Optical scanning device and image forming apparatus using the same
AssigneeCanon Kabushiki Kaisha
InventorsHidekazu Shimomura, Ken Tanimura
Life of this patent
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Abstract
There is provided a diffraction grid which is easily produced without reducing a grid size. There is provided an optical scanning device having effects such as a chromatic aberration correction and a temperature compensation even when a short wavelength light source having a wavelength of 500 nm or less is used, and an image forming apparatus using the optical scanning device. In the optical scanning device having the diffraction grid, for which the short wavelength light source having a wavelength of 500 nm or less is used, a design order of the diffraction grid is set to a diffraction order equal to or larger than a second order to obtain a grid shape which is easily formed.
Claims15
An optical scanning device, comprising:
- light source means for emitting at least one light flux having a wavelength of 500 nm or less;
- deflecting means for deflecting the at least one light flux emitted from the light source means;
- a first optical system for guiding the light flux emitted from the light source means to the deflecting means;
- and
- a second optical system for imaging the light flux deflected by the deflecting means on a surface to be scanned, wherein:
- one of the first optical system and the second optical system includes a diffraction grating;
- and
- provided that the total number of gratings of the diffraction grating is represented by m, an effective range of the diffraction grating is represented by L (mm), a minimum grating pitch of the diffraction grating is represented by P (μm), and the wavelength of the light flux is represented by λ (μm), the following expressions are satisfied:
- m·L·λ<300000
- 30<P/λ
Dependencies are inferred from the claim text.