| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical scanner that can be reduced in size and cost and improves detection accuracy for synchronous light.SOLUTION: The optical scanner comprises: a semiconductor laser light source 10A including a light emitting part LS and a light detecting part PD arranged close to the light emitting part; a light deflector that reflects a laser luminous flux from the light emitting part to deflect to scan; a condensing optical system that guides the diverging laser luminous flux from the light emitting part to a deflective reflection surface of the light deflector; and a scanning optical system that guides the deflected laser luminous flux deflected by the light deflector onto a scanning target surface to form a light spot. The optical scanner detects the laser luminous flux reflected by the deflective reflection surface through the light detecting part to obtain a synchronizing signal for optical scanning. In the optical scanner, an optical arrangement from the semiconductor laser light source 10A to the light deflector is set in such a manner that a laser luminous flux L2 reflected by the light deflector and guided toward the light source device via the condensing optical system forms an image in a sub-scanning direction near a light-receiving part of the light detecting part PD, and then the luminous flux as diverging or converging in the sub-scanning direction propagates to enter the light detecting part. |
