| 摘要 |
PURPOSE:To remove the unevenness in the amplitude or the phase of a frequency generator pulse in initial condition such as start-up, etc. so as to improve the effect by selectively change over the filter coefficient according to the condition of a control system. CONSTITUTION:A speed detector 7 detects a speed differential signal from a frequency generator 3, and a phase detector 6 detects a phase differential signal. A signal unevenness removing circuit 8 outputs a speed differential signal 300 where signal unevenness ingredients are removed from a speed differential signal 200. An adder 10 adds both, and the addition result is output to a drum motor 1 through a loop filter 11 and a driver circuit 12. A speed phase error detection circuit 9 is detecting whether or not the outputs of a speed detector 7 and a phase detector 6 are controlled to the target speed and the target phase respectively, and it operates to select the value of the coefficient K of the signal removing circuit 8 by this detection result 400. |
