EP0544332A1
Expired / Lapsed
EP
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Surface light source device
Assignee: Enplas Corp
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Filing: 1992-11-27
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Granted: —
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Expires: 2012-11-27
Abstract
Abstract A surface light source device which comprises a light-conducting member consisting of a sheet of transparent material, a linear light source disposed adjacent to an edge surface of the light-conducting member, a diffusion plate disposed on a front surface of the light-conducting member and a reflective plate disposed on a rear side of the light-conducting member. The rear surface of the light-conducting member has depressions or projections. These depressions or projections have rough surfaces. By selecting the shape of the depressions or projections, and controlling the roughness of the rough surfaces, an enhanced uniform brightness distribution is provided.
Inventors
- 👤 Kazuaki Yokoyama
- 👤 Tsuyoshi Ishikawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 04:30
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/0001; G02B6/0011; G02B6/0033; G02B6/0035; G02B6/0038; G02B6/0036; G02B6/0058; G02B6/0061; G02B6/005; G02B6/0055; G02B6/0066; G02B6/0068; G02B6/007; G02B6/0071; Y; Y10; Y10S; Y10S385/00; Y10S385/901
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
86 words
A surface light source device comprising a light-conducting member consisting of a sheet of transparent material, a linear light source disposed adjacent to an edge surface of incidence of said light-conducting member, a diffusion plate disposed on a front surface of said light-conducting member therealong, and a reflective surface disposed on a surface of said light-conducting member therealong opposite said diffusion plate, said light-conducting member comprising a multiplicity of tiny depressions formed on said surface adjacent to said reflective surface and said depressions having rough surfaces.
Claim 2
Dependent Claim
16 words
The surface light source device of claim 1 wherein said tiny depressions are of conical shape.
Claim 3
Dependent Claim
16 words
The surface light source device of claim 1 wherein said tiny depressions are of pyramidal form.
Claim 4
Dependent Claim
46 words
The surface light source device of claim 1 wherein said tiny depressions are of hemispherical form and have an increased size as they lie farther from said edge surface of incidence, with depressions of the smallest size being disposed close to said edge surface of incidence.
Claim 5
Dependent Claim
46 words
The surface light source device of claim 1 wherein said tiny depressions are of cylindrical shape and have an increased size as they lie farther from said edge surface of incidence, with depressions of the smallest size being disposed close to said edge surface of incidence.
Claim 6
Dependent Claim
20 words
The surface light source device of claim 5 wherein the innermost surface of said tiny depressions has a spherical form.
Claim 7
Dependent Claim
79 words
A surface light source device comprising a light-conducting member consisting of a sheet of transparent material, a linear light source disposed adjacent to an edge surface of incidence of said light-conducting member, a diffusion plate disposed on a front surface of said light-conducting member therealong, and a reflective surface disposed on a surface of said light-conducting member therealong opposite said diffusion plate, said member comprising a multiplicity of tiny projections formed on said surface adjacent to said reflective surface.
Claim 8
Dependent Claim
15 words
The surface light source device of claim 7 wherein said projections have a hemispherical shape.
Claim 9
Dependent Claim
15 words
The surface light source device of claim 7 wherein said projections have a cylindrical shape.
Claim 10
Dependent Claim
15 words
The surface light source device of claim 9 wherein said projections have a curved tip.
Claim 11
Dependent Claim
42 words
The surface light source device of any of claims 8, 9 and 10 wherein said projections have an increased size as they lie farther from said edge surface of incidence with the smallest projections lying close to said edge surface of incidence.
Claim 12
Dependent Claim
45 words
The surface light source device of claim 1 wherein said depressions are identically shaped and sized and equally spaced and wherein said depressions have rough surfaces and the roughness of said rough surfaces become greater as they lie farther from said edge surface of incidence.
Claim 13
Dependent Claim
42 words
The surface light source device of claim 1 wherein said depressions are identically shaped and wherein said depressions become larger as they lie farther from said edge surface of incidence with the largest depressions lying close to said edge surface of incidence.
