PURPOSE: To take a copy corresponding to reduction and enlargement magnification appropriately, by providing an optical system controller and adjusting the optical position of an optical system corresponding to the magnification finely.

CONSTITUTION: When a magnification signal is outputted by operating a magnification key, the number of reference pulses corresponding to the magnification is calculated and stored in an RAM17d. When an operator operates a fine adjustment dial 23 at the same time, the number of pulses corresponding to a dial value is stored in the RAM17d. If the selection rate of the magnification is 100% and the dial is set to a center value 8 among dial set values 1W16, driving circuits 19 and 20 output pulses to drive stepping motors 11 and 12 forward, moving a mirror 4 and a lens 16 to a position corresponding to 100% magnification. Thus, the fine adjustment dial value is variable over the range of, for example, 1W16, so a copy corresponding to the magnification appropriately is taken.