Invalidity dossier
US 5604843
Method and system for interfacing with a computer output device
Current assignee: Microsoft Technology Licensing LLC
Added 9/24/2026, 1:57:24 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 5,604,843
Title: Method and system for interfacing with a computer output device.
Assignee/Current Assignee (per source listing): Original assignee Microsoft Corp; current assignee Microsoft Technology Licensing LLC (recorded reassignment dated 2014-12-09). Inventors: Lin F. Shaw, Eric J. Bidstrup, and Zhanbing Wu.
Key dates: Filed 1992-12-23 (application US07/995,287); priority date listed as 1992-12-23; granted/published 1997-02-18; anticipated expiration 2014-02-18. Legal status listed as "Expired - Lifetime."
Purpose: The invention addresses the impracticality of having an operating system support every output device protocol. It relates to a computer method and system for implementing device drivers, using a graphics device interface (GDI) that insulates an application program from device characteristics and communicates with devices via drivers.
Plain-language scope (from the excerpt): A device driver comprises a minidriver associated with each output device plus a universal driver. Each minidriver implements device driver functions for controlling output to its device by invoking functions of the universal driver. An initialization function of each minidriver invokes the universal driver's initialization function, passing an indication and attributes of the selected output device; the universal driver processes and stores those attributes (preferably within a device context), and other minidriver functions forward invocations to analogous universal driver functions passing the device indication. The universal driver's functions then control interfacing using device characterization data, passed parameters, and device state. The excerpt lists typical driver function categories (initialization, information, output, attribute, mode, escape) and mentions figures covering configurations, device data layout, and flow diagrams. Classifications include G06F13/10 (device driver program control) and G06F3/12 (digital output to print units).
Source: https://patents.google.com/patent/US5604843/en
What the excerpt does not establish: The excerpt is expressly noted as partial ("consult the source for omitted text"), so it does not provide complete claims or claim language, the full written description, all referenced figures/tables, or the exact scope of any claim. It also does not establish prosecution details beyond the listed dates/status, and no conclusions about validity, enforceability, infringement, or prior art should be drawn from it. The listed assignees are described in the source as potentially inaccurate and are not a legal conclusion.
Generated 10/1/2026, 9:30:59 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
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Obviousness
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Extensions
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Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.