Lens Drive Coil-Spring Layout for Compact Camera Module Reliability
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Solution Overview
Problem
Existing camera modules, particularly those in miniature low-power devices like smartphones, face challenges with structural complexity, size reduction, and electromagnetic force enhancement while preventing disconnection and separation of AF drive coils, as well as magnetic-field interference.
Innovation Solution
A lens moving apparatus with a simplified structure, incorporating a housing with a bobbin, magnets, coils, and springs, which includes a sensing magnet and a balancing magnet to enhance electromagnetic force and linearity, and suppress magnetic-field interference, thereby preventing coil disconnection and separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the camera module structure is simplified, then manufacturing ease and device complexity are improved, but reliability may worsen due to potential coil disconnection and separation
Solution Approach 1:
The patent combines the AF drive coil and AF drive magnet into an integrated assembly that moves together as a single unit. The coil is fixed to the bobbin which is coupled to the magnet, eliminating separate connection points and preventing disconnection during operation. This merging approach simplifies the overall structure while maintaining reliability.
Solution Approach 2:
The patent establishes predetermined connection paths and structural arrangements during the design phase to prevent coil disconnection. The bobbin is designed with specific coupling mechanisms to the magnet and housing that ensure stable connections before operation begins, preventing separation during use.
2Volume of moving object
If the camera module size is reduced, then compactness is improved, but electromagnetic force may worsen due to limited space for coils and magnets
Solution Approach 1:
The patent optimizes the local arrangement of magnetic poles and coil windings to maximize electromagnetic force density within the limited space. The magnet is divided into multiple poles with specific polarity patterns, and the coil is positioned to closely match the magnetic field distribution, enhancing force generation in a compact volume.
Solution Approach 2:
The patent utilizes three-dimensional space efficiently by arranging the coil and magnet in a radial configuration rather than a linear one. The coil wraps around the magnet in a cylindrical arrangement, utilizing the radial dimension to increase the effective interaction area between magnetic field and current, thereby generating stronger electromagnetic force in a compact form factor.
3Force
If magnets and coils are positioned to increase electromagnetic force, then force is improved, but magnetic-field interference may worsen affecting linearity in displacement
Solution Approach 1:
The patent employs asymmetric positioning of the sensing magnet relative to the AF drive magnet, and places magnetic shielding materials at specific locations to counterbalance interference fields. The shielding arrangement is asymmetric to effectively cancel out magnetic flux leakage in critical areas while maintaining the desired electromagnetic force for actuation.
4Reliability
If multiple components are integrated to prevent coil disconnection, then reliability is improved, but device complexity may worsen
Solution Approach 1:
The patent merges the AF drive coil, bobbin, and AF drive magnet into a single integrated assembly that moves together. This combination eliminates the need for separate mounting structures and connection mechanisms, reducing overall device complexity while ensuring the coil remains securely attached and preventing disconnection during operation.
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 achieves a reduced size, increased electromagnetic force, and improved linearity in displacement, while simplifying the structure and preventing coil disconnection, effectively addressing the challenges faced by existing camera modules.
Implementation Method 1
a first coil disposed at the housing so as to correspond to the first magnet, a second coil disposed at the housing so as to correspond to the second magnet
Implementation Method 2
first to third springs coupled to the bobbin
Data Source
AI summary
An embodiment of the present invention comprises: a housing; a bobbin disposed within the housing; a first magnet disposed on a first side of the bobbin; a second magnet disposed on a second side of the bobbin; a first coil disposed in the housing so as to correspond to the first magnet; a second coil disposed in the housing so as to correspond to the second magnet; first to third springs coupled to the bobbin; and a circuit board disposed in the housing and having first and second terminals, wherein the first spring connects one end of the first coil with the first terminal of the circuit board, the second spring connects one end of the second coil with the second terminal of the circuit board, and the third spring connects the other end of the first coil with the other end of the second coil.