Three-Zone Conic Reflector for LED Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED illumination systems face inefficiencies in energy collection and distribution due to chromatic aberration and energy loss in traditional reflector designs, particularly in 'white' LED systems, which are not optimal for all applications and result in uneven illumination patterns.
Innovation Solution
A reflector design with three distinct conic zones - parabolic, straight conic, and elliptical - is used to create a designer-controlled composite energy distribution pattern, optimizing energy collection and distribution by combining directly radiated and reflected energy, with a total internal reflector (TIR) and optional reflective coatings for enhanced efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a hemispherical ball lens is used to modify LED beam pattern, then a relatively smooth spot with controlled beam angle is achieved, but chromatic aberration is generated and collection efficiency is limited to about 60%
Solution Approach 1:
The reflector is divided into three distinct conic zones (parabolic, straight conic, and elliptical) that each handle different angular ranges of reflected energy. This segmentation allows optimized control of light distribution while maintaining high collection efficiency across the entire hemisphere.
Solution Approach 2:
Each conic zone is designed with specific local optical properties tailored to its function: the parabolic zone for broad angular distribution, the straight conic zone for intermediate angles, and the elliptical zone for focused energy concentration. This local optimization achieves both smooth illumination and high efficiency.
2Illumination intensity
If a conic reflector with long focus is used to generate beam, then brighter center is achieved, but periphery is less illuminated and efficiency is lost
Solution Approach 1:
The reflector surface is segmented into three conic zones that collectively redistribute energy from the bright center to the darker periphery. The parabolic zone handles broad angular ranges, the straight conic zone manages intermediate angles, and the elliptical zone focuses specific energy, achieving balanced illumination.
Solution Approach 2:
The reflector design changes the angular distribution parameters of reflected light by using different conic sections with varying focal properties. This transforms the initial non-uniform energy distribution into a controlled composite pattern that balances center and periphery illumination.
3Speed
If a single surface of rotation conic reflector is used, then beam directionality is achieved, but smooth beam requires diffuser which causes substantial efficiency loss
Solution Approach 1:
Instead of using a diffuser, the reflector is segmented into three conic zones that inherently produce smooth beam distribution through geometric optics. Each zone redirects light at specific angles, creating a naturally smooth composite pattern without requiring additional diffusing elements.
Solution Approach 2:
The optical diffusion function is replaced by a geometric reflection system. The three-zone conic reflector uses precise angular redirection of light rays to achieve smooth illumination, substituting the mechanical diffuser with a deterministic geometric optical path design.
4Loss of energy
If integrated optical system with ball lens and conic reflector is used, then slightly improved efficiency is achieved, but chromatic aberration remains similar to ball lens system
Solution Approach 1:
The ball lens component that causes chromatic aberration is extracted and removed from the system. The patent uses only reflective optics (the three-zone conic reflector) to achieve beam shaping, eliminating the refractive element responsible for color separation while maintaining or improving collection efficiency.
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 achieves energy efficiencies of over 90% by minimizing energy loss and ensuring a smooth, controlled illumination pattern, suitable for various LED applications without the need for additional diffusers, thereby improving upon existing methods.
Implementation Method 1
a reflector having a base and aperture. The reflector is proximate to the light source and defines a system half angle by its aperture, which allows directly radiated energy to propagate from the light source through the aperture of the reflector to the surface
Implementation Method 2
In one embodiment the reflector comprises a total internal reflector (TIR)
Data Source
AI summary
A reflector for a light source, such as an LED, is provided with a shape which efficiently collects and directs energy to an illumined surface whereby almost 100% of the light is collected and distributed into a designer composite beam. The shape in one embodiment is comprised of three zones beginning with a parabolic surface of revolution at the base of the reflector, followed by a transition or straight conic zone and ending with an elliptical zone. In another embodiment the reflector shape is determined according to a transfer function which allows for arbitrary designer control of the reflected rays at each point on the reflector, which when combined with direct radiation from the source, results in a designer controlled composite beam or illumination. The device is more than 90% energy efficient and allows replacement of higher power, less energy efficient light sources with no loss in illumination intensity.