Disclosed are an apparatus and method for controlling auto focus of a camera module. The present invention includes a lens unit, a moving coil, a fixed coil, and a controller configured to provide a signal comprising first frequency signal and second frequency signal to the moving coil, the fixed coil receiving a variable current or a variable voltage through the second frequency signal, calculate a focus location value based on the received variable current or variable voltage and an image signal, and control the lens unit to move by applying the first frequency signal to the moving coil according to the calculated focus location value, the second frequency signal is higher than the first frequency signal and is comprised of the signal during a prescribed time.

Disclosed are an apparatus and method for controlling auto focus of a camera module. The present invention includes a lens unit, a moving coil, a fixed coil, and a controller configured to provide a signal comprising first frequency signal and second frequency signal to the moving coil, the fixed coil receiving the variable current or the variable voltage through the second frequency signal, calculate a focus position value based on the received variable current or the variable voltage and an image signal, and control the lens unit to move by applying the first frequency signal to the moving coil according to the calculated focus position value, wherein the controller is further configured to detect a temperature change of the fixed coil and to correct a focus position of the lens unit corresponding to the detected temperature change of the fixed coil.

Disclosed are an apparatus and method for controlling auto focus of a camera module. The present invention includes a lens unit, a moving coil, a fixed coil, and a controller configured to provide a signal comprising first frequency signal and second frequency signal to the moving coil, the fixed coil receiving the variable current or the variable voltage through the second frequency signal, calculate a focus position value based on the received variable current or the variable voltage and an image signal, and control the lens unit to move by applying the first frequency signal to the moving coil according to the calculated focus position value, wherein the controller is further configured to detect a temperature change of the fixed coil and to correct a focus position of the lens unit corresponding to the detected temperature change of the fixed coil.

The present disclosure relates to controllers of linear motion devices and control methods of the same, in particular, to a controller of a linear motion device and a control method of the same capable of controlling the position of the linear motion device accurately, in a case where a misalignment of the mounting position of a magnetic sensor or a magnetizing variation of a magnet occurs, or in a case where a magnetic field detected by the magnetic sensor receives an interference of the magnetic field generated by a driving coil of the linear motion device.