Display Edge Structure for Protection Layer Flow Control

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Solution Overview

Problem

Existing light emitting display apparatuses face issues with the flow and spread of protection layers in the edge areas, leading to reduced touch sensitivity, increased electric field interference, and compromised display quality due to moisture and oxygen ingress, as well as design limitations in bezel thickness.

Innovation Solution

The apparatus incorporates first and second patterns and a dam to control the flow of the protection layer, minimizing its spread into driving circuit areas, enhancing touch sensitivity, and improving moisture and oxygen blocking capabilities while reducing bezel thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the protection layer is allowed to flow freely during manufacturing, then the coverage area is improved, but the protection layer invades the driving circuit area causing driving failure

Engineering Contradiction:
Improvecoverage area of protection layerVSAvoiddriving circuit functionality
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The non-active area is divided into a first part and a second part with different planarization layer heights. The first part has a higher planarization layer that acts as a barrier to contain the protection layer, while the second part has a lower planarization layer. This segmentation prevents the protection layer from flowing into the driving circuit area while still providing adequate coverage in the display area.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the substrate are given different local properties through varying planarization layer heights. The first part of the non-active area has a higher planarization layer to restrict protection layer flow, while the second part has a lower planarization layer to allow adequate protection layer coverage. This local differentiation resolves the contradiction between coverage and circuit protection.

Inventive Principle:
Principle #3Local quality

2Length of moving object

If the planarization layer is etched in the non-active area to reduce bezel thickness, then the bezel width is reduced, but the touch sensitivity in the outer peripheral area deteriorates

Engineering Contradiction:
Improvebezel widthVSAvoidtouch sensitivity
Core Design Contradiction:
Length of moving objectVSMeasurement precision

Solution Approach 1:

The planarization layer is selectively etched only in the second part of the non-active area, while the first part maintains its original height. This creates a local quality difference where the touch-sensitive outer peripheral area (first part) retains adequate thickness for sensitivity, while the bezel area (second part) has reduced thickness for aesthetic purposes.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The non-active area is segmented into two parts with different planarization layer configurations. The first part maintains full thickness for touch sensitivity, while the second part has reduced thickness for bezel appearance. This segmentation allows both requirements to be satisfied simultaneously in different regions.

Inventive Principle:
Principle #1Segmentation

3Quantity of substance

If the protection layer thickness is reduced in the non-active area, then the manufacturing cost is reduced, but the electric field interference increases and display quality deteriorates

Engineering Contradiction:
Improveprotection layer material quantityVSAvoidelectric field interference
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The protection layer thickness is optimized differently in different regions: the first part of the non-active area maintains adequate thickness to prevent electric field interference and ensure display quality, while the second part uses reduced thickness to minimize material consumption. This local differentiation resolves the contradiction between material quantity and performance.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4255152B1Light emitting display apparatus
Publication Date: 2026.04.15 LG DISPLAY CO LTD
  • EP4255152B1 patent drawingFigure 1
  • EP4255152B1 patent drawingFigure 2
  • EP4255152B1 patent drawingFigure 3

AI summary

A light emitting display apparatus includes: a substrate (110) including an active area (AA) and a non-active area (NA) adjacent to the active area; a planarization layer (130) in the active area and a first part (P1) of the non-active area; a first pattern (400) disposed on the planarization layer (130); a second pattern (500) and a dam (600) disposed in a second part (P2) adjacent to the first part of the non-active area and having different heights.