Invalidity dossier
US 5504511
Ink container
Current assignee: Canon Inc
Added 9/23/2026, 9:52:38 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 5,504,511 ("Ink container")
Bibliographic data (as supplied): Title, "Ink container." Inventors: Kazuhiro Nakajima and Keiichiro Tsukuda. Original and current assignee: Canon Inc. / Canon Kabushiki Kaisha. Priority date: 1992-05-22. Filing date: 1993-05-20. Publication (grant) date: 1996-04-02. Application number: US 08/063,682. Legal status: Expired – Lifetime; anticipated expiration 2013-05-20.
Purpose: The invention addresses problems in prior art ink containers for ink jet recording. In one prior approach the container is separate from the recording head and the ink level is kept below the discharge ports; others use a porous material, a dome-shaped flexible cover, or a sliding movable wall whose sliding friction generates negative pressure. The patent states these approaches yield dynamic negative pressure that fails when the head meniscus breaks, and that varying printer posture causes different water heads and thus an inconsistent ink discharge condition. The stated object is an ink container suitable for a small-sized ink jet printer that maintains constant negative pressure irrespective of posture, avoids ink leakage, and provides good printing.
Plain-language scope (per the supplied characterization): The container has a housing; a shiftable member inside that holds ink and moves as ink is consumed; an ink outlet supplying ink to the recording head; and an ink guide outlet extending to the side opposite the ink outlet, with an ink suction outlet at that end. In the described embodiments, a bag (movable partition, fixed at the suction-outlet side with a free end) isolates ink from atmospheric pressure; an air conduit hole keeps internal pressure near atmospheric; and an ink guide tube runs from the ink outlet to a suction outlet near the rear end face, so ink is drawn from the point farthest from the recording-head junction.
Source: https://patents.google.com/patent/US5504511/en
Not established by this excerpt: the full claim text and claim count; the complete description and all drawing details; the omitted remainder of the first embodiment; whether the granted claims are limited to the bag/tube arrangement or cover alternatives; and any examination history, validity, or ownership changes.
Generated 10/1/2026, 9:33:59 PM
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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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