Display Device Pad Region Light Absorption Layer Bezel Reduction

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Solution Overview

Problem

There is a limit to reducing the bezel area of display devices due to process tolerances and errors in organic light emitting display devices, making it difficult to minimize the bezel effectively.

Innovation Solution

A display device and method that involve forming a substrate with a display region and a pad region, including a low potential electrode and a light absorption layer in the pad region, and then cutting the pad region along a specific line to minimize the bezel area, using either mechanical or optical cutting methods while preventing damage to internal layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the pad region area is reduced to minimize the bezel, then the bezel area is reduced, but process tolerances and errors prevent further reduction

Engineering Contradiction:

Improvebezel areaVSAvoidpad region precision

Core Design Contradiction:

Area of stationary objectVSManufacturing precision

Solution Approach 1:

The pad region is segmented into two parts: a first pad region that is retained and a second pad region that is removed through cutting. This segmentation allows the bezel area to be minimized by removing the second pad region while maintaining the necessary functional area (first pad region) for electrical connections, thereby resolving the conflict between minimizing bezel area and maintaining manufacturing precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The low potential electrode and light absorption layer are formed in advance in the second pad region before the cutting process. This preliminary action ensures that these components are properly positioned and formed before the pad region is cut, allowing the cutting to proceed with high precision along the predetermined line without affecting the display region or causing manufacturing errors.

Inventive Principle:

Principle #10Preliminary action

2Area of stationary object

If the pad region is cut after component formation, then the bezel area is reduced, but damage to internal layers may occur

Engineering Contradiction:

Improvebezel areaVSAvoidinternal layer integrity

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

A light absorption layer is introduced as an intermediary component between the low potential electrode and the external environment. This light absorption layer serves as a protective mediator that absorbs light during the cutting process, preventing light from reaching and damaging the low potential electrode or other internal layers, thereby maintaining internal layer integrity while allowing the pad region to be cut for bezel reduction.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The light absorption layer is formed in advance to counteract the potential harmful effect of light exposure during the cutting process. By establishing this protective layer beforehand, the patent prevents damage to internal layers before the cutting operation occurs, resolving the contradiction between cutting the pad region and maintaining internal layer integrity.

Inventive Principle:

Principle #9Preliminary anti-action

3Area of stationary object

If mechanical or optical cutting is used to remove the pad region, then the bezel area is reduced, but signal delay or heat generation may increase

Engineering Contradiction:

Improvebezel areaVSAvoidsignal delay and heat generation

Core Design Contradiction:

Area of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The low potential electrode is designed with local quality variations: it has a first area in the first pad region and a second area in the second pad region. The second area is specifically optimized for the cutting process, allowing the electrode to be cut along the predetermined line. This local differentiation enables the cutting to proceed without increasing signal delay or heat generation in the functional first area, while still achieving bezel reduction.

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 approach allows for a significant reduction in the bezel area by removing a portion of the pad region after component formation, resulting in a narrower bezel without affecting the display's functionality or increasing signal delay or heat generation.

Implementation Method 1

a light absorption layer disposed on the low potential electrode in the pad region

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS11569488B2Display device including light absorption layer and low potential electrode in pad region and method of fabricating the same

Publication Date: 2023.01.31 LG DISPLAY CO LTD

AI summary

A display device comprises a substrate including a display region including a plurality of sub-pixels and a pad region outside the display region; a display element disposed in each of the plurality of sub-pixels; a low potential electrode formed in the pad region to apply a low potential voltage to the display element; a light absorption layer disposed on the low potential electrode in the pad region; and an encapsulation layer formed in the display region and the pad region.