Anechoic Dampening Material for Ultrasonic Touch Detection

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Solution Overview

Problem

Existing ultrasonic touch location detection systems face inefficiencies due to signal reflections from edges and boundaries, which consume excessive computational resources and can interfere with the detection of touch inputs, particularly on surfaces like glass where unwanted noise and higher order propagation modes are excited.

Innovation Solution

The use of an acoustic transmitter and receiver system with an acoustic dampening material, specifically a shaped dampening material with a gradual attenuation property and anechoic shape, to minimize signal reflections and selectively excite the AO propagation mode, reducing noise and improving detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If signal filters and other signal processing are utilized to reduce the effects of reflections, then the detection accuracy is improved, but the computation resources consumed increase excessively

Engineering Contradiction:
Improvedetection accuracyVSAvoidcomputation resources
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies anechoic material to the edges and boundaries of the touch-sensitive surface to absorb ultrasonic reflections that would otherwise interfere with touch detection. By converting the harmful reflected signals into absorbed energy, the system eliminates the need for complex computational filtering while maintaining high detection accuracy. The anechoic material physically removes the reflection problem at its source rather than attempting to process it computationally.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Ease of operation

If ultrasonic signals are transmitted through the touch detection surface, then touch location detection is enabled, but signal reflections from edges and boundaries interfere with detection

Engineering Contradiction:
Improvetouch detection capabilityVSAvoidsignal reflections
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the harmful reflection problem by applying anechoic material specifically to edges and boundaries where reflections originate. This targeted approach removes the interfering reflections from the system while preserving the useful ultrasonic signal transmission through the main body of the touch surface, allowing clean touch detection without edge interference.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The anechoic material serves as an intermediary element between the ultrasonic signals and the edge boundaries. Instead of allowing direct interaction between signals and hard edges that cause reflections, the anechoic material mediates by absorbing the ultrasonic energy, preventing harmful reflections while maintaining the overall functionality of the touch detection system.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach enhances the efficiency of touch input detection by reducing unwanted reflections and noise, allowing for more accurate and resource-efficient detection of touch inputs on surfaces like glass without compromising user experience.

Implementation Method 1

an acoustic dampening material, specifically a shaped dampening material with a gradual attenuation property and anechoic shape, to minimize signal reflections

Methodology Applied
Scientific EffectAcoustic dampening: Damping

Implementation Method 2

acoustic dampening material... to dampen reflections of the transmitted acoustic wave

Methodology Applied
Scientific EffectAcoustic absorption: Acoustic Absorption

Implementation Method 3

ultrasonic waves may be used for touch location detection... ultrasonic signals are transmitted through a medium of the touch detection surface

Methodology Applied
Scientific EffectUltrasonic wave propagation: Ultrasound

Implementation Method 4

acoustic transmitter... emits a signal to be propagated through the propagating medium

Methodology Applied
Scientific EffectAcoustic wave transmission: Sound

Implementation Method 5

a receiver coupled to the propagating medium receives the signal... to determine a location on the surface associated with the touch input

Methodology Applied
Scientific EffectAcoustic wave detection: Sound

Data Source

PatentEP2860617B1Damping vibrational wave reflections
Publication Date: 2022.11.30 SENTONS
  • EP2860617B1 patent drawingFigure 1A
  • EP2860617B1 patent drawingFigure 1B
  • EP2860617B1 patent drawingFigure 1C

AI summary

A touch input detector is disclosed. The touch input detector includes an acoustic transmitter for transmitting an acoustic wave across a touch input medium. The touch input detector also includes an acoustic receiver for receiving the transmitted acoustic wave, wherein the timing of the incidence of the acoustic wave on the acoustic receiver indicates at least a portion of a touch input location on a surface of the touch input medium. The touch input detector further includes an acoustic dampening material coupled to the touch input medium to dampen reflections of the transmitted acoustic wave.