| 摘要 |
PURPOSE:To accurately detect the change with the lapse of time of an image carrier by forming a constant shaped exposing pattern outside the image forming region of the image carrier by means of an auxiliary light emitting element. CONSTITUTION:The image carrier 14 disposed to face oppositely an electrifying part 19 is rotatively provided, and a large number of light emitting elements 30 facing the inside of the image forming region of the outer periphery of the image carrier 14 and the auxiliary light emitting element 31 facing the outside of the image forming region are provided on an exposing part 24 arraied in a main scanning direction. A potential detecting part 25 facing the part out of the image forming region of the image carrier 14 is attached to a holding part 23 where the exposing part 24 is attached. The constant shaped exposing pattern is formed outside the image forming region of the image carrier 14 by the auxiliary light emitting element 31. Therefore, the potentials of the exposing pattern out of the image region and a non-exposing part can be accu rately detected by the potential detecting part 25. Thus, the change with the lapse of the time of the image carrier can be accurately detected. |
