| 摘要 |
PURPOSE:To demodulate information on a medium which is written at different rotating speeds by performing rotation control for switching the rotating speed of a spindle at least in two stages. CONSTITUTION:A sensor signal 1 outputted by a sensor circuit B which detects whether a notch F for high density provided to a floppy disk E is present or not goes up to a high level when the notch F is detected. A control circuit D receives it to vary the rotating speed of the spindle motor A from (a) to (b). This control is carried out even by a switch signal 2 outputted by an external switch C. |
