Drive device and method for controlling the drive device

1. A drive device comprising:

a fixed frame on which one of a drive coil and a magnet facing the drive coil is disposed;

a movable frame on which another one of the drive coil and the magnet is disposed and which is movable relative to the fixed frame;

a detector that is disposed on one of the fixed frame and the movable frame on which the drive coil is disposed, and that detects and outputs a detection signal corresponding to a magnetic flux of the magnet;

a detection coil that is disposed on one of the fixed frame and the movable frame on which the magnet is disposed, and in a position facing the drive coil with the magnet interposed; and

a drive controller that controls a drive signal on which a high-frequency drive signal is superimposed on a drive current to drive the movable frame and which is to be applied to the drive coil, and that drives the movable frame to a predetermined position based on the detection signal detected by the detector and a high-frequency signal of a predetermined frequency band including a frequency of the high-frequency drive signal that is generated in the detection coil when the drive signal is applied to the drive coil.

2. The drive device according to claim 1 , wherein the drive controller acquires an amplitude of the predetermined frequency band including the frequency of the high-frequency drive signal from the high-frequency signal, calculates a distance-equivalent value equivalent to a distance between the detection coil and the drive coil based on the acquired amplitude, and corrects the drive signal to be applied to the drive coil based on the calculated distance-equivalent value.

3. The drive device according to claim 2 , wherein the drive coil and the detection coil are disposed so that a center of gravity of the drive coil coincides with a center of gravity of the detection coil.

4. The drive device according to claim 2 , further comprising: an imaging element that is disposed in the movable frame and that generates a video signal relating to an object; and a display unit that displays an image based on the video signal, wherein

the drive controller causes the display unit to display an error notification that the drive signal to be applied to the drive coil is uncorrectable when the distance-equivalent value is outside a predetermined range.

5. A method for controlling a drive device comprising: a fixed frame on which one of a drive coil and a magnet facing the drive coil is disposed; a movable frame on which another one of the drive coil and the magnet is disposed and which is movable relative to the fixed frame; a detector that is disposed on one of the fixed frame and the movable frame on which the drive coil is disposed, and that detects and outputs a detection signal corresponding to a magnetic flux of the magnet; and a detection coil that is disposed on one of the fixed frame and the movable frame on which the magnet is disposed, and in a position facing the drive coil with the magnet interposed, the method comprising:

applying to the drive coil a drive signal on which a high-frequency drive signal is superimposed on a current that drives the movable frame;

acquiring an amplitude of a predetermined frequency band including a frequency of the high-frequency drive signal from a high-frequency signal of the predetermined frequency band including the frequency of the high-frequency drive signal that is generated in the detection coil;

calculating a distance-equivalent value equivalent to a distance between the detection coil and the drive coil based on the acquired amplitude;

correcting the drive signal to be applied to the drive coil based on the calculated distance-equivalent value; and

driving the movable frame to a predetermined position by applying the corrected drive signal to the drive coil.