| 摘要 |
PURPOSE:To shorten the stop time of a spindle motor and perform unloading of a recording medium and loading just after unloading safely and surely by supplying an exciting current, which generates an inverting torque in the spindle motor, in accordance with a stop indication control signal and cutting off the supply of the exciting current in accordance with an inversion detection signal of the motor. CONSTITUTION:Though a motor control signal S6 is changed from '0' to '1' because of the control of stop indication, a signal S9 is '0' as it is and a switch 24 is kept turned on because an AND gate 102 of a mode control part 100 receives a signal S13 '0' by one input terminal. Meanwhile, when the second mode control signal S10 is changed to '1', a motor driving amplifier 300 is changed to the inversion mode, and the exciting current which gives a reverse rotation torque to a spindle motor 7 is given. When the motor starts to rotate in the reverse direction, phase relations between frequency signals FG and FG' are inverted, and a rotation direction display signal S8 of a phase comparator 200 rises to '1' from '0' to reset an FF101, and the signal S13 is changed to '1', and the signal S9 rises to '1' from '0', and the switch 24 is turned off to cut off the exciting current.
|
