| 摘要 |
PROBLEM TO BE SOLVED: To decrease color slipping that occurs periodically due to eccentricity, etc. of a photoreceptor drum and to have an image of high quality output by adjusting each frequency of video clocks generated by a multiple number of generating means according to the amount of eccentricity of each photoreceptor drum and phases. SOLUTION: In this image forming device, the amount of deviation in the carrying direction is detected by a controller 1000 from a straight line pattern extended in the direction of laser scanning and the amount of deviation in the laser scanning direction is detected from the straight line pattern, extended in the carrying direction utilizing the position deviation detection patterns read from optical sensors 6a and 6b. Compensation for laser scanning width is carried out by providing a video clock generating device for image signal for each color, making the frequencies of the video clock variable for each color independently and adjusting the frequency. In this case, the minute adjustment of the frequency is carried out with the frequency of the video clock that is already adjusted at the video clock generating device according to each amount of eccentricity and phase of each photoreceptor drum 1a to 1d detected by the controller 1000 as a reference. |
