Stacked RGB Light Emission Layout for High-Density Pixel Brightness

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In light emitting devices with miniaturized semiconductor elements, the luminous efficiency and pixel density are compromised due to limited power supply and heating issues, leading to insufficient light emission and image quality.

Innovation Solution

A light emitting device configuration with a first, second, and third layer of light emitting elements, where the third layer has an indium gallium nitride-based light emitting layer and a gallium nitride-based cathode layer, with a larger light emission area to enhance luminous efficiency and match the light emission of other colors, thereby improving pixel brightness and image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If semiconductor elements are miniaturized to increase pixel density, then pixel density is improved, but luminous efficiency deteriorates

Engineering Contradiction:
Improvepixel densityVSAvoidluminous efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent applies local quality by making the light emission area of the red light emitting element larger than those of blue and green light emitting elements. This localized adjustment compensates for the lower luminous efficiency of red elements without requiring all elements to be uniformly enlarged, thus maintaining high pixel density while improving overall light emission balance.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If electric power is increased to improve light emission amount, then brightness is improved, but heat generation increases

Engineering Contradiction:
ImprovebrightnessVSAvoidheat generation
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent applies local quality by making the light emission area of the red light emitting element larger than those of blue and green light emitting elements. This localized adjustment compensates for the lower luminous efficiency of red elements without requiring all elements to be uniformly enlarged, thus maintaining high pixel density while improving overall light emission balance.

Inventive Principle:
Principle #3Local quality

3Loss of energy

If light emission area is increased to improve luminous efficiency, then light emission amount is improved, but pixel size increases

Engineering Contradiction:
Improveluminous efficiencyVSAvoidpixel size
Core Design Contradiction:
Loss of energyVSArea of stationary object

Solution Approach 1:

The patent applies local quality by making the light emission area of the red light emitting element larger than those of blue and green light emitting elements. This localized adjustment compensates for the lower luminous efficiency of red elements without requiring all elements to be uniformly enlarged, thus maintaining high pixel density while improving overall light emission balance.

Inventive Principle:
Principle #3Local quality

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 configuration increases the light emission of the red color to match blue and green colors, achieving high-definition and high-quality images without enlarging pixel size or increasing heat emission, ensuring sufficient luminance across all colors.

Implementation Method 1

a third light emitting element that makes a third light emission region, at least partially overlapping with the first light emission region and the second light emission region as viewed from the light emission direction, emit light

Methodology Applied
Scientific EffectLight emitting diode effect: Light Emitting Diode

Implementation Method 2

a gallium nitride-based cathode layer in contact with the light emitting layer

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4394870A1Light emitting device
Publication Date: 2024.07.03 OKI ELECTRIC INDUSTRY CO LTD
  • EP4394870A1 patent drawingFigure 1~2B
  • EP4394870A1 patent drawingFigure 3~5
  • EP4394870A1 patent drawingFigure 6A~6B

AI summary

A light emitting device (1) includes a first layer (20B) including a first light emitting element (21B) that makes a first light emission region (24B) emit light and a first transparent insulation member (26B) that covers the first light emitting element; a second layer (20G) stacked on a light emission direction side of the first layer (20B) and including a second light emitting element (21G) that makes a second light emission region (24G) emit light and a second transparent insulation member (26G) that covers the second light emitting element (21G); and a third layer (20R) stacked on the light emission direction side of the second layer (20G) and including a third light emitting element (21R) that makes a third light emission region (24R), at least partially overlapping with the first light emission region (24B) and the second light emission region (24G) as viewed from the light emission direction, emit light and a third transparent insulation member (26R) that covers the third light emitting element (21R), wherein the third light emission region (24R) is formed so that its area as viewed from the light emission direction is larger than the first light emission region (24B) and the second light emission region (24G).