Invalidity dossier
US 6386674
Independent power supplies for color inkjet printers
Current assignee: Hewlett Packard Development Co LP
Added 9/17/2026, 5:17:05 AM
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 6,386,674 B1
Title: Independent power supplies for color inkjet printers
Patent number / application: US 6,386,674 B1; application US09/429,942, filed 1999-10-29.
Assignee / inventors: Original assignee Hewlett-Packard Co.; later recorded as Hewlett-Packard Development Company, L.P. Inventors: George H. Corrigan, III; John M. Wade; Pere Esterri; Clayton L. Holstun; Glenn T. Haddick; Jeffery S. Beck; Dennis J. Schloeman.
Key dates: Priority 1997-10-28 (claimed from US08/958,951); a further priority claim from US09/183,949 dated 1998-10-31; granted and published 2002-05-14; anticipated expiration 2017-10-28. Status listed as expired – fee related.
Purpose and plain-language scope: The supplied text establishes only the title, bibliographic data, and classification. The classification record places the disclosure in inkjet printing, specifically arrangements for supplying and controlling power to ink-ejection actuators: driver/control circuits, block driving (driving groups of actuators), power-line details of the control circuit, control according to how many actuators are used simultaneously, and detecting or varying the power supply level. In plain terms, and consistent with the title, the disclosed subject matter concerns independent power supplies for color inkjet printers, with circuitry organized to drive groups of ink-ejection elements and to manage supply levels based on actuator usage. Beyond the title, these classifications, and the bibliographic record, the excerpt does not set out the claims, written description, drawings, or embodiments, so the precise claimed scope cannot be stated from it.
What the excerpt does not establish: It does not reproduce the claims, abstract, detailed description, or figures; therefore the exact claimed invention, its limitations, and any specific circuit topology are not verifiable from the supplied text alone. It also does not establish prosecution history, the content or relevance of cited prior art, or the accuracy of the legal-status and assignee listings, which the source itself characterizes as assumptions rather than legal conclusions. No litigation, validity, or ownership-transfer analysis is offered or supported here.
Generated 10/1/2026, 10:03:15 PM
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Litigation summary
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Proceedings on file (0)
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No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.
PTAB challenges
AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.
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.
Prior art
Earlier patents, publications, and products that may anticipate or render the claims unpatentable.
Obviousness
Combinations of prior art that suggest the claimed invention would have been obvious under 35 U.S.C. § 103.
Extensions
Patent term adjustments, term extensions, continuations, divisionals, family members, and expiration dates.
Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.