Patent attributes
An actuation system is proposed for an optical system, comprising a voice coil motor for actuating the optical system, the voice coil motor comprising a magnet and an electric coil, a position measuring unit for measuring the position of the electric coil and providing a position feedback signal, and a control unit for closed loop control of the position of the optical system based on a target position and the position feedback signal, used for generating a drive signal for the electric coil. According to the disclosure, a ferromagnetic element is arranged in proximity to the electric coil so that the inductance of the electric coil depends on its position. Further, the position-measuring unit measures the inductance of the electric coil and determines the position of the electric coil based on the determined inductance.
