EP0395344A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Planar light-source device and illumination apparatus using the same
Assignee: Mitsubishi Chemical Corp
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Filing: 1990-04-24
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Granted: —
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Expires: 2010-04-24
Abstract
Abstract A box-type planar light-source device has incorporated therein a linear light source and is provided with a reflecting surface and a multi-prism sheet. The reflecting surface has such function that a major portion of a light reflected by the reflecting surface is obliquely incident upon the multi-prism sheet. The multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction. Accordingly, so as to eliminate portion by the fact that the light outgoing at an angle separated from the normal direction converges at the dark portion. A dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on the side of the front face of the multi-prism sheet. An illumination apparatus can satisfactorily exhibit its optical performance by incorporation of the planar light-source device as illumination apparatuses of various display devices. The display devices include an internal-illumination type display device, a liquid-crystal display device, a display device mounted to an automatic vending machine, an observation device for a film, or an illumination apparatus mounted to a wall surface of a building.
Inventors
- 👤 Makoto C/O Tokyo Kenkyusho Mitsubishi Rayon Oe
- 👤 Issei C/Otokyo Kenkyusho Mitsubishi Rayon Chiba
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 04:13
CPC Classifications
G; G09; G09F; G09F13/00; G09F13/04; G09F13/0409; G09F13/14; G09F13/0418; G09F13/0422; G09F2013/05; G09F2013/145
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
143 words
A box-type planar light-source device having incorporated therein a linear light source or a light source arranged linearly and provided, at its rear face, with a reflecting surface and, at its front face, with a multi-prism sheet, characterized in that said reflecting surface has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, that said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and that a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on the side of the front face of said multi-prism sheet.
Claim 2
Dependent Claim
143 words
A box-type planar light-source device having incorporated therein a linear light source or a light source arranged linearly and provided, at its rear face, with a reflecting surface and, at its front face, with a multi-prism sheet, characterized in that said reflecting surface has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, that said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and that a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on the side of the front face of said multi-prism sheet.
Claim 3
Dependent Claim
207 words
A box-type planar light-source device having incorporated therein linear light sources or a plurality of light sources arranged linearly in parallel relation to each other and provided, at its rear face, with reflecting surfaces and, at its front face, with a multi-prism sheet, characterized in that each of said reflecting surfaces has such function that a major portion of a light reflected by the reflecting surface is obliquely incident upon said multi-prism sheet, that said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light sources and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, that the reflecting surfaces between said light sources are contiguous to each other with an inclination in accordance with a location between said light sources, that a top of a ridgeline between the reflecting surfaces is so constructed as to be located above a bottom of the light sources and below tops of the light sources, and that a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light sources is arranged on the side of the front face of said multi-prism sheet.
Claim 4
Dependent Claim
207 words
A box-type planar light-source device having incorporated therein linear light sources or a plurality of light sources arranged linearly in parallel relation to each other and provided, at its rear face, with reflecting surfaces and, at its front face, with a multi-prism sheet, characterized in that each of said reflecting surfaces has such function that a major portion of a light reflected by the reflecting surface is obliquely incident upon said multi-prism sheet, that said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light sources and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, that the reflecting surfaces between said light sources are contiguous to each other with an inclination in accordance with a location between said light sources, that a top of a ridgeline between the reflecting surfaces is so constructed as to be located above a bottom of the light sources and below tops of the light sources, and that a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light sources is arranged on the side of the front face of said multi-prism sheet.
Claim 5
Dependent Claim
213 words
A box-type planar light-source device for illuminating both sides, which has incorporated therein a linear light source or a light source arranged linearly and which is provided, at its opposite front and rear faces, with respective multi-prism sheets and, at its both side surfaces, with respective reflecting surfaces, characterized in that said reflecting surfaces have their generally wedge-like cross-section in which their forward sharp ends are oriented toward the light source, and said reflecting surfaces are so arranged as to extend in parallel relation to said light source, that each of said reflecting surfaces has such function that major portions of lights reflected respectively by a front-face side portion and a rear-face side portion of the reflecting surface are obliquely incident upon said multi-prism sheets on said front-face side and said rear-face side, that said multi-prism sheets have their inner surfaces formed respectively with groups of prisms so arranged as to extend in parallel relation to the light sources and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and that a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light sources is arranged on the side of the front face of each of said multi-prism sheets.
