Invalidity dossier
US 5384658
Added 9/23/2026, 6:40:00 PM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview: US5384658A
Title: Plastic optical member and light-quantity-controlling member each having a light-diffusing layer on its surface
Patent number: US5384658A (application US07/849,398)
Assignee: OHNO Research & Development Laboratories Company, Ltd. (a corp. of Japan); original assignee OHNO RES & DEV LABS CO Ltd.
Inventors: Genji Ohtake, Hisao Morohashi, Souichi Hasegawa
Key dates: Priority 1990-09-04 (JP2233978A); second priority 1990-10-30 (JP2292991A); filed 1991-09-03; granted/published 1995-01-24; anticipated expiration 2012-01-24; status listed as Expired – Fee Related.
Purpose (plain language): The invention concerns plastic optical members that diffuse light through a specific "micro-joints" layer formed on all or part of their surfaces. It covers two related items: (1) an optical member usable in planar light sources, projection screens, window materials, displays, office automation appliances, and precision optical instruments; and (2) a "light-quantity-controlling member" that carries a white pattern of these micro-joints, used to even out brightness in thin light boxes such as backlights for personal-computer liquid crystal displays, medical schaukastens, and electrically illuminated displays. The described approach avoids perceived drawbacks of chemical surface treatment (violent reaction, coloring, weak diffusion, resist difficulty), sandblasting (high energy, limited fineness), and white-pigment coatings (imbalanced spectral absorption, binder/pigment refractive-index limits, difficult application on curved surfaces).
Scope note: The supplied excerpt describes the problem context and background, including edge-light and lighting-curtain light boxes, but does not set out the claims. Classifications cover light guides, diffusing elements, and liquid-crystal backlights.
What the excerpt does not establish: It does not quote the claims, detailed description, working examples, specific materials, manufacturing steps, or cited prior-art documents (JP-A-57-128383, JP-A-2-126501, JP-B-59-8809 are mentioned only in background context). The text was excerpted; consult the source for omitted content.
Source: https://patents.google.com/patent/[US5384658](/patent/US5384658)/en
Generated 10/1/2026, 9:42:38 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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