| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which is capable of more directly estimating a toner charge amount Q/M than conventional techniques in a less disturbance and difference state, suppressing variations of the toner charge amount Q/M within a developing device, and improving the reproducibility of an output image. <P>SOLUTION: A current detection circuit 141b detects a transfer current when a toner image is transferred to an intermediate transfer belt 81. A patch detection sensor 31 detects a toner density of a toner image transferred onto the intermediate transfer belt 81. A toner supply part 272 supplies toner to a developing device 2. A control part 100 forms a toner image Q for measurement on a photosensitive drum 1 at a time of non-image formation, and transfers it to the intermediate transfer belt 81 using a transfer voltage lower than a discharge start voltage. Then, the control part 100 controls, according to the detection results of the current detection circuit 141b and the patch detection sensor 31, the supply performance of the toner supply part 272 so that the transfer current amount per unit transferred toner is within a predetermined range. <P>COPYRIGHT: (C)2013,JPO&INPIT |
