LED Lens with Fly's Eye Refractive Lenses for Light Extraction
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Solution Overview
Problem
Current LED package structures face limitations in maximizing light extraction efficiency due to total internal reflection of light emitted from the LED chip, despite efforts to enhance optical characteristics through surface textures and configurations.
Innovation Solution
A lens with refractive lenses having a sub-radius of curvature smaller than the main radius of curvature, arranged in a fly's eye pattern on the outer surface, reduces internal reflection by allowing light to enter within the critical angle, thereby increasing light extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional lens surface is used, then the structure is simple, but light extraction efficiency is low due to total internal reflection
Solution Approach 1:
The lens surface is segmented into multiple refractive lenses with different curvatures. Each refractive lens has a sub-radius of curvature smaller than the main radius of curvature, creating zones that redirect light at different angles to prevent total internal reflection and improve light extraction efficiency
Solution Approach 2:
Different regions of the lens surface are given different optical properties through varying curvature radii. The refractive lenses are strategically positioned with specific sub-radius of curvature values to optimize light extraction in different areas, creating local optical quality variations that enhance overall performance
2Loss of energy
If the sub-radius of curvature is made smaller, then light extraction efficiency increases, but manufacturing precision requirements increase
Solution Approach 1:
The invention optimizes the relationship between the sub-radius of curvature and main radius of curvature by establishing a specific ratio range (0.1 to 0.5). This parameter optimization allows the refractive lenses to effectively redirect light within the critical angle while maintaining feasible manufacturing tolerances for the curvature radii
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 effectively prevents total internal reflection, enhancing light extraction efficiency by optimizing the curvature ratio and spacing of refractive lenses, allowing more light to be emitted from the LED package.
Implementation Method 1
a plurality of refractive lenses each having a sub-radius of curvature smaller than one main radius of curvature of an outer surface of the lens
Implementation Method 2
increase light extraction efficiency by reducing the amount of light, emitted from a light emitting diode chip, being totally reflected internally by a lens surface
Data Source
AI summary
A lens for a light emitting diode package and a light emitting diode package having the same have simple structures and increase light extraction efficiency by preventing light emitted from a light emitting diode chip from being internally reflected by a lens surface through a structural change in the lens surface.