An embodiment method includes rectifying a back electromotive force of a spindle motor in a hard disk drive and energizing a voice coil motor in the hard disk drive using the rectified back electromotive force of the spindle motor via a voice coil motor power stage to retract a head of the hard disk drive to a park position. The head is retracted by moving the head towards the park position during a first retract phase and retaining the head in the park position during a second retract phase by applying a bias voltage to the voice coil motor power stage during a bias interval of the second retract phase. The method also includes producing a saturation signal indicative of onset of saturation in the voice coil motor power stage and controlling the bias voltage during the second retract phase.

An improved system and method for monitoring operation of movers in an independent cart system reduces the required communication bandwidth for monitoring operation of movers in a system where control is distributed among multiple controllers spaced along the track. As the mover is travelling along the track segment, each distributed controller monitors at least one operating characteristic of the mover. As a mover travels along the track, each distributed controller transmits the operating characteristic to a successive distributed controller, such the monitored operating characteristic is transmitted along the track as the mover travels along the track. At a reduced rate or upon request from a central controller, each distributed controller may transmit the status of a mover present on the corresponding track segment controlled by that distributed controller to the central controller.

An improved system and method for monitoring operation of movers in an independent cart system reduces the required communication bandwidth for monitoring operation of movers in a system where control is distributed among multiple controllers spaced along the track. As the mover is travelling along the track segment, each distributed controller monitors at least one operating characteristic of the mover. As a mover travels along the track, each distributed controller transmits the operating characteristic to a successive distributed controller, such the monitored operating characteristic is transmitted along the track as the mover travels along the track. At a reduced rate or upon request from a central controller, each distributed controller may transmit the status of a mover present on the corresponding track segment controlled by that distributed controller to the central controller.

A method for estimating actuator parameters for an actuator, in-situ and in real-time, may include driving the actuator with a test signal imperceptible to a user of a device comprising the actuator during real-time operation of the device, measuring a voltage and a current associated with the actuator and caused by the test signal, determining one or more parameters of the actuator based on the voltage and the current, determining an actuator type of the actuator based on the one or more parameters, and controlling a playback signal to the actuator based on the actuator type.

A control apparatus for a camera system that includes an image pickup apparatus and a lens apparatus including a driven unit, an output unit that is supplied with power from the image pickup apparatus, an actuator configured to move the driven unit includes a driving unit configured to drive the actuator by a PWM output method or a linear output method using the power from the output unit, and a control unit configured to control an output of the power from the output unit to the driven unit. The control unit causes the output unit to output a first power in a case where the driving unit drives the actuator by the PWM output method, and in a case where the driving unit drives the actuator by the linear output method, the control unit causes the output unit to output a second power different from the first power.

A control apparatus for a camera system that includes an image pickup apparatus and a lens apparatus including a driven unit, an output unit that is supplied with power from the image pickup apparatus, an actuator configured to move the driven unit includes a driving unit configured to drive the actuator by a PWM output method or a linear output method using the power from the output unit, and a control unit configured to control an output of the power from the output unit to the driven unit. The control unit causes the output unit to output a first power in a case where the driving unit drives the actuator by the PWM output method, and in a case where the driving unit drives the actuator by the linear output method, the control unit causes the output unit to output a second power different from the first power.

An exemplary embodiment of the present invention a rotor including a lens and formed with a first driving unit, a stator formed with a second driving unit driving the rotor in response to electromagnetic interaction with the first driving unit, and a base on which the stator is fixed, wherein the rotor is brought into contact with the base, in a case the lens is in a UP posture, and the rotor is distanced from the base, in a case the lens is in a DOWN posture.

An exemplary embodiment of the present invention a rotor including a lens and formed with a first driving unit, a stator formed with a second driving unit driving the rotor in response to electromagnetic interaction with the first driving unit, and a base on which the stator is fixed, wherein the rotor is brought into contact with the base, in a case the lens is in a UP posture, and the rotor is distanced from the base, in a case the lens is in a DOWN posture.

Disclosed herein is a motor driver circuit including a first output terminal to be connected to a first end of a to-be-driven motor via a sense resistor, a second output terminal to be connected to a second end of the motor, an error detector that generates an error signal, an A/D converter that obtains a digital signal, a compensator that generates a voltage command value, a D/A converter that converts the voltage command value to an analog control signal, a pulse width modulator that generates a first pulse and a second pulse, and an output stage that generates a first driving voltage and a second driving voltage. During a first mode, the compensator uses the error signal obtained by the A/D converter at a negative edge timing of the first pulse, for the error signal at a positive edge timing of the second pulse.

Disclosed herein is a motor driver circuit including a first output terminal to be connected to a first end of a to-be-driven motor via a sense resistor, a second output terminal to be connected to a second end of the motor, an error detector that generates an error signal, an A/D converter that obtains a digital signal, a compensator that generates a voltage command value, a D/A converter that converts the voltage command value to an analog control signal, a pulse width modulator that generates a first pulse and a second pulse, and an output stage that generates a first driving voltage and a second driving voltage. During a first mode, the compensator uses the error signal obtained by the A/D converter at a negative edge timing of the first pulse, for the error signal at a positive edge timing of the second pulse.