OLED Display Without Polarizing Plate for Flexibility

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Solution Overview

Problem

Conventional organic light emitting displays with integrated touchscreens face challenges in achieving flexibility and thinness due to the use of separate glass substrates and the necessity of a polarizing plate, which increases thickness, complexity, and cost.

Innovation Solution

The organic light emitting display configuration excludes a polarizing plate by using a black matrix layer and color filter layer for exterior light shielding, integrated within the touch electrode array, and employs a laminate structure with inorganic films for the buffer layers to prevent moisture and exterior light, allowing for thinner, more flexible displays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a polarizing plate is used for exterior light shielding, then visibility is improved, but thickness increases and flexibility deteriorates

Engineering Contradiction:
ImprovevisibilityVSAvoidthickness
Core Design Contradiction:
Illumination intensityVSLength of stationary object

Solution Approach 1:

The patent extracts and removes the polarizing plate from the display structure, replacing it with an exterior light shielding layer formed directly on the touch electrode array. This elimination of the separate polarizing plate component reduces overall thickness while maintaining exterior light shielding functionality through the integrated black matrix and color filter layers.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the exterior light shielding function with the touch electrode array structure by forming the black matrix and color filter layers as part of the same structural assembly. This integration combines multiple functions (touch sensing, light emission, and exterior light shielding) into a unified structure, eliminating the need for separate polarizing plate components.

Inventive Principle:
Principle #5Merging (Combining)

2Strength

If separate glass substrates are used for the display panel and touchscreen, then structural strength is improved, but device complexity and thickness increase

Engineering Contradiction:
Improvestructural strengthVSAvoidcomplexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent merges the display panel and touchscreen into a single integrated structure where the touch electrode array is formed directly on the display structure. This consolidation combines multiple components (display panel, touchscreen, polarizing plate) into one unified assembly, reducing device complexity and the number of separate glass substrates required while maintaining structural integrity.

Inventive Principle:
Principle #5Merging (Combining)

3Illumination intensity

If a polarizing plate is used for exterior light shielding, then visibility is improved, but manufacturing cost increases

Engineering Contradiction:
ImprovevisibilityVSAvoidcost
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent extracts and eliminates the expensive polarizing plate component from the manufacturing process. Instead, it uses a simplified exterior light shielding layer formed through standard thin film deposition techniques, significantly reducing material costs and manufacturing complexity while achieving the same exterior light shielding effect.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the expensive polarizing plate with a cost-effective exterior light shielding layer formed using inexpensive materials and standard manufacturing processes. This substitution uses cheaper materials (black matrix and color filter layers) that can be deposited through conventional techniques, reducing overall manufacturing cost.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 configuration reduces the display thickness, enhances flexibility, and improves transmittance while maintaining effective exterior light shielding, thereby addressing the limitations of conventional designs and offering cost savings by eliminating the need for expensive polarizing plates.

Implementation Method 1

When electric charges are injected into an organic film formed between an electron injection electrode (cathode) and a hole injection electrode (anode), electrons pair with holes and the pairs then decay. At this time, an organic light emitting diode emits light.

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

a black matrix layer and a color filter layer that perform a function of shielding exterior light incident on the organic light emitting display

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

employ a laminate structure with inorganic films for the buffer layers to prevent moisture and exterior light

Methodology Applied
Scientific EffectBarrier protection:

Data Source

PatentEP3454375B1Organic light emitting display and method for manufacturing the same
Publication Date: 2020.04.15 LG DISPLAY CO LTD
  • EP3454375B1 patent drawingFigure 1
  • EP3454375B1 patent drawingFigure 2
  • EP3454375B1 patent drawingFigure 3

AI summary

Disclosed are an organic light emitting display that has a configuration excluding a polarizing plate and exhibits improved flexibility and visibility, and a method for manufacturing the same, the organic light emitting display includes a touch electrode array (230) facing the organic light emitting diode (150) on the second buffer layer (220), the touch electrode array (230) including first and second touch electrodes (2331, 2332) intersecting each other and an exterior light shielding layer (2400, 3400, 4400, 5400, 6400) including at least a color filter layer, an adhesive layer (400) formed between the organic light emitting diode (150) and the touch electrode array (230).