| 摘要 |
PURPOSE:To detect stabilized toner density with accuracy by detecting variation in toner concentration by utilizing variation in the bulk concentration of a developer with the toner concentration. CONSTITUTION:A 50gr. developer is so stored as to coincide with a previously calculated toner concentration-flowability curve, and when an output drops abruptly owing to the exhaustion of a developer a specific time later, the time from the 1st abrupt variation in oscillation frequency from a coil 16 to the final abrupt variation is detected by a frequency detector 17. Flowability to toner concentration variation calculated by experiment is stored or programmed in a reference circuit 18. Both otputs are compared with each other by a comparing circuit 19 to operate the current toner concentration from flowability detected by the frequency detector 17 and the rotation of a toner supplementing roller 21 is controlled by a driving circuit 22 so that toner is supplemented until specific toner concentration is obtained. Thus, invariably proper toner concentration is maintained. |
