LED Light Source With Side-Emitting Light Excitation Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LED light sources have limited light emitting angles, leading to uneven brightness, poor light mixing, and increased thickness in surface light source modules, which are costly and inefficient.
Innovation Solution
An LED light source with a first reflective layer on the bottom and a light excitation layer on the top, combined with a second reflective layer, increases the light emitting angle and reduces blue light absorption, while a transparent waveguide layer enhances light mixing and reduces module thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the light emitting angle of LED light source is increased, then the light mixing effect is improved and uniformity is enhanced, but the device structure becomes more complex
Solution Approach 1:
The patent transitions from conventional top-emitting LED structure to side-emitting LED structure, changing the light emission dimension. The light excitation layer is positioned on the side surface of the LED chip rather than the top surface, enabling light to propagate laterally through the transparent waveguide layer. This dimensional change achieves wide-angle light emission (170 degrees) and improved light mixing without requiring additional complex optical components.
Solution Approach 2:
The patent introduces a transparent waveguide layer as an intermediary medium between the LED light source and the diffusion plate. This waveguide layer has a refractive index higher than the surrounding medium, enabling total internal reflection and guiding light propagation. The waveguide layer mediates the light transmission process, allowing light to travel laterally and mix uniformly across the display surface without direct line-of-sight propagation, thereby improving light mixing effect.
2Length of stationary object
If the distance between adjacent LED light sources is reduced to decrease module thickness, then the module thickness is reduced, but the number of LED light sources increases squared and cost increases greatly
Solution Approach 1:
The patent changes from vertical light emission to lateral light emission by positioning the light excitation layer on the side surface of the LED chip. This enables light to propagate horizontally through the transparent waveguide layer, allowing the diffusion plate to be placed much closer to the LED array (only 0.5-2mm distance). This dimensional change in light propagation direction reduces the required module thickness without needing to increase LED density.
3Device complexity
If conventional LED light source with limited light emitting angle is used, then the device structure is simple, but dark regions form and light mixing uniformity is poor
Solution Approach 1:
The patent repositions the light excitation layer from the top surface to the side surface of the LED chip, changing the light emission dimension. This enables light to propagate laterally at wide angles (170 degrees) through the transparent waveguide layer, illuminating the entire diffusion plate surface uniformly without forming dark regions. The side-emitting configuration naturally achieves wide-angle coverage without complex optical components.
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 achieves a larger light emitting angle, improved light mixing, and reduced module thickness, resulting in more uniform brightness and lower costs by increasing the light emitting angle and enhancing light mixing effects.
Implementation Method 1
The light excitation layer is configured for emitting light upon excitation with a blue light
Implementation Method 2
The first reflective layer is located on a bottom surface of the LED chip... The second reflective layer is disposed on a top surface of the light excitation layer
Implementation Method 3
a top surface of the second reflective layer is defined as a total reflection or a partial reflection region
Data Source
AI summary
The present disclosure provides an LED light source, a surface light source display module, and a preparation method for the LED light source. The LED light source includes: an LED chip including a first reflective layer, a P—GaN layer, a light-emitting layer, an N—GaN layer and a substrate, which are sequentially arranged from bottom to top; a light excitation layer configured for emitting light upon excitation with a blue light, wherein the LED chip is covered by the light excitation layer, that is, the light excitation layer is disposed on a top surface of the substrate of the LED chip and in contact with a side surface of the LED chip, wherein four side surfaces of the light excitation layer are defined as light output regions; and a second reflective layer disposed on a top surface of the light excitation layer, and a top surface of the second reflective layer is defined as a total reflection region or a partial reflection region. The light emission angle of the LED light source can be enlarged.