| 摘要 |
PURPOSE:To stabilize image density temporarily or for a long period through simple constitution by performing slow-reaction control over the supplement amount of toner and fast-reaction control over a latent image potential on the basis of the measurement signal of the density of a monitor image. CONSTITUTION:If the density of the monitor image decreases with the mixing ratio in a developer and the charging potential of a photosensitive body 1, the detection output of a photoelectric detector 13 increases and the output signal generated by a toner supplementation driving circuit 52 by receiving the detection signal is passed through a control signal circuit 50 to enter a high-level signal state for toner supplementation. Further, the output signal of a high- voltage power source control circuit 51 passed through the control signal circuit 50 becomes a corrected signal for high voltage application. When the toner mixing ratio in the developer and the electrostatic charging potential of the photosensitive body are both proper, the toner supplementation is controlled to an intermediate level and the output voltage of the high voltage power source of a corona charger 2 is also controlled to the intermediate level. Thus, the image density is stabilized temporarily and for a long period. |
