| 摘要 |
PROBLEM TO BE SOLVED: To obtain a stable-quality image by preventing the surface potential of a photoreceptor from lowering at the time of electrostatically charging again in the case of repeating electrostatic charging and discharging irrespective of whether it is a normal developing mode or a reversal developing mode, in the case of forming the image by using bipolar photoreceptor. SOLUTION: An electrostatic charger 32, a developing device 36, a transfer charger 37 and a main eraser 39 are arranged around a drum 31 having the bipolar photoreceptor which can be electrostatically charged to have a positive polarity or a negative polarity. The main eraser 39 irradiates the photoreceptor after transfer with light so as to erase charge. The wavelength of light and/or light quantity of the main eraser 39 is changed for the time of executing the normal developing mode and the time of executing the reversal developing mode. |
