The present invention relates to an apparatus for controlling an optical system for a copying machine in which the number of selectable reduction/magnification factors is increased without increasing the cost of the machine.
In a conventional copying machine optical system control apparatus, for example, the position of an optical system is controlled in accordance with the reduction/magnification factor which is set by a reduction/magnification scale button provided on a console of a copying machine. This copying machine optical control apparatus comprises reduction/magnification scale buttons for selectively producing a signal corresponding to a desired reduction/magnification factor; position detector sections the number of which corresponds to the number of selectable reduction/magnification factors and which are disposed in predetermined positions corresponding to the respective reduction/magnification factors, each for producing a position signal in accordance with the position of the optical system constituted by a lens, a mirror, etc.; a control section for receiving the reduction/magnification factor signal and the position signal to produce an optical system position control signal; and a driving section for moving the optical system in response to the control signal.
In the thus-arranged apparatus, upon the reception of the signal corresponding to a desired reduction/magnification factor, the control section actuates the driving system in accordance with the desired reduction/magnification factor to cause the optical system to move to a predetermined position on the basis of the result of detection of the position detector sections. The size control in the lateral direction is performed by the above-mentioned positional control, while the control in the longitudinal direction is achieved by controlling the velocity of original document scanning in accordance with the desired reduction/magnification factor. An operator may obtain a copy with his desired reduction/magnification factor by the longitudinal and lateral control as described above.
However, in the conventional copying machine optical system control apparatus, when the number of selectable reduction/magnification factors is increased, the space required for the position detector sections increases and the apparatus also becomes expensive, because the number of mounting positions for optical system position control mechanisms must be increased in accordance with the available number of reduction/magnification factors.