Optical Element Driving Mechanism with Magnetoresistance Sensors
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Solution Overview
Problem
Current optical element driving mechanisms using Hall effect sensors for voice coil motors face challenges such as increased volume and complexity due to the need for multiple sensors, inadequate sensitivity for small-angle rotation, and signal interference from other axial directions, making miniaturization difficult.
Innovation Solution
The proposed optical element driving mechanism employs magnetoresistance sensors and a directional sensing magnet configuration, where a first sensing magnet and corresponding magnetoresistance sensors detect displacement in perpendicular directions, reducing the number of required sensing magnets and simplifying circuit design, while maintaining sensitivity and avoiding signal interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two Hall effect sensors are used on each axis to measure large-angle rotation, then measurement capability is improved, but device volume and circuit complexity increase
Solution Approach 1:
The patent combines multiple sensing functions into a single Hall effect sensor by using a magnet array with multiple poles arranged in a specific pattern. The single sensor detects the composite magnetic field signal, which contains information about rotation angle, thereby eliminating the need for multiple separate sensors and reducing circuit complexity.
Solution Approach 2:
The single Hall effect sensor is designed to perform multiple measurement functions simultaneously - it can measure both large-angle rotation and small-angle rotation, as well as detect displacement in multiple directions, by processing the composite magnetic field signal from the multi-pole magnet configuration.
2Measurement precision
If two Hall effect sensors are used on each axis to measure large-angle rotation, then measurement capability is improved, but device volume increases
Solution Approach 1:
The patent merges multiple sensing elements into a single Hall effect sensor that detects the composite magnetic field from a multi-pole magnet array. This consolidation reduces the number of discrete components and decreases the overall volume of the driving mechanism while maintaining the capability to measure large-angle rotation.
3Device complexity
If Hall effect sensors are used for small-angle rotation measurement, then measurement capability is reduced, but device simplicity is maintained
Solution Approach 1:
The patent changes the magnetic field parameters by using a magnet array with multiple poles and specific pole arrangements. This creates a magnetic field gradient that enhances the sensitivity of the Hall effect sensor, enabling it to detect small-angle rotations with high precision while maintaining device simplicity.
Solution Approach 2:
The patent uses a composite magnetic field structure created by multiple magnet poles with different polarities arranged in a specific pattern. This composite magnetic field configuration amplifies the signal response to small angular displacements, improving measurement sensitivity without adding complex sensing hardware.
4Reliability
If sensing magnets are added to avoid signal interference from other axial directions, then signal accuracy is improved, but device volume and manufacturing difficulty increase
Solution Approach 1:
The patent applies local quality by creating a magnet array with specific pole arrangements and orientations tailored to each sensing location. The magnetic poles are strategically positioned to generate field patterns that are sensitive to displacement in one direction while being insensitive to displacement in other directions, thereby achieving directional selectivity without adding extra magnets.
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 more compact and efficient optical element driving mechanisms with improved sensitivity for both large and small-angle rotations, reducing the overall volume and complexity, and enhancing the miniaturization of the driving mechanism.
Implementation Method 1
The first sensing element is a magnetoresistance sensor
Implementation Method 2
Hall effect sensors and corresponding magnets are usually used to detect displacement in voice coil motors (VCM)
Data Source
AI summary
An optical element driving mechanism includes a fixed module, a movable module, an optical element, a first sensing magnet, and a first sensing element. The movable module is movably connected to the fixed module. The optical element is disposed on the movable module. The first sensing magnet is disposed corresponding to the optical element, and has a polar direction. The first sensing element is disposed corresponding to the first sensing magnet for sensing displacement of the first sensing magnet relative to the fixed module in a first direction, wherein the first direction is perpendicular to the polar direction.