Camera Module Magnetic Field Shaping for Long-Stroke Lens Motion
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Solution Overview
Problem
Existing camera modules face challenges with increased component count and complex control operations due to the need for miniaturization and diverse functionalities, particularly in Lorentz type driving modules.
Innovation Solution
A camera module design with a moving frame and fixed frame configuration, utilizing a magnet and coil arrangement with a magnetic field blocking unit, where the coil height exceeds the magnet height, and a magnetic field blocking unit is positioned to concentrate magnetic field effects, minimizing component count and simplifying control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the number of magnets and coils is increased to increase the moving distance of the lens assembly, then the stroke distance is improved, but the number of components and control complexity increase
Solution Approach 1:
The coil is designed with different heights in the optical axis direction, creating a non-uniform magnetic field distribution along the optical axis. This dimensional variation allows a single coil to generate differentiated magnetic forces at different positions, enabling long stroke movement without increasing the number of coil components.
Solution Approach 2:
The magnetic field blocking unit is positioned at the center portion of the coil to concentrate and shape the magnetic field in specific regions. This local modification of magnetic field distribution creates distinct force zones within a single coil-magnet assembly, allowing controlled movement over a long distance without adding more components.
2Length of moving object
If the number of magnets and coils is increased to increase the moving distance of the lens assembly, then the stroke distance is improved, but the control operation becomes complicated
Solution Approach 1:
The single coil is designed to perform multiple functions by having different heights, allowing it to generate different magnetic force magnitudes at different optical axis positions. This multi-functionality enables the coil to control the magnet's movement throughout the entire long stroke distance without requiring multiple separate control circuits.
Solution Approach 2:
The magnetic field strength and force distribution are changed by varying the coil height parameter. This creates a gradient magnetic field that naturally guides the magnet through the desired range of motion, simplifying control operations compared to systems requiring multiple discrete components.
3Length of moving object
If the coil height is increased to exceed the magnet height, then the magnetic field distribution is improved for long stroke movement, but the device volume increases
Solution Approach 1:
The coil height variation is implemented specifically in the optical axis direction, utilizing the Z-dimension efficiently. This allows the magnetic field to extend over a long distance in the critical optical axis direction while maintaining compact dimensions in other directions, optimizing the device volume for its primary function.
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
This design enables a long stroke movement with reduced components and simplified control, enhancing the functionality of the camera module.
Implementation Method 1
in a Lorentz type driving module, the coil or the magnet is moved in parallel by a Lorentz force
Implementation Method 2
a magnetic field blocking unit, the coil being spaced apart from the magnet in the first direction and the magnetic field blocking unit being arranged at a center portion of the coil
Data Source
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AI summary
A camera module includes at least one lens assembly, a moving frame mounted with the at least one lens assembly, moving the at least one lens assembly in an optical axis direction, and including a magnet having an N pole and an S pole arranged in a first direction perpendicular to the optical axis direction, and a fixed frame supporting the moving frame to be movable in the optical axis direction, and including a coil and a magnetic field blocking unit, the coil being spaced apart from the magnet in the first direction and the magnetic field blocking unit being arranged at a center portion of the coil and extending in the optical axis direction, wherein the coil includes a first region provided between the magnetic field blocking unit and the magnet, and a second region provided to face the first region with the magnetic field blocking unit therebetween.