| 摘要 |
PURPOSE:To protect the quality of copies by switching one color tone which ends to another developing color even in the middle of copying and continuing the copying so that a transfer sheet in the middle of being copied is not left in a machine when one color toner ends in case of color synthesis or both- surface copying. CONSTITUTION:The title device is constituted of a photosensitive drum 9, a 1st developing device 12a, a 2nd developing device 12b, a 3rd developing device 12c, photosensors 33-35 and a toner cartridge sensor 36, etc. When one color toner ends during copying in such a copying mode that the color synthesis or the both-surface copying is executed by combining plural colors, the copying is continued by switching to another developing color even in the middle of copying. When the transfer sheet in the machine is completed being ejected, the developing device containing one color toner which ends is moved to a toner displacing position or a toner replenishing position. Thus, the transfer sheet is not left in the machine even if the toner of one developing color ends in the middle of copying in such a copying mode that the color synthesis or the both-surface copying is executed by combining the plural colors, thereby protecting copying paper from the stain by toner and damage. |
