| 摘要 |
PROBLEM TO BE SOLVED: To definitely judge that a life nearly ends because of the deterioration of an original illuminating lamp. SOLUTION: After the surface of a photoreceptor is electrified by a primary electrifier 106 and is exposed by the original illuminating lamp 103, surface potential is detected by a potential sensor 108, and electrifying quantity and exposure are adjusted by a CPU 501 based on its result so as to make the surface potential at a specified value, and data is stored in a RAM 503. In the case that the adjustment value of the exposure then is larger than that previously stored in the RAM 504, it is judged that the original illuminating lamp 103 is deteriorated, so that a warning is given. |
