Lens Structure with Total Reflection Portion for LED Brightness Control
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Solution Overview
Problem
The existing LED lighting systems experience unduly high brightness above the light element due to light reflection from the circuit board, which is not effectively addressed by conventional lens structures.
Innovation Solution
A lens structure with a total reflection portion and a light outgoing portion, where the total reflection portion is designed to reflect light from the center of the lighting top surface and the light outgoing portion allows light to exit, ensuring that the brightness above the lighting element is not excessively high even when light from the lateral surface is reflected upwardly by the circuit board.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a second lens is employed to cover the LED package to adjust illumination distribution, then the illumination distribution is improved, but unduly high brightness appears above the LED chip due to light reflection from the circuit board
Solution Approach 1:
The outer surface of the lens structure is divided into three distinct regions: a first region for light emission, a second region for total reflection, and a third region for light emission. This segmentation allows different portions of light from the LED chip to be treated differently - some light is emitted normally while other light is totally reflected to prevent unduly high brightness above the LED chip.
Solution Approach 2:
Different regions of the lens outer surface are assigned different optical properties. The first and third regions have properties that allow light emission, while the second region has properties that cause total reflection. This local differentiation of optical characteristics enables the lens to simultaneously achieve proper illumination distribution and prevent harmful brightness spots.
2Ease of manufacture
If the reflective cup is omitted and fluorescent film is used to cover the LED chip, then manufacturing is simplified, but light from the lateral surface of the LED chip is reflected by the circuit board causing unduly high brightness
Solution Approach 1:
The harmful reflected light from the circuit board is extracted and redirected by the total reflection region of the lens. Instead of allowing this light to create unduly high brightness above the LED chip, the lens captures and redirects it to appropriate directions, effectively removing the harmful effect while maintaining the simplified manufacturing approach without a reflective cup.
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 proposed lens structure effectively reduces unduly high brightness above the lighting element by totally reflecting light from the center and allowing controlled exit of light, improving illumination distribution and reducing unwanted brightness.
Implementation Method 1
The outer surface includes a total reflection portion and a light outgoing portion. The light outgoing portion surrounds the total reflection portion. because some lights emitted by the center of the lighting top surface of the lighting element is totally reflected by the total reflection portion
Implementation Method 2
n is a refractive index of a material of the lens structure
Data Source
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AI summary
A lens structure includes a bottom surface, an inner surface caved in the bottom surface, and an outer surface. The outer surface includes a total reflection portion and a light outgoing portion surrounding the total reflection portion. A central axis of the lens structure and an imaginary coplanar plane coplanar with the bottom surface crosses at a crossover point, and geometry of the total reflection portion substantially satisfies an equation associated at least with a refractive index of a material of the lens structure.