Shape Memory Alloy Camera Actuation for Low-Power Stabilization
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Solution Overview
Problem
Conventional voice coil motor (VCM) technology is difficult to apply to micro-scale camera devices requiring low power consumption and high-resolution, multifunctional actuators for cellular phone cameras, especially for autofocus, shutter shaking prevention, and zooming, and there is a need for improved temperature compensation and reliable conductive connections in camera modules.
Innovation Solution
A camera device with a simple structure using a shape memory alloy member for movement and rotation, coupled with a position sensing unit and controller to accurately detect movement and rotation, and a fixed unit with magnets for precise image stabilization, reducing power consumption and interference with peripheral elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If voice coil motor (VCM) technology is used in conventional camera devices, then driving force and control performance are improved, but power consumption increases and applicability to micro-scale devices decreases
Solution Approach 1:
The patent replaces the electromagnetic VCM actuation system with a purely mechanical shape memory alloy (SMA) actuation system. The SMA member uses thermal-mechanical coupling to generate driving force through phase transformation, eliminating the need for electromagnetic coils and magnets, thereby significantly reducing power consumption while maintaining adequate driving force for micro-scale camera devices
Solution Approach 2:
The patent changes the actuation mechanism from electromagnetic field-based (VCM) to thermal-mechanical field-based (SMA). By utilizing temperature-induced phase transformation in the SMA material, the system achieves mechanical actuation with lower energy consumption, suitable for portable and micro-scale camera applications
2Measurement precision
If multiple sensors are added to accurately detect movement and rotation, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent implements a multi-functional sensor integration strategy where a single sensor system performs multiple detection functions. The detection unit simultaneously measures movement amount in X and Y directions, rotation amount, and temperature, allowing the system to achieve comprehensive measurement precision without proportionally increasing device complexity through multiple separate sensors
Solution Approach 2:
The patent merges multiple sensing functions into an integrated detection unit. By combining movement detection, rotation detection, and temperature sensing capabilities into a unified sensor system, the patent achieves accurate multi-parameter measurement while minimizing the increase in device complexity through functional integration
3Use of energy by moving object
If shape memory alloy member is used instead of VCM, then power consumption is reduced and device size is decreased, but temperature compensation accuracy must be improved
Solution Approach 1:
The patent implements a feedback-based temperature compensation mechanism. The detection unit continuously monitors the temperature of the shape memory alloy member, and the control unit adjusts the driving signal in real-time based on temperature variations. This closed-loop feedback system ensures accurate temperature compensation, maintaining reliable actuation performance despite the inherent temperature sensitivity of SMA materials
Solution Approach 2:
The patent applies preliminary temperature compensation by pre-characterizing the temperature-dependent behavior of the shape memory alloy member. The control unit stores compensation data and applies corrective actions in advance or proactively based on detected temperature changes, ensuring consistent actuation performance across varying temperature conditions
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
Accurate detection of movement and rotation, reduced power consumption, minimized interference, and improved temperature compensation, facilitating smaller device size and enhanced reliability in conductive connections.
Implementation Method 1
a shape memory alloy member coupled to the fixed unit and the moving unit and conductively connected to the board unit
Implementation Method 2
Each of the first sensor and the third sensor may detect movement of the moving unit in an x-axis direction in a plane perpendicular to the optical axis, and the second sensor may detect movement of the moving unit in a y-axis direction in the plane perpendicular to the optical axis
Implementation Method 3
The fixed unit may include a first magnet facing the first sensor in a direction parallel to the optical axis, a second magnet facing the second sensor in the direction parallel to the optical axis, and a third magnet facing the third sensor in the direction parallel to the optical axis
Data Source
AI summary
One embodiment comprises: a fixing part; a moving part including a substrate part arranged to be spaced from the fixing part, and an image sensor arranged on the substrate part; a shape memory alloy member which is coupled to the fixing part and the moving part, and which is electrically connected to the substrate part; a location sensing unit including first, second and third sensors arranged on the substrate part; and a control unit which supplies a driving signal to the shape memory alloy member, and which moves the moving part in the direction that is perpendicular to the optical axis or rotates the moving part around the optical axis by means of the shape memory alloy member.