Invalidity dossier
US 5530235
Interactive contents revealing storage device
Current assignee: Contentguard Holdings Inc
Added 9/23/2026, 5:26:20 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: US5530235A
Title: Interactive contents revealing storage device
Patent number: US5530235A
Application number: US08/389,670
Filing date / Priority date: 1995-02-16
Publication (grant) date: 1996-06-25
Original assignee: Xerox Corp
Current assignee (per listing): Contentguard Holdings Inc
Legal status (per listing): Expired – Lifetime; anticipated expiration 2015-02-16
Inventor(s): Mark J. Stefik; Daniel G. Bobrow; Stuart K. Card; Michalene M. Casey; Richard J. Goldstein; Michael G. Lamming; Jock D. Mackinlay; Roy Want; George G. Robertson; Mark D. Weiser; Daniel M. Russell.
Classifications (selected): G06F21/10 (protecting distributed programs or content / DRM), G06F21/1086 (superdistribution), G06F21/77 (smart cards), G06K19/07703 (record carrier with visual human interface), G07F7/0846 (on-card display means), G07F7/0853 (on-card keyboard means), G06Q20/346 (cards serving only as information carrier of service). Prior-art keywords listed include "docucard," "user," "document," "repository," and "documents."
Purpose and plain-language scope: The supplied excerpt identifies the invention as an interactive contents revealing storage device. Its classification footprint indicates a portable card-type record carrier with integrated circuitry, a visual human interface, and on-card input/output means, directed to controlled distribution and protection of digital content, including superdistribution and content/license transfer. It is dated in the mid-1990s Xerox PARC context and is associated with later Japanese and European family members (e.g., JP3564221B2, EP0727727B1, EP1944713B1), and with a litigation flag in the family record.
What the excerpt does not establish: It contains no abstract, claims, written description, drawings, or prior-art citations. Therefore it does not establish the actual claimed scope, the specific components or methods, how "revealing" is implemented, or the technical problems solved. Dates shown are labeled assumptions in the source, and assignee/status listings are disclaimed as non-legal conclusions.
Source: https://patents.google.com/patent/[US5530235](/patent/US5530235)/en
Generated 10/1/2026, 9:43:36 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)
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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.