| 摘要 |
PROBLEM TO BE SOLVED: To accurately control the position and the speed of a scanner with a high precision by detecting the scanner position with a high precision without an influence of the change of the operation condition at the time of scanner driving operation. SOLUTION: The scanner is moved back and forth by a DC servo motor 1 to read a document picture, and interrupt handling of a microcontroller 5 is performed by the encoder signal of an encoder 2 due to rotation of the DC servo motor 1. The encoder signal has the frequency divided by a frequency divider 3, and the frequency divider 3 is initialized in a prescribed position of the scanner by the reset signal, and plural flip flops of the frequency divider 3 are synchronized with one another at the time of switching the frequency division ratio of the frequency divider during running of the scanner. The position of the scanner is detected by output signals of a photo sensor 6 and the frequency divider 3, and the control gain is accurately changed with each frequency division ratio correspondingly to the scanner position, and speed control and position control of the scanner are stably performed. |
