| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device in which downtime-less is realized and high reliability is secured by detecting the service life of a pre-exposure device and an electrifier at an early stage. SOLUTION: The image forming device is provided with a primary electrifier (an electrifying device) 4 having a grid to uniformly charge a photosensitive drum (an image carrier body) 1, an image exposing device 13 which forms an electrostatic latent image by exposing the drum 1, a surface potential meter 7 which measures the surface potential of the drum 1, a developing device 9 which makes the electrostatic latent image visible by developer, a pre-exposure device 2 which eliminates residual charges on the drum 1, and a CPU (a potential controlling means) 14 which controls the surface potential of the drum 1 at a constant value by controlling the grid potential by a constant total current supplied to the electrifier 4. Then, a means is provided to hold the value of the grid potential obtained every time the CPU 14 conducts a potential control. Then, the service life of a pre-exposure light source of the device 2 and the degree of staining of a wire grid 4-2 of the electrifier 4 are detected from the tendency of the changes in the values of the grid potential and a warning display is provided. |
