| 摘要 |
PURPOSE:To change a color tone from the arbitrary position of an image without increasing the time required for forming an image, by constituting the titled device so that one developing means can be switched to the other developing means on the way of forming the image. CONSTITUTION:In a state that a black developing device is turned on, a scanner is started, and from the time point when a picture tip signal generated, a developing bias DC portion is applied by a value adding 70V to VL obtained by a potential control, and a bias AC is superposed. A scan clock is counted up while extending from the picture tip signal to a designated position, and thereafter, the timing by which the designated position is developed by the black developing device is measured, and thereafter, the black developing device, a color developing device, a bias AC, and a bias DC are set to OFF, ON, OFF, and +500V, respectively. Subsequently, the timing by which the designated position comes to a red developing device is counted up, and thereafter, measured by the timer, VL+50V is applied to the bias DC, and the bias AC is turned on. In such a way, a copy whose color tone is changed on the way of an image is obtained. |
