| 摘要 |
PURPOSE:To output an exact information as to a residual quantity of a toner and to cause no malfunction by constituting so that a picture forming operation is inhibited by giving a warning such as ''no toner exists'', etc., only in case when a developer detector detects ''no developer exists'' continuously for a prescribed time. CONSTITUTION:When a developer level drops, a developer detector 38 outpusts alternately a developer non-existence level and a developer existence level by synchronizing with an operation of a developing sleeve 35 and a stirring blade 34. In that case, the time is counted, and when the developer detector 38 outputs the developer non-existence continuously for a prescribed time, the first signal is outputted and a display of toner non-existence, etc. and others are executed, but when the display becomes toner existence before the prescribed time elapses, the count is cleared so that the first signal is not outputted. Also, in case when the toner non-existence is detected continuously for many hours, an image forming process is inhibited, therefore, the probability for causing a malfunction due to a variation of height of the developer becomes low. |
