OLED Pixel Structure with Common Gate Line and Double Capacitor

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The complexity of organic light emitting display device pixel structures increases with the number of signal lines required for various functions, leading to manufacturing challenges, reduced opening ratios, and shorter lifespan due to step differences caused by contact holes.

Innovation Solution

A simplified and compact pixel structure incorporating a double capacitor and a 3T1C based 1 scan structure, where each pixel receives one scan signal through a common gate line, reducing the number of signal lines and enhancing the opening ratio while preventing defects caused by contact holes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the number of signal lines is increased to provide various functions (sensing, compensation, higher resolution), then the functionality and resolution are improved, but the pixel structure becomes more complex

Engineering Contradiction:
ImprovefunctionalityVSAvoidpixel structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Multiple gate lines (first gate line and second gate line) are merged into a single common gate line that provides scan signals to multiple pixels. This consolidation reduces the total number of signal lines required while maintaining the ability to address and control individual pixels through selective activation patterns

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The common gate line serves multiple functions by providing scan signals to multiple pixels simultaneously. A single gate line structure replaces what would traditionally require separate dedicated gate lines for each pixel, achieving multi-functionality without increasing structural complexity

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

2Measurement precision

If the number of signal lines is increased, then the resolution is improved, but the pixel structure becomes more complex

Engineering Contradiction:
ImproveresolutionVSAvoidpixel structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple gate line functions into a single common gate line, reducing the signal line count while maintaining high resolution capability through selective pixel addressing schemes

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If contact holes are used to connect signal lines, then the connectivity is improved, but step differences are caused which reduce lifespan

Engineering Contradiction:
ImproveconnectivityVSAvoidlifespan
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The invention eliminates contact holes from the pixel structure by采用ing a planar design where signal lines are connected through overlapping conductive layers without requiring vertical penetration holes. This removes the source of step differences while maintaining electrical connectivity

Inventive Principle:
Principle #2Taking out (Extraction)

4Measurement precision

If more transistors are added to pixels for sensing and compensation functions, then the compensation accuracy is improved, but the number of IC pads and signal lines increases

Engineering Contradiction:
Improvecompensation accuracyVSAvoidnumber of IC pads and signal lines
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple gate lines are merged into a common gate line structure, reducing the number of external IC pads and signal lines required while maintaining the pixel-level transistor functionality needed for sensing and compensation operations

Inventive Principle:
Principle #5Merging (Combining)

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 approach results in a more efficient manufacturing process with higher throughput, improved opening ratios, and extended lifespan of the display panel, especially beneficial for high-resolution and large-size displays.

Implementation Method 1

organic light emitting display devices have been in the spotlight as being display devices having fast response rates, high light emitting efficiency, high luminance, and wide viewing angles. These advantages are due to the use of an organic light emitting diode, which is self-illuminating (emits light by itself).

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2874143B1Organic light emitting display device
Publication Date: 2019.04.10 LG DISPLAY CO LTD
  • EP2874143B1 patent drawingFigure 1
  • EP2874143B1 patent drawingFigure 2
  • EP2874143B1 patent drawingFigure 3A

AI summary

An organic light emitting display pixel (P) comprises a driving transistor (DT) for driving an organic light emitting diode (OLED). A first transistor (T1) is controlled by a scan signal (GL) and connected between a reference voltage line (RVL) and a first node (N1) of the driving transistor. A second transistor (T2) is also controlled by the same scan signal (GL) and is connected between a data line (DL) and a second node (N2) of the driving transistor. A storage capacitor (Cst) comprises a first plate with an improved conductive characteristic and connected to the semiconductor layer of the driving transistor and the semiconductor layer of the first transistor. A second plate of the storage capacitor is positioned on the first plate, and connected to the semiconductor layer of the second transistor and a gate electrode of the driving transistor. A pixel electrode of the organic light emitting diode, positioned on the second plate, is connected to the first plate through a contact hole.