Camera Actuator Magnetic Drive for Low-Friction Lens Positioning
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Solution Overview
Problem
Existing camera modules face issues with optical performance due to misalignment of lens groups, increased friction leading to reduced driving force and power consumption, and assembly defects, which affect autofocus and image stabilization functions.
Innovation Solution
A camera actuator design with a specific arrangement of magnets, yokes, coils, and ball bearings that allows precise alignment and reduced contact points, using asymmetrical guide portions and adhesive coupling to manage lens assemblies effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a ball bearing is used in the actuator to enable mechanical movement, then the lens can be moved for autofocus and zooming functions, but frictional torque is generated which reduces driving force, increases power consumption, and deteriorates control characteristics
Solution Approach 1:
The patent replaces the traditional mechanical ball bearing system with a magnetic field-based driving system. The actuator uses a magnet, coil, and yoke configuration to generate electromagnetic force that moves the lens assembly without physical contact, eliminating frictional torque and the need for ball bearings while maintaining lens movement capability for autofocus and zooming functions
2Manufacturing precision
If the actuator includes a ball bearing for mechanical movement, then the lens can be positioned, but the camera module needs to strictly manage the ball bearing and contact components which increases the number of management factors, widens dispersion, and increases product defects
Solution Approach 1:
The patent extracts and removes the ball bearing and its associated contact components from the actuator system. By eliminating these mechanical elements, the design reduces the number of components that require strict management and quality control, thereby reducing dispersion and product defects while maintaining lens positioning capability through electromagnetic actuation
3Ease of manufacture
If the center of the spherical surface between lens groups deviates from the optical axis or lens groups are misaligned, then assembly is simpler, but image quality and resolution deteriorate due to tilt and misalignment
Solution Approach 1:
The patent employs a magnet holder that integrates multiple functions: it positions the magnet, provides a mounting interface for the lens assembly, and serves as a reference for optical alignment. This multi-functional component enables precise alignment of lens groups with the optical axis while maintaining assembly simplicity, as the magnet holder structure itself provides alignment references that eliminate the need for complex separate alignment procedures
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
Improves optical characteristics, reduces assembly defects, and enhances autofocus and image stabilization by maintaining precise alignment and controlling vibrations, resulting in improved image quality and resolution.
Implementation Method 1
a driving portion for moving the second lens assembly in an optical axis direction... the driving portion includes a magnet disposed on the magnet holder, a yoke facing the magnet in a first direction, a coil disposed between the magnet and the yoke
Data Source
AI summary
A camera actuator disclosed to an embodiment includes a first lens assembly, a second lens assembly disposed under the first lens assembly and including a second lens portion, a third lens assembly disposed under the second lens assembly, a driving portion for moving the second lens assembly in an optical axis direction, and a magnet holder disposed between the second lens assembly and the driving portion. The driving portion includes a magnet disposed on the magnet holder, a yoke facing the magnet in a first direction, and a coil disposed between the magnet and the yoke, and a center of the yoke may be disposed on a plane different from a first plane passing through the optical axis and a center of the magnet.