| 摘要 |
PURPOSE:To eliminate the excessive consumption of toner by making it possible to set a dark potential part in a part between latent images, which are provided correspondingly to images on an image carrier, distinctively from a bright potential part. CONSTITUTION:A member to which gray or black member is stuck to the lower face of the front end part of a platen 6, on which an original is placed, to form a bright potential part forming target 6a, and the potential of the bright potential part is set to the leading part of the image carrier, and its information is detected by a reflective sensor after a toner image is transferred to a form, and the detection result is inputted to a comparator to control the quantity of toner supply of a developing device 20. A shutter 30 intercepts an optical path for a very short time to form the dark potential part on the image carrier, and the shutter is shaken by a solenoid 35. |
