Stepped Substrate Buffer Layer for Rollable Display Side Protection

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Solution Overview

Problem

Rollable display apparatuses face challenges in protecting their side surfaces from external damage and moisture ingress due to the exposure of substrate sides, leading to issues like cracking and water penetration.

Innovation Solution

A display apparatus design featuring a base substrate with a stepped portion, a buffer layer covering the stepped portion, and a cover layer that encases the side surfaces of the encapsulation substrate, enhancing protection against external elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate protection case is provided on the side surface, then protection against external damage is improved, but device complexity increases and rolling operation becomes difficult

Engineering Contradiction:

Improveprotection against external damageVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The protection function is merged into the substrate structure itself by forming a stepped portion that integrates the protective feature with the base substrate, eliminating the need for a separate protection case and reducing overall device complexity

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The protection mechanism transitions from a lateral addition (separate protection case) to a vertical structure (stepped portion extending in the thickness direction), utilizing the thickness dimension to provide protection without increasing lateral complexity

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If the side surface is externally exposed, then ease of manufacture is improved, but water penetration and cracking occur

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidwater penetration and cracking

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The buffer layer is formed in advance to cover the stepped portion before final assembly, creating a preliminary protective barrier that prevents water penetration and cracking while maintaining manufacturing efficiency

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A thin film buffer layer is used to provide protection against water and cracks, offering sufficient barrier functionality without adding significant complexity or compromising ease of manufacture

Inventive Principle:

Principle #30Flexible shells and thin films

3Reliability

If the side surface is protected with multiple layers, then reliability is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improveprotection effectivenessVSAvoidalignment precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The buffer layer serves multiple functions simultaneously - covering the stepped portion, preventing water penetration, and reducing cracks - thereby achieving reliable protection without requiring multiple separate layers that would increase precision requirements

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10957875B2Display apparatus

Publication Date: 2021.03.23 LG DISPLAY CO LTD

AI summary

Disclosed is a display apparatus for protecting a side surface of a substrate from the outside. The display apparatus includes a base substrate including a stepped portion, a buffer layer provided on the base substrate, a pixel array layer provided on the buffer layer, an encapsulation substrate provided on the pixel array layer, and a cover layer covering a side surface of the encapsulation substrate. The buffer layer covers the stepped portion of the base substrate.