Display Panel Color-Subpixel Layout for Evaporation Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The challenge of improving display quality in organic light emitting display devices lies in the difficulty of manufacturing high-resolution displays due to the high precision requirements and increased costs associated with reducing pixel size and spacing, which can lead to issues like dark spots, uneven brightness, and color deviation.

Innovation Solution

A display panel design with varying effective light emitting region areas for different color sub-pixels, where the area ratio of the second color light emitting layer to its effective light emitting region is greater than that of the first color, allowing for a larger process margin and more stable light emitting layer quality, particularly in sub-pixels with smaller effective light emitting regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pixel size and spacing are reduced to improve resolution, then display quality is improved, but manufacturing precision requirements increase and costs increase

Engineering Contradiction:
Improvedisplay resolutionVSAvoidpixel size control precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent applies local quality by making different color sub-pixels have different effective light emitting region areas. Specifically, the first color sub-pixels have larger effective light emitting regions while the second color sub-pixels have smaller effective light emitting regions. This non-uniform local design allows each color channel to be optimized independently, compensating for the reduced overall pixel size and spacing while maintaining manufacturing feasibility.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If pixel size is reduced to improve resolution, then display quality is improved, but dark spots and uneven brightness occur

Engineering Contradiction:
Improvedisplay resolutionVSAvoiddisplay uniformity
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent addresses display uniformity issues by implementing local quality variations where different color sub-pixels have different effective light emitting region areas. The first color sub-pixels with larger areas compensate for potential brightness losses, while the second color sub-pixels with smaller areas prevent overheating and material degradation. This balanced approach maintains overall display uniformity despite reduced pixel dimensions.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If pixel size is reduced to improve resolution, then display quality is improved, but color deviation occurs

Engineering Contradiction:
Improvedisplay resolutionVSAvoidcolor accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent corrects color deviation through local quality adjustments by assigning different effective light emitting region areas to different color sub-pixels. The varied areas compensate for differences in luminous efficiency among color channels, ensuring that each color contributes appropriately to the overall display output and maintaining color accuracy at higher resolutions.

Inventive Principle:
Principle #3Local quality

4Measurement precision

If manufacturing precision is increased to reduce pixel size, then display resolution is improved, but manufacturing costs increase

Engineering Contradiction:
Improvedisplay resolutionVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent reduces manufacturing costs by implementing local quality variations in effective light emitting region areas. This approach allows standard manufacturing processes to be used without requiring extreme precision controls, as the design compensates for variability through the non-uniform area distribution among color sub-pixels, making high-resolution displays more cost-effective to produce.

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 stabilizes the quality of the light emitting layers, reducing the impact of manufacturing deviations and improving display uniformity and brightness, especially for sub-pixels with smaller effective light emitting regions.

Implementation Method 1

an organic light-emitting diode, and a pixel defining layer, wherein the organic light-emitting diode includes an anode, a cathode, and a light emitting layer between the anode and the cathode

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3961717B1Display panel and display device
Publication Date: 2025.10.01 BOE TECHNOLOGY GROUP CO LTD
  • EP3961717B1 patent drawingFigure 1A
  • EP3961717B1 patent drawingFigure 1B~1C
  • EP3961717B1 patent drawingFigure 1D~1F

AI summary

A display panel and a display device are provided. The display panel includes a first color sub-pixels (100), a second color sub-pixel (200) and a pixel defining layer (400). The pixel defining layer (400) includes a plurality of openings (401), the first color sub-pixel (100) includes a first effective light emitting region (101), the second color sub-pixel (200) includes a second effective light emitting region (201), an area of the second effective light emitting region (201) is smaller than that of the first effective light emitting region (101). The first color sub-pixel (100) includes a first color light emitting layer (110) located in an opening (401) and on the pixel defining layer (400), the second color sub-pixel (200) includes a second color light emitting layer (210) located in an opening (401) and on the pixel defining layer (400), an area ratio between orthographic projections of the first color light emitting layer (110) and the first effective light emitting region (101) on the base substrate (10) is less than an area ratio between orthographic projections of the second color light emitting layer (210) and the second effective light emitting region (201) on the base substrate (10). In the embodiment of the present disclosure, the area ratios between light-emitting layers and effective light emitting regions of different color sub-pixels are different to ensure that the deviation brought by evaporation process is more balanced for each sub-pixel.