JPS5536816A - Optical system driving method - Google Patents

Abstract

PURPOSE: To make possible operating the optical system at a constant acceleration with a simple constitution by performing scanning of the optical system by the use of a pulse motor for a driving source.

CONSTITUTION: An optical system 11 is driven by a motor 4 via belt 12. When the start signal is applied to a VOC 15 and a counter circuit 16, the output A of the circuit 16 becomes logic 1 and a pulse is generated from a triangle wave generating circuit 17. This pulse enters the VOC 15 through a voltage control circuit 18 which in turn emits the clock pulses D of the frequency proportional to its input voltage C, causing the motor 14 to be run by a driving circuit 19 at the number of revolutions proportional to the output voltage of the circuit 17. Hence, the motor 14 runs forward under constant accelerating voltage because the output voltage of the circuit 17 increases or decreases constantly with respect to time. The circuit 16 counts the pulses from the VOC and when it counts the number of pulses corresponding to the timing at which the optical system 11 comes at the intermediate point (a), the output A becomes logic value 0. As a result, the output voltage B of the circuit 17 begins to decrease and the running speed of the motor 14 begins to lower. When it comes to the reset point (b), it stops.

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