| 摘要 |
PURPOSE:To prevent the degradation of image precision due to eccentricity of a photosensitive drum by detecting the peripheral speed of the cylindrical photosensitive drum where an electrostatic latent image is developed and is transferred onto a recording paper and comparing this detected speed with a reference speed to control the speed of a driving motor. CONSTITUTION:Bar codes 13 are provided at equal intervals in the end part of the peripheral surface of a cylindrical photosensitive drum 1 where the electrostatic latent image is developed and is transferred to the recording paper omitted in the figure, and one bar code 20 out of them is defined as a reference point. When the drum is rotated, the bar code is read by a photocoupler 14 to detect the reference point 20 by a means 17, and the detection output is inputted to a microcomputer 18, and meanwhile, a generated frequency is converted to a voltage by an F/V converter 15 and is subjected to A/D conversion and is inputted to the microcomputer 18. This input is compared with a reference value by a ROM, and a CPU in the microcomputer 18; and if deviation is detected, the microcomputer 18 issues an output to control the speed of a motor 11 through a motor driving circuit 19 so that the deviation from the reference value is zero. Thus, the variance of the peripheral speed due to eccentricity of the drum is corrected to hold the precision of images. |
