Phosphor-Converted Red LED Layers to Block Blue Pass-Through
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current PC Red LEDs using narrowband red fluoride phosphors face challenges such as high cost, low absorption efficiency, and susceptibility to moisture, leading to reduced color purity and device failure due to 'blue pass through' and chemical reactivity.
Innovation Solution
Incorporating a combination of narrowband red fluoride phosphors with broadband red phosphors in a single or double-layer structure, where the broadband phosphor enhances absorption efficiency and provides environmental protection, reducing the amount of narrowband phosphor needed and minimizing 'blue pass through'.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If narrowband red fluoride phosphors are used in PC Red LEDs, then color purity is improved, but absorption efficiency deteriorates and cost increases
Solution Approach 1:
The patent combines narrowband red fluoride phosphor (for color purity) with broadband red phosphor (for absorption efficiency) into a single phosphor layer or multiple layers. This merging allows the system to simultaneously achieve high color purity from the narrowband phosphor and high absorption efficiency from the broadband phosphor, resolving the technical contradiction between these two parameters.
2Measurement precision
If narrowband red fluoride phosphors are used in PC Red LEDs, then color purity is improved, but device reliability deteriorates due to moisture susceptibility
Solution Approach 1:
The patent introduces an intermediary protective layer or encapsulation structure between the moisture-sensitive narrowband red fluoride phosphor and the external environment. This intermediary protection prevents moisture from reaching the phosphor particles, thereby maintaining device reliability while preserving the color purity benefits of the narrowband phosphor.
3Measurement precision
If narrowband red fluoride phosphors are used in PC Red LEDs, then color purity is improved, but manufacturing cost increases
Solution Approach 1:
The patent optimizes the concentration ratio and distribution parameters of narrowband and broadband phosphors to achieve the desired color purity at lower manufacturing costs. By carefully controlling the phosphor mixing ratios, particle sizes, and spatial distribution, the system achieves high color purity without requiring excessive amounts of expensive narrowband phosphor material.
4Measurement precision
If narrowband red fluoride phosphors are used in PC Red LEDs, then color purity is improved, but blue pass through increases
Solution Approach 1:
The patent merges narrowband red fluoride phosphor with broadband red phosphor in a combined phosphor layer structure. The broadband phosphor component absorbs blue light effectively and converts it to red light, preventing blue pass through, while the narrowband phosphor maintains high color purity. This combination resolves the contradiction between color purity and blue light absorption.
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 improves color purity and reliability of PC Red LEDs by increasing absorption efficiency, reducing phosphor usage, and protecting against moisture, resulting in high-brightness, narrowband red light emission.
Implementation Method 1
a blue LED chip and a photoluminescence material that converts substantially all of the excitation light generated by the LED chip to light of a selected color such as, for example, green, yellow, orange or red through a process of photoluminescence wavelength conversion
Data Source
AI summary
A light emitting device comprising: at least one first LED for generating red light; at least one second LED for generating green light; at least one third LED for generating blue light; at least one fourth LED for generating light of a CCT in a range from 1800K to 5000K; and first package and a second package that in combination comprise the at least one first LED, the at least one second LED, the at least one third LED, and the at least one fourth LED, and wherein the at least one first LED comprises a phosphor-converted LED comprising a narrowband red phosphor with a FWHM less than 55 nm.