SHAPE-MEMORY-ALLOY DRIVING SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a camera lens element driving system capable of being downsized and of performing accurate drive because of a shape-memory-alloy (SMA) actuator.

SOLUTION: A camera lens element driving system comprises: a supporting structure 2; a camera lens element that is supported on the supporting structure by a suspension system; and an SMA actuator 30 that is connected to a position between the supporting structure and a movable element and drives a movement of the camera lens element. The driving system executes a preliminary calibration operation including: a step for heating the SMA actuator 30; a step for monitoring a measurement resistance; a step for detecting a maximum resistance and a minimum resistance; and a step for deriving and storing a size of resistance range that is equal to or less than a difference between a value of the detected maximum resistance and a value of the detected minimum resistance. Then, the driving system applies heat within the stored resistance range in a focus detection operation.

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