| 摘要 |
PURPOSE:To improve the precision of density adjustment by providing an original density detector in front of the position of a corresponding part where an image is formed by an original exposure system in an original scanning direction, and allowing the original density detector to face an original at the home position of a scanning system. CONSTITUTION:When an original unit 6 is at the home position, the incidence part of an optical fiber 18 faces the original 2, whose surface is scanned as shown by an arrow. Namely, light containing density information on the original 2 on the basis of the detection light 15 of the optical fiber 18 is entered into the optical fiber 18 from the incidence part 18a, and guided to and converted by a photodetecting element 17 photoelectrically. Then, a developing voltage VB corresponding to an output VOUT is applied to a developing sleeve 12 from a VB power source 27 by a CPU26 right before the front end of a latent image formed on a photosensitive body 14 with latent image formation light 14 through the scanning reaches the development position of the developing sleeve 12. Thus, an original density detection area becomes larger and the precision of the density adjustment is improved. |
