Rotational Angle Sensor IC Substrate Orientation for Compact Design
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Solution Overview
Problem
Conventional position detecting devices experience accuracy deterioration due to external magnetic fields and have a larger size, which affects the precision and compactness of rotational angle detection.
Innovation Solution
A position detecting device is designed with multiple magnetic field generators and a yoke forming a closed magnetic circuit, where Hall elements are positioned within a region surrounded by these generators and yoke, reducing noise from external magnetic fields and allowing the IC substrate to extend along the rotational axis, thereby enhancing robustness and reducing device size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the IC substrate is arranged so that the one surface of the IC substrate extends along the magnetic flux lines of the magnetic field formed by the magnet, then the size is increased in a direction perpendicular to the rotational axis, but the measurement precision is maintained
Solution Approach 1:
The patent reorients the IC substrate so that its one surface extends along the rotational axis direction rather than along the magnetic flux lines. This dimensional reorientation allows the Hall elements to detect magnetic flux through the thickness direction of the substrate, reducing the device size in the direction perpendicular to the rotational axis while maintaining detection accuracy through proper alignment of the magnetic field with the Hall element sensing direction.
2Volume of moving object
If the Hall elements are positioned outside the region surrounded by the magnetic field generators and yoke, then the device size is reduced, but the accuracy of detecting a rotational angle deteriorates due to external magnetic fields
Solution Approach 1:
The patent positions the Hall elements within the region surrounded by the magnetic field generators and yoke, converting the potential harm of external magnetic field interference into a beneficial shielding effect. The yoke and magnetic field generators form a closed magnetic circuit that acts as a magnetic shield, containing the magnetic field within the designated region and blocking external magnetic fields from reaching the Hall elements, thereby improving measurement accuracy while maintaining compact device size.
3Measurement precision
If the Hall elements are positioned within a region surrounded by the magnetic field generators and yoke, then the accuracy of detecting a rotational angle is improved by suppressing external magnetic field noise, but the device complexity increases
Solution Approach 1:
The yoke serves multiple functions simultaneously: it forms part of the closed magnetic circuit to guide and concentrate the magnetic field for accurate detection, and it acts as a magnetic shield to block external magnetic field interference from reaching the Hall elements. This multi-functionality reduces the need for separate shielding components, thereby improving measurement accuracy while minimizing the increase in device complexity.
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 enhances the accuracy of rotational angle detection by minimizing noise from external magnetic fields and decreasing the device's size, while maintaining robustness against environmental temperature changes.
Implementation Method 1
two vertical Hall elements, and a lateral Hall element. The magnet generates a magnetic field having magnet flux lines in a direction perpendicular to a rotational axis of detection object. The IC substrate has a plate shape and is disposed in the magnetic field. The two vertical Hall elements are disposed in one surface of the IC substrate to detect a magnetic flux in a direction parallel to the one surface. The lateral Hall element detects a magnetic flux in a direction perpendicular to the one surface.
Data Source
AI summary
The present disclosure provides a rotational angle detecting device. An IC substrate has a flat surface extending along a rotational axis of a throttle valve. Yokes forms, together with the magnets, a closed magnetic circuit. A first Hall element outputs a first signal according to the magnetic flux density in a first direction along the flat surface. A second Hall element outputs a second signal according to the magnetic flux density in a second direction intersecting the flat surface. The first and second Hall elements are positioned within a region that is surrounded by the magnets and the yoke and that is between an edge surface and an edge surface.