| 摘要 |
PURPOSE:To realize highly accurate constant speed operation of drive motor. CONSTITUTION:A drive motor, i.e., a scan motor, comprises stator and rotor having structures similar to those of hybrid permanent magnet type step motor. A basic pattern generating circuit 48 generates basic cosine wave pattern PC and basic sine wave pattern PS based on a frequency control clock signal FCK fed from a frequency control clock forming unit 47, while furthermore correction patterns PHC, PHS for offsetting detent torque produced due to magnetic inbalance between rotor and stator are generated based on a position detection signal SC fed from a rotational position detecting circuit 50 and the frequency control clock signal FCK. A drive circuit 36 then performs conduction/ interruption control of phase A coil 26A and phase B coil 26B in stator coils based on a current pattern combining the basic patterns PC, PS and the correction patterns PHC, PHS. |
