| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of reliably reducing the occurrence of phase shifts in a short period of time and with a simple configuration even if a printing mode is switched between a color mode and a monochrome mode. <P>SOLUTION: A rotation stop position 16a2 of a black photosensitive drum 2K is detected in a color mode and time Ti since an immediately preceding rotational reference position 16a1 is measured by a timer in accordance with a detection signal at a rotational reference position 16a1, and then it is stored. When the black photosensitive drum 2K is stopped in the monochrome mode using the stored time Ti, the phase of the black photosensitive drum 2K is matched with the phases of color photosensitive drums 2Y, 2C and 2M whose rotations are stopped in the color mode, thereby preventing positional shifts between color toner images and a black toner image. <P>COPYRIGHT: (C)2009,JPO&INPIT |
