PURPOSE: To control inversion adequately in a min. time and to move a scanning system and a photoreceptor relatively with ease and high accuracy, by determining the position determined beforehand according to the size of a cassette and a variable power.
CONSTITUTION: A motor M2 is run forward with a DC amplifiers 34, and transistors 35-1, 35-2 by the H signal of the forward signal FAW from a microcomputer 30, whereby scanning is accomplished. In the stage of changing a magnification, a CV37 divides down the pulse train E1 from an encoder 36 in accordance with the data m1 on the frequency dividing ratio from the microcmputer 30 and converts the same to the pulse train E2 of the same frequency as a clock frequency CLK. A PLL 32 compares the E2 and the CLK, outputs the voltage V of an H level and controls the speed of the motor M2 with a filter 33 and the DC amplifier 34. A main motor M1 is controlled similarly. When the FAW goes to an L and a backward signal BAW to an H according to the size of a cassette and the ratio m1, the TRs 35-1, 35-2 turn off and 35-3, 35-4 turn off, by which the motor M2 is run backward and the scanning system is moved relatively with the photoreceptor with high accuracy.
MAEJIMA KATSUYOSHI
INUZUKA TSUNEKI
SAKAMAKI HISASHI
