Touch Sensor Integrated Display Device Aperture Ratio Optimization

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Solution Overview

Problem

Touch sensor integrated type display devices face issues with low aperture ratio and non-uniformity of touch driving and sensing signals due to complex wire intersections and varying RC delay across large display panels, affecting accurate touch recognition.

Innovation Solution

The solution involves forming touch driving electrodes and sensing electrodes as common electrodes on a substrate, with specific routing and connection configurations to reduce wire complexity and maintain signal uniformity, using transparent conductive materials for electrodes and metal for connecting wires to minimize resistance, and adjusting electrode positions to prevent aperture ratio decreases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If touch driving wires and touch sensing wires cross each other in the display area to connect electrodes on the same layer, then the electrodes can be interconnected to avoid contact, but the aperture ratio decreases

Engineering Contradiction:
Improveease of wire connectionVSAvoidaperture ratio
Core Design Contradiction:
Ease of manufactureVSArea of stationary object

Solution Approach 1:

The patent moves the wire routing from the display area (2D plane) to the non-display area by utilizing the third dimension (depth/layers). Touch driving wires and touch sensing wires are routed through different layers and connected via contact holes, allowing them to cross without occupying the display area, thus maintaining aperture ratio while enabling electrode interconnection.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If display device size increases to meet consumer demand, then the display area expands, but RC delay differences increase causing signal non-uniformity

Engineering Contradiction:
Improvedisplay area sizeVSAvoidsignal uniformity
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The patent divides the display panel into multiple regions with separate touch driving electrode groups and sensing electrode groups. Each group is independently controlled and routed, allowing localized optimization of signal transmission. This segmentation reduces the overall RC delay variation across the large display area by preventing long signal paths from causing uniformity issues.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements different routing configurations for different regions of the display panel. Touch driving wires and sensing wires are routed through non-display areas specific to each region, allowing local optimization of wire lengths and routing paths to minimize RC delay variations while maintaining overall signal uniformity across the expanded display area.

Inventive Principle:
Principle #3Local quality

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 configuration simplifies the formation of complex wires, maintains signal integrity, and improves touch recognition accuracy by ensuring consistent RC delay and aperture ratio across the display panel.

Implementation Method 1

using transparent conductive materials for electrodes and metal for connecting wires to minimize resistance

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

measuring a change in mutual capacitance caused by touching

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2879026B1Touch sensor integrated type display device
Publication Date: 2018.08.29 LG DISPLAY CO LTD
  • EP2879026B1 patent drawingFigure 1~2
  • EP2879026B1 patent drawingFigure 3
  • EP2879026B1 patent drawingFigure 4

AI summary

A touch sensor integrated type display device comprises: a plurality of gate lines and data lines crossing each other; a plurality of pixel electrodes formed in regions defined by the crossings of the gate lines and the data lines; and a plurality of common electrodes overlapping the pixel electrodes, the common electrodes comprising: a plurality of electrode groups comprising first electrodes divided in a first direction and a second direction perpendicular to the first direction; and a plurality of second electrodes divided in parallel in the second direction, with the first electrodes arranged in the second direction interposed between the second electrodes, wherein first electrode connecting wires respectively connected to the first electrodes of the first electrode group for one row arranged in the first direction are arranged in the first direction.