| US 7,537,367 B2 | ||
| Illumination device, image reading device, and image forming apparatus | ||
| Yasuo Sakurai, Tokyo (Japan) | ||
| Assigned to Ricoh Company, Ltd., Tokyo (Japan) | ||
| Filed on Feb. 02, 2006, as Appl. No. 11/345,485. | ||
| Claims priority of application No. 2005-057541 (JP), filed on Mar. 02, 2005. | ||
| Prior Publication US 2006/0197822 A1, Sep. 07, 2006 | ||
| Int. Cl. G02B 6/00 (2006.01); H01L 33/00 (2006.01); H01J 3/14 (2006.01) | ||
| U.S. Cl. 362—551 [362/555; 362/800; 250/216; 250/234] | 16 Claims |
| 1. An illumination device for illuminating a document, comprising:
a plurality of light emitting diodes arranged at a predetermined interval in a predetermined direction; and
a light guide that guides light beams emitted from the plurality of light emitting diodes, from a first end surface thereof
to a second end surface thereof, emitting surfaces of the plurality of light emitting diodes facing the first end surface
of the light guide,
wherein an illumination distribution at the second end surface of the light guide is uniform in the predetermined direction,
and
wherein the light beams emitted from the plurality of light emitting diodes are totally reflected on every surface of the
light guide except for the first and second end surfaces thereof.
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