Patent 7587430

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. 2006-04-18 · Assignment of Assignor's Interest

    FUJIWARA, SHINJI; MIZUNO, KAZUHIKO; WATANABE, SATORU; KAWAMURA, NOBUO; SUZUKI, YOSHIOHITACHI, LTD.

    initial assignment

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

  • Yoshio Suzuki (Hitachi Ltd.)
  • Nobuo Kawamura (Hitachi Ltd.)
  • Satoru Watanabe (Hitachi Ltd.)
  • Shinji Fujiwara (Hitachi Ltd.)
  • Kazuhiko Mizuno (Hitachi Ltd.)

All named inventors were employed by Hitachi Ltd. at the time of filing. In the US, the ownership of an invention initially vests in the named inventors, but it is standard for employees to assign their rights to their employer as a condition of employment, especially when the invention is made within the scope of their employment duties and using company resources.

Original assignee

The original assignee named on the issued patent is Hitachi Ltd. Hitachi Ltd. is a Japanese multinational conglomerate founded in 1910, headquartered in Chiyoda, Tokyo. The company is highly diversified, operating in various industries including digital systems, power and renewable energy, railway systems, healthcare products, and financial systems. They ship a wide range of products embodying various technologies, including those related to information technology and data storage. As of May 29, 2026, Hitachi Ltd. is an active, publicly traded company on the Tokyo Stock Exchange (TYO: 6501).

Assignment timeline

  • 2006-04-18 (executed) / recorded 2006-04-18 — Reel 017770/0471
    • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
    • Assignor: FUJIWARA, SHINJI; MIZUNO, KAZUHIKO; WATANABE, SATORU; KAWAMURA, NOBUO; SUZUKI, YOSHIO
    • Assignee: HITACHI, LTD.
    • Correspondent: BROWDY AND NEIMARK, PLLC, 1625 K STREET, N.W. SUITE 1000, WASHINGTON, DC 20006
    • Context: Original assignment from inventors to the corporate entity.

Timeline diagram

timeline
    title Ownership of US 7587430
    2006 : Filed by Hitachi Ltd
         : Assigned from inventors to Hitachi Ltd
    2009 : Issued

NPE / troll-pattern signals

  1. Shell-entity transfer — not present. The only recorded assignee is Hitachi, Ltd., a large operating company.
  2. Known asserter in the chain — not present. Hitachi, Ltd. is not listed as a known NPE or patent asserter on RPX or Unified Patents.
  3. Repeat correspondent across the chain — unclear. The correspondent for the initial assignment is BROWDY AND NEIMARK, PLLC. Without further assignment records for this patent or other patents being tracked, it's not possible to determine if this correspondent recurs.
  4. Cascading transfers — not present. There is only one assignment recorded.
  5. Pre-litigation transfer — not present. There are no recorded litigation events for this patent.
  6. Bankruptcy fire-sale — not present. Hitachi, Ltd. is an active, operating company.
  7. Privateering — not present. There is no evidence of Hitachi, Ltd. transferring the patent to an NPE for assertion on its behalf.
  8. Defensive aggregator (anti-NPE) — not present. The patent remains assigned to Hitachi, Ltd.

Verdict

Insufficient data. The only recorded assignment is the initial one from the inventors to Hitachi, Ltd. (Reel 017770/0471, recorded 2006-04-18). Hitachi, Ltd. is a large, diversified operating company and there are no other recorded transfers or litigation events to suggest NPE activity.

USPTO Assignment Center search page: https://assignmentcenter.uspto.gov/

Generated 5/29/2026, 8:48:12 PM