SMA Image Sensor Shift Layout for Low-Power Camera Stabilization

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Solution Overview

Problem

Conventional camera modules with voice coil motors for optical image stabilization consume high power due to the heavy load required to shift the camera lens, leading to increased power consumption and heat generation.

Innovation Solution

A camera module using a Shape Memory Alloy (SMA) motor to actuate the image sensor instead of the camera lens, reducing the actuation load and power consumption by shifting the image sensor on a plane perpendicular to the optical axis, with SMA cables generating a pulling force through phase transformation to achieve image stabilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a voice coil motor is used to shift the camera lens for optical image stabilization, then image stabilization function is achieved, but power consumption increases due to heavy actuation load

Engineering Contradiction:

Improveimage stabilization functionVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of shifting the camera lens (conventional approach), this patent shifts the image sensor in the opposite direction to achieve the same optical stabilization effect. The image sensor is moved perpendicular to the optical axis while the lens remains stationary, thereby reducing the actuation load and power consumption.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent separates the lens and image sensor into independent movable components. The image sensor is decoupled from the lens assembly and can be moved independently by the SMA motor, allowing the lighter image sensor to be shifted rather than the heavier lens assembly.

Inventive Principle:

Principle #1Segmentation

2Reliability

If a voice coil motor shifts the camera lens, then optical path compensation is achieved, but the heavy load of the lens increases power consumption

Engineering Contradiction:

Improveoptical path compensationVSAvoidactuation load

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent inverts the conventional approach by keeping the lens stationary and moving the image sensor instead. This reversal allows the system to achieve the same optical path compensation with a significantly lighter moving mass, reducing the actuation load on the motor.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces the conventional voice coil motor mechanism with a shape memory alloy (SMA) based actuation system. The SMA motor uses phase transformation of shape memory alloy cables to generate mechanical force, providing a lighter and more energy-efficient alternative to traditional electromagnetic actuation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the camera lens is shifted for image stabilization, then stabilization is achieved, but the compensated shift distance required is large increasing power consumption

Engineering Contradiction:

Improveimage stabilization performanceVSAvoidcompensated shift distance

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The patent changes the operational parameters of the stabilization system by shifting the image sensor instead of the lens. This parameter change allows for a smaller required shift distance because the image sensor can be moved more efficiently and precisely by the SMA motor, reducing the total travel distance needed for compensation.

Inventive Principle:

Principle #35Parameter changes

4Reliability

If a voice coil motor is used, then electromagnetic forces are required to actuate components, but this increases power consumption and generates magnetic interference

Engineering Contradiction:

Improveactuation capabilityVSAvoidmagnetic interference

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the electromagnetic voice coil motor system with a shape memory alloy-based mechanical actuation system. The SMA motor uses phase transformation of the alloy material (martensite-austenite transformation) to generate mechanical force, eliminating the need for electromagnetic fields and thereby removing the source of magnetic interference while maintaining actuation capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 SMA motor implementation results in lower image stabilization power consumption, improved performance, and reduced magnetic interference, enabling better image stabilization with reduced power usage and a simpler, more compact structure.

Implementation Method 1

the SMA cable shrinks when being electrified and heated

Methodology Applied

Scientific EffectPhase transformation: Phase Change

Implementation Method 2

A camera module using a Shape Memory Alloy (SMA) motor to actuate the image sensor

Methodology Applied

Scientific EffectShape memory alloy: Shape Memory Alloy

Implementation Method 3

the SMA cable shrinks when being electrified and heated

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS12177549B2Camera system and shape memory alloy motor

Publication Date: 2024.12.24 HUAWEI TECH CO LTD

AI summary

A camera, camera lens, image sensor, and a shape memory alloy (SMA) motor are stacked within a frame. The SMA motor is located on an out-light side of the camera lens. The image sensor is located between the lens and the SMA motor and is fastened to the SMA motor. The SMA motor is configured to actuate the image sensor to shift on a plane perpendicular to an optical axis of the camera lens. The camera may be associated with an electronic device.