Invalidity dossier
US 6402302
Liquid discharge head, manufacturing method thereof, and microelectromechanical device
Current assignee: Canon Inc
Added 9/23/2026, 9:48:18 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 6,402,302 B1
Title: Liquid discharge head, manufacturing method thereof, and microelectromechanical device
Patent number: US 6,402,302 B1
Application number: US 09/584,784
Inventors: Teruo Ozaki; Akihiro Yamanaka; Yoshiyuki Imanaka; Masahiko Kubota; Muga Mochizuki
Original assignee / current assignee (as listed): Canon Inc. / CANON KABUSHIKI KAISHA
Priority date (as listed): 1999-06-04
Filing date: 2000-06-01
Publication (grant) date: 2002-06-11
Legal status (as listed): Expired – Fee Related; anticipated expiration 2020-06-01
Purpose and plain-language scope (from the supplied text):
The patent concerns a liquid discharge head (an ink-jet "bubble jet" print head), a method of making it, and a microelectromechanical device. Per the supplied classifications, it sits in on-demand ink-jet head structures, specifically bubble-jet print heads, including pressure-chamber structure, a movable member in the chamber, and sensor-containing structures. It also covers fabrication of such heads — front-shooter type — using etching (dry and wet), photolithography, and thin-film formation such as CVD. The listed prior-art keywords — substrate, heat generating, liquid, flow path, heater — indicate the subject matter centers on a heater-bearing substrate defining a liquid flow path that generates bubbles to eject liquid. The listed technical classifications indicate microelectromechanical devices and substrates with heat-generating elements more generally.
Caveats — what this excerpt does not establish:
The supplied text contains no abstract, no claims, no written description, and no drawing text. Therefore the specific claimed scope, the exact structural relationships, materials, dimensions, process steps, and any stated advantages cannot be verified from this excerpt. The legal status, assignee listing, and priority/filing dates are expressly flagged in the source as assumptions, not legal conclusions. Inventorship, claim coverage, and enforceability are not addressed here. The classification entries and prior-art keywords are bibliographic metadata, not claim language, and should not be read as defining the invention.
Generated 10/1/2026, 9:34:00 PM
Cases on file (0)
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Litigation summary
Past and pending lawsuits — plaintiffs, defendants, jurisdictions, outcomes, and notable rulings.
Proceedings on file (0)
All PTAB activity →AIA trial proceedings (IPR / PGR / CBM) filed at the USPTO Patent Trial and Appeal Board against this patent. Sourced from the USPTO Open Data Portal and refreshed every six hours; each proceeding number deep-links to the PTAB E2E docket.
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.