| 摘要 |
PURPOSE:To improve picture quality by controlling a bias voltage of the opposite polarity of the electrostatic charging polarity of toner which is impressed to the reverse surface of a recording material according to image density and preventing a decrease in the sticking force of toner to recording paper when image density is large. CONSTITUTION:More toner T sticks on recording paper P when a transfer image is thick than when thin. A recording paper image density adjusting lever 26 arranged on an image density adjusting operation part D is composed of a variable resistance and an analog voltage corresponding to the lever position is outputtes to a bias transformer 20 and a lamp dimming part 22 through a voltage converting circuit 25. The bias voltage impressed to a guide plate 10 is raised as the lever 26 is moved in a direction E to increase image density, thereby increasing the surface sticking force of toner T to the recording paper P. Thus, a decrease in the sticking force of the toner to the recording paper is prevented when the image density is thick, thereby improving the picture quality. |
