OLED Display Filling Agent for External Light Reflection

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Solution Overview

Problem

Conventional OLED displays face issues with external light reflection, leading to poor black color expression and contrast, and significant loss of emitted light due to the use of polarizing and phase delay plates, which are not effective in suppressing reflection without sacrificing a substantial amount of emitted light.

Innovation Solution

An OLED display design incorporating a filling agent between the display and encapsulation substrates that selectively absorbs external light based on wavelength, using a resin with aromatic hydrocarbon light-absorbing materials to control transmittance and minimize light loss, acting as a filter to suppress external light reflection while maintaining high emissive light transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a polarizing plate and phase delay plate are used to suppress external light reflection, then visibility is improved, but a large amount of emitted light is lost

Engineering Contradiction:
ImprovevisibilityVSAvoidlight loss
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The filling agent is designed with wavelength-selective light absorption properties, where it strongly absorbs external light in specific wavelength ranges (480-510nm and 580-610nm) while maintaining high transmittance for emitted light wavelengths. This local quality differentiation in the optical properties of the filling agent allows selective suppression of reflected external light without blocking the desired emitted light, thereby improving visibility while minimizing light loss.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If conventional light suppression methods are used, then external light reflection is reduced, but light use efficiency decreases

Engineering Contradiction:
Improveexternal light reflectionVSAvoidlight use efficiency
Core Design Contradiction:
Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The filling agent's optical parameters are specifically optimized to achieve wavelength-dependent transmittance. By controlling the absorption characteristics of the filling agent across different wavelength ranges, the system achieves high suppression of external light reflection in harmful wavelength bands while maintaining high transmittance in the emitted light wavelength bands, thereby preserving light use efficiency.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the OLED display is used in bright locations, then it can operate in various environments, but black color expression and contrast deteriorate due to light reflection

Engineering Contradiction:
Improveenvironmental adaptabilityVSAvoidblack color expression and contrast
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The filling agent acts as an intermediary substance between the external environment and the OLED display. It selectively absorbs harmful external light wavelengths that would otherwise reflect and degrade display quality, while allowing the emitted light to pass through. This intermediary function enables the display to maintain excellent black color expression and contrast even when used in bright environments, thereby improving environmental adaptability without sacrificing display quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enhances impact durability and visibility by reducing external light reflection and minimizing light loss, improving the overall light use efficiency and luminance of the OLED display, while also potentially reducing power consumption and extending the display's lifespan.

Implementation Method 1

the filling agent is adapted to selectively absorb external light entering through the encapsulation substrate assembly and incident on the organic light emitting element as a function of wavelength in a wavelength band of the external light

Methodology Applied
Scientific EffectSelective light absorption: Absorption (EM radiation)

Implementation Method 2

The filling agent includes a resin containing a light absorbing material comprising an aromatic hydrocarbon, wherein the aromatic hydrocarbon is selected from a group consisting of Formula 13, Formula 14 or Formula 15

Methodology Applied
Scientific EffectLight absorption by aromatic hydrocarbon: Absorption (EM radiation)

Data Source

PatentEP2284924B1Organic light emitting diode display
Publication Date: 2018.09.19 SAMSUNG DISPLAY CO LTD
  • EP2284924B1 patent drawingFigure 1
  • EP2284924B1 patent drawingFigure 2
  • EP2284924B1 patent drawingFigure 3

AI summary

An organic light emitting diode includes a display substrate assembly including an organic light emitting element; an encapsulation substrate assembly (210) disposed on the display substrate assembly (110) with a space therebetween and sealed with the display substrate assembly in a vacuum-tight manner; and a filling agent (300) filling the space between the display substrate assembly (110) and the encapsulation substrate assembly (210). The filling agent is adapted to selectively absorb external light entering through the encapsulation substrate assembly (210) and incident on the organic light emitting element as a function of wavelength in a wavelength band of the external light to control transmittance.