Porous Bending Encapsulation for OLED Luminance

Solution Overview

Problem

Bendable OLED displays experience significant luminance deterioration at the bending part, limiting their usability and visibility compared to the front display side, where maximum luminance is achieved at a 0-degree viewing angle.

Innovation Solution

A thin film encapsulation layer with a bending encapsulation layer containing pores of varying sizes from 10 Å to 10,000 Å is applied only to the bending display part, refracting light to enhance luminance and visibility without compromising the front display efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thin film encapsulation layer is applied to the bending display part, then the OLED is protected from moisture and oxygen, but the luminance is sharply deteriorated at the bending display part

Engineering Contradiction:

Improveprotection from moisture and oxygenVSAvoidluminance at bending display part

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent applies different encapsulation layer structures to different regions: the front display part has a standard encapsulation layer, while the bending display part has an encapsulation layer with pores. This local differentiation allows the bending region to have enhanced light extraction properties while maintaining protection, resolving the contradiction between reliability and luminance at the bending part.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent introduces a porous structure in the encapsulation layer at the bending display part. The pores have a refractive index different from the surrounding material, creating optical contrast that enhances light extraction and prevents total internal reflection at the bending region, thereby improving luminance while maintaining the protective function.

Inventive Principle:

Principle #31Porous materials

2Adaptability or versatility

If the OLED display is bent to create a bending display part, then the display can be viewed from the side and flexibility is improved, but the luminance at the bending part is sharply deteriorated

Engineering Contradiction:

Improveviewability from side and flexibilityVSAvoidluminance at bending display part

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent applies different encapsulation layer structures to different regions: the front display part has a standard encapsulation layer, while the bending display part has an encapsulation layer with pores. This local differentiation allows the bending region to have enhanced light extraction properties while maintaining protection, resolving the contradiction between reliability and luminance at the bending part.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent addresses the curvature-induced optical problems by introducing pores in the encapsulation layer at the bending region. The curved geometry of the bending display part causes total internal reflection that traps light, but the pores provide escape paths for light rays, enabling effective light extraction from the curved surface and improving visibility.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Ease of manufacture

If a standard encapsulation layer is used throughout the display, then manufacturing is simplified, but the bending display part has reduced luminance and visibility

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidluminance at bending display part

Core Design Contradiction:

Ease of manufactureVSIllumination intensity

Solution Approach 1:

The patent applies different encapsulation layer structures to different regions: the front display part has a standard encapsulation layer, while the bending display part has an encapsulation layer with pores. This local differentiation allows the bending region to have enhanced light extraction properties while maintaining protection, resolving the contradiction between reliability and luminance at the bending part.

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 solution increases the luminance of the bending display part, making it more recognizable while maintaining the efficiency of the front display, thus addressing the luminance disparity between the front and bending parts.

Implementation Method 1

A thin film encapsulation layer with a bending encapsulation layer containing pores of varying sizes from 10 Å to 10,000 Å is applied only to the bending display part, refracting light to enhance luminance and visibility

Methodology Applied

Scientific EffectLight refraction: Refraction

Data Source

PatentUS9029886B2Organic light emitting diode display

Publication Date: 2015.05.12 SAMSUNG DISPLAY CO LTD

AI summary

An organic light emitting diode (OLED) display includes: a display layer including a front display layer configured to display an image at a front of the OLED display and a bending display layer bent at an end of the front display layer, and a thin film encapsulation layer covering the display layer. The thin film encapsulation layer includes a front encapsulation layer disposed on the front display layer and a bending encapsulation layer disposed on the bending display layer and having a plurality of pores.