Lens Drive Roller Rail Mechanism for Extended Movable Distance
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Solution Overview
Problem
Conventional lens driving devices for camera modules have limited movable distance due to the elastic range of springs, restricting their use to only auto focus functions and not allowing for zoom functions.
Innovation Solution
A lens driving device comprising a bobbin with a magnet and coil configuration, along with a roller and rail system that allows increased movement, enabling both auto focus and zoom functions by minimizing frictional force through a two-point contact mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a spring is used to support the bobbin movement, then the structure is simple, but the movable distance is limited within the elastic range of the spring
Solution Approach 1:
The patent replaces the spring-based mechanical support system with a magnetic field-based support system. The bobbin is supported by magnetic repulsion force between magnets attached to the bobbin and a magnetic sheet on the housing, eliminating the elastic range limitation of springs while enabling longer movable distances for both auto focus and zoom functions.
2Adaptability or versatility
If the movable distance is increased for zoom function, then the versatility is improved, but the frictional force increases
Solution Approach 1:
The patent eliminates mechanical contact between the bobbin and housing by using magnetic repulsion force for support. This substitution of mechanical support with magnetic field interaction dramatically reduces frictional force, enabling smooth long-distance movement required for zoom functionality while maintaining auto focus capability.
Solution Approach 2:
The patent changes the physical state of interaction from mechanical contact to magnetic field interaction. By attaching magnets to the bobbin and a magnetic sheet to the housing, the system transitions from solid-to-solid contact with high friction to field-based interaction with minimal resistance, enabling extended movable distance for versatile 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 increases the movable distance of the bobbin, enabling the lens driving device and camera module to perform both auto focus and zoom functions effectively, with reduced frictional force and enhanced operational range.
Implementation Method 1
a magnet disposed on the bobbin; a coil disposed on the housing and facing the magnet
Data Source
AI summary
A lens drive device includes a housing; a bobbin arranged inside the housing; a magnet arranged on the bobbin; a coil arranged on the housing and facing the magnet; a coupling member arranged on the inner surface of the housing; a roller rotatably arranged on the coupling member; and a rail arranged on the bobbin. The rail is guided according to the rotation of the roller.