| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device which seldom causes image defect, and has excellent highlight gradation characteristics. SOLUTION: An electric potential level of non imaging part is made to be lower potential than the electric potential of the non imaging part when a pulse width is 0, by regulating the bias level of the reference pattern so as to make electric potential in non-imaging area cross with threshold value of which the reference pattern shows the smallest analog signal 0 (curve B) imaging. Also, regulate the electric potential so that when the smallest analog signal is 0, disparity between the electric potential in non-imaging area and direct current voltage of developing bias keeps the value that doesn't develop. |
