| 摘要 |
PURPOSE:To simplify the structure and to improve the reliability by detecting the rotary torque of a sun gear at the time of the developing device decreasing below a prescribed value and displaying a toner end state. CONSTITUTION:When the mean amount of a developer in a developer storage chamber becomes less than the prescribed quantity, the resistance to an agitator member when the developing device 4 is rotated decreases, so torque operating on a cam 4-9a united with the sun gear 4-9 also decreases and the moment by a spring 13-3 is larger, so a photosensor 20 is still shielded by a shutter 13-2C from light. Therefore, when the developing device is rotated and the photosensor does not operate, the toner end state is decided and displayed on a display part. Consequently, the developing device 4 and a copying machine main body are coupled mechanically with each other and the operability and reliability are improved. |
