Invalidity dossier
US 7440660
Transducer for heat assisted magnetic recording
Current assignee: Seagate Technology LLC
Added 9/23/2026, 1:00:49 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 7,440,660 B1
Title: Transducer for heat assisted magnetic recording
Assignee: Seagate Technology LLC (original assignee; listed current assignee is also Seagate Technology LLC)
Inventor(s): Xuhui Jin; Chubing Peng; William Albert Challener; Edward Charles Gage; Michael Allen Seigler
Key dates (per supplied source): Priority/filing date 2007-10-16; granted and published 2008-10-21; anticipated expiration 2027-10-16. Legal status listed as Active.
Purpose: The patent addresses heat assisted magnetic recording. Per the supplied definitions, a planar solid immersion mirror (PSIM) lens is fabricated on a planar waveguide, and a metallic nano-structure — a "near-field optical transducer" — is placed near the PSIM focus. The PSIM directs light onto the near-field transducer to form a local surface plasmon (LSP), which is sensitive to the transducer's shape and its location in the waveguide. The near-field transducer may be buried in a dielectric of low thermal dissipation; light absorbed in it creates heat requiring a cooling mechanism.
Plain-language scope (from the supplied claims summary): The disclosure recites an apparatus with (1) a first waveguide that focuses an electromagnetic wave to a focal region, and (2) a second waveguide defining an opening whose end sits adjacent to the focal region. The second waveguide includes a first metallic layer with second and third layers on opposite sides, the first metallic layer having a larger propagation constant than the second and third layers. A further aspect recites a metallic structure defining an opening with a multilayer dielectric structure inside it, including specified wall arrangements. Another aspect is expressed in means-plus-function terms for focusing. Figures 1–21 depict transducer structures, write poles, waveguides, air bearing surfaces, a modeled storage medium, and simulated light-absorption graphs (FIGS. 13–18).
Source: https://patents.google.com/patent/US7440660/en
What the excerpt does not establish: It does not provide the full claim text, complete specification, detailed description, or reference numerals; nor does it establish exact claim count, claim dependency, drawings' content beyond captions, or figures 2–21 in full. No litigation, ownership-transfer, validity, or prior-art analysis is offered.
Generated 10/1/2026, 9:53:18 PM
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Litigation summary
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Proceedings on file (0)
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
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