| 摘要 |
PROBLEM TO BE SOLVED: To obtain a DC motor controller by which the speed of a DC motor used to drive the CCD unit of a scanner part is controlled in a wide range from a high-speed rotation up to a low-speed rotation. SOLUTION: A control signal is given to a DC motor 11 via a motor drive circuit 25. A CCD unit 5 is moved back and forth in a scanning direction at a set speed according to its resolution. The rotational speed of the DC motor 11 is detected by an encoder sensor 17 for low speed and an encoder sensor 19 for high speed. A detection signal from one sensor out of the encoder sensors 17, 19 is input to a sensor-signal processing circuit 29 by a sensor selector 27 according to the resolution. The detection signal which is input to the sensor- signal processing circuit 29 is input to a motor-speed control circuit 31. A feedback control operation is performed on the basis of the detection signal. A control signal as its result is output to the motor drive circuit 25. Thereby, the DC motor 11 is turned at a set speed in a wide range from a low speed up to a high speed. |
