| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain stable image quality by suppressing the generation of rear end chipping of a solid image even when toner density becomes high due to the deterioration of charging. <P>SOLUTION: An image forming device includes a developing device 110 having developing rolls 111a and b including a developing roll 111b rotating in a reversed direction of a photoreceptor 100; a speed control portion 152 for controlling the rotation speed of the photoreceptor 100 and the developing rolls 111a and b; a development potential control portion 153; a toner density sensor 112; and a toner replenishing control portion 151 for controlling toner density. A main control portion 150 is provided, which changes the development potential when switching an action of high-speed printing to an action of low-speed printing, and decrease the rotation speed of the developing rolls 111a and b to rotation speed lower than rotation speed after switching the speed of the low-speed printing, and then increases the rotation speed of the developing rolls 111a and b to the rotation speed after switching the speed, until the toner density reaches a predetermined output value. <P>COPYRIGHT: (C)2013,JPO&INPIT |
