Cylindrical Fresnel Lens Rectangular Grooves Light Distribution
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Solution Overview
Problem
Prior art Fresnel lenses suffer from uneven brightness distribution, reduced light output, and aesthetic issues due to constant groove width and depth, leading to inefficient light usage and high production costs.
Innovation Solution
A cylindrical Fresnel lens with rectangular cross-sections and varying angulations, offset from a curved surface, which enhances diffuser appearance and light usage by dividing the lens into sections for improved light distribution and reduced material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the depth of the grooves is reduced to reduce lens thickness, then the lens thickness is reduced, but diffraction effects are reduced and light efficiency is impaired
Solution Approach 1:
The patent applies local quality by varying the groove depth and width at different radial positions from the lens center. Grooves are deeper and wider near the center and shallower toward the edges, optimizing light transmission at each location while maintaining overall compact thickness. This non-uniform groove configuration reduces diffraction losses compared to uniform groove designs.
2Ease of manufacture
If constant groove width is used in prior art Fresnel lenses, then manufacturing is simplified, but brightness distribution becomes uneven and light output is reduced
Solution Approach 1:
The patent implements parameter changes by systematically varying both groove depth and width as functions of radial distance from the lens center. This creates a gradient groove structure that compensates for optical path differences and achieves uniform brightness distribution across the lens output, while remaining compatible with standard Fresnel lens manufacturing processes.
3Shape
If V grooves are used in prior art Fresnel lenses, then the plane appearance is removed, but light output at the required area is reduced
Solution Approach 1:
The patent employs asymmetry by creating non-uniform groove patterns that vary in depth and width across the lens surface. This asymmetric groove configuration maintains the aesthetic non-planar appearance while optimizing light transmission paths to achieve higher light output at the required area compared to symmetric V-groove designs.
4Ease of manufacture
If spherical surface is used on the lens, then the lens can be manufactured with standard optics, but spherical aberration is produced
Solution Approach 1:
The patent applies segmentation by dividing the lens into multiple radial zones with progressively shallower and narrower grooves from center to edge. This segmented groove structure reduces spherical aberration by compensating for the varying optical path lengths, while still allowing manufacturing using standard Fresnel lens techniques.
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 results in a 50% increase in light output and an aesthetically appealing, efficient, and cost-effective diffuser application, with a square-like pattern and effective light utilization.
Implementation Method 1
Fresnel lenses basically include a series of concentric prismatic grooves, designed to cooperatively direct incident light rays to a common focus
Implementation Method 2
Diffraction effects, however, caused by the grooves of the lens provide different path lengths, which can give rise to a destructive interference at the detector
Data Source
AI summary
A Fresnel lens having a curved surface and a large number of Fresnel lens steps with rectangular cross sections for enhancing the aesthetics while providing a diffuser appearance. The cylindrical Fresnel lens can be uniformly divided into rectangular sections across the lens axis. The rectangular sections are alternative and are offset from the curved surface by a distance, which produces a very parallel output beam. The front face of the cylindrical Fresnel lens provides a square like pattern, which results in an aesthetic appearance with the effective usage of light and reduced production costs.