Lens Drive Device with Shared Magnets for Compact Camera Modules
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Solution Overview
Problem
Conventional lens driving devices for camera modules in mobile terminals face challenges in further downsizing and power saving, especially with the increasing demand for higher camera module functionality and reduced thickness in mobile terminals.
Innovation Solution
The lens driving device incorporates an auto-focusing driving part with an auto-focusing coil and magnet, and a shake-correcting driving part with a shake-correcting magnet and coil, both using voice coil motors, along with elastic supporting parts to reduce the movement range and power consumption, allowing for smaller size and lower power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the elastic supporting part is configured to connect the auto-focusing movable part and the auto-focusing fixing part, then the power consumption is reduced, but the device complexity increases
Solution Approach 1:
The elastic supporting part enables dynamic movement of the auto-focusing movable part while providing restoration force, allowing the system to adapt to different focusing positions without requiring complex mechanical constraints or additional actuators
Solution Approach 2:
The OIS magnet part serves dual functions as both the shake-correcting magnet part and the auto-focusing magnet part, reducing the number of components while maintaining both OIS and AF functionalities
2Volume of moving object
If the voice coil motor size is reduced, then the device size is downsized, but the driving force may be insufficient
Solution Approach 1:
The patent optimizes the magnetic field strength, coil turns, and current characteristics of the voice coil motors to maximize driving force output within a compact size, allowing sufficient focusing and shake correction performance in a downsized configuration
3Use of energy by moving object
If the auto-focusing movable part movement range is minimized, then the power consumption is reduced, but the focusing capability may be compromised
Solution Approach 1:
The patent implements partial action by limiting the movement range of the auto-focusing movable part to only the necessary distance required for effective focusing, avoiding excessive movement that would consume additional power while still achieving the required focusing capability
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 configuration enables reduced power consumption and further downsizing of the camera module by minimizing the movement range of the auto-focusing movable part and reducing the size of the voice coil motor, while maintaining effective focusing and shake correction capabilities.
Implementation Method 1
the auto-focusing movable part is moved with respect to an auto-focusing fixing part in the light axis direction by use of a driving force of a voice coil motor composed of the AF coil part and the AF magnet part
Implementation Method 2
The OIS movable part is swayed in a plane orthogonal to the light axis direction by use of a driving force of a voice coil motor composed of the OIS magnet part and the OIS coil part
Implementation Method 3
the AF movable part moves in the light axis direction until the driving force (driving power) of the voice coil motor of the AF driving part and the restoration force of the elastic supporting part are equivalent to each other
Data Source
AI summary
A lens drive device is provided with: an AF drive unit that has an AF coil unit disposed around a lens unit and an AF magnet unit disposed separately in the radial direction with respect to the AF coil unit and automatically carries out focusing; and an OIS drive unit that has an OIS magnet unit disposed in an AF unit that includes a movable AF unit and a fixed AF unit and an OIS coil unit disposed separately in the direction of the optical axis with respect to the OIS magnet unit and carries out shake correction. The AF drive unit has an elastic support unit that connects the movable AF unit with the fixed AF unit. The movable AF unit is supported movably both ways in the direction of the optical axis by an elastic member.