| 摘要 |
PURPOSE:To measure exactly surface potential of a photosensitive drum by obtaining sequential standard signals from rotation of a photosensitive drum, and correcting sequential control timing. CONSTITUTION:A clock pulse generating disc 111 rotating in synchronism with a photosensitive drum 1 crosses a photointerruptor 113 during the rotation, the collector 115 of a transistor Q generates clock pulses, and delivers them through an interface 117 to a microcomputer 119. This microcomputer 119 counts the pulses, and turns on and off each action load at prescribed timings in accordance with the count value. During the second rotation of the drum 1 surface potentials on the drum 1 exposed through a gray scale GS having ten steps are measured with a potential sensor displayed on a display part. Surface potential on the drum 1 can be thus exactly measured. |
