Aperture Magnet Position Sensing With Temperature-Compensated Hall Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing position detecting devices for aperture modules in camera modules face challenges in accurately detecting the position of a magnet due to changes in hall voltage caused by temperature variations, which affect the linearity and accuracy of aperture displacement detection.
Innovation Solution
A position detecting device that utilizes a combination of first and second hall devices, a subtractor, an adder, a divider, and a subtraction voltage changing unit to maintain a constant subtraction voltage at target points and transition sections, applying correction coefficients to the hall voltages to compensate for temperature-induced changes and ensure linearity in aperture displacement detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single hall device is used to detect magnet position, then the device structure is simple, but the detection accuracy deteriorates due to temperature-induced hall voltage changes
Solution Approach 1:
The patent divides the detection system into multiple hall devices (first hall device and second hall device) positioned at different locations. Each hall device independently detects magnetic flux, and their outputs are processed through subtraction and addition operations to separate position information from temperature drift, thereby improving measurement precision while maintaining reasonable structural complexity
Solution Approach 2:
The patent introduces intermediate processing components (subtractor, adder, divider) that act as mediators between the raw hall device outputs and the final position detection. These intermediaries process the voltage signals to eliminate temperature-induced offsets, enabling accurate position detection despite environmental variations
2Measurement precision
If temperature compensation is implemented using multiple hall devices and complex processing, then position detection accuracy is improved, but device complexity increases
Solution Approach 1:
The patent changes the processing parameters by performing mathematical operations (subtraction, addition, division) on the hall device outputs. By transforming the raw voltage signals through these parameter changes, the system extracts position information while canceling out temperature drift effects, achieving high accuracy without requiring complex hardware modifications
Solution Approach 2:
The patent implements a feedback mechanism where the detected position information is used to control the aperture blade movement. The system continuously monitors the magnet position through the hall devices and adjusts the aperture accordingly, creating a closed-loop control system that maintains precision despite temperature variations
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 solution effectively compensates for temperature-related changes in hall voltage, maintaining linearity and accuracy in detecting the position of the magnet, thereby improving the precision and reliability of aperture position detection.
Implementation Method 1
a first hall device configured to generate a first hall voltage, a second hall device configured to generate a second hall voltage
Data Source
AI summary
A position detecting device for detecting a position of a magnet configured to move over a first target point and a second target point in steps includes a first hall device configured to generate a first hall voltage, a second hall device configured to generate a second hall voltage, a subtractor configured to generate a subtraction voltage based on a difference between the first hall voltage and the second hall voltage, an adder configured to generate an addition voltage based on a combination of the first hall voltage and the second hall voltage, a divider configured to calculate a ratio of the subtraction voltage to the addition voltage, and a subtraction voltage changing unit configured to maintain the subtraction voltage at the first target point and the second target point and in a transition section between the first target point and the second target point to be constant.