Claims
- 1. A surface light source device comprising a light conducting member made of transparent material, a linear light source disposed adjacent to one of edge surfaces of said light conducting member, and a diffusion plate disposed on a light emitting surface side of said light conducting member, said light conducting member comprising a multiplicity of concave portions formed on an opposite side surface of said light emitting surface of said light conducting member and a light diffusing material applied on all over the opposite side surface of the light conducting member.
- 2. A surface light source device according to claim 1, wherein each of said concave portion are arranged to be conical or polygonal pyramid shape.
- 3. A surface light source device according to claim 1, wherein said concave portions have the same shapes and the same dimensions but the pitches are arranged to be larger on a light source side and become smaller farther from said light source.
- 4. A surface light source device according to claim 1, wherein dimensions of said concave portions are smaller on a light source side and become larger farther from said light source.
- 5. A surface light source device according to claim 2, wherein depths of said conical or polygonal pyramid-shaped concave portions are the same and top angles thereof are smaller on a light source side and become larger as farther from said light source.
- 6. A surface light source device according to claim 2, wherein depths and top angles of said conical or polygonal pyramid-shaped concave portions are smaller on a light source side and become larger as farther from said light source.
- 7. A surface light source device according to claim 2, wherein top portions of said conical or polygonal pyramid-shaped concave portions are directed toward said light source.
- 8. A surface light source device comprising a light conducting member made of transparent material, a linear light source disposed adjacent to one of edge surfaces of said light conducting member, a diffusion plate disposed on a light emitting surface side of said light conducting member, and a reflective member disposed on an opposite side surface of said light emitting surface of said light conducting member, said light conducting member comprising a multiplicity of concave portions formed on said opposite side surface of the light conducting member and a light diffusing material or a light scattering material is provided in said concave portions.
- 9. A surface light source device according to claim 8, wherein each of said concave portions are of conical or polygonal pyramid shape.
- 10. A surface light source device according to claim 8, wherein said concave portions have the same shapes and the same dimensions but are spaced farther apart on a light source side and closer to each other away from said light source.
- 11. A surface light source device according to claim 8, wherein dimensions of said concave portions are smaller on a light source side and larger away from said light source.
- 12. A surface light source device according to claim 9, wherein depths of said conical or polygonal pyramid shaped concave portions are the same and top angles thereof are smaller on a light source side and larger away from said light source.
- 13. A surface light source device according to claim 9, wherein depths and top angles of said conical or polygonal pyramid-shaped concave portions are smaller on a light source side and larger away from said light source.
- 14. A surface light source device according to claim 9, wherein top portions of said conical or polygonal pyramid-shaped concave portions are directed toward said light source.
Parent Case Info
This is a division of application Ser. No. 08/290,087, filed Aug. 12, 1994, now U.S. Pat. No. 5,575,549.
US Referenced Citations (6)
Foreign Referenced Citations (3)
Number |
Date |
Country |
3-31782 |
Mar 1991 |
JPX |
3-189679 |
Aug 1991 |
JPX |
94802-1993 |
Dec 1993 |
JPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
290087 |
Aug 1994 |
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