Invalidity dossier
US 5386347
Illuminating apparatus and a method of manufacturing an edge light conductor for use therein
Current assignee: Photo Craft Co Ltd
Added 9/23/2026, 7:37:59 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
US5386347 — Patent Overview
Title: Illuminating apparatus and a method of manufacturing an edge light conductor for use therein
Patent number: US5386347A
Inventor: Iwao Matsumoto
Original/current assignee (per listing): Photo Craft Co Ltd
Key dates (as listed):
- Priority date: 1992-10-02 (priority claimed from JP4265038A / JP26503992A)
- Filing date: 1994-07-07 (application US08/271,582)
- Publication/grant date: 1995-01-31
- Anticipated expiration: 2012-11-09; legal status: Expired – Lifetime
Purpose: The invention relates to an illuminating apparatus and to a method of manufacturing an edge light conductor for use therein. The apparatus comprises an edge light conductor including a plate of transparent or semitransparent optical medium, with light sources opposed to end surfaces of the plate for introducing light inwardly through the end surfaces. At least one of the front and back surfaces of the plate defines a diffusing plane including irregular reflector regions distributed over that plane.
Plain-language scope: Light enters the plate through an end face. When beams strike the irregular reflector regions on the diffusing plane, they are irregularly reflected and exit the plate to illuminate an object. Beams that do not hit the irregular reflector regions continue along the plate (as the excerpt's partial sentence about beams b3 and b4 indicates and then cuts off). The disclosure thus covers a plate-type light guide with a patterned, irregular reflecting surface, plus a method of making that light conductor.
Classification highlights (as listed): G02B6/0011, G02B6/0035, G02B6/0036, G02B6/0058, G02B6/0061, G02B6/0065; G09F13/18 and G09F2013/1813 (coating showing a pattern of dots of variable density).
What the excerpt does not establish: It does not establish the full claim language, the complete manufacturing steps (only isolated terms such as screen printing, sandblasting, etching and blasting appear), the exact geometry or arrangement of the irregular reflector regions, the complete description, or the content of any drawing. It also does not establish the accuracy of the legal status, assignee, priority or expiration data, or any prior-art relationship.
Generated 10/1/2026, 9:41:54 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
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.