IMAGE CARRIER LIFE DETECTING METHOD, IMAGE FORMING DEVICE AND PROCESS CARTRIDGE

摘要

PROBLEM TO BE SOLVED: To accurately detect the life of a photoreceptor drum, in a process cartridge using AC and DC voltages jointly as an electrifying means and contact electrification having plural electrifying conditions in the process of forming an image and provided with a storage element. ;SOLUTION: A time (tn) for application with a bias applying condition (n) is detected (S1) and the damage index D of a photoreceptor is calculated from the equation of D=k1×t1+k2×t2...kn by using the detected times t1-tn and coefficients k1, k2...kn stored in the storage element 30 (S3). The damage index D of the photoreceptor is integrated to obtain a life integrated value S and the integrated value obtained by the integration is compared with previously set life information R (S5). When the photoreceptor damage integrated value S obtained by the integration is an integrated time as the life of a photoreceptor drum previously set or more, based on the result of the comparison, a user is warned of the life of the photoreceptor drum or it is displayed.;COPYRIGHT: (C)1998,JPO