Green Light Display Panel with Conversion Layers

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Solution Overview

Problem

Existing color display technologies using white light with a color filter suffer from low light transmittance and degraded display effects due to the color filtration process.

Innovation Solution

A display panel design that eliminates the need for a color filter by using sub-pixels with light-emitting elements emitting green light and conversion layers to produce red and blue light, maintaining brightness and increasing light transmittance by altering the wavelength of green light emitted.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a color filter layer is used to achieve color display, then color display is implemented, but light transmittance is reduced and display effect is degraded

Engineering Contradiction:

Improvelight transmittanceVSAvoidcolor filter layer

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The patent removes the color filter layer from the display structure and replaces it with light-emitting elements that directly generate colored light through electroluminescence. This extraction of the harmful color filter component eliminates the light absorption problem while maintaining color display capability through organic light-emitting materials with different emission wavelengths.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent substitutes the passive optical filtering mechanism (color filter layer that blocks and transmits light based on wavelength) with an active light generation mechanism (organic light-emitting elements that generate light at specific wavelengths through electroluminescence). This replacement fundamentally changes from a filtering approach to a direct emission approach, improving light efficiency.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If a color filter layer is used for color display, then color filtration is achieved, but display quality is degraded

Engineering Contradiction:

Improvedisplay qualityVSAvoidcolor filtration degradation

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent converts the limitation of organic light-emitting materials (initially only emitting green light with long stability) into an advantage by using them as the core light source and combining them with phosphor conversion layers. This approach transforms the material constraint into a design feature where green light-emitting elements with long service life are converted to produce red, green, and blue colors through phosphor down-conversion, achieving both high display quality and extended device lifetime.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Illumination intensity

If white light is used with color filter, then color display is achieved, but light transmittance is low

Engineering Contradiction:

Improvelight transmittanceVSAvoidcolor filtration process

Core Design Contradiction:

Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent changes the fundamental parameter of light generation from broadband white light emission followed by spectral filtering to narrowband wavelength-specific light emission through electroluminescence. By using organic light-emitting materials with tailored HOMO-LUMO energy gaps, the system directly emits light at specific wavelengths (red, green, blue) without requiring filtration, thereby maximizing light transmittance and simplifying the optical path.

Inventive Principle:

Principle #35Parameter changes

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 achieves higher light transmittance and improved display quality by converting green light into red and blue light without reducing brightness, extending the service life of the display panel with OLED devices.

Implementation Method 1

the first sub-pixel includes a first conversion layer at a first light outgoing side of the light-emitting element thereof and emits light having a first color at the first light outgoing side of the light-emitting element

Methodology Applied

Scientific EffectLight conversion: Photoluminescence

Data Source

PatentUS9923034B2Display panel and display device

Publication Date: 2018.03.20 BOE TECHNOLOGY GROUP CO LTD

AI summary

The present invention provides a display panel and a display device including the display panel. The display panel comprises a plurality of pixels each comprising at least a first sub-pixel, a second sub-pixel and a third sub-pixel, and each of the first sub-pixel, the second sub-pixel and the third sub-pixel comprises a light-emitting element emitting green light having a first wavelength. The first sub-pixel comprises a first conversion layer at a first light outgoing side of the light-emitting element thereof and emits light having a first color at the first light outgoing side of the light-emitting element thereof, and the second sub-pixel comprises a second conversion layer at a first light outgoing side of the light-emitting element thereof and emits light having a second color different from the first color at the first light outgoing side of the light-emitting element thereof.