| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of the level difference of density and lateral black bands in an output image, and achieve the shortest first image output time (FCOT).SOLUTION: An image forming apparatus includes a charging bias output unit 22 that outputs charging bias to a charging roller 15, a developing bias output unit 23 that outputs developing bias to a developing roller 32, a transfer bias output unit 24 that outputs transfer bias to a primary transfer roller 5, and a control unit 20 that controls a power source unit 21 of these units and these units. The control unit 20 controls the transfer bias output unit 24 to output the transfer bias from a time point, after the start of the output of the charging bias, at which a position where the charging roller 15 has started charging of the surface of a photoreceptor drum 2 reaches a position where the primary transfer roller 5 transfers an image; and controls the transfer bias to be an initial value smaller than a normal setting value from a time point of the start of the output of the transfer bias for a predetermined time period within a time corresponding to a time required for starting up a surface potential of the photoreceptor drum 2 with the output of the charging bias. |
