Camera Module Magnet Layout for Low-Power AF and OIS
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional voice coil motor (VCM) technology is challenging to apply in micro-scale camera devices due to difficulties in achieving low power consumption while maintaining high performance for features like autofocus and optical image stabilization (OIS).
Innovation Solution
A camera device design incorporating a fixed unit with a first magnet and a moving unit featuring a coil, an image sensor, and yokes to enhance electromagnetic forces for AF and OIS operations, with a bipolar-magnetized magnet and strategically positioned yokes to improve driving forces and reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional VCM technology is used in micro-scale camera devices, then the device structure is simple, but the electromagnetic force for AF and OIS operations is insufficient and power consumption is high
Solution Approach 1:
The patent divides the magnet system into multiple magnets (first magnet, second magnet, third magnet) with different polarities arranged in a specific pattern. This segmentation creates multiple electromagnetic interaction zones between the magnets and the coil, thereby increasing the total electromagnetic force while maintaining efficient energy utilization in the micro-scale camera device
Solution Approach 2:
The patent employs asymmetric arrangement of magnets with different polarities (N and S poles) at different positions relative to the coil. This asymmetric configuration optimizes the magnetic field distribution to maximize electromagnetic force generation while minimizing energy loss, resolving the contradiction between force magnitude and power consumption
2Volume of moving object
If the camera device size is reduced to micro-scale, then the device portability is improved, but the electromagnetic force generation capability deteriorates
Solution Approach 1:
The patent implements a nested arrangement where multiple magnets are positioned within the limited space of the micro-scale camera device, with magnets of different polarities nested around the coil structure. This maximizes the use of available space to generate sufficient electromagnetic force despite the reduced overall device volume
Solution Approach 2:
The patent utilizes three-dimensional spatial arrangement of magnets with different polarities at various heights and radial positions relative to the coil. By optimizing the magnetic field distribution in multiple dimensions, the patent achieves effective electromagnetic force generation within the constrained micro-scale volume
3Ease of operation
If multiple magnets with different polarities are arranged to improve electromagnetic force, then the driving force for OIS operation is enhanced, but the device complexity increases
Solution Approach 1:
The patent designs the multi-magnet arrangement to serve dual functions: the same set of magnets with different polarities provides both autofocus (AF) driving force along the optical axis and optical image stabilization (OIS) driving force in perpendicular directions. This multi-functionality enhances OIS performance without proportionally increasing device complexity
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 design enhances electromagnetic forces for both autofocus and OIS operations, reducing power consumption and improving the linearity of displacement output, thereby addressing the limitations of conventional VCM technology in micro-scale camera devices.
Implementation Method 1
The second moving unit is moved in a direction perpendicular to the optical-axis direction by interaction between the first magnet and the second coil
Implementation Method 2
a first moving unit, which includes a first coil and is configured to be moved in an optical-axis direction by interaction between the first magnet and the first coil
Data Source
AI summary
An embodiment comprises: a stationary part; a first magnet disposed in the stationary part; a first movable part including a first coil and moving in an optical-axis direction by interaction between the first magnet and the first coil; a second movable part including a first substrate portion spaced apart from the stationary part, a second coil opposite to the first magnet in the optical-axis direction, and an image sensor disposed in the first substrate portion; and a first yoke disposed in the stationary part and arranged to be opposite to the first magnet in the optical-axis direction, wherein the second movable part moves in a direction perpendicular to the optical-axis direction by interaction between the first magnet and the second coil.