Optical scanning device, optical writing device, and image forming apparatus
AssigneeRicoh Company, Ltd.
InventorsKohji Sakai, Yoshinori Hayashi, Takeshi Ueda, Daisuke Ichii, Kenichiroh Saisho
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Abstract
An optical scanning device includes a first optical system for guiding light beams emitted from a plurality of light emitting units to an optical deflector, and a second optical system for focusing the light beams to optically scan a surface to be scanned. At least one of the first optical system and the second optical system includes a resin lens having a diffractive surface. The diffractive surface includes a diffractive portion and a refractive portion. A power of the diffractive portion and a power of the refractive portion cancel each other.
Claims9
An optical scanning device comprising:
- a first optical system that shapes at least one light flux emitted from a light source unit and guides the at least one light flux to an optical deflector;
- and
- a second optical system that guides the at least one light flux deflected by the optical deflector to a surface to be scanned to form an image on the surface, wherein
- the first optical system has a diffractive surface, and
- the diffractive surface including a plurality of linear grooves of increasing depth from a periphery to a center of the diffractive surface.
Dependencies are inferred from the claim text.