Claim 6
Dependent Claim
213 words
A box-type planar light-source device for illuminating both sides, which has incorporated therein a linear light source or a light source arranged linearly and which is provided, at its opposite front and rear faces, with respective multi-prism sheets and, at its both side surfaces, with respective reflecting surfaces, characterized in that said reflecting surfaces have their generally wedge-like cross-section in which their forward sharp ends are oriented toward the light source, and said reflecting surfaces are so arranged as to extend in parallel relation to said light source, that each of said reflecting surfaces has such function that major portions of lights reflected respectively by a front-face side portion and a rear-face side portion of the reflecting surface are obliquely incident upon said multi-prism sheets on said front-face side and said rear-face side, that said multi-prism sheets have their inner surfaces formed respectively with groups of prisms so arranged as to extend in parallel relation to the light sources and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and that a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light sources is arranged on the side of the front face of each of said multi-prism sheets.
Claim 7
Dependent Claim
23 words
The planar light-source device according to claim 1, characterized in that said reflecting surface consists of a planar surface or a combination thereof.
Claim 8
Dependent Claim
25 words
The planar light-source device according to claim 2, characterized in that each of said reflecting surfaces consists of a planar surface or a combination thereof.
Claim 9
Dependent Claim
29 words
The planar light-source device for illuminating both sides, according to claim 3, characterized in that each of said reflecting surfaces consists of a planar surface or a combination thereof.
Claim 10
Dependent Claim
23 words
The planar light-source device according to claim 1, characterized in that said reflecting surface has a curved surface concave toward the multi-prism sheet.
Claim 11
Dependent Claim
25 words
The planar light-source device according to claim 2, characterized in that each of said reflecting surfaces has a curved surface concave toward the multi-prism sheet.
Claim 12
Dependent Claim
29 words
The planar light-source device for illuminating both sides, according to claim 3, characterized in that each of said reflecting surfaces has a curved surface concave toward the multi-prism sheet.
Claim 13
Dependent Claim
28 words
The planar light-source device according to claim 1, characterized in that a transparent plate for prevention of deflection is interposed between the multi-prism sheet and the light source.
Claim 14
Dependent Claim
28 words
The planar light-source device according to claim 2, characterized in that a transparent plate for prevention of deflection is interposed between the multi-prism sheet and the light source.
Claim 15
Dependent Claim
37 words
12 The planar light-source device for illuminating both sides, according to claim 3, characterized in that a transparent plate for prevention of deflection is interposed between each of the multi-prism sheets and each of the light sources.
Claim 16
Dependent Claim
164 words
An illumination apparatus used for an internal-illumination type display device comprising a box-type housing provided with a display surface, a linear light source or a light source arranged linearly accommodated in said housing, a reflecting surface provided at a rear face of said light source, and a multi-prism sheet provided at an inner surface of said display surface, characterized in that said reflecting surface has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, wherein said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and wherein a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on the side of the front face of said multi-prism sheet.
Claim 17
Dependent Claim
164 words
An illumination apparatus used for an internal-illumination type display device comprising a box-type housing provided with a display surface, a linear light source or a light source arranged linearly accommodated in said housing, a reflecting surface provided at a rear face of said light source, and a multi-prism sheet provided at an inner surface of said display surface, characterized in that said reflecting surface has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, wherein said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and wherein a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on the side of the front face of said multi-prism sheet.
Claim 18
Dependent Claim
179 words
An illumination apparatus for use with a box-type planar light-source device having incorporated therein a linear light source or a light source arranged linearly and provided, at its rear face, with a reflecting surface and, at its front face, with a multi-prism sheet, and a liquid-crystal display device for conducting a display in illumination with a liquid-crystal element mounted on the multi-prism sheet serving as a back light, characterized in that said reflecting surface of said planar light-source device has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, wherein said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and wherein a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on the side of the front face of said multi-prism sheet.
Claim 19
Dependent Claim
179 words
An illumination apparatus for use with a box-type planar light-source device having incorporated therein a linear light source or a light source arranged linearly and provided, at its rear face, with a reflecting surface and, at its front face, with a multi-prism sheet, and a liquid-crystal display device for conducting a display in illumination with a liquid-crystal element mounted on the multi-prism sheet serving as a back light, characterized in that said reflecting surface of said planar light-source device has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, wherein said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and wherein a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on the side of the front face of said multi-prism sheet.
