| 摘要 |
PURPOSE:To execute exactly an image density adjustment without decreasing a copying speed by executing a preliminary operation for detecting the density of an original in the course of a pre-stage required for an image formation. CONSTITUTION:When an original O is set to an original placing plate 11 and a copy button is turned on, as soon as the pre-rotation of a photosensitive body 1 is started, optical systems (16, 12 and 13) move from the initial position to a prescribed position A of a prearranged minimum original area, and stop. That is to say, this movement is ended in the course of the prerotation. When a prescribed time elapses (corresponding to the end of the pre-rotation) after the copy button is turned on, the optical system is moved in the direction as indicated with an arrow (a) to a position B from the position A by a timer signal, also, an original exposure lamp 16 is turned on by a reference turn-on voltage, an original exposing light is rotated in the direction as indicated with an arrow through movable mirrors 12, 13, an inmirror lens 14 and a fixed mirror 15, exposed to the surface of a photosensitive body which passes through under electrostatic latent image formation processes 2-6, and a latent image corresponding to an original image is formed. |
