OLED Buffer Layer Hides Non-Display Line Patterns

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Solution Overview

Problem

In bottom emission type organic light emitting display devices, the pattern of lines in the non-display area is visible due to light reflection, degrading the external aesthetic appearance and making it difficult to achieve a borderless panel design.

Innovation Solution

The use of a buffer layer made of the same metal material as the link lines, which overlaps the spaces between the link lines and log lines, ensures uniform light reflection and prevents the pattern from being visible, thereby enhancing the aesthetic appearance by creating a borderless panel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If link lines and log lines are formed in the non-display area to supply driving signals, then the display device can be driven properly, but the pattern of lines becomes visible due to light reflection, degrading external aesthetic appearance

Engineering Contradiction:
Improvedriving signal supplyVSAvoidlight reflection visibility
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The buffer layer is formed using the same metal material as the link lines and log lines, ensuring uniform light reflection characteristics across all conductive structures in the non-display area. This homogeneity in material composition causes the buffer layer to reflect light at the same rate as the link lines, making the entire pattern invisible to the human eye and eliminating the aesthetic degradation caused by visible line patterns

Inventive Principle:
Principle #33Homogeneity

2Ease of manufacture

If the encapsulating substrate covers only part of the non-display area, then the manufacturing process is simplified, but light reflection varies between covered and uncovered areas, making line patterns more visible

Engineering Contradiction:
Improveencapsulation processVSAvoidlight reflection uniformity
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The buffer layer is selectively formed only in specific regions of the non-display area where link lines and log lines are present, rather than uniformly across the entire non-display area. This local application of the buffer layer precisely targets the areas where light reflection visibility is problematic, while leaving other areas unchanged, thus maintaining manufacturing simplicity while solving the visibility issue in critical regions

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

The buffer layer effectively hides the pattern of lines in the non-display area from view by matching the light reflection rate of the link lines, resulting in an improved external aesthetic appearance and a more aesthetically pleasing borderless panel design.

Implementation Method 1

the buffer layer made of the same metal material as the link lines, which overlaps the spaces between the link lines and log lines, ensures uniform light reflection and prevents the pattern from being visible

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP2950349B1Organic light emitting display device and method of manufacturing the same
Publication Date: 2022.04.27 LG DISPLAY CO LTD
  • EP2950349B1 patent drawingFigure 1
  • EP2950349B1 patent drawingFigure 2
  • EP2950349B1 patent drawingFigure 3

AI summary

Provided are an organic light emitting display (OLED) device and a method of manufacturing the same. The OLED device includes: an array substrate (101), an intermediate layer over the array substrate (101), an insulating layer (103) over the intermediate layer, and a plurality of driving signal lines over the insulating layer (103) in a non-display area of the array substrate (101), the plurality of driving signal lines being completely separated from the intermediate layer by the insulating layer (103), each of the plurality of driving signal lines being configured to supply a driving signal from a driving circuit unit to a respective sub-pixel of a pixel among a plurality of pixels, wherein the intermediate layer under the plurality of driving signal lines is configured to reduce visibility of the driving signal lines such that incident light on the intermediate layer is uniformly reflected or absorbed with the plurality of driving signal lines.