Concentric Ridge Texture for LED Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Light emitting diode (LED) based light emitting apparatuses face inefficiencies due to light reflection and attenuation at the encapsulation layer surface, particularly at incident angles around 45 degrees, where a significant portion of light is reflected back and attenuated by phosphors, hindering high efficiency emission.
Innovation Solution
A light emitting apparatus with a texture layer featuring concentric ridge structures on the encapsulation layer, where the radial cross section of each ridge has a triangular shape with altitude angles less than or equal to 40 degrees, designed to redirect reflected light and enhance extraction efficiency by minimizing total reflection and phosphor collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a protrusion such as a pyramid is formed on the surface of the encapsulation layer, then light extraction is enhanced, but reflected light returns in the opposite direction and is attenuated by phosphor collision
Solution Approach 1:
The patent employs curved ridge structures with specific altitude angles (≤40 degrees) instead of sharp pyramidal protrusions. This curvature design allows reflected light to be redirected at optimal angles that avoid returning toward the phosphor layer, thereby maintaining light extraction enhancement while preventing phosphor collision attenuation.
Solution Approach 2:
The patent optimizes the altitude angle parameter of the ridge structures to be less than or equal to 40 degrees. This specific parameter range is designed to redirect reflected light away from the phosphor layer while still maintaining effective light extraction, thus resolving the contradiction between enhancing extraction and avoiding attenuation.
2Illumination intensity
If light is received at an incident angle of about 45 degrees, then the intensity of light emitted from the LED is greatest, but the light may not be properly extracted as light emitted from the light emitting apparatus
Solution Approach 1:
The patent specifically designs the ridge altitude angle to be ≤40 degrees, which is optimized to intercept and redirect light at the high-intensity 45-degree incident angle. This parameter optimization ensures that the most intense light rays are effectively redirected toward extraction paths, simultaneously improving both intensity utilization and extraction efficiency.
Solution Approach 2:
The ridge structures act as intermediary elements that intercept light at the encapsulation layer surface and redirect it toward optimal extraction angles. This intermediary mechanism captures the high-intensity 45-degree light and transforms its trajectory, enabling both high intensity and efficient extraction to be achieved.
3Reliability
If the refractive index of the encapsulation layer is greater than that of air, then light is protected and contained, but a relatively large portion of light is reflected back at the interface, hindering high efficiency
Solution Approach 1:
The patent introduces curved ridge structures on the encapsulation layer surface that create gradual refractive index transitions. This curvature design reduces abrupt interface reflections while maintaining the encapsulation layer's light containment function, thus preserving reliability while reducing energy loss.
Solution Approach 2:
The ridge structures serve as intermediary elements at the interface between the encapsulation layer and external environment. They provide a transitional path for light, reducing direct interface reflection while maintaining the protective containment function of the encapsulation layer.
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 significantly increases light extraction efficiency by redirecting and extracting a broader range of incident angles (15-65 degrees) with higher intensity, reducing attenuation, and improving heat dissipation, thus enhancing the overall performance and reliability of the LED-based light emitting apparatus.
Implementation Method 1
a relatively large portion of light emitted from the LED chip is reflected to the encapsulation layer at an interface between the encapsulation layer and the air
Implementation Method 2
because a refractive index of the encapsulation layer is greater than that of air
Data Source
AI summary
A light emitting device includes a light emitting device on a substrate; an encapsulation layer covering the light emitting device; and a texture layer on the encapsulation layer. A surface of the texture layer has a ridge structure. A radial cross section of the ridge structure has a triangular shape with a distal vertex relative to the encapsulation layer surface. The distal vertex has one or more altitude angles, and the one or more altitude angles are less than or equal to 40 degrees.