PANASONIC CORPORATION
  • Correspondent: NOT LISTED
  • Context: Original assignment from inventor to corporation.
• 2020-08-17 (executed) / recorded 2020-08-24 — Reel 053570/0429
  • Conveyance: Assignment
  • Assignor: PANASONIC CORPORATION
  • Assignee: PANASONIC SEMICONDUCTOR SOLUTIONS CO., LTD.
  • Correspondent: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
  • Context: Internal reorganization; transfer of semiconductor-related assets.
• 2020-09-02 (executed) / recorded 2024-03-20 — Reel 066849/0802
  • Conveyance: Change of Name
  • Assignor: PANASONIC SEMICONDUCTOR SOLUTIONS CO., LTD.
  • Assignee: NUVOTON TECHNOLOGY CORPORATION JAPAN
  • Correspondent: PANASONIC CORPORATION, 1000, KADOMA, KADOMA-SHI, OSAKA, JAPAN
  • Context: Change of name, likely following Nuvoton Technology Corporation's acquisition of Panasonic's semiconductor business.
• 2024-03-25 (executed) / recorded 2024-04-22 — Reel 067184/0869
  • Conveyance: Assignment
  • Assignor: NUVOTON TECHNOLOGY CORPORATION JAPAN
  • Assignee: ADVANCED MEMORY TECHNOLOGIES LLC
  • Correspondent: KEMPER DIEHL, SUSMAN GODFREY LLP, 1000 LOUISIANA STREET, SUITE 5100, HOUSTON, TX 77002. This correspondent appears on other active patent litigation.
  • Context: Transfer to a patent assertion entity.

Timeline diagram

timeline
    title Ownership of US 7969231
    2008 : Filed by Panasonic Corp
    2009 : Assigned from inventor to Panasonic
    2011 : Issued
    2020 : Internal transfer to Panasonic Semi
    2024 : Name changed to Nuvoton Tech Japan
         : Assigned to Advanced Memory Technologies LLC

NPE / troll-pattern signals

1. Shell-entity transfer — present. The patent was assigned to Advanced Memory Technologies LLC (AMT) on 2024-04-22 (Reel 067184/0869). AMT is a Delaware limited liability company with its principal place of business at 825 Watters Creek Blvd. Suite 250, Allen, Texas 75013. Public records do not identify the personnel or management of Advanced Memory Technologies. AMT has been identified as a non-practicing entity (NPE) or patent assertion entity (PAE) in recent patent infringement lawsuits.

2. Known asserter in the chain — present. Advanced Memory Technologies LLC (AMT) is identified as a non-practicing entity (NPE) that has recently filed patent infringement lawsuits. In December 2024, AMT sued SK Hynix Inc. for infringing four patents, including US7969231, in the Eastern District of Texas. AMT also filed a complaint against Micron Technology, Inc. in the Western District of Texas in June 2025.

3. Repeat correspondent across the chain — present. Kemper Diehl of Susman Godfrey LLP is listed as the correspondent for the assignment to Advanced Memory Technologies LLC on 2024-04-22 (Reel 067184/0869). Susman Godfrey LLP attorneys, including Justin Nelson and Kalpana Srinivasan, are representing Advanced Memory Technologies LLC in its patent infringement lawsuit against SK Hynix Inc. This firm has been involved in several high-profile IP enforcement cases.

4. Cascading transfers — not present. There are no multiple consecutive assignments through chained LLCs in a short timeframe that suggest cascading transfers.

5. Pre-litigation transfer — present. The assignment to Advanced Memory Technologies LLC was executed on 2024-03-25 and recorded on 2024-04-22 (Reel 067184/0869). Advanced Memory Technologies LLC filed a patent infringement lawsuit against SK Hynix Inc. in the Eastern District of Texas on December 30, 2024. This is approximately 8 months after the assignment was recorded, falling within a pattern often seen before assertion.

6. Bankruptcy fire-sale — not present. The original assignee, Panasonic Corp, and its successors in the chain are currently operating.

7. Privateering — unclear. While the transfer is to an NPE, there is no public information readily available in the provided context to confirm if Nuvoton Technology Corporation Japan or any other prior operating company is funding or directing the litigation against their competitors.

8. Defensive aggregator (anti-NPE) — not present. The patent is currently held by Advanced Memory Technologies LLC, which is actively asserting the patent.

Verdict

NPE — high confidence

This verdict is driven by several strong signals. The patent was transferred from an operating company (Nuvoton Technology Corporation Japan) to Advanced Memory Technologies LLC, a known shell entity with no identified products and a registered-agent address, as recorded on 2024-04-22 (Reel 067184/0869). This transfer was a pre-litigation event, occurring approximately eight months before Advanced Memory Technologies LLC filed a patent infringement lawsuit against SK Hynix Inc. in December 2024. Furthermore, the correspondent for the final assignment, Kemper Diehl of Susman Godfrey LLP, is associated with a firm actively engaged in patent assertion.

Verification: USPTO Assignment Center search for US7969231