LED Module Lens With Stepped Profile For Material Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED module designs for achieving uniform planar surface illumination using batwing intensity distribution require significant material and often compromise on efficiency or form factor, as they need to change Lambertian intensity distribution into batwing distribution, which is costly and inefficient due to mass manufacturing constraints.
Innovation Solution
A refractive lens with a smooth outer surface and a stepped inner surface, where the stepped profile minimizes material usage by allowing only the inner surface to perform the primary beam shaping function, reducing the lens thickness and material volume while maintaining the desired batwing light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional lens design with smooth surfaces is used to achieve batwing intensity distribution, then the beam shaping function is provided, but the amount of material needed increases and manufacturing cost rises
Solution Approach 1:
The lens surface is segmented into two distinct zones: a first surface that is substantially free of optical features (minimal material interaction) and a second surface containing the optical features (grooves, ridges, aspheres) that perform beam shaping. This segmentation allows the optical functionality to be concentrated in one zone while minimizing material usage in the other zone, directly resolving the contradiction between manufacturing precision and material quantity.
2Manufacturing precision
If lens thickness is increased to provide sufficient beam shaping capability, then the batwing distribution is achieved, but the form factor increases and efficiency decreases
Solution Approach 1:
The lens employs local quality by concentrating optical features (grooves, ridges, aspheric surfaces) only in the second surface region where they are needed for beam shaping, while the first surface remains substantially free of such features. This localized approach allows effective batwing intensity distribution control without requiring increased overall lens thickness, thus resolving the contradiction between intensity distribution control and lens volume.
3Illumination intensity
If scattering surfaces are used to increase spatial uniformity, then uniform illumination is achieved, but efficiency is reduced and form factor increases
Solution Approach 1:
The patent replaces scattering-based mechanical uniformity approaches with an optical design based on controlled refraction and reflection at the second surface features. The grooves, ridges, and aspheric surfaces create the desired batwing intensity distribution through precise optical path control rather than random scattering, thereby achieving spatial uniformity while maintaining higher light efficiency and avoiding the need for additional scattering layers that would increase form factor.
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 design reduces the amount of material needed for the lens while maintaining the batwing intensity distribution, achieving uniform illumination over a planar surface with reduced manufacturing costs and improved efficiency, suitable for applications like street lighting and luminaire housing.
Implementation Method 1
a refractive lens over the LED for providing beam shaping of the light output of the LED, wherein the lens comprises an inner surface and an outer surface, wherein the outer surface is a smooth, beam shaping surface which provides a beam shaping function essentially only via refraction
Data Source
Figure 1~3
Figure 4a~4b
Figure 4c~4d
AI summary
A lighting module comprises an LED and a lens over the LED. The lens has a beam shaping surface and a pass through surface with a stepped profile. The steps of the stepped profile each comprise a riser portion and an output portion, wherein the riser portions are parallel with the ray direction passing through the surface at that location and the output portions are normal to the ray direction passing through the surface at that location. The pass through surface for example performs no beam shaping function. The stepped profile enables the thickness of the lens to be reduced to reduce the amount of material needed.