Remote Phosphor Wavelength Conversion Component with Light Diffusing Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Remote phosphor LED devices face issues with non-white color appearance in the OFF state, color uniformity with emission angle, and high costs due to the large quantity of phosphor materials required.
Innovation Solution
Incorporating a light diffusing layer with light diffractive particles, such as titanium dioxide, in direct contact with the wavelength conversion layer, which scatters excitation radiation more than phosphor-generated light, reducing the need for phosphor material and improving color uniformity and appearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a remote phosphor wavelength conversion component is used, then the LED device can be configured with spatial separation between the light source and phosphor material, but the device exhibits non-white color appearance in the OFF state
Solution Approach 1:
The invention segments the wavelength conversion component into two distinct layers: a wavelength conversion layer containing phosphor particles and a light diffusing layer containing diffractive particles positioned between the LED and the phosphor layer. This segmentation allows each layer to perform its specific function independently, resolving the contradiction by maintaining spatial separation while improving color appearance.
Solution Approach 2:
The light diffusing layer acts as an intermediary component between the LED light source and the phosphor wavelength conversion layer. This intermediary layer diffracts incident light to improve the white appearance of the device in the OFF state, while still allowing excitation light to reach the phosphor material when the device is ON.
2Device complexity
If a remote phosphor wavelength conversion component is used, then the LED device can be configured with spatial separation, but the device exhibits color variation with emission angle
Solution Approach 1:
By segmenting the wavelength conversion component into separate functional layers (light diffusing layer and wavelength conversion layer), the invention enables the light diffusing layer to uniformly scatter light across different emission angles, thereby stabilizing color uniformity while maintaining spatial separation.
Solution Approach 2:
The light diffusing layer introduces local optical modification at the interface between the LED and phosphor layers. The diffractive particles in this layer create localized light scattering that compensates for angular color variations, ensuring uniform color perception across different viewing angles.
3Device complexity
If a remote phosphor wavelength conversion component is used, then the LED device can be configured with spatial separation, but the quantity of phosphor material required increases significantly
Solution Approach 1:
The light diffusing layer serves as an intermediary that optimizes light coupling between the LED and phosphor material. By diffracting incident light to increase the optical path length and interaction probability, this layer improves phosphor excitation efficiency, thereby reducing the total quantity of phosphor material needed while maintaining the remote configuration.
Solution Approach 2:
The invention changes the optical parameters of the system by introducing a light diffusing layer with specific diffractive properties. This parameter change enhances light-phosphor interaction efficiency, allowing for reduced phosphor material quantity while maintaining effective wavelength conversion in the remote configuration.
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 enhances the white appearance in the OFF state, improves color uniformity over a wide emission angle range, and reduces the quantity of phosphor material needed by up to 40%, thereby lowering production costs.
Implementation Method 1
a light diffusing layer comprising particles of a light diffractive material... which scatters excitation radiation more than phosphor-generated light
Implementation Method 2
containing particles of a photoluminescence material... operable to convert at least a portion of the excitation radiation to light of a different wavelength
Data Source
AI summary
A light emitting device comprises at least one solid-state light source (LED) operable to generate excitation light and a wavelength conversion component located remotely to the at least one source and operable to convert at least a portion of the excitation light to light of a different wavelength. The wavelength conversion component includes a light diffusing layer having particles of a light scattering material, where the light diffusing layer has a shape with an inner surface that defines an interior volume, and a wavelength conversion layer having particles of at least one photoluminescence material within the interior volume.