| 摘要 |
PURPOSE:To make the moving extent and the moving time of a lens minimum in the case that new magnification is inputted when the lens is moved so as to obtain the magnification set at an initial stage when copying is in operating. CONSTITUTION:When the new magnification is inputted while the lens 2d of an exposure optical system for an electrostatic copying machine is moved so as to change the magnification, the lens 2d, which is moving on the positions of plural position sensors (a), (b) and (c) as the reference of the newly inputted magnification value and on the pedestal 27, is moved to the closest sensor position a for a while, and then, the lens 2d is moved to the newly set magnification position. When the lens is positioned on the part which is equally located from two position sensors, the lens is moved to the position sensor positioned in a moving direction. |
