| 摘要 |
PROBLEM TO BE SOLVED: To stabilize the surface potential of a body to be electrified with great certainty. SOLUTION: This electrifying device 5 is provided with an electrifying roller electrifying a photoreceptor drum 3 by discharge, a power source 23 applying electrifying voltage on the electrifying roller, a speed detecting part 29 detecting the speed of the surface of the drum 3, and a CPU 25 controlling the applied voltage to the electrifying roller in accordance with the detection signal of the part 29. The inclination of the surface potential of the drum 3 with respect to the applied voltage in accordance with the speed is previously inputted to the CPU 25, the CPU 25 applies fixed voltage on the electrifying roller, measures a current made to flow by applying the specified voltage, calculates discharge start voltage by using the current and the fixed voltage, and applies voltage calculated from the discharge start voltage and the inclination of the surface potential in accordance with the detection signal of the part 29 to the electrifying roller from the power source 23. |
