Patent ID: 8692929

Claim:
A lens drive device comprising: a lens movable in a moving region; an actuator made of shape memory alloy for moving the lens; a controller for controlling a position of the lens based on a characteristic value associated with the actuator, the characteristic value being varied by deformation of the actuator wherein the characteristic value fluctuates responsive to variance of an electrical signal; and a detector for detecting that the characteristic value has reached an upper level and later reached a lower level lower than the upper level; wherein said controller modifies said electrical signal in order to maintain said characteristic value between said upper level and said lower level, wherein while the controller obtains image data from a given field among from the respective fields and when the detector detects that the characteristic value of the actuator is maintained in a predetermined range, the detector outputs a detection signal, and wherein when the detection signal is supplied, the controller moves the lens to a place corresponding to a field next to the given field, and when no detection signal is supplied, the controller obtains the image data again from the given field.