Patent 11812091

Assignment history

Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.

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Ownership chain (1)

Asserters network →

Structured records extracted from the assignment-history narrative below. Each entity links to its full ownership-network profile.

  1. 2023-11-06 · reel 057072/0858 · Assignment

    Hitachi-LG Data Storage, Inc.MAXELL, LTD.

    Correspondent: Jeffrey M. Linger · Maxell

    internal reorg

Assignment history

Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.

✓ Generated

Inventors

  • Yoshihiro Machida (Maxell Ltd)
  • Nobuhiro Tsutsumi (Maxell Ltd)
  • Kouji Kamogawa (Maxell Ltd)

There is no readily available information indicating that all inventors departed the original assignee within 12 months of filing.

Original assignee

Maxell Ltd. is the entity named on the issued patent. Maxell Ltd. is a Japanese company known for manufacturing various electronics, including batteries, optical media, and audio products. It is plausible they shipped products embodying the claims, especially given the patent's focus on multimedia players. Maxell Ltd. is currently operating.

Assignment timeline

The USPTO Patent Assignment Search shows the following assignment records for US11812091:

  • 2023-11-06 (executed) / recorded 2023-11-06 — Reel 057072/0858
    • Conveyance: Assignment
    • Assignor: Hitachi-LG Data Storage, Inc.
    • Assignee: Maxell, Ltd.
    • Correspondent: Jeffrey M. Linger, Maxell, Ltd., 3333 Bowers Avenue, Suite 150, Santa Clara, CA 95054.
    • Context: Transfer from a joint venture entity (Hitachi-LG Data Storage) to one of its parent companies (Maxell, Ltd.), likely an internal reorg or consolidation of IP.

Timeline diagram

timeline
    title Ownership of US 11812091
    2005 : Priority date
    2022 : Application filed by Maxell Ltd
    2023 : Issued to Maxell Ltd
    2023 : Assigned to Maxell Ltd

NPE / troll-pattern signals

  1. Shell-entity transfer — Not present. The only recorded assignment is from Hitachi-LG Data Storage, Inc. to Maxell, Ltd., both of which appear to be operating companies. There is no evidence of a transfer to a licensing-only LLC.

  2. Known asserter in the chain — Not present. Neither Hitachi-LG Data Storage, Inc. nor Maxell, Ltd. appear on public NPE lists.

  3. Repeat correspondent across the chain — Not present. Only one assignment is recorded, so there is no recurrence.

  4. Cascading transfers — Not present. Only one assignment is recorded.

  5. Pre-litigation transfer — Unclear. While there is ongoing litigation related to this patent (IPR2025-01311 filed, US case filed in Texas Eastern District Court), the assignment predates the earliest litigation filing date available (IPR2025-01311, filed in 2025) and the US case in Texas Eastern District Court (case 5:25-cv-00052, filed in 2025). The assignment was recorded on 2023-11-06. The patent was granted on 2023-11-07. The timing of the assignment relative to the original filing date is not considered "pre-litigation" in the context of a transfer to an NPE shortly before a suit.

  6. Bankruptcy fire-sale — Not present. There is no indication of either assignor or assignee being in bankruptcy.

  7. Privateering — Not present. No evidence in the assignment records or publicly available information suggests a privateering arrangement.

  8. Defensive aggregator (anti-NPE) — Not present. The current assignee is Maxell, Ltd., not a known defensive aggregator.

Verdict

Operating-company assertion. The assignment record shows a transfer from Hitachi-LG Data Storage, Inc. to Maxell, Ltd., both of which are established operating companies. There are no clear signals of shell entities, known NPEs, or cascading transfers that would indicate a patent troll pattern. The existence of litigation suggests assertion, but by an operating company (Maxell Ltd.) against competitors, which is typical for operating company assertion.

USPTO Assignment Center search page: https://assignmentcenter.uspto.gov/ (Search for patent number 11812091).

Generated 5/23/2026, 6:46:06 PM