| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical scanner able to set quantities of beam light emitted from a light source such that the quantities have appropriate values when detecting a writing position on a target scan surface in a main scanning direction and when starting the scanning of the target scan surface in the main scanning direction.SOLUTION: An optical scanner comprises: an SOS sensor configured to receive at a predetermine position beam light deflected by a polygon mirror 14 and to output an SOS signal used as a reference signal when the writing timing in the main scanning direction of the target scan surface of a photoreceptor drum 60 is set; and a control circuit 51 configured to control a driving section 70 provided to drive a light source such that a quantity of beam light is equal to a first quantity of light when an SOS sensor 18 is caused to receive beam light and output an SOS sensor and to control the driving section 70 such that until a predetermined time passes after the SOS signal is input from the SOS sensor 18, a quantity of beam light when scanning in the main scanning direction of the scanned surface is started is equal to a second quantity of light, which differs in value according to each position in the sub-scanning direction of the scanned surface. |
