| 摘要 |
PURPOSE:To make it possible to eliminate wasteful waiting time and to respond to dispersion in characteristics or secular changes by monitoring whether the revolution of a motor continues longer than predetermined second time period and it is a normal revolution and judging whether a constant speed control is normal at that point in time within a predetermined first time period after starting. CONSTITUTION:Within a motor control portion 20 performing a constant speed drive control of a polygon motor 15, a rotation stability detection circuit 21 is provided for detecting whether the rotation is stable at the normal revolution within the predetermined range of a target revolution by receiving an output from a rotary encoder 17. Then, the revolution is quickly raised by supplying a high power immediately after starting of the polygon motor 15 and overshoot and is gradually converged within the range of the target revolution. Here, the stability of rotation is judged by detecting whether it is continuously within the range of target revolution during a predetermined second time period (for example 2 seconds) within a predetermined first time interval (such as 10 seconds) after starting. |
