| US 7,548,352 B2 | ||
| Illumination device, document reading device, adjusting device, and image forming apparatus | ||
| Yasuo Sakurai, Kanagawa (Japan); and Masashi Kohchi, Tokyo (Japan) | ||
| Assigned to Ricoh Company, Limited, Tokyo (Japan) | ||
| Filed on Apr. 09, 2004, as Appl. No. 10/820,734. | ||
| Claims priority of application No. 2003-107979 (JP), filed on Apr. 11, 2003; and application No. 2003-140927 (JP), filed on May 19, 2003. | ||
| Prior Publication US 2005/0135840 A1, Jun. 23, 2005 | ||
| Int. Cl. G03G 15/04 (2006.01) | ||
| U.S. Cl. 358—475 [358/484; 358/509; 250/552; 355/67; 399/220] | 20 Claims |
| 1. An illumination device, which is used in a document-reading device configured to irradiate light over at least a predetermined
illumination width including a reading area having a predetermined reading width extending in a main scanning direction of
a document and to read the light reflected from the document using an image-reading element, the illumination device comprising:
a point light source;
a light-guiding member having an incident surface opposed to a light-emitting surface of the point light source and a light-emitting
surface opposed to the reading area;
a carriage configured to shift an illumination area in a sub-scanning direction; and
a support base configured to support and hold the point light source and the light-guiding member together as a unit, and
to be attached to the carriage adjustably in the sub-scanning direction,
wherein an illumination area generated by the light irradiated from the point light source has a high illuminance distribution
range of a substantially constant illuminance, and the high illuminance distribution range coincides substantially with the
reading area.
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