Light-Emitting Device Green Fluorescent Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light-emitting devices for liquid crystal displays, particularly those using β sialon fluorescent materials, face limitations in achieving both high luminance and wide color reproduction due to their relatively wide emission spectrum and low green color purity, which restricts the expansion of color reproduction range.
Innovation Solution
A light-emitting device comprising a light-emitting element with a peak emission wavelength between 400 nm to 470 nm, combined with a fluorescent member containing specific aluminate, β sialon, and sulfide fluorescent materials, optimized to have a narrow half bandwidth and adjusted emission intensity in the green region, enhancing color reproducibility and luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If β sialon fluorescent materials are used to achieve high luminance, then luminous flux is improved, but color reproduction range deteriorates due to wide emission spectrum
Solution Approach 1:
The patent segments the green fluorescent material into two distinct materials: a first green fluorescent material with peak emission wavelength of 510-530 nm and a second green fluorescent material with peak emission wavelength of 520-540 nm. This segmentation allows each material to contribute differently to the overall emission spectrum, achieving both high luminance and wide color reproduction range by combining their complementary emission characteristics.
Solution Approach 2:
The patent uses a composite fluorescent layer containing multiple fluorescent materials including the first green fluorescent material, second green fluorescent material, and red fluorescent material. This composite structure combines the advantages of different materials to achieve both high luminous flux and wide color reproduction range that cannot be achieved with single materials alone.
2Adaptability or versatility
If conventional fluorescent materials are used to achieve wide color reproduction, then color purity is improved, but luminance deteriorates due to low emission efficiency
Solution Approach 1:
The patent optimizes the emission wavelength parameters of the fluorescent materials. The first green fluorescent material emits at 510-530 nm and the second green fluorescent material emits at 520-540 nm, with specific half bandwidths that balance color purity and luminance. This parameter optimization ensures high color reproduction while maintaining high emission efficiency and luminance.
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 enables a wider color reproduction range and higher luminance for liquid crystal displays, particularly meeting the standards of BT. 2020, by effectively separating colors through color filters and improving visibility, while maintaining high emission efficiency.
Implementation Method 1
A light-emitting device includes a light-emitting element and a fluorescent member. The light-emitting element has a peak emission wavelength in a range of from 400 nm to 470 nm
Implementation Method 2
The fluorescent member includes a first fluorescent material, a second fluorescent material, and a third fluorescent material
Data Source
AI summary
Provided is a light-emitting device including a light-emitting element having a peak emission wavelength in a range of from 400 nm to 470 nm, and a fluorescent member including a first fluorescent material including an aluminate that contains Mg, Mn, and at least one alkali earth metal selected from the group consisting of Ba, Sr, and Ca, a second fluorescent material having a different composition from the first fluorescent material, and a third fluorescent material. The first, second and third fluorescent materials have a peak emission wavelength in a range of from 510 nm to 525 nm, from 510 nm to 550 nm, and from 620 nm to 670 nm, respectively.