| 摘要 |
PURPOSE:To prevent the generation of the irregularity of an electrostatic latent image by making the quantity of the ion accumulated on a dielectric drum constant, by controlling the time applying voltage to a control electrode corresponding to the output signal of an ion detector for detecting the quantity of the ion from an ion generator. CONSTITUTION:When an image data generator 10 drives a driver IC 9 according to predetermined image data, the driver IC 9 performs selective operation so that the potential of the second power supply 11 is applied only to a pattern electrode 7, to which the voltage corresponding to the image data must be applied, for a predetermined time. When the quantity of the ion generated from a corotron 1 is larger than a standard value, an ion detector 14 generates a signal shortening a voltage applying time to an applying time control apparatus 15 which in turn shortens the current supply time of the driver IC 9. Contrarily, when the quantity of the ion is less, the current supply time of the driver IC 9 is made long. Therefore, the quantity of the ion passing through a hole 6 becomes equal to that when the quantity of the ion generated from the crotron 1 is the standard value and the quantity of the ion accumulated on a dielectric drum 12 becomes constant. |
