Patent ID: 8866918

Claim:
A camera apparatus comprising: a support structure; a camera unit comprising an image sensor and a lens system for focussing an image on the image sensor, the camera unit being supported on the support structure in a manner allowing the camera unit to tilt relative to the optical axis of the lens system; a plurality of SMA actuators arranged to drive tilting of the camera unit; a sensor arrangement mounted on the camera unit and arranged to generate output signals representative of the movement of the camera unit; and a control circuit arranged to generate drive signals and supply them to the SMA actuators, wherein the control circuit is arranged to derive closed-loop control signals representative of a desired degree of variation in the power of the drive signals from the output signals of the sensor arrangement for reducing the movement of the camera unit, without dependence on any measurement of the resistance of the SMA actuators, and the control circuit is arranged to generate the drive signals with powers that vary from set-point powers in correspondence with the closed-loop control signal.