Electrical Field Tomography Interface for Large-Area Gesture Sensing

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Solution Overview

Problem

Existing touch-sensitive systems face challenges in scaling up to larger surfaces due to tradeoffs between detection speed and accuracy, requiring more hardware and complex signal processing, which complicates multi-touch input and gesture recognition.

Innovation Solution

The use of electrical tomography techniques, such as electrical impedance tomography (EIT), electrical field tomography (EFT), and electrical capacitive tomography (ECT), to create advanced touch-sensitive systems that can detect touch and hover operations with high accuracy and speed, enabling systems to 'see' and 'predict' interactions like humans.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If traditional touch-sensitive systems are scaled up to larger surfaces, then coverage area increases, but detection speed and accuracy deteriorate due to increased hardware requirements and complex signal processing

Engineering Contradiction:
Improvetouch surface areaVSAvoiddetection speed
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The patent replaces traditional mechanical/electrical touch sensing hardware with electrical field-based sensing. By using electrical field tomography to detect changes in electrical fields caused by touch or hover operations, the system achieves large-area coverage without proportionally increasing hardware complexity, thereby maintaining fast detection speeds across extended surfaces.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The electrical field sensing system serves multiple functions simultaneously: it detects touch operations, hover operations, and can potentially identify gesture patterns. This multi-functionality is achieved through a unified electrical field measurement approach that processes different types of interactions through the same sensing mechanism, reducing overall system complexity while expanding capabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Area of stationary object

If traditional touch-sensitive systems are scaled up to larger surfaces, then coverage area increases, but hardware complexity and signal processing requirements increase

Engineering Contradiction:
Improvetouch surface areaVSAvoidhardware complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical/electrical touch sensing hardware with electrical field-based sensing. By using electrical field tomography to detect changes in electrical fields caused by touch or hover operations, the system achieves large-area coverage without proportionally increasing hardware complexity, thereby maintaining fast detection speeds across extended surfaces.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system changes the fundamental measurement parameter from electrical contact resistance or capacitance changes to electrical field distribution patterns. This parameter change enables the use of tomographic reconstruction algorithms that can process data from fewer sensors to create detailed images of touch locations and characteristics, reducing hardware requirements while maintaining accuracy.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If detection accuracy is improved in traditional systems, then measurement precision increases, but processing time and hardware requirements increase

Engineering Contradiction:
Improvetouch detection accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary calibration by establishing baseline electrical field patterns for different regions of the touch surface before actual operation. This pre-characterization of the electrical field distribution allows for faster real-time processing during actual touch detection, as the system only needs to compare current measurements against pre-stored reference patterns rather than performing full analysis from scratch.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces traditional mechanical/electrical touch sensing hardware with electrical field-based sensing. By using electrical field tomography to detect changes in electrical fields caused by touch or hover operations, the system achieves large-area coverage without proportionally increasing hardware complexity, thereby maintaining fast detection speeds across extended surfaces.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

These systems achieve fast and accurate detection of touch and hover events, allowing for improved multi-touch interactivity and gesture recognition, even on large surfaces, with reduced hardware complexity and faster processing times.

Implementation Method 1

leverage electrical impedance tomography (EIT), electrical capacitive (ECT) tomography, electrical field tomography (EFT), and/or other electrical field sensing technologies

Methodology Applied
Scientific EffectElectrical Impedance Tomography: Electrical Impedance Tomography

Implementation Method 2

create and passively detecting changes in electrical fields

Methodology Applied
Scientific EffectElectrical Field: Electric Field

Data Source

PatentUS11635803B2Industrial safety systems and/or methods for creating and passively detecting changes in electrical fields
Publication Date: 2023.04.25 GUARDIAN GLASS LLC
  • US11635803B2 patent drawing
  • US11635803B2 patent drawing
  • US11635803B2 patent drawing

AI summary

A detection system has an interface including a substrate supporting a conductive coating. Electrodes are provided to the substrate. A multiplexer provides current to the electrodes. A demultiplexer receives voltages from electrodes and provides corresponding signals to a controller. The controller receives these signals and determines therefrom an operation performed in connection with the interface by applying an algorithmic approach. Static interaction is recognizable, and machine learning can be used for gesture recognition and/or identification of other interaction types. The technology can be used in a broad array of applications, e.g., where it is desirable to sense interactions with a defined region such as, for example, in the case of touches, gestures, hovers, and/or the like.