Shape Memory Alloy Aperture Switching for Camera Modules
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Solution Overview
Problem
Conventional aperture switcher structures in mobile phone camera modules are complex and difficult to miniaturize, with electromagnetic interference issues and a lack of modularity, making them unsuitable for integration with camera motor structures.
Innovation Solution
A simplified aperture switching device using a shape memory alloy wire, clamping parts, a movable bump, sliding groove, and optical aperture switching unit with light-shielding sheets, allowing independent mounting on camera lenses and adjusting aperture sizes without electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a voice coil motor type aperture switcher is used, then the aperture switching function is achieved, but the driving structure becomes complex and the volume cannot be easily reduced
Solution Approach 1:
The patent replaces the electromagnetic voice coil motor with a shape memory alloy wire-based actuation system. The shape memory alloy wire undergoes phase transformation under electrical stimulation to produce mechanical displacement, directly driving the aperture blade without requiring complex electromagnetic coils, magnets, and control circuits. This substitution dramatically simplifies the driving structure and reduces the overall volume of the aperture switcher.
Solution Approach 2:
The patent utilizes the phase transformation parameter change of the shape memory alloy wire (from austenite to martensite phase) to achieve large-strain actuation. By controlling the electrical current parameters, the shape memory alloy wire can reversibly change its length, providing the necessary driving force for aperture switching with a compact structure.
2Adaptability or versatility
If the aperture switcher structure is integrated with the camera motor structure, then assembly is simplified, but the aperture switcher cannot be a separate functional component for selective assembly
Solution Approach 1:
The patent divides the aperture switcher into independent modular components: the optical aperture switching unit with light-shielding sheets, the shape memory alloy wire actuator, the sliding groove mechanism, and the mounting interface. This segmentation allows the aperture switcher to be designed, tested, and assembled as a separate functional module that can be selectively integrated with different camera module configurations without forcing integration complexity.
Solution Approach 2:
The patent designs the aperture switcher with a universal mounting interface and standardized connection protocols that enable it to function as a standalone component compatible with various camera module types. The shape memory alloy wire actuation mechanism provides universal actuation capability, and the modular structure allows the same aperture switcher design to be adapted to different lens configurations and form factors.
3Object-affected harmful factors
If an electromagnetic component is used in the aperture switcher, then aperture control is achieved, but electromagnetic interference is generated with the camera voice coil motor
Solution Approach 1:
The patent replaces the electromagnetic aperture control mechanism with a shape memory alloy-based mechanical actuation system. The shape memory alloy wire responds to electrical stimulation through solid-state phase transformation rather than electromagnetic interaction, producing mechanical displacement to drive the aperture blade. This eliminates electromagnetic field generation from the aperture switcher, preventing interference with the camera's voice coil motor while maintaining reliable aperture control through the shape memory effect.
Solution Approach 2:
The patent introduces the shape memory alloy wire as an intermediary between the electrical control signal and the mechanical aperture adjustment. Instead of directly using electromagnetic forces to move the aperture blade, the electrical signal triggers a phase transformation in the shape memory alloy, which then mechanically pushes the aperture through a sliding groove mechanism. This intermediary approach decouples the electrical control from electromagnetic field generation, eliminating interference while preserving control functionality.
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 solution enables a compact, adjustable aperture switching device that can be easily integrated with camera modules, reducing complexity and electromagnetic interference, and allowing for precise control of light entrance to the lens.
Implementation Method 1
a shape memory alloy wire having two ends respectively electrically connected to the clamping parts
Implementation Method 2
an elastic member disposed between the position regulating part and the movable bump
Data Source
AI summary
An aperture switching device is described that includes a base, a casing fitted to cover the base, and clamping parts fixed to the base. The clamping parts are driving power source input terminals and a shape memory alloy wire with two ends electrically connects the clamping parts. The base has a first light transmission hole, a rotary connecting part, a sliding groove, and a position regulating part. The casing has a second light transmission hole that corresponds to the first light transmission hole. A movable bump is connected to the shape memory alloy wire and slidably disposed within the sliding groove. An elastic member is disposed between the position regulating part and the movable bump. An optical aperture switching unit is positioned with one end portion mounted on the rotary connecting part and the end portion includes a switching slot mounted on the movable bump.