| 摘要 |
PURPOSE:To prevent the trouble by clogging of a developer in a coil by comparing the detection output before pouring of the developer in the coil and the detection output after the pouring therein, then displaying abnormality and stopping the operation of a developing device when the difference therebetween is below a prescribed value. CONSTITUTION:The two-component type developer 3 is housed in a developing container 2 and a developing sleeve 5 consisting of a nonmagnetic material is disposed to face a belt-like photosensitive body 4 which is one constituting example of latent image carriers. The developer 3 is passed into the coil 11 and the concn. of the toner in the developer 3 is detected from a change in the inductance thereof to control the concn. of the toner. The detection output before the developer 3 is poured into the coil 11 and the detection output after the developer is poured into the coil are compared. The abnormality is displayed and the operation of the developing device 1 is stopped when the difference therebetween is below the prescribed value. The trouble occurring in the clogging of the developer 3 in the coil 11 is prevented in this way. |
