In-Cell Touch Electronic Paper Display with Segmented Common Electrode

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Solution Overview

Problem

Electronic paper display panels lack touch control functionality, which is essential for modern display devices, due to the inability to effectively detect changes in capacitance caused by user input, resulting in incomplete or inaccurate image display.

Innovation Solution

Incorporating a common electrode layer with openings in the display panel, where the maximum aperture of these openings is less than or equal to the space between adjacent pixel electrodes, allows for the detection of capacitance changes during touch operations, enabling touch control and display in an in-cell touch electronic paper display panel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a common electrode layer is provided without openings, then the display panel can maintain a complete electrophoretic display function, but the touch control function cannot be realized due to inability to detect capacitance changes

Engineering Contradiction:

Improvetouch control functionVSAvoiddisplay completeness

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The common electrode layer is segmented by providing multiple openings in it, allowing the electrophoretic layer to be divided into multiple display regions separated by non-display regions. This segmentation enables the touch electrode to detect capacitance changes through the openings while the pixel electrodes maintain display functionality in their respective regions, thus resolving the contradiction between achieving touch control and maintaining complete display.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If the aperture of openings in the common electrode layer is large, then the touch electrode can effectively detect capacitance changes, but display blind zones appear and charged particles cannot be driven correctly

Engineering Contradiction:

Improvecapacitance detection accuracyVSAvoiddisplay accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The aperture of the openings in the common electrode layer is precisely controlled to be less than or equal to the space between adjacent pixel electrodes. This parameter optimization ensures that the openings are small enough to prevent display blind zones and maintain proper electric field distribution for charged particle movement, while still being large enough to allow the touch electrode to effectively detect capacitance changes during touch operations.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the aperture of openings in the common electrode layer is small, then display blind zones are prevented, but the touch electrode cannot effectively detect capacitance changes

Engineering Contradiction:

Improvedisplay completenessVSAvoidcapacitance detection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The aperture of the openings is optimized to a specific range - not too small to prevent detection, not too large to cause display issues. By setting the aperture to be less than or equal to the space between adjacent pixel electrodes, the design achieves the optimal balance where the openings are sufficiently large for capacitance detection while remaining small enough to prevent display blind zones and maintain proper electric field distribution.

Inventive Principle:

Principle #35Parameter changes

4Adaptability or versatility

If multiple openings are provided in the common electrode layer, then in-cell touch functionality is achieved, but the structure becomes more complex

Engineering Contradiction:

Improvein-cell touch functionalityVSAvoidcommon electrode layer structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

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 enables effective touch functionality and reliable image display by ensuring that charged particles in the electrophoretic layer can be driven correctly, preventing display blind zones and ensuring accurate user input detection.

Implementation Method 1

charged particles in the electrophoretic layer between the common electrode layer and the pixel electrode layer can move under the action of the electric field

Methodology Applied

Scientific EffectElectrophoresis: Electrophoresis

Implementation Method 2

a touch electrode located inside the display panel can detect a change in capacitance caused by a user finger during a touch operation

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS10317768B2Display panel and display device

Publication Date: 2019.06.11 SHANGHAI AVIC OPTO ELECTRONICS CO LTD

AI summary

Disclosed are a display panel and a display device. The display panel includes: an upper substrate, a lower substrate and an electrophoretic layer located between the upper substrate and the lower substrate; wherein, the lower substrate includes a plurality of pixel electrodes arranged in a matrix and a plurality of touch electrodes; the upper substrate includes a common electrode layer, a plurality of openings are provided on the common electrode layer, the maximum aperture of the openings is less than or equal to a space between adjacent pixel electrodes.