Claim 14
Dependent Claim
54 words
The surface light source device of claim 1 wherein said depressions have an identical depth, but said depressions have an increased diameter as they lie farther from said edge surface of incidence with the depressions of the smallest breadth lying close to said edge surface of incidence, and wherein said depressions have rough surfaces.
Claim 15
Dependent Claim
47 words
The surface light source device of claim 1 wherein said depressions have an identical diameter, but said depressions have an increased depth as they lie farther from said edge surface of incidence with the depressions of the smallest depth lying close to said edge surface of incidence.
Claim 16
Dependent Claim
45 words
The surface light source device of claim 7 wherein said projections are identically shaped and sized and equally spaced and wherein said projections have rough surfaces and the roughness of said rough surfaces become greater as they lie farther from said edge surface of incidence.
Claim 17
Dependent Claim
39 words
The surface light source device of claim 7 wherein said projections have an identical diameter, but have an decreased height along the length of said light-conducting member with the lowest projections lying close to said edge surface of incidence.
Claim 18
Dependent Claim
42 words
The surface light source device of claim 7 wherein said projections have an identical height, but have an increased diameter along the length of said light-conducting member with the projections of the smallest diameter lying close to said edge surface of incidence.
Claim 19
Dependent Claim
34 words
The surface light source device of any of claims 13, 14, 15, 17 and 18 wherein the roughness of said rough surfaces become greater as they lie farther from said edge surface of incidence.
Claim 20
Dependent Claim
100 words
A surface light source device comprising a linear light source, a light-conducting member having an edge surface of incidence disposed adjacent to said light source, a diffusion plate disposed on the front surface of said light-conducting member therealong, and a reflective surface disposed on a surface of said light-conducting member opposite to said diffusion plate, said device comprising a multiplicity of corrugations formed on said suface of said light-conducting member close to said reflective surface, said corrugations having either curved surfaces or a combination of curved and planar surfaces continuously formed in all directions, and said corrugations having rough surfaces.
Claim 21
Dependent Claim
38 words
The surface light source device of claim 20 wherein said curved surfaces have an increased height as they lie farther from said edge surface of incidence, with the lowest ones lying adjacent to said edge surface of incidence.
Claim 22
Dependent Claim
40 words
The surface light source device of claim 20 wherein said corrugations have an decreased wavelength as they lies farther from said edge surface of incidence and the ones with the largest wavelength lying close to said edge surface of incidence.
Claim 23
Dependent Claim
56 words
The surface light source device of claim 20 wherein said corrugations have an increased or decreased incline between a crest and a base of a waveform as they lie farther from said edge surface of incidence, in such a way that the incline is about 45° to 60° for the corrugations lying at the farthest position.
Claim 24
Dependent Claim
27 words
The surface light source device of claim 20 wherein the roughness of said rough surfaces become greater as they lie farther from said edge surface of incidence.
Claim 25
Dependent Claim
44 words
The surface light source device of claim 20 wherein said corrugations have variations by appropriately selecting and changing two or more factors comprising a height, wavelength, incline between a crest and base of a waveform as well as the roughness of said rough surfaces.
Claim 26
Dependent Claim
127 words
A surface light source device comprising a linear light source, a light-conducting member having an edge surface of incidence disposed adjacent to said light source, a light-reflective member placed on a surface of said light-conducting member opposite to said edge surface of incidence, a diffusion plate disposed on an emitting surface of said light-conducting member, and a reflective surface of said light-conducting member, said device comprising corrugations formed on said reflective surface of said light-conducting member, said corrugations having either curved surfaces or a combination of curved and planar surfaces continuously formed in all directions, said corrugations having rough surfaces and said corrugations having an increased height with the lowest ones lying close to said edge surface of incidence, and again becoming lower toward said light-reflective member.
