OLED Inorganic Layer Suppresses Blue Light

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Solution Overview

Problem

Existing OLED devices emit blue lights with wavelengths below 435nm, causing harm to human eyes and leading to eye fatigue and potential health issues, with existing solutions like blue light resistant films reducing overall light transmissivity and brightness.

Innovation Solution

An organic electroluminescent device structure incorporating a titanium dioxide or silicon carbide inorganic layer, which suppresses blue and violet light emission while protecting the device and improving color purity, comprising a first electrode layer, organic functional layer, second electrode layer, and an inorganic layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a blue light resistant film is pasted on a 3C product to suppress high-energy blue lights, then the harmful blue light emission is reduced, but the transmissivity of lights of all wavelengths decreases, affecting the brightness of the product

Engineering Contradiction:
Improveblue light harm to human eyesVSAvoidbrightness of product
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent changes the optical parameters of the OLED device by introducing an inorganic layer with specific optical properties. This layer selectively suppresses blue light wavelengths below 435nm while maintaining transmissivity for other wavelengths, thus reducing blue light harm without significantly affecting overall brightness. The inorganic layer acts as a wavelength-selective filter that modifies the spectral composition rather than uniformly reducing all light transmission.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The inorganic layer serves as an intermediary element between the OLED structure and the user's eyes. This intermediate layer selectively interacts with blue light wavelengths, absorbing or reflecting harmful high-energy blue light while allowing other wavelengths to pass through. This mediator approach resolves the contradiction by targeting only the harmful portion of the spectrum rather than blocking all light.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If existing OLED devices emit blue lights with wavelengths below 435nm, then the device maintains good brightness and color performance, but it causes harm to human eyes and leads to eye fatigue and potential health issues

Engineering Contradiction:
Improvebrightness of OLED deviceVSAvoidblue light harm to human eyes
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the spectral emission parameters of the OLED by incorporating an inorganic layer that selectively filters blue light wavelengths below 435nm. This changes the emission spectrum to remove harmful wavelengths while preserving the overall brightness through maintained emission in other wavelength ranges. The inorganic layer acts as a spectral modifier that adjusts the wavelength distribution without uniformly reducing intensity.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If an inorganic layer is added to the OLED device to suppress blue light, then blue light emission is reduced and device protection is improved, but the device structure becomes more complex

Engineering Contradiction:
Improveblue light suppressionVSAvoidstructure of OLED device
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent employs a composite structure combining organic functional layers with an inorganic layer. This composite approach integrates the blue light suppression function within the existing OLED architecture, where the inorganic layer works synergistically with the organic emission layers. The composite material strategy allows adding functionality without proportionally increasing overall device complexity, as the inorganic layer is integrated into the existing layer structure.

Inventive Principle:
Principle #40Composite materials

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

Effectively suppresses blue and violet light emission, protecting human eyes and prolonging the device's lifespan by enhancing color purity and maintaining brightness.

Implementation Method 1

the inorganic layer may function as a protection on the cover layer and the second electrode layer... the micro-cavity structures of the inorganic layer and the organic material together may improve the color purity of the OLED device... effectively suppress blue and violet lights that do harm to human eyes

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

An organic electroluminescent device including: a first electrode layer; an organic functional layer, disposed on the first electrode layer

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2996168B1Organic electroluminescent device and display having the same
Publication Date: 2020.10.07 EVERDISPLAY OPTRONICS (SHANGHAI) CO LTD
  • EP2996168B1 patent drawingFigure 1
  • EP2996168B1 patent drawingFigure 2
  • EP2996168B1 patent drawingFigure 3

AI summary

The present disclosure provides an organic electroluminescent device including: a first electrode layer (1); an organic functional layer (2), disposed on the first electrode layer (1); a second electrode layer (3), disposed on the organic functional layer (2); and an inorganic layer (5), disposed on the second electrode layer (3). There also provides a display including the above organic electroluminescent device. The organic electroluminescent device of the present disclosure may effectively suppress blue and violet lights that do harm to human eyes, and prevents human bodies from damages caused by high-energy blue lights. Meanwhile, the inorganic layer may function as a protection on the cover layer and the second electrode layer, so as to prolong the lifetime of the OLED device, and the micro-cavity structures of the inorganic layer and the organic material together may improve the color purity of the OLED device.