Flexible Touch Sensor Layout for Input Surface Differentiation

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Solution Overview

Problem

Traditional sensor designs face challenges in integrating conductive lines within objects, particularly in distinguishing between intentional and unintentional touch inputs at different surfaces of a touch sensor, especially in wearable devices, where movement can interfere with input detection.

Innovation Solution

A touch sensor system with a plurality of conductive sensing elements integrated into a flexible substrate, where one subset is on one side and another subset is on the opposite side, allowing for differentiation of touch inputs based on response patterns, enabling the system to determine whether inputs are from an intended input surface or an adjacent surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional sensor designs with conductive lines are used, then the sensor can detect touch inputs, but it cannot distinguish between intentional and unintentional touch inputs at different surfaces

Engineering Contradiction:

Improvetouch input detection accuracyVSAvoidinput surface identification

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The conductive sensing elements are divided into two separate subsets: a first subset on the first surface and a second subset on the second surface. This segmentation allows the system to determine which surface received the touch input by comparing the responses of the two subsets, thereby resolving the inability to distinguish between intentional and unintentional inputs.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each subset of conductive sensing elements is positioned at a specific location (first surface or second surface) with distinct functional characteristics. The first subset is optimized for detecting intentional inputs while the second subset detects unintentional inputs, allowing local differentiation of input quality and origin.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If additional shielding layers are added to differentiate touch inputs, then input surface differentiation can be achieved, but the device bulkiness increases

Engineering Contradiction:

Improveinput surface differentiationVSAvoiddevice bulkiness

Core Design Contradiction:

Measurement precisionVSVolume of moving object

Solution Approach 1:

Instead of adding shielding layers in the lateral dimension, the solution moves the sensing elements to different surfaces (vertical dimension) of the flexible substrate. The first subset is positioned on the first surface while the second subset is positioned on the second surface, enabling surface differentiation without increasing lateral device volume.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Both subsets of conductive sensing elements are integrated within the same flexible substrate structure, with one subset nested on each side of the substrate. This nested arrangement allows both sensing functions to coexist within a single compact component without requiring separate shielding layers.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Adaptability or versatility

If conductive sensing elements are integrated into a flexible substrate, then the sensor can be tightly integrated with wearable devices, but it becomes difficult to distinguish touch inputs from different surfaces

Engineering Contradiction:

Improvewearable device integrationVSAvoidtouch input source identification

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The conductive sensing elements are segmented into two subsets positioned on opposite sides of the flexible substrate. This segmentation maintains the flexibility and integrability of the substrate while enabling the system to identify which surface received the touch input by comparing the responses of the two subsets.

Inventive Principle:

Principle #1Segmentation

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 solution effectively differentiates between intentional and unintentional touch inputs, enhancing the capability to detect gestures accurately without the need for additional shielding layers, thus facilitating tighter integration with wearable devices and reducing bulkiness.

Implementation Method 1

capacitive touch sensor that is configured to detect touch input

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS11635857B2Touch sensors for interactive objects with input surface differentiation

Publication Date: 2023.04.25 GOOGLE LLC

AI summary

A sensor system includes a touch sensor having a plurality of conductive sensing elements integrated with a flexible substrate. A first subset of sensing elements is coupled to a first side of the flexible substrate and a second subset of sensing elements is coupled to a second side of the flexible substrate. The sensor system is configured to obtain touch data associated with a touch input to the touch sensor. The touch data is based at least in part on a respective response to the touch input by the plurality of conductive sensing elements. The sensor system is configured to determine whether the touch input is associated with the first subset of conductive sensing elements or the second subset of conductive sensing elements based at least in part on the respective response to the touch input by the sensing elements.