Magnetic Sensor With Converging Areas For Flux Isolation
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Solution Overview
Problem
Magnetic sensors with three magnetic layers forming two gaps suffer from reduced detection accuracy due to magnetic flux interference between bridge-connected magnetic sensing elements, as current flowing in one element affects the other.
Innovation Solution
A magnetic sensor design with four bridge-connected magnetic sensing elements, utilizing three magnetic layers with converging areas and external magnetic members to isolate and balance magnetic flux, preventing interference and enhancing detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If three magnetic layers are used to form two gaps with four bridge-connected magnetic sensing elements, then the bridge circuit can be constituted, but magnetic flux generated by current in one sensing element interferes with adjacent elements, deteriorating detection accuracy
Solution Approach 1:
The patent divides the magnetic sensing structure into four separate gaps instead of using two gaps. Each gap is isolated by magnetic walls that extend from the sensor substrate, creating independent magnetic flux paths. This segmentation prevents magnetic flux generated by current in one sensing element from interfering with adjacent elements, thereby improving detection accuracy while maintaining the bridge circuit configuration.
2Measurement precision
If magnetic layers are used to concentrate magnetic flux on sensing elements, then detection accuracy can be enhanced, but the number of gaps is limited to two, requiring two sensing elements per gap which causes current interference
Solution Approach 1:
The patent transitions from a two-gap configuration to a four-gap configuration by utilizing the planar dimension of the sensor substrate more effectively. Magnetic walls are extended from the substrate to create additional isolated gaps, allowing four sensing elements to be arranged with each occupying its own gap. This dimensional expansion eliminates the need to place multiple elements in the same gap, preventing current interference while maintaining flux concentration.
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 achieves higher detection accuracy by isolating magnetic flux between sensing elements and ensuring balanced magnetic flux distribution, reducing leakage and improving selectivity.
Implementation Method 1
a plurality of magnetoresistance effect elements whose resistance value changes according to the direction of a detection magnetic field are connected
Implementation Method 2
magnetic flux to be detected is concentrated on the magnetic sensing element by the magnetic layer
Implementation Method 3
magnetic sensors can be provided with an external magnetic member for collecting magnetic flux to a magnetic sensing element
Data Source
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AI summary
An object of the present invention is to enhance detection accuracy of a magnetic sensor having four bridge-connected magnetic sensing elements. A magnetic sensor includes magnetic layers 41-43 provided on a surface of the sensor substrate 20 and bridge-connected magnetic sensing elements R1-R4. The magnetic layer 41 includes a main area M1 and a converging area S1 having a width gradually reduced with increasing distance from the main area M1, the magnetic layer 42 includes a main area M2 and converging areas S5, S7 each having a width gradually reduced with increasing distance from the main area M2, and the magnetic layer 43 includes a main area M3 and converging areas S6, S8 each having a width gradually reduced with increasing distance from the main area M3. The end portions of the converging areas S1-S4 and the end portions of the converging areas S5-S8 face each other, respectively, through gaps G1-G4, respectively. The magnetic sensing elements R1-R4 are disposed on magnetic paths formed by the gaps G1-G4, respectively. According to the present invention, detection accuracy is enhanced because a magnetic flux generated by current flowing in one magnetic sensing element does not affect the other sensing element.