Magnetometer Array Layout for Accurate Magnetic Input Detection
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Solution Overview
Problem
Existing electronic devices with magnetometers face inaccuracies and unreliability in determining the location of user-borne devices due to ferromagnetic and ferrimagnetic elements, and limited placement options for magnetometer arrays.
Innovation Solution
The arrangement of magnetometers on the sides, front, and rear of electronic devices, such as laptops, extends the sensing volume and improves detection accuracy by enhancing the signal-to-noise ratio, using flexible printed circuit boards to conform to the device's curvature, and integrating magnetometers along the edges to cover areas like the keyboard.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetometers are arranged in a limited placement configuration, then device complexity is reduced, but measurement precision deteriorates due to inaccurate location determination
Solution Approach 1:
The magnetometer array is divided into multiple discrete magnetometers positioned at specific locations around the enclosure (front, rear, left, right sides). This segmentation allows each magnetometer to contribute to location determination in its local region, improving overall measurement precision while maintaining manageable device complexity through modular arrangement.
Solution Approach 2:
Multiple magnetometer measurements from different locations are combined through triangulation algorithms to determine the precise location of magnetic objects. By merging data from multiple sensing points, the system achieves high measurement precision without requiring an overly complex single-point sensing system.
2Measurement precision
If magnetometers are placed away from enclosure surfaces, then measurement precision improves, but the sensing volume is reduced
Solution Approach 1:
Magnetometers are positioned at multiple three-dimensional locations around the enclosure (front, rear, left, right sides at different heights), creating a volumetric sensing array. This spatial distribution in multiple dimensions extends the sensing volume throughout the enclosure space while maintaining adequate distance from surfaces to preserve signal-to-noise ratio.
3Volume of moving object
If magnetometers are integrated along device edges, then sensing volume is extended, but manufacturing precision requirements increase
Solution Approach 1:
The magnetometer array configuration and placement specifications are predetermined in the design phase, with specific locations defined relative to the enclosure geometry. This preliminary planning allows manufacturing processes to follow established guidelines, reducing the actual manufacturing precision requirements while still achieving the desired extended sensing volume coverage.
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 detecting user interactions by expanding the sensing volume and improving signal-to-noise ratio, particularly in areas where accessories like computer mice and styli are used, while meeting integration constraints.
Implementation Method 1
the provision of a plurality of magnetometers allows to measure a magnetic field associated with a magnetic object arranged in or coupled to the user-borne device
Data Source
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AI summary
An electronic device (10, 800) configured to obtain user interactions from a user-borne device (100) comprising at least one magnetic object (110), wherein the electronic device (10, 800) comprises an enclosure (12) comprising a plurality of surfaces (14, 16, 18, 20), wherein the enclosure (12) defines a mounting region of a plurality of components, wherein a spatial extent of the enclosure (12) is characterised by an orthogonal set of dimensions comprising a length (L), a width (W), and a height (H), and a first plurality of magnetometers (MA1) relative to a reference coordinate system of the enclosure (12), wherein the first plurality of magnetometers (MA1) is encompassed by the enclosure (12). The first plurality of magnetometers (MA1) is located within a first portion (14a) of the enclosure (12), wherein the location of the first portion (14a) is within a first outer boundary plane coterminous with a first surface (14) of the enclosure (12), and a first inner boundary plane (14b) parallel to the first outer boundary plane.