Invalidity dossier
US 5207493
Edge light panel device
Current assignee: Meitaku Shisutemu KK
Added 9/23/2026, 3:28:02 PM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 5,207,493
Title: Edge light panel device
Patent number: US5207493A
Application number: US07/725,661
Inventors: Shinzo Murase; Hirokazu Matsui
Assignee: KABUSHIKI KAISHA MEITAKU SHISUTEMU (Meitaku Shisutemu KK)
Priority date: 1990-07-03 (claimed from JP2176546A); a further priority claim dated 1990-07-31 from JP20448090A is also listed
Filing date: 1991-07-03
Publication/grant date: 1993-05-04
Legal status (as listed): Expired – Fee Related; anticipated expiration 2011-07-03
Source: https://patents.google.com/patent/US5207493/en
Purpose: The invention relates to an edge light panel device usable as a surface light source for back lights of liquid crystal displays, illuminated displays, or signboards. Known edge light panels, which use screen-printed white ink dots on a transparent substrate for irregular reflection, tend to show reduced brightness in round regions near the edge adjacent to the primary light source, and printed dots can become visible, especially as the substrate is made thinner (1.5 mm or less). The stated object is to provide an edge light panel device that is very thin while ensuring very even brightness.
Plain-language scope: The device comprises a transparent substrate with irregular-reflection means, a front surface diffusion layer substantially covering the front, a rear surface reflection layer substantially covering the rear, a pair of peripheral edge reflection layers on opposite edges adjacent to the primary light source, and a pair of margin reflection layers along those same edges on the front surface. These layers help prevent light from escaping through the edges, improving brightness and evenness. Margin reflection layers may be separate or integral with related layers (forming a frame-like holder that also resists dirt from static electricity), and may be slightly spaced from the diffusion/reflection layers so the irregular reflection means does not become visible. Embodiments include a word processor application and several sectional-view variants.
What the excerpt does not establish: It does not include full claim language, the complete description, the full prior-art list, prosecution history, or the omitted portion of FIG. 10's description. It does not establish litigation, ownership changes beyond the recorded assignment, validity, or a legal conclusion on status.
Generated 10/1/2026, 9:51:34 PM
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Litigation summary
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Proceedings on file (0)
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PTAB challenges
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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.