Lens Position Detection Using Composite Magnetic Fields
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Solution Overview
Problem
Position detection units using magnetic sensors face challenges in achieving high detection accuracy, particularly in accurately tracking the position of moving lenses in imaging apparatuses, such as those found in cameras, due to limitations in existing magnetic field generation and sensing technologies.
Innovation Solution
The implementation of a position detection unit comprising a magnetic sensor, a first magnetic field generator with a first magnet, and a second magnetic field generator with a second magnet, where the second magnet is movable and has a different magnetic material and shape, generating a composite magnetic field that the sensor can detect for positional changes, enhancing sensitivity and reducing temperature-dependent errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single magnetic field generator is used, then the device complexity is reduced, but the detection precision is insufficient
Solution Approach 1:
The magnetic field detection system is divided into two separate magnetic field generators: a first magnetic field generator that generates a primary magnetic field, and a second magnetic field generator that generates a secondary magnetic field. This segmentation allows each generator to be optimized for specific functions, improving overall detection precision while maintaining manageable device complexity through modular design.
2Measurement precision
If magnets with different magnetic materials and shapes are used, then the detection precision is improved, but the manufacturing precision requirements increase
Solution Approach 1:
Different magnetic materials and shapes are used for the first and second magnets based on their specific functional requirements. The first magnet uses a magnetic material optimized for generating a strong primary magnetic field, while the second magnet uses a different magnetic material and shape optimized for generating the secondary magnetic field. This local quality approach allows each component to be manufactured with precision tailored to its specific function, rather than requiring uniform high precision across all components.
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 significantly improves the accuracy of lens position detection, reduces temperature-induced variations, and enhances the overall performance of imaging apparatuses by providing a more precise and stable detection mechanism.
Implementation Method 1
The first magnetic field generator includes a first magnet and generates a first magnetic field. The second magnetic field generator includes a second magnet, generates a second magnetic field
Implementation Method 2
The magnetic sensor is configured to generate a detection signal that corresponds to the direction of a magnetic field of interest, and configured to detect a positional change of the second magnetic field generator
Data Source
AI summary
A position detection unit includes a magnetic sensor, a first magnetic field generator, and a second magnetic field generator. The first magnetic field generator includes a first magnet and generates a first magnetic field. The first magnet includes a first magnetic material and has a first shape. The second magnetic field generator includes a second magnet, generates a second magnetic field, and is movable along a first direction with respect to the first magnetic field generator and the magnetic sensor. The second magnet includes a second magnetic material and has a second shape. The magnetic sensor generates a detection signal corresponding to the direction of a magnetic field of interest, and detects a positional change of the second magnetic field generator. The magnetic field of interest is a composite of the first magnetic field along a first plane and the second magnetic field along the first plane.