LED Lens Array Optic with Negative Lenses for Uniform Illumination
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Solution Overview
Problem
Existing LED lighting technologies are inadequate for providing uniform illumination over large surface areas, as they often result in high illuminance ratios exceeding 10:1 and hotspots, failing to meet the requirements of applications like parking garages and roadways.
Innovation Solution
An optical system incorporating an array of negative lenses integrated into a light cover, which redirects higher intensity light away from the central axis, maintaining wide-angle light emission and ensuring uniform illumination by controlling lens dimensions and spacings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional LED optics with collimating lenses are used, then light is concentrated into a narrow beam, but illuminance uniformity deteriorates with high ratios exceeding 10:1
Solution Approach 1:
The patent inverts the conventional optical approach by using negative (diverging) lenses instead of positive (converging) lenses. This inversion causes light to spread out rather than concentrate, redirecting higher intensity light away from the central axis to achieve uniform illuminance distribution across large surface areas while maintaining the desired light spread for general illumination applications
2Illumination intensity
If multiple separate optics are used for high-power LEDs, then collimation is achieved, but device complexity and cost increase
Solution Approach 1:
The patent merges the secondary optic function directly into the light cover by integrating an array of negative lenses into the light cover structure itself. This eliminates the need for separate collimating optics, reducing device complexity and cost while achieving the desired light redistribution for uniform illumination across large areas
3Ease of manufacture
If light cover and optic are separate components, then manufacturing is flexible, but light losses increase due to multiple interfaces
Solution Approach 1:
The patent combines the light cover and optic into a single integrated component where the negative lenses are formed as part of the light cover structure. This eliminates additional optical interfaces between separate components, reducing light losses from reflections and transmissions while maintaining manufacturing flexibility through integrated molding or forming processes
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 solution minimizes the number of LEDs required, achieving a uniform illuminance ratio of 10:1 or less, reducing light losses, and enhancing cost-effectiveness by integrating lenses into the light cover, thus providing efficient and uniform illumination for general illumination applications.
Implementation Method 1
the higher intensity light emitted mainly forward of the LEDs is diverted away from the central axis by the negative lenses
Data Source
AI summary
An LED (light emitting diode) illumination device that can generate a uniform light output illumination pattern. The illumination source includes an array of LEDs. Forward of the LEDs is an array of negative lens surfaces. At a distance from the LED the width W of the lens and the spacing D between the LEDs enhances creating the uniform light output illumination pattern. The negative lens surface can be non-symmetric and take a conic or conic-like shape.