Claim 27
Dependent Claim
130 words
A surface light source device comprising a linear light source, a light-conducting member having an edge surface of incidence disposed adjacent to said light source, a light-reflective member placed on a surface of said light-conducting member opposite to said edge surface of incidence, a diffusion plate disposed on an emitting surface of said light-conducting member, and a reflective surface of said light-conducting member, said device comprising corrugations formed on said reflective surface of said light-conducting member, said corrugations having either curved surfaces or a combination of curved and planar surfaces continuously formed in all directions, said corrugations having rough surfaces, and said corrugations having a decreased wavelength as the ones having the largest wavelength lie close to said edge surface of incidence, and again becoming larger toward said light-reflective member.
Claim 28
Dependent Claim
131 words
A surface light source device comprising a linear light source, a light-conducting member having an edge surface of incidence disposed adjacent to said light source, a light-reflective member placed on a surface of said light-conducting member opposite to said edge surface of incidence, a diffusion plate disposed on an emitting surface of said light-conducting member, and a reflective surface disposed on a surface of said light-conducting member opposite to said diffusion plate, said device comprising corrugations formed on said reflective surface of said light-conducting member, said corrugations having an increased or decreased incline between a crest and a base of a waveform, approaching 45° to 60° and after attaining 45° to 60°, increasing or decreasing toward said light-reflective member so as to deviate from an angle less than 45° to 60°.
Claim 29
Dependent Claim
116 words
A surface light source device comprising a linear light source, a light-conducting member having an edge surface of incidence disposed adjacent to said light source, a light-reflective member placed on a surface of said light-conducting member opposite to said edge surface of incidence, a diffusion plate disposed on an emitting surface of said light-conducting member, and a reflective surface disposed on a surface of said light-conducting member opposite to said diffusion plate, said device comprising corrugations formed on said reflective surface of said light-conducting member, said corrugations having rough surfaces, and the roughness of said rough surfaces becoming greater as they lie farther from said edge surface of incidence, again being smaller toward said light-reflective member.
Claim 30
Dependent Claim
109 words
A surface light source device comprising a linear light source, a light-conducting member having an edge of incidence disposed adjacent to said light source, a light-reflective member placed on a surface of said light-conducting member opposite to said edge of incidence, a diffusion plate disposed on an emitting surface of said light-conducting member, and a reflective surface of said light-conducting member, said device comprising corrugations formed on said reflective surface of said light-conducting member, said corrugations having variations by appropriately selecting and changing two or more factors comprising a height, wavelength, incline between a crest and base of a waveform as well as the roughness of a rough surfaces.
Claim 31
Dependent Claim
19 words
The surface light source device of claim 11 wherein said rough surfaces are produced by an electric-discharge machining process.
Claim 32
Dependent Claim
19 words
The surface light source device of claim 19 wherein said rough surfaces are produced by an electric-discharge machining process.
Claim 33
Dependent Claim
23 words
The surface light source device of any of claims 20 to 29 wherein said rough surfaces are produced by an electric-discharge machining process.
Claim 34
Dependent Claim
18 words
The surface light source device of any of claims 7 to 10 wherein said depressions have surface irregularities.
Claim 35
Dependent Claim
19 words
The surface light source device of claim 34 wherein said rough surfaces are produced by an electric-discharge machining process.
Claim 36
Dependent Claim
29 words
The surface light source device of claim 1 wherein said light-conducting member has a decreased thickness along its length with its thickest portion lying close to said lighting source.
Claim 37
Dependent Claim
41 words
The surface light source device of claim 1 wherein a pair of light sources are disposed adjacent to the opposed ends of said light-conducting member and wherein said light-conducting member has depressions formed on its surface close to said reflective surface.
Claim 38
Dependent Claim
40 words
The surface light source device of claim 1 wherein said light source is disposed close to each of four sides of said light-conducting member and wherein said light-conducting member has depressions formed on its surface close to said reflective surface.
Claim 39
Dependent Claim
32 words
The surface light source device of any of claims 37 and 38 wherein said light-conducting member has a decreased thickness toward its center and said depressions are disposed in a corresponding incline.
References Cited (Backward Citations)
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