| 摘要 |
PURPOSE:To prevent a faulty image caused by receiving direct electrostatic charging by means of a transferring means in the case of projecting the leading edge or the trailing edge of a paper from occurring in an image forming device adopting a reversal development system in which an electrifying polarity is different from a transferring polarity. CONSTITUTION:The current value of an electrifier is switched to a larger value (-400muA) than a normal value (-200muA) at a time t3 which is earlier than the time when a part corresponding to the leading edge part P1 of the transferring material on the photosensitive body arrives at an electrifying position by a specified time T (as to a transferring process, which is equal to the time for making an electric field directly act on the area of the photosensitive body projected from the leading edge or the trailing edge part of the transferring material); then is switched to the normal value when the part corresponding to the leading edge part P1 arrives to the electrifying position. The current value of the electrifier is switched to a large value at the time when the part corresponding to the trailing edge P2 of the transferring material on the photosensitive body arrives at the electrified position, then is switched to the normal value at the time t4 which is delayed by the specified time T from the time. |
