Abstract: A magnetic sensor arranged on a second line forming an angle of 45° at a switched position for switching a state being set up on a first line that projects displacement of center of magnetic field generating means generating a magnetic field.

Abstract: A magnetic sensor arranged on a second line forming an angle of 45° at a switched position for switching a state being set up on a first line that projects displacement of center of magnetic field generating means generating a magnetic field.

Abstract: A motor control circuit for reducing current consumption. A stepping motor control circuit includes an A/B phase current setting signal generation circuit for generating an A/B phase current signal setting signals provided to a stepping motor driver to supply a stepping motor with a predetermined amount of drive current. Based on a switch signal, first and second switches selectively output an A/B phase current setting signal and an A/B phase reference signal, for reducing the drive current of the stepping motor more than the A/B phase current setting signal. An intermittent drive control circuit generates the switch signal. The stepping motor control circuit provides the motor driver with the A/B phase reference signal in accordance with the switch signal.

Abstract: A motor control circuit for reducing current consumption. A stepping motor control circuit includes an A/B phase current setting signal generation circuit for generating an A/B phase current signal setting signals provided to a stepping motor driver to supply a stepping motor with a predetermined amount of drive current. Based on a switch signal, first and second switches selectively output an A/B phase current setting signal and an A/B phase reference signal, for reducing the drive current of the stepping motor more than the A/B phase current setting signal. An intermittent drive control circuit generates the switch signal. The stepping motor control circuit provides the motor driver with the A/B phase reference signal in accordance with the switch signal.

Abstract: A control circuit provided in an optical disk apparatus which apparatus has a motor to move an optical pickup unit for performing record/playback control of an optical disk in a radial direction of the optical disk, sets a plurality of concentric annular zones on the optical disk, and performs record/playback control, for each zone, of the optical disk. The control circuit comprises a pulse period detector for detecting pulse periods of a periodic pulse control signal which drives the motor; and a zone determination section that determines the zone which the optical pickup unit is facing on the basis of the number of pulse period detection times detected by the pulse period detector.

Abstract: A slice level control circuit for obtaining optimal filter characteristics depending on optical disc data reading speed or optical disc condition, while achieving superior stability and response with respect to slice level. The control circuit cuts DC components in analog input signals to generate C-cut RF signals having adjusted DC levels. A comparator compares two C-cut RF signals to generate a binary RF signal for driving a charge pump circuit. An analog lowpass filter eliminates high-frequency components from the output signal of the charge pump circuit. An A/D converter circuit converts the cutoff output signal of the analog lowpass filter into a digital value signal according to sampling periods. A digital filter filters the digital value signal. A D/A converter converts the filtered digital value signal into an analog voltage signal. The analog voltage signal controls the slice level of the binary circuit.