Touch Sensor Integrated Display Device Aperture Ratio Optimization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing touch sensor integrated type display devices face issues with complex designs and reduced display characteristics due to the need for separate wires and contact holes for connecting touch driving and sensing electrodes, which also lead to increased thickness and manufacturing costs.

Innovation Solution

The solution involves forming touch driving and sensing electrodes on a common layer with resistance reducing wires that cross over bottlenecks, eliminating the need for contact holes and reducing mutual capacitance, thereby improving aperture ratio and touch performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate wires and contact holes are used to connect touch driving and sensing electrodes, then electrical connection is achieved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveelectrical connectionVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the touch driving electrode and touch sensing electrode into a single common electrode layer, eliminating the need for separate connection wires and contact holes. This integration reduces structural complexity while maintaining electrical functionality through capacitive coupling between overlapping electrode regions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The common electrode layer serves multiple functions simultaneously: it acts as both the touch driving electrode and touch sensing electrode, and also functions as the common electrode for the liquid crystal display. This multi-functionality eliminates the need for separate dedicated touch sensor electrodes and their associated connection structures.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If contact holes are formed to connect electrodes, then electrical connection is established, but aperture ratio decreases

Engineering Contradiction:
Improveelectrical connectionVSAvoidaperture ratio
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent extracts and eliminates the contact hole structure from the design by using capacitive coupling between overlapping transparent electrode regions. This removal of contact holes increases the aperture ratio while maintaining electrical connection functionality through the electric field formed between the driving and sensing electrode regions.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If multiple layers and processes are used for on-cell touch sensor, then integration is achieved, but manufacturing cost increases

Engineering Contradiction:
ImproveintegrationVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent combines the touch sensor electrode formation process with the existing liquid crystal display manufacturing process. The common electrode layer is formed using the same transparent conductive material and deposition processes already used for the display electrodes, eliminating the need for separate touch sensor manufacturing steps and reducing overall manufacturing cost.

Inventive Principle:
Principle #5Merging (Combining)

4Length of stationary object

If touch electrodes are formed on the same layer, then thickness is reduced, but mutual capacitance interference increases

Engineering Contradiction:
ImprovethicknessVSAvoidmutual capacitance
Core Design Contradiction:
Length of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent segments the common electrode layer into distinct driving electrode regions and sensing electrode regions that are spatially separated and patterned to minimize overlapping area. This segmentation reduces mutual capacitance interference while maintaining the thin-profile advantage of single-layer construction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different local patterns and spacing to different regions of the electrode layer. The driving and sensing electrode regions are designed with specific geometric configurations and spacing that optimize touch detection while minimizing parasitic capacitance, creating local quality variations that reduce interference.

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 design simplifies the connection of touch electrodes, increases the aperture ratio, and enhances touch sensitivity by reducing mutual capacitance and parasitic capacitance, making it suitable for large-sized high-resolution products.

Implementation Method 1

measures changes in a mutual capacitance generated in a touch operation and recognizes a touch or non-touch input and a touch position in the touch input

Methodology Applied
Scientific EffectMutual capacitance: Capacitance

Data Source

PatentEP2881843B1Touch sensor integrated type display device
Publication Date: 2019.07.17 LG DISPLAY CO LTD
  • EP2881843B1 patent drawingFigure 1
  • EP2881843B1 patent drawingFigure 2
  • EP2881843B1 patent drawingFigure 3

AI summary

A touch sensor integrated type display device capable of recognizing a user's touch operation is disclosed. The touch sensor integrated type display device includes a plurality of first electrodes each including a plurality of first electrode patterns, which are connected through a plurality of first bottlenecks, the plurality of first electrodes being arranged in a first direction, and a plurality of second electrodes arranged in a second direction crossing the first direction. The plurality of first electrode patterns and the plurality of second electrodes are alternately disposed. At least one unit pixel electrode is disposed corresponding to each of the plurality of first electrode patterns.