| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device which can prevent error detection of a toner end previously by performing confirmation of detecting movement whether the detecting movement by a toner sensor is normal or not. SOLUTION: This device has a developing unit rotatably supporting four sets of developing machines and a toner hopper 23 around a rotational shaft and a drive motor for rotates and drives the developing unit. In this case, a detected part 28 for detecting the toner end is set in respective toner hoppers 23 so as to detect rotation of the developing unit at designated rotational angle by a toner end sensor and also a detected part 38 for confirming detection movement in which an optical path to which light emitted from an emit part 30 of the toner end sensor can reach a light receiving part unrelated to residual amount of toner in the toner hopper 23 is formed is set in at least one of the toner hopper 23. |
