| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize an image forming apparatus equipped with only one laser scanner unit for a plurality of image carriers in which deterioration of image quality is eliminated with a small circuit scale even when the image forming apparatus is equipped with only one sensor (BD sensor) for detecting the image writing position in main scanning. <P>SOLUTION: The image forming apparatus comprises a rotary polygon mirror being driven to rotate by a laser scanner motor and reflecting modulated laser lights from a plurality of laser light sources on a plurality of reflective surfaces, a BD sensor for receiving reflected light from the rotary polygon mirror and outputting the reference signal of writing start position in the main scanning direction on an image carrier, and a means for generating a pseudo BD sensor signal upon elapsing a predetermined time after the reference signal is outputted from the BD sensor wherein the reference signal of writing start position in the main scanning direction on the image carrier of a laser light impinging and reflecting on a surface different from that of a laser light impinging on the BD sensor is generated from the pseudo BD sensor signal generating means. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
