| 摘要 |
PROBLEM TO BE SOLVED: To extend the life of a laser diode(LD) while shortening a fast copy- out time(FCOT) in an image forming apparatus performing pre-exposure. SOLUTION: Before pre-exposure is performed, the main motor for the rotational driving of a photosensitive drum is controlled so as to be rotated at a constant speed in the number C1 of rotations at a time of pre-exposure higher than the usual number C2 of rotations. In such a state that a scanner motor and the main motor are rotated at a high speed, a laser diode is driven to start pre-exposure to execute pre-exposure only for the time T allowing the photosensitive drum to make one revolution. That is, since the main motor is rotated at a constant speed in the number C1 of rotations at a time of pre- exposure higher than the usual number C2 of rotations, the time T allowing the photosensitive drum to make one revolution becomes shorter than the time (t) allowing the drum to make one revolution at a time of the usual forming processing of an image and the time required in pre-exposure can be shortened. Accompanied by this, the cumulated lighting time of the LD and the time up to the completion of the printing of a first page can be shortened. |
