Tri-lobe Optic Spreads Light to Reduce Viewing Discomfort
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Solution Overview
Problem
Fluorescent tubes in indoor lighting fixtures suffer from degradation due to plasma-induced damage, leading to reduced efficiency and hazardous mercury disposal, while traditional LED lighting can be uncomfortable to view due to high light intensity per unit area.
Innovation Solution
The development of a tri-lobe optic for linear LED light sources that spreads light over a larger area, matching the light flux density of T8 fluorescent tubes, using a constant cross-sectional profile with concave and convex curves to distribute light evenly, and a retrofit kit for existing fixtures incorporating LEDs with a printed circuit board and end caps to maintain compatibility and comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LED light sources are used to replace fluorescent tubes, then energy efficiency and reliability are improved, but light intensity per unit area becomes too high causing viewing discomfort
Solution Approach 1:
The optic is divided into multiple lobes (first lobe, second lobe, third lobe) with different refractive index profiles. Each lobe segments the light path and distributes the light intensity across different spatial regions, preventing concentration of light in a single area and thereby reducing viewing discomfort while maintaining high overall luminous output.
Solution Approach 2:
Different portions of the optic have different refractive indices. The first, second, and third lobes are defined by specific refractive index ranges (e.g., first lobe: 1.49-1.51, second lobe: 1.52-1.54, third lobe: 1.55-1.57). This local variation in refractive index allows each region to control light distribution differently, achieving uniform overall light intensity while maintaining high efficiency.
2Illumination intensity
If fluorescent tubes are used, then comfortable viewing is achieved, but plasma damage causes degradation and failure over time
Solution Approach 1:
The patent replaces the fluorescent tube's plasma generation mechanism with an LED light source that does not produce plasma. This eliminates the plasma-induced degradation and sputtering that caused the tube ends to darken and fail over time, while maintaining comfortable viewing conditions through the tri-lobe optic's light distribution.
3Productivity
If large LED chips are produced to increase light output, then manufacturing cost decreases, but viewing discomfort increases due to high light concentration
Solution Approach 1:
The optic segments the light from large LED chips into multiple lobes with different refractive indices. This segmentation distributes the high light output across a larger apparent area, reducing the light concentration per unit area that causes viewing discomfort, while still utilizing the high productivity of large LED chip manufacturing.
Solution Approach 2:
The patent changes the refractive index parameter across different lobes of the optic. By varying the refractive index (first lobe: 1.49-1.51, second lobe: 1.52-1.54, third lobe: 1.55-1.57), the system controls light refraction and distribution, converting high-intensity concentrated light into uniformly distributed light across multiple regions.
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 provides a cost-effective, high-lumen output LED lighting system that minimizes viewing discomfort by matching the light intensity per unit area of T8 fluorescent tubes, while eliminating hazardous mercury disposal concerns and extending the life of lighting fixtures.
Implementation Method 1
The cross-sectional profile includes concave and convex curves relative to the axis. The curves are a first concave curve coupled with the first azimuthal side, a first convex curve, a second concave curve, a second convex curve and a third concave curve. Each of the concave curves defines a lobe of the optical material along the direction of the axis.
Data Source
AI summary
A tri-lobe optic for a linear light source, and related light rails, retrofit kits and light fixtures, are disclosed. The linear light source defines a light emitting region along an axis. The tri-lobe optic includes an optical material having a constant cross-sectional profile along a direction of the axis from a first axial end to a second axial end. The cross-sectional profile includes a first azimuthal side relative to the axis and concave and convex curves relative to the axis. The curves are a first concave curve coupled with the first azimuthal side, a first convex curve, a second concave curve, a second convex curve and a third concave curve. Each of the concave curves defines a lobe of the optical material along the direction of the axis. The cross-sectional profile further includes a second azimuthal side relative to the axis, coupled with the third concave curve.