| US 7,602,554 B2 | ||
| Optical scanning apparatus | ||
| Shin Mogi, Kashiwa (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Dec. 17, 2007, as Appl. No. 11/957,778. | ||
| Claims priority of application No. 2006-355158 (JP), filed on Dec. 28, 2006; and application No. 2007-291332 (JP), filed on Nov. 08, 2007. | ||
| Prior Publication US 2008/0158633 A1, Jul. 03, 2008 | ||
| Int. Cl. G02B 27/30 (2006.01); G02B 3/00 (2006.01) | ||
| U.S. Cl. 359—641 [359/642] | 12 Claims |
| 1. An optical scanning apparatus comprising:
a collimating lens which parallelizes a light beam from a light source, wherein said collimating lens is formed by an electro-optics
crystal, and is configured to change a focal length by applying an electrical signal to the electro-optics crystal through
electrodes placed inside said collimating lens and on side surfaces thereof;
a detection unit which detects a focusing characteristic of a light beam on a surface to be scanned; and
a control unit which controls a voltage of an electrical signal applied to the electrodes on the basis of a detection signal
obtained by said detection unit.
|