Peripheral Touch Detection Using Third Electrode and Code Division Multiplexing

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Solution Overview

Problem

Existing touch detection systems in display devices face challenges in accurately detecting objects in the peripheral region due to the large distance between detection electrodes and objects, leading to unsatisfactory detection performance.

Innovation Solution

A display device configuration that includes a substrate with first and second electrodes in the active area, third electrodes in the peripheral region, and a drive circuit supplying phase-determined drive signals based on a predetermined code to improve touch detection sensitivity and range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If electrodes and drive configuration are used to detect objects in the peripheral region, then the detection coverage is expanded, but the detection accuracy deteriorates due to large distance between object and detection electrodes

Engineering Contradiction:

Improvedetection coverage areaVSAvoiddetection accuracy

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent transitions from planar electrode arrangement to a three-dimensional configuration by introducing a third electrode extending in the thickness direction of the substrate. This vertical dimension allows the detection electrode to be positioned closer to objects in the peripheral region, maintaining detection accuracy while expanding coverage area.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent applies different electrode configurations to different regions of the display device. The third electrode is specifically positioned in the peripheral region where detection accuracy was deteriorating, while the first and second electrodes remain in the active area. This localized optimization resolves the contradiction by addressing the specific problem area without affecting overall system performance.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If code division multiplex drive is used for touch detection, then the detection function is integrated, but the peripheral region detection performance is insufficient

Engineering Contradiction:

Improvetouch detection integrationVSAvoidperipheral region detection performance

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent divides the electrode system into three distinct segments: first electrodes in the active area, second electrodes facing the first electrodes, and a third electrode extending into the peripheral region. This segmentation allows each electrode to be optimized for its specific function, with the third electrode dedicated to peripheral region detection, thereby maintaining both integration and detection performance.

Inventive Principle:

Principle #1Segmentation

3Measurement precision

If detection electrodes are positioned closer to active area, then detection accuracy is improved, but detection range in peripheral region is limited

Engineering Contradiction:

Improvedetection accuracyVSAvoiddetection range

Core Design Contradiction:

Measurement precisionVSArea of stationary object

Solution Approach 1:

The third electrode extends in the thickness direction of the substrate, utilizing the vertical dimension to reach into the peripheral region while maintaining close proximity to potential touch objects. This three-dimensional positioning allows the electrode to simultaneously achieve good detection accuracy and extended detection range.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The third electrode serves multiple functions: it extends the detection range into the peripheral region while maintaining detection accuracy, and it integrates with the existing code division multiplex drive system. This multi-functionality resolves the contradiction by achieving both extended range and maintained accuracy with a single electrode design.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enhances touch detection accuracy and sensitivity in both the active and peripheral regions by expanding the detection range and increasing the signal-to-noise ratio without increasing the drive signal output.

Implementation Method 1

a plurality of second electrodes facing the first electrodes and configured to form capacitance between the first electrodes and the second electrodes

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

a drive circuit configured to supply a drive signal having a phase determined based on a predetermined code to the first electrodes and the third electrode

Methodology Applied

Scientific EffectCode division multiplex drive:

Data Source

PatentUS10540038B2Display device with improved detection in peripheral region thereof

Publication Date: 2020.01.21 MAGNOLIA WHITE CORP

AI summary

A display device includes a substrate, a plurality of first electrodes, a plurality of second electrodes, at least one third electrode, and a drive circuit. The first electrodes are arrayed in an active area of the substrate. The second electrodes face the first electrodes and form capacitance between the first electrodes and the second electrodes. The third electrode is provided in a peripheral region positioned on the outside of the active area. The drive circuit supplies a drive signal having a phase determined based on a predetermined code to the first electrodes and the third electrode.