| 摘要 |
PURPOSE:To preclude a decrease in image density beforehand and a fault by displaying the abnormality of a device unless detection outputs before and after a two-component developer is supplied to a bobbin for toner concn detection are within a specific range, and stopping copying operation. CONSTITUTION:The abnormality of the device is displayed and the copying operation is stopped unless the detection outputs before and/or after the two- component developer 23 is supplied to the bobbin 21 which detects toner concn from the inductance of the two-component developer 23 by supplying the two- component developer 23. Consequently, the misrecognition of the toner concn due to the clogging of the bobbin constituting an F(flow) sensor is judged and if the F sensor becomes abnormality, the copying operation is stopped and that is displayed, so other subsystems are prevented from being faulty owing to a decrease in image density and toner scattering. |
