| 摘要 |
PURPOSE:To make judgement accurate by judging that the quantity of a toner is not enough when the output state from a toner sensor which indicates that the quantity of the toner for developing of electrostatic latent images is smaller than the specified quantity continues for a time longer than the agitating period of the toner. CONSTITUTION:The preceding end part of a blade 3 supported by a hopper 1 of a developing device abuts on a developing sleeve 2. An agitating bar 5 supported freely turnably by a driving shaft 4 for the agitating bar is provided in the hopper 1, and when the bar 5 is turned, the toner 6 packed in the hopper is agitated. Whether the quantity of the toner attains the specified quantity or not is judged by a toner sensor 7. The sensor 7 is so constituted as to output a logical level ''1'' when the sensor detects that the toner is less than the specified quantity and to output a ''0'' when the toner attains the specified quantity. |
