Transparent Touch Display Device with Integrated Cathode Electrodes

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Solution Overview

Problem

Designing a touch sensor integrated touch display device that satisfies self-emission and transmittance requirements while reducing thickness and improving image quality has been challenging, especially with the integration of light emitting elements like OLEDs in the display panel.

Innovation Solution

A transparent touch display device with a touch sensor configuration featuring two or more cathode electrodes separated in a cathode electrode layer, integrated into the display panel without affecting transmittance, and a touch shield structure to reduce coupling noise between touch lines and display driving patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a touch sensor structure with multiple touch electrodes and touch lines is integrated into the display panel, then touch sensing function is enabled, but device thickness increases and transmittance decreases

Engineering Contradiction:

Improvetouch sensing functionVSAvoiddevice thickness

Core Design Contradiction:

Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The touch sensor structure is merged with the display panel structure by integrating touch electrodes and touch lines directly into the display panel layers. The touch cathode electrode is formed in the same cathode electrode layer as the display cathode electrode, and touch lines are integrated with display driving patterns, eliminating the need for separate touch sensor layers and reducing overall device thickness.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The cathode electrode layer serves dual functions: as the display cathode electrode for light emission and as the touch cathode electrode for touch sensing. The touch lines share routing with display driving patterns, allowing the same structural layers to perform both display and touch sensing functions simultaneously.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a touch sensor structure with multiple touch electrodes and touch lines is integrated into the display panel, then touch sensing function is enabled, but image quality and transmittance deteriorate

Engineering Contradiction:

Improvetouch sensing functionVSAvoidtransmittance

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The touch cathode electrode is positioned at specific locations (first and second sides of the display cathode electrode) rather than covering the entire display area, allowing light to transmit through the central display region while maintaining touch sensing capability at the edges. This localized placement minimizes impact on overall transmittance and image quality.

Inventive Principle:

Principle #3Local quality

3Device complexity

If touch lines and display driving patterns are placed close together, then device complexity is reduced, but coupling noise increases

Engineering Contradiction:

Improvestructure integrationVSAvoidcoupling noise

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

A touch shield line is introduced as an intermediary element between the touch line and display driving patterns. The touch shield line is electrically connected to a reference potential and acts as a barrier to prevent capacitive coupling noise from the display driving patterns from interfering with the touch sensing signals, while still allowing the touch line and display patterns to be positioned close together for integrated design.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Ease of manufacture

If the cathode electrode layer is used for both display and touch functions, then manufacturing complexity is reduced, but touch sensing accuracy may deteriorate

Engineering Contradiction:

Improvemanufacturing complexityVSAvoidtouch sensing accuracy

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The cathode electrode layer is segmented into functionally distinct regions: the display cathode electrode area for light emission and the touch cathode electrode areas at the edges for touch sensing. This segmentation allows each region to be optimized for its specific function while using the same material layer, maintaining manufacturing simplicity while ensuring touch sensing accuracy through proper spatial separation of functions.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP4206877B1Transparent touch display device

Publication Date: 2024.10.23 LG DISPLAY CO LTD

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AI summary

The present invention relates to a transparent touch display device including: a substrate including a pixel area, a first transmission area located on a first side of the pixel area, and a second transmission area located on a second side of the pixel area, a driving transistor disposed in the pixel area, an anode electrode disposed in the pixel area, located over the driving transistor, and electrically connected to a source electrode or a drain electrode of the driving transistor, an emission layer located on the anode electrode, a display cathode electrode located on the emission layer, a first touch cathode electrode disposed in the first transmission area and located on a first side of the display cathode electrode, a second touch cathode electrode disposed in the second transmission area and located on a second side of the display cathode electrode, a first touch line electrically connected to at least one of the first touch cathode electrode and the second touch cathode electrode, and a first upper touch shield disposed over the first touch line and overlapping at least a portion of the first touch line.