| 摘要 |
PURPOSE:To grasp a state of contamination before a fault of a recording function occurs, by detecting the contamination caused by scatter of a toner, and generating an alarm, etc. CONSTITUTION:When a detector 16 such as a phototransistor, etc. is contaminated by scatter of a toner, an output of the detector 16 according to irradiation of a lumi?nous flux by a filter 14 is lowered. This detection output is applied to a comparator to which a prescribed reference value is set, and when an alarm, etc. are generated by a comparison output in case the detection output has exceeded the reference value, a state of contamination prior to generation of a fault of the recording function can be grasped. Accordingly, when cleaning is executed at a suitable time, the generation of a faulty picture by contamination which is caused by scatter of a toner is prevented. |
