| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect the life of a photosensitive drum in a process cartridge concurrently using the AC voltage and DC voltage as electrifying means and using the contact electrification having multiple electrification conditions during image formation. SOLUTION: The application time tn based on the bias application condition (n) is detected (S1), the damage index D of a photoreceptor is calculated (S2) from the equation of D=k1×t1+k2×t2...kn with the detected time t1-tn and coefficients k1, k2... kn, the photoreceptor damage index D is integrated into the life integrated value, and the integrated value is compared with the life information determined in advance (S4). If the damage integrated value of the photoreceptor becomes the predetermined life integrated time of the photoreceptor or above, the life of the photoreceptor is warned or displayed to a user (S5). |
