| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical scanner and an image forming apparatus reducing the size of a means for controlling optical deflection, reducing cost, improving environmental stability, and reducing power consumption, while maintaining excellent image quality. SOLUTION: The optical scanner includes: a light source; a pre-light deflection means optical system which shapes a plurality of luminous fluxes emitted from the light source; an optical deflection means which deflects and scans the luminous flux; and a scanning optical system which forms the image of the luminous flux on a face to be scanned. The pre-light deflection means optical system includes: a first optical system which converts the luminous fluxes into parallel luminous fluxes or substantially parallel luminous fluxes; an aperture member independent in the deflecting and scanning direction and the direction perpendicular to the deflecting and scanning direction; a second optical system which has refractive power only in the deflecting and scanning direction; an optical control element which electrically deflects and controls the advancing direction of the plurality of luminous fluxes into the direction perpendicular to the deflecting and scanning direction; and a third optical system which has refractive power only in the direction perpendicular to the deflecting and scanning direction. The optical control element is disposed in the vicinity of a point at which the luminous fluxes emitted from the light source are condensed in the deflecting and scanning direction, and the width of the luminous flux in the deflecting and scanning direction at the disposed position is smaller than the aperture width of the aperture member in the deflecting and scanning direction. COPYRIGHT: (C)2011,JPO&INPIT
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