Abstract: A motor driver circuit according to the present invention comprises an edge signal generation means for generating an edge signal indicating the timing of phase-switching according to the values of a plurality voltages induced when driving the motor and a drive voltage control means for controlling the highest value of the drive voltage for driving the motor according to the edge signal. The drive voltage control means includes a first drive voltage control means for controlling the highest value of the drive voltage before the timing of phase-switching and a second drive voltage control means for controlling the highest value of the drive voltage after the timing of phase-switching. With this arrangement, it is possible to realize soft switching control while the motor is driven to rotate at high speed and reduce the noise due to the motor being driven to rotate.

Abstract: A disk drive apparatus drives, by means of a motor, a disk mounted thereon so as to reproduce signals recorded in the disk. The disk drive apparatus has an edge detecting unit for generating an edge signal XEG indicating a timing of phase switching, in accordance with a plurality of signals CU, CV and CW induced when the motor is driven. The disk drive apparatus further has a drive voltage controlling unit for controlling, in accordance with the edge detection signal XEG, the maximum value of a drive voltage VS for driving said motor. This arrangement implements optimal motor control, while reducing circuit scale and cost and, at the same time, enhancing adaptability of the disk drive apparatus.

Abstract: A disk drive apparatus drives, by means of a motor, a disk mounted thereon so as to reproduce signals recorded in the disk. The disk drive apparatus has an edge detecting unit for generating an edge signal XEG indicating a timing of phase switching, in accordance with a plurality of signals CU, CV and CW induced when the motor is driven. The disk drive apparatus further has a drive voltage controlling unit for controlling, in accordance with the edge detection signal XEG, the maximum value of a drive voltage VS for driving said motor. This arrangement implements optimal motor control, while reducing circuit scale and cost and, at the same time, enhancing adaptability of the disk drive apparatus.

Abstract: The present invention provides a disk driving apparatus which includes an interpolating edge circuit for generating an interpolating signal in accordance with a cycle of an edge detection signal, and a phase switching unit for performing phase switching by both the timing signal and the interpolating signal when a period for which the edge detection signal is normally generated reaches a predetermined value.

Abstract: A disk drive apparatus drives, by means of a motor, a disk mounted thereon so as to reproduce signals recorded in the disk. The disk drive apparatus has an edge detecting unit for generating an edge signal XEG indicating a timing of phase switching, in accordance with a plurality of signals CU, CV and CW induced when the motor is driven. The disk drive apparatus further has a drive voltage controlling unit for controlling, in accordance with the edge detection signal XEG, the maximum value of a drive voltage VS for driving said motor. This arrangement implements optimal motor control, while reducing circuit scale and cost and, at the same time, enhancing adaptability of the disk drive apparatus.

Abstract: A motor driver circuit according to the present invention comprises an edge signal generation means for generating an edge signal indicating the timing of phase-switching according to the values of a plurality voltages induced when driving the motor and a drive voltage control means for controlling the highest value of the drive voltage for driving the motor according to the edge signal. The drive voltage control means includes a first drive voltage control means for controlling the highest value of the drive voltage before the timing of phase-switching and a second drive voltage control means for controlling the highest value of the drive voltage after the timing of phase-switching. With this arrangement, it is possible to realize soft switching control while the motor is driven to rotate at high speed and reduce the noise due to the motor being driven to rotate.

Abstract: A sensorless motor starting system of a simplified structure is capable of starting a sensorless spindle motor under optimal target starting conditions with low power consumption in accordance with the motor type and the kind of an optical disc to be driven, by executing manual fine adjustment of start parameters in response to any abnormal rotation caused at the start time. In this system, a rotation frequency signal is outputted from an edge detector on the basis of position signals in a start acceleration mode, and then is compared with a reference frequency signal by a comparator. And if the result of the decision therefrom signifies abnormal rotation, a switch is turned to its another terminal to select a manual setting mode. An operator performs manual fine adjustments of a phase switching time, a phase switching number and a drive voltage in order while monitoring phase switching control signals and position signals to thereby normalize the start state of the sensorless spindle motor.

Abstract: The present invention provides a disk driving apparatus which includes an interpolating edge circuit for generating an interpolating signal in accordance with a cycle of an edge detection signal, and a phase switching unit for performing phase switching by both the timing signal and the interpolating signal when a period for which the edge detection signal is normally generated reaches a predetermined value.

Abstract: A disk drive apparatus drives, by means of a motor, a disk mounted thereon so as to reproduce signals recorded in the disk. The disk drive apparatus has an edge detecting unit for generating an edge signal XEG indicating a timing of phase switching, in accordance with a plurality of signals CU, CV and CW induced when the motor is driven. The disk drive apparatus further has a drive voltage controlling unit for controlling, in accordance with the edge detection signal XEG, the maximum value of a drive voltage VS for driving said motor. This arrangement implements optimal motor control, while reducing circuit scale and cost and, at the same time, enhancing adaptability of the disk drive apparatus.

Abstract: A motor control apparatus according to the present invention comprises: a servo circuit for outputting a pulse width modulation signal; a low-pass filter for receiving the pulse width modulation signal outputted by the servo circuit as an input; and a driver circuit for receiving an output voltage of the low-pass filter as an input and thereby driving a brushless sensorless motor; wherein the servo circuit controls pulse width of the pulse width modulation signal so as to maintain rotational speed of the motor at a target rotational speed on the basis of an FG pulse signal outputted by the motor, the FG pulse signal representing the rotational speed of the motor by frequency. The motor control apparatus further includes a rotational speed changing means, the rotational speed changing means changing the rotational speed of the motor by gradually varying a voltage outputted by the driver circuit from a current voltage to a target voltage on input of a control start signal.

Abstract: A sensorless motor starting system of a simplified structure is capable of starting a sensorless spindle motor under optimal target starting conditions with low power consumption in accordance with the motor type and the kind of an optical disc to be driven, by executing manual fine adjustment of start parameters in response to any abnormal rotation caused at the start time. In this system, a rotation frequency signal is outputted from an edge detector on the basis of position signals in a start acceleration mode, and then is compared with a reference frequency signal by a comparator. And if the result of the decision therefrom signifies abnormal rotation, a switch is turned to its another terminal to select a manual setting mode. An operator performs manual fine adjustments of a phase switching time, a phase switching number and a drive voltage in order while monitoring phase switching control signals and position signals to thereby normalize the start state of the sensorless spindle motor.

Abstract: A motor control apparatus according to the present invention comprises: a servo circuit for outputting a pulse width modulation signal; a low-pass filter for receiving the pulse width modulation signal outputted by the servo circuit as an input; and a driver circuit for receiving an output voltage of the low-pass filter as an input and thereby driving a brushless sensorless motor; wherein the servo circuit controls pulse width of the pulse width modulation signal so as to maintain rotational speed of the motor at a target rotational speed on the basis of an FG pulse signal outputted by the motor, the FG pulse signal representing the rotational speed of the motor by frequency. The motor control apparatus further includes a rotational speed changing means, the rotational speed changing means changing the rotational speed of the motor by gradually varying a voltage outputted by the driver circuit from a current voltage to a target voltage on input of a control start signal.