US 8,077,411 B2Granted

Lens displacement mechanism using shaped memory alloy

AssigneeE-Pin Optical Industry Co., Ltd.

InventorsSan-Woei Shyu, Shr-Bin Wu, Chih-Hsiung Huang

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Abstract

A lens displacement mechanism using shaped memory alloy (SMA) applied to an auto-focusing lens module is disclosed. The lens displacement mechanism comprising at least one SMA wire. Two opposite ends of the SMA wire are fixed and a longitudinal mid-point of an intermediate movable portion between the two opposite ends is tightened and is fixed on a corresponding hook disposed on an outer edge of the lens so that the intermediate movable portion is tightened between the two opposite ends. When the SMA wire is heated, the intermediate movable portion contracts to pull the hook of the lens for driving the lens to move and slide along with an optical axis so as to achieve auto-focus control. The present lens displacement mechanism is simple in structure and reflow process. Therefore, the present displacement mechanism is suitable to be used in portable camera or mobile phone or PDA, which needs to be small and have easily mass production by SMT.

Claims8

Dependent claims

An auto-focusing lens module, comprising:

a housing;
a lens having a lens group;
a lens holder holding the lens arranged in the housing and along an optical axis;
and
a lens displacement mechanism, also arranged in the housing, for moving and sliding the lens towards or away from an object side for auto-focusing, the lens displacement mechanism comprising:
at least one shaped memory alloy (SMA) wire;
wherein the at least one SMA wire having two opposite ends and an intermediate movable portion between the two opposite ends is controlled by a control current to drive the moving and sliding lens, the two opposite ends being fixed and a longitudinal mid-point of the intermediate movable portion being hooked on a corresponding hook arranged on an outer edge of the lens holder so as to tighten the intermediate movable portion between the two opposite ends, and wherein when the at least one SMA wire is heated by control current, the intermediate movable portion contracts to pull the hook so as to drive the moving and sliding lens along the optical axis for auto-focusing.

4 more elements

Dependencies are inferred from the claim text.