Display Device Using Color Conversion Layer for Pixel Density

Solution Overview

Problem

In display devices, increasing the number of pixels leads to a decrease in sub-pixel area and light emission quantity due to the use of different light emitting layers for each color, which affects the overall display efficiency.

Innovation Solution

A display device configuration that includes a substrate with alternating first and second light emitting layers and a color conversion layer, where the color conversion layer absorbs light from the first light emitting layer and converts it to a longer wavelength, allowing for representation of multiple colors using fewer light emitting layers, thereby maintaining sub-pixel area and enhancing light emission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If different light emitting layers are used for each light emitting color, then color display capability is improved, but sub-pixel area and light emission quantity decrease when pixel density is increased

Engineering Contradiction:

Improvecolor display capabilityVSAvoidsub-pixel area

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent merges the color generation function from multiple separate light emitting layers into a single blue light emitting layer combined with a color conversion layer. The color conversion layer contains red, green, and yellow phosphors that convert the blue light into different colors, allowing one light emitting layer to serve multiple color functions that previously required three separate layers.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The color conversion layer acts as an intermediary between the blue light emitting layer and the final displayed colors. Instead of directly emitting different colors through separate light emitting layers, the system uses the color conversion layer to transform the blue light into red, green, and yellow wavelengths, thereby achieving full-color display with a single light emitting layer.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If different light emitting layers are used for each light emitting color, then color display capability is improved, but light emission quantity decreases when pixel density is increased

Engineering Contradiction:

Improvecolor display capabilityVSAvoidlight emission quantity

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent merges the color generation function from multiple separate light emitting layers into a single blue light emitting layer combined with a color conversion layer. The color conversion layer contains red, green, and yellow phosphors that convert the blue light into different colors, allowing one light emitting layer to serve multiple color functions that previously required three separate layers.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single blue light emitting layer serves multiple functions by illuminating the color conversion layer, which then generates all necessary colors (red, green, yellow) for display. This multi-functional approach allows one light emitting layer to replace what previously required three separate layers, maintaining light emission quantity while achieving full-color display.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If pixel density is increased, then display resolution is improved, but sub-pixel area decreases leading to reduced light emission

Engineering Contradiction:

Improvedisplay resolutionVSAvoidsub-pixel area

Core Design Contradiction:

Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent merges the color generation function from multiple separate light emitting layers into a single blue light emitting layer combined with a color conversion layer. The color conversion layer contains red, green, and yellow phosphors that convert the blue light into different colors, allowing one light emitting layer to serve multiple color functions that previously required three separate layers.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from a vertical stacking approach (multiple layers in the thickness direction) to a lateral conversion approach (single layer with color conversion particles distributed within). This dimensional reorganization allows the light emitting layer to maintain its area in the pixel plane while still achieving full-color output through the color conversion mechanism.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 enables the representation of multiple colors with fewer light emitting layers, ensuring that sub-pixel area is secured even with increased pixel density, preventing a decrease in light emission quantity.

Implementation Method 1

a color conversion layer that is arranged at a position for covering at least part of the first light emitting layer, absorbs light emitted from the first light emitting layer

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 2

converts the absorbed light so that a wavelength of the absorbed light becomes longer

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentUS9666645B2Display device

Publication Date: 2017.05.30 MAGNOLIA WHITE CORP

AI summary

A display device includes: a substrate; a first light emitting layer extending in a first direction along a column or a row of a plurality of sub-pixels arranged in a matrix on the substrate; a second light emitting layer that extends in the first direction, is arranged alternately with the first light emitting layer in a second direction, and emits light of a wavelength different from that of the first light emitting layer; and a color conversion layer that is arranged at a position for covering at least part of the first light emitting layer, absorbs light emitted from the first light emitting layer, and converts the absorbed light so that a wavelength of the absorbed light becomes longer.