JPS6424273A - Method for controlling start position of optical system in variable power copying machine - Google Patents

Abstract

PURPOSE:To improve the efficiency of a copying operation, by starting an optical system after setting it at a start position at the time of reduction copying, and starting the optical system as it stands setting the fact that the optical system stays at a side nearer to a return side than a home position as a condition at the time of unmagnification or enlargement copying. CONSTITUTION:The optical system 3 is started from the start position after setting it at the start position since a long approach run distance is required at the time of reduction copying. Therefore, the optical system 3 can scan an original after being accelerated to constant speed. Also, since it is enough to scan the original at slow speed by the optical system 3 at the time of the unmagnification and enlargement copying, it is possible to accelerate the optical system 3 sufficiently until it starts the scan of the original when the optical system 3 is set at a position where a home position sensor HPS is turned ON, that is, the return side. Therefore, it is possible to start the optical system 3 only by confirming the turning ON of the home position sensor HPS at the time of the unmagnification and the enlargement copying. In such a way, copying speed can be accelerated.