| 摘要 |
PURPOSE:To stop an optical system accurately at its home position even if the optical system is replaced and its specification changes or if conditions change as a rod is stained by setting brake timing corresponding to a moving load at the time of the movement start of the optical system. CONSTITUTION:The encoder 62 consisting of 1st and 2nd sensors 66a and 66b which are difference in position from a slit disk 64 is coupled directly with the shaft of a motor 61 which drives an unshown traveling optical system, and the encoder generates pulses P1 and P2 which are 90 deg. out of phase with each other when the motor 61 rotates at a prescribed rotating speed. Then those pulses are supplied to a rotating direction detecting circuit 68 to decide rotation in a normal or reverse direction and while its output is supplied to a microcomputer 69, the pulse P2 of the sensor 66b is supplied directly to the computer 69. Then the output of the computer 69 is sent to a motor driving circuit 70 which incorporates four transistors(TR) to monitor the current position of the optical system and also brake the motor 61 at need. |