Claim 20
Dependent Claim
191 words
An illumination apparatus for an internal-illumination type display device which is arranged at a front face of an automatic vending machine, characterized in that said internal-illuminating type display device comprises a box-type housing provided with a display at an outer side of a display surface of said housing, a linear light source or a light source arranged linearly accommodated in said housing, a reflecting surface provided at a rear face of said light source, and a multi-prism sheet provided at an inner surface of said display surface, that said reflecting surface has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, wherein said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and wherein a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on the side of the front face of said multi-prism sheet.
Claim 21
Dependent Claim
191 words
An illumination apparatus for an internal-illumination type display device which is arranged at a front face of an automatic vending machine, characterized in that said internal-illuminating type display device comprises a box-type housing provided with a display at an outer side of a display surface of said housing, a linear light source or a light source arranged linearly accommodated in said housing, a reflecting surface provided at a rear face of said light source, and a multi-prism sheet provided at an inner surface of said display surface, that said reflecting surface has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, wherein said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and wherein a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on the side of the front face of said multi-prism sheet.
Claim 22
Dependent Claim
161 words
An illumination apparatus for use with an observation device such as a film or the like comprising a box-type housing, a linear light source or a light source arranged linearly accommodated in said housing, a reflecting surface provided at a rear face of said light source, and a multi-prism sheet provided at an inner surface of an observation surface of said housing, characterized in that said reflecting surface has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, wherein said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and wherein a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on said multi-prism sheet.
Claim 23
Dependent Claim
161 words
An illumination apparatus for use with an observation device such as a film or the like comprising a box-type housing, a linear light source or a light source arranged linearly accommodated in said housing, a reflecting surface provided at a rear face of said light source, and a multi-prism sheet provided at an inner surface of an observation surface of said housing, characterized in that said reflecting surface has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, wherein said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and wherein a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on said multi-prism sheet.
Claim 24
Dependent Claim
182 words
An illumination apparatus mounted to a wall surface of a building, characterized in that said illumination apparatus comprises an internal-illumination type illumination apparatus, that said illumination device comprises a box-type housing provided with an illumination surface for illumination outwardly, a linear light source or a light source arranged linearly accommodated in said housing, a reflecting surface provided at a rear face of said light source, and a multi-prism sheet provided at an inner surface of said illumination surface, that said reflecting surface has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, that said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and that a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on the side of the front face of said multi-prism sheet.
Claim 25
Dependent Claim
182 words
An illumination apparatus mounted to a wall surface of a building, characterized in that said illumination apparatus comprises an internal-illumination type illumination apparatus, that said illumination device comprises a box-type housing provided with an illumination surface for illumination outwardly, a linear light source or a light source arranged linearly accommodated in said housing, a reflecting surface provided at a rear face of said light source, and a multi-prism sheet provided at an inner surface of said illumination surface, that said reflecting surface has such function that a major portion of a light reflected by said reflecting surface is obliquely incident upon said multi-prism sheet, that said multi-prism sheet has its inner surface formed with a group of prisms so arranged as to extend in parallel relation to the light source and having such function that the light incident directly or obliquely in reflection outgoes in concentration toward a predetermined direction, and that a dark-portion removing sheet for eliminating a dark portion at a location immediately above the light source is arranged on the side of the front face of said multi-prism sheet.
Claim 26
Dependent Claim
71 words
An optical sheet forming an illumination surface of a plane light-source device or an illumination apparatus, characterized in that said optical sheet comprises a multi-prism layer made of a transparent material and having a group of prisms extending in an axis direction and arranged in parallel relation to each other, and a semi-transparent layer having diffuseness, and that said semi-transparent layer is bonded to a non-prism surface of said multi-prism layer.
Claim 27
Dependent Claim
71 words
An optical sheet forming an illumination surface of a plane light-source device or an illumination apparatus, characterized in that said optical sheet comprises a multi-prism layer made of a transparent material and having a group of prisms extending in an axis direction and arranged in parallel relation to each other, and a semi-transparent layer having diffuseness, and that said semi-transparent layer is bonded to a non-prism surface of said multi-prism layer.
References Cited (Backward Citations)
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