| US 7,586,661 B2 | ||
| Optical scanning device and image forming apparatus | ||
| Daisuke Ichii, Kanagawa (Japan) | ||
| Assigned to Ricoh Company, Ltd., Tokyo (Japan) | ||
| Filed on Jun. 29, 2007, as Appl. No. 11/771,275. | ||
| Claims priority of application No. 2006-182956 (JP), filed on Jul. 03, 2006; and application No. 2007-115133 (JP), filed on Apr. 25, 2007. | ||
| Prior Publication US 2008/0247021 A1, Oct. 09, 2008 | ||
| Int. Cl. G02B 26/08 (2006.01) | ||
| U.S. Cl. 359—205.1 | 18 Claims |
| 1. An optical scanning device, comprising:
a light source configured to emit light beams;
a deflector configured to deflect the light beams in a main scanning direction;
a coupling optical system configured to guide the light beams from the light source to the deflector; and
a scanning optical system configured to scan the light beams on a target surface to form an image, wherein
the coupling optical system includes at least one diffractive optical surface, and
when linearly approximated, a temperature dependence dλ/dT of a wavelength of the light source satisfies dλ/dT<0.15, wherein
an optical system including both the coupling optical system and the scanning optical system satisfies |βs|<|βm|, where βs
is a lateral magnification in a sub-scanning direction perpendicular to the main scanning direction and βm is a lateral magnification
in the main scanning, direction.
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