| 摘要 |
PROBLEM TO BE SOLVED: To prevent electric noise (high voltage noise) from being produced by conducting a photoreceptor drum to ground through a conductive material, detecting the potential value of the conductive material through a potential detection means, inputting the potential value detected by a means for deciding whether grounding is good or not and deciding whether the grounding is good or not in accordance with the potential value. SOLUTION: An electrostatic latent image is formed based on applied voltage on the photoreceptor drum 102. The conductive material 103 conducts the drum 102 to the ground. An electrode plate 104 conducts the material 103 to the ground. Amonitoring electrode plate 105 outputs the potential value of the material 103 to a CPU 107. When the grounding of the plate 104 is good, the CPU 107 inputs the potential value 0 of the material 103. Meanwhile, when the faulty grounding of the plate 104 occurs, in other words, when the electric noise (high voltage noise) caused by faulty grounding may cause the error of a laser beam printer, the CPU 107 inputs the potential value connected to a pull-up resistance. |
