To accurately grasp the service-life of a photoreceptor drum.
This image forming device is provided with a photoreceptor drum 17 in the process cartridge 18, and an electrifying roller 19 and a cleaning blade 22a are arranged in contact with the drum 17. As the number of printed sheets is increased, the surface of the drum 17 is shaved. The shaving amount of the drum 17 when only DC voltage is applied to the drum 17 is different from that when DC voltage+AC voltage is applied thereto, and it is increased when AC voltage is applied. Then, the service life of the drum 17 is grasped based on the rotation integrating time of the drum 17 corresponding to the application of the DC voltage, and AC voltage application integrating time when the AC voltage is applied. Thus, the service life of the drum 17 is accurately grasped so as to prevent a fogged image before the occurrence of void.
SAKAI HIROAKI
ONO KAZURO
YUNAMOCHI TAKAYASU
OBARA YASUNARI
OKUBO MASAHARU
MATSUKUMA MINORU
HASHIMOTO NORIO
