Lens Module Using Shape Memory Alloy Wires for OIS

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Solution Overview

Problem

The existing lens modules with voice coil motors for optical image stabilization are costly, prone to magnetic interference, and difficult to miniaturize due to their large volume, making them unsuitable for portable devices.

Innovation Solution

A lens module utilizing a shape memory alloy wire assembly to drive the lens assembly, eliminating the need for a Hall sensor by using the resistance of the wires to obtain position information, thus reducing cost and size while avoiding magnetic interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a voice coil motor (VCM) is used to drive the lens assembly for optical image stabilization, then the lens assembly can achieve auto-focusing and shake correction functions, but the structure requires an additional Hall sensor which increases cost and cannot avoid magnetic interference

Engineering Contradiction:

Improveoptical image stabilization functionVSAvoidmagnetic interference

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the voice coil motor (electromagnetic system) with a shape memory alloy wire-driven bearing member (mechanical system). The shape memory alloy wires directly drive the bearing member to rotate, eliminating the need for VCM and Hall sensors, thus avoiding magnetic interference while maintaining optical image stabilization function.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a voice coil motor (VCM) structure is used, then the lens assembly can achieve auto-focusing and shake correction functions, but the lens module has a larger volume making it difficult to reduce height

Engineering Contradiction:

Improveoptical image stabilization functionVSAvoidlens module height

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent replaces the bulky voice coil motor structure with a compact shape memory alloy wire-driven bearing member. The bearing member rotates about the optical axis to drive the lens assembly, significantly reducing the lens module height while maintaining the optical image stabilization function.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If a Hall sensor is added to obtain position information of the lens assembly, then the lens module can achieve precise positioning, but the cost increases

Engineering Contradiction:

Improvelens assembly position informationVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent makes the shape memory alloy wires serve dual functions: driving the bearing member to rotate and simultaneously providing position information through their resistance values. This eliminates the need for separate Hall sensors, reducing cost while maintaining precise positioning capability.

Inventive Principle:

Principle #25Self-service

4Volume of moving object

If a shape memory alloy wire assembly is used to drive the bearing member, then the lens module achieves miniaturization and cost reduction, but the structure becomes more complex with multiple wire-binding clamp members

Engineering Contradiction:

Improvelens module heightVSAvoidwire-binding clamp member structure

Core Design Contradiction:

Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent segments the wire-binding clamp members into first and second types, with each type responsible for binding specific shape memory alloy wires at different locations. This modular segmentation simplifies the assembly process and makes the complex structure more manageable and manufacturable.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The lens module achieves cost-effectiveness and miniaturization by using shape memory alloy wires for optical image stabilization, eliminating the need for a Hall sensor and minimizing magnetic interference, enabling efficient anti-shake correction in a compact form factor.

Implementation Method 1

a shape memory alloy wire assembly configured to drive the bearing member to move relative to the base

Methodology Applied

Scientific EffectShape memory alloy: Shape Memory Alloy

Implementation Method 2

eliminating the need for a Hall sensor by using the resistance of the wires to obtain position information

Methodology Applied

Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentUS12099288B2Lens module

Publication Date: 2024.09.24 CHANGZHOU RAYTECH OPTRONICS CO LTD

AI summary

A lens module includes a base, a lens assembly, a bearing member including fixing and rotating frames, a shape memory alloy wire assembly including first and second shape memory alloy (SMA) wires, and at least one first and second wire-binding clamp members. The first SMA wires drive rotating frame to rotate relative to base about a first direction, and the second SMA wires drive the fixing frame to rotate relative to the rotating frame about a second direction. The first and second directions are perpendicular to each other and perpendicular to optical axis of the lens assembly. The rotating frame includes first and second rotating side plates. Each first wire-binding clamp member is connected to two first SMA wires, and each second wire-binding clamp member is connected to two second SMA wire. The lens module has low cost and occupies a small space, and the magnetic interference can be avoided.