OLED Display Shield Electrode Noise Resistance

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Solution Overview

Problem

Existing OLED displays with touch screen functionality face challenges in effectively integrating capacitive touch sensing while maintaining resistance to external and internal noise, and in optimizing the structural layout for efficient signal transmission and capacitance differences in electrode units.

Innovation Solution

The OLED display incorporates a shield electrode connected to a low potential voltage source, a touch screen panel with a single-layered electrode unit having first and second electrodes arranged in alternating directions, and printed circuit boards for driving and sensing signals, ensuring consistent capacitance differences and noise resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a multi-layered electrode unit structure is used in the touch screen panel, then the touch sensitivity can be improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvetouch sensing precisionVSAvoidelectrode unit structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The electrode unit is segmented into first electrodes extending in a first direction and second electrodes extending in a second direction perpendicular to the first direction. This segmentation allows for simplified single-layer construction while maintaining effective capacitive coupling for touch detection in multiple directions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The single-layer electrode unit performs multiple functions: it serves as both the touch sensing electrode and provides shielding against external noise when combined with the shield electrode. This multi-functionality reduces the need for additional separate layers while maintaining touch sensitivity and noise resistance

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

2Object-affected harmful factors

If a shield electrode is added to the OLED display structure, then the resistance to external and internal noise is improved, but the device complexity increases

Engineering Contradiction:
Improvenoise resistanceVSAvoiddisplay structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The shield electrode is merged with the existing substrate structure of the OLED display. The shield electrode is formed on the substrate in a region corresponding to the touch screen panel, integrating the shielding function into the existing display architecture rather than adding a completely separate component

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The shield electrode acts as an intermediary element between the touch screen panel electrodes and external noise sources. It provides electrostatic shielding by creating a reference potential plane that isolates the sensitive touch sensing electrodes from external electromagnetic interference

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If the first electrodes and second electrodes have the same area, then the manufacturing process is simplified, but the capacitance difference needed for effective touch sensing is reduced

Engineering Contradiction:
Improveelectrode fabrication easeVSAvoidtouch sensing precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The first electrodes and second electrodes are designed with different areas to create local variations in capacitance. This local quality difference enhances the capacitive coupling effect when a touch occurs, improving touch detection precision while maintaining a relatively simple single-layer fabrication process

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 enhances the OLED display's resistance to noise and allows for precise touch position sensing, enabling reliable capacitive touch functionality and efficient signal transmission.

Implementation Method 1

a shield electrode on one surface of the second substrate that is not facing the subpixels, the shield electrode being connected to a low potential voltage source

Methodology Applied
Scientific EffectElectrostatic shielding: Faraday Cage

Implementation Method 2

a touch screen panel on a surface of the shield electrode facing away from the second substrate

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentEP2869346B1Organic light emitting diode display
Publication Date: 2022.05.25 LG DISPLAY CO LTD
  • EP2869346B1 patent drawingFigure 1~2
  • EP2869346B1 patent drawingFigure 3~4
  • EP2869346B1 patent drawingFigure 5~6

AI summary

An organic light emitting diode (OLED) display is disclosed. The OLED display includes a plurality of subpixels (SP) on one surface of a first substrate (110a), a second substrate (110b) attached to the first substrate, a shield electrode (140) on one surface of the second substrate that is not opposite to the subpixels, the shield electrode being connected to a low potential voltage source, a touch screen panel (150) on the shield electrode, a first printed circuit board (PCB) attached to the one surface of the first substrate, the first PCB receiving a driving signal driving the subpixels from a driving device, and a second PCB attached to the one surface of the second substrate, the second PCB transmitting a sensing signal generated by the touch screen panel to an external device.