| 摘要 |
PURPOSE:To execute satisfactory density control by detection of high accuracy, by counting the frequency from a density detector at constant time intervals, and replenishing a toner only when the number of times which has gone out of the first reference value exceeds the second reference value. CONSTITUTION:A detecting part 18 is constituted by winding a coil 18b around a bobbin 18a which a developer passes through, and a density detector 20 is constituted by connecting the coil 18b to an oscillating circuit 19. A frequency signal (f) outputted from this detector 20 is inputted to a microcomputer (MIC ON) 21, and is counted as a pulse by an internal event counter. In the microcomputer 21, the number of times by which this event counter has become a prescribed value or below in a prescribed time is counted by the second counter. When this number of times of counting exceeds a set value and the lower limit density is detected, a toner replenishing signal is generated, a replenishing clutch is turned on, and a toner is replenished. |
