Invalidity dossier
US 5649754
Illuminating apparatus and a method of manufacturing an edge light conductor for use therein
Current assignee: Photo Craft Co Ltd
Added 9/23/2026, 10:15:54 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 5,649,754 A
Title: "Illuminating apparatus and a method of manufacturing an edge light conductor for use therein"
Patent number: US5649754A. Application number: US08/372,102. Inventor: Iwao Matsumoto. Assignee (original and current, per the listing): Photo Craft Co Ltd.
Key dates: Priority date 1992-10-02 (priority claimed from JP4265038A / JP26503992A). Filing date 1995-01-13. Publication/grant date 1997-07-22. Anticipated expiration 2014-07-22; legal status listed as "Expired - Lifetime" (the source notes legal status is an assumption, not a legal conclusion).
Purpose: To eliminate stated disadvantages of prior edge-light illuminating apparatus. In the described conventional construction, irregular reflector regions were distributed with larger areas at positions remote from the plate's end surfaces than close to them. The text states this yields less total irregular reflection in the regions where no irregular reflector regions are formed, making the apparatus dark with reduced illuminating intensity, failing to use light effectively, and producing visible pattern contrast between irregular reflector regions and transparent regions on the illuminating plane.
Plain-language scope: The apparatus comprises an edge light conductor with a plate of transparent or semitransparent optical medium, light sources opposed to end surfaces of the plate introducing light inwardly, and at least one of front and back surfaces defining a diffusing plane. Besides irregular reflector regions distributed over that plane, the diffusing plane further includes modified irregular reflector regions formed in at least some parts from which the irregular reflector regions are absent; the modified regions provide a lesser quantity of irregular reflection than the irregular reflector regions. The quantity of irregular reflection per unit area may be adjusted by varying the ratio between the two region types occupying unit areas. Because the modified regions also reflect light, illuminating intensity may be increased while remaining adjustable, with smaller intensity contrast than between irregular reflector regions and transparent regions. The invention also relates to a method of manufacturing the edge light conductor.
Source: https://patents.google.com/patent/US5649754/en
Not established by the excerpt: the full claims, the complete manufacturing method, drawing details (e.g., FIGS. 12–13), the full description and any examples or embodiments, and the identity of any cited prior-art references.
Generated 10/1/2026, 9:33:36 PM
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Litigation summary
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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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