Thin Remote Phosphor Coating on Reflective Substrate for LED Luminaire
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED lighting systems face challenges in achieving high color rendering index (CRI) due to limitations in wavelength conversion materials, particularly in reducing phosphor costs and accommodating different thermal profiles of LEDs, which affect color accuracy and efficiency.
Innovation Solution
The use of GaN-based LEDs with a thin or dilute remote phosphor coating on a reflective substrate, allowing for the production of substantially white light with improved CRI, and eliminating the need for engineering around different thermal profiles of GaN and GaP LEDs, while reducing phosphor costs through a thinner layer application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phosphor particles are randomly distributed within encapsulant material, then wavelength conversion is achieved, but phosphor cost increases and color accuracy decreases
Solution Approach 1:
The patent changes the physical state and distribution parameters of phosphor from random particulate distribution to a controlled thin film or coating layer. This parameter change reduces the quantity of phosphor material needed while improving color accuracy through more uniform wavelength conversion across the LED surface.
Solution Approach 2:
The patent extracts phosphor from the traditional encapsulant matrix and applies it as a separate thin layer on the LED surface. This separation allows for more precise control of phosphor distribution and reduces the total amount of phosphor material required while maintaining or improving color rendering.
2Adaptability or versatility
If different thermal profiles of GaN and GaP LEDs are accommodated, then device compatibility is improved, but engineering complexity increases
Solution Approach 1:
The patent creates a universal phosphor application system that works with different LED types (GaN and GaP) without requiring type-specific engineering. The thin film phosphor layer can be applied as a general solution that accommodates various thermal profiles, eliminating the need for separate engineering approaches for each LED type.
3Quantity of substance
If a thin phosphor layer is applied to remote reflector, then phosphor cost is reduced and CRI is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent introduces a remote reflector as an intermediary substrate for phosphor application. This mediator provides a stable surface that facilitates more controlled and uniform phosphor deposition, reducing the difficulty of manufacturing precision while still achieving the benefits of thin phosphor layers.
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 approach enables the production of light with a CRI of at least 70, 80, or 95, achieving substantially white light with improved color accuracy and reduced phosphor costs, suitable for various lighting applications, including troffer-style fixtures and residential down-lighting.
Implementation Method 1
Phosphor absorbs light at one wavelength and re-emits light at a different wavelength
Implementation Method 2
wavelength conversion material is sometimes used in lighting systems. The wavelength conversion materials may produce white light when struck by light of a specified color
Implementation Method 3
a thin phosphor layer applied to a remote reflector
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A luminaire including a thin phosphor layer applied to a remote reflector is disclosed. In some embodiments of the luminaire, LEDs illuminate and activate a thin remote phosphor coating applied to a reflective substrate. In some embodiments, the LED light source includes at least one LED with a GaN emitting layer. The LEDs can be packaged with or without a local phosphor. The thin remote phosphor can include red, red/orange, yellow, green or cyan emitting phosphor so that the luminaire produces white light. The thin remote phosphor layer can include two or more different color emitting phosphors. In some embodiments, the luminaire is a light fixture including a diffuser lens assembly and a pan to support the fixture when mounted in a ceiling.