scholarly journals Designing Safe General LED Lighting that Provides the UVB Benefits of Sunlight

2019 ◽  
Vol 9 (5) ◽  
pp. 826 ◽  
Author(s):  
Seung-Taek Oh ◽  
Dae-Hwan Park ◽  
Jae-Hyun Lim
Keyword(s):  
Vitamin D ◽  
Light Source ◽  
Safety Evaluation ◽  
Spectral Irradiance ◽  
Evaluation Standard ◽  
Led Lighting ◽  
Led Light ◽  
Uvb Exposure ◽  
Indoor Lighting ◽  
Uv Rays

The ultraviolet (UV) rays emitted from sunlight greatly influence human health. Excessive exposure to UV rays can be harmful to eyes and skin; however, limited UVB exposure is essential for the synthesis of vitamin D. Nowadays, owing to insufficient exposure to natural light, there is increasing concerns about low vitamin D amongst individuals. To address this issue, many lighting devices that provide UVB doses have been released; however, such devices are only used for treatments or for special purposes. This study proposes a general indoor lighting system with a UVB LED light source to provide safe UVB doses to users who spend large amounts of time indoors. The optical characteristics of two UVB LEDs with output of 20 and 100 mW were analyzed based on their distances and applied currents. The light source combination of UVB LEDS that meets the UV hazard standard of IEC-62471 was derived; this is a photobiological safety evaluation standard of LED lighting devices. We then produced a lighting module in which the UVB LED light source was applied to general LED lighting and measured and analyzed the spectral irradiance of the proposed lighting according to the measurement standard for the general lighting of IEC 62471. The actinic UV hazard (AUV) and near-UV hazard (NUV) were calculated to be 0.001 and 10 W/m2, respectively. Thus, the provision of UVB dose did not pose any risks. In addition, the total EUV (Erythemal weighted UV) dose when the proposed lighting was implemented for 16 h was 187.66 J/m2, confirming that this dose did not cause erythema for the general skin types (Skin Types 1–6). Further, the design plan of general indoor lighting with a UVB LED light source is presented.

Spectral Irradiance Distribution in Underwater Light Field Generated by an LED Light Source

2020 ◽  
Vol 103 (sp1) ◽  
pp. 453
Author(s):  
Ping Yang ◽  
Zizhao Wu ◽  
Yao Chen ◽  
Yilu Guo ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Light Source ◽  
Light Field ◽  
Spectral Irradiance ◽  
Led Light ◽  
Underwater Light Field ◽  
Underwater Light

scholarly journals Optimization of LED Lighting for Clinical Settings

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Snjezana Soltic ◽  
Andrew Chalmers
Keyword(s):  
Light Source ◽  
Performance Criteria ◽  
Source Spectrum ◽  
Clinical Settings ◽  
Colour Properties ◽  
Led Lighting ◽  
Led Light ◽  
De Algorithm ◽  
Lighting Systems ◽  
Spectral Design

The advent of the LED light source has promoted the concept of human-centric lighting (HCL). The LED has also been responsible for increases in the electrical efficiency of lighting systems, coupled with recent improvements in their colour properties. We have found that it is also possible to create a lit environment with enhanced clinical attributes by providing a source spectrum that meets the requirements of the Cyanosis Observation Index (COI). This paper describes the use of a differential evolution (DE) algorithm for the spectral design of a mixed LED light source capable of meeting COI recommendations as well as HCL performance criteria.

scholarly journals Design and Implementation of a radio controlled led lighting system

2016 ◽  
Vol 10 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Ádám Bálint ◽  
József Sárosi
Keyword(s):  
Radio Frequency ◽  
Light Emitting Diode ◽  
Lighting System ◽  
Light Emitting ◽  
Led Lighting ◽  
Led Light ◽  
Design And Implementation ◽  
Technological Advances ◽  
History Of ◽  
Indoor Lighting

Technological advances allow us to control LED (Light Emitting Diode) lighting at home, in the office it can even allow us to change the intensity of the light and this is just the beginning of what the future holds for us. In this study an LED internal lighting fixture of our own design will be presented focusing on each step in its design. Firstly, the features, types and history of LEDs will be presented, next the products available in market that are required for the completion of the device. Finally, the design and implementation as well as the radio frequency controlled LED indoor lighting fixture will be shown.

Research and Implementation on Methods of Evaluating Lifetime of LED Light Source for LED Lighting System

2014 ◽  
Vol 941-944 ◽  
pp. 635-639
Author(s):  
Rong Wang ◽  
Hai Bo Ma ◽  
Bin Qu
Keyword(s):  
Light Source ◽  
Comprehensive Evaluation ◽  
Real Life ◽  
Practical Work ◽  
Lighting System ◽  
Led Lighting ◽  
Led Light ◽  
The Real ◽  
Attenuation Rate

This research adopts comprehensive evaluation to evaluate lifetime of LED light source for lighting system. By the method, under the condition of LED light source working outside, the situations of LED light source lifetime are analyzed with attenuation rate of illumination got from illumination data of LED light source in practical work. The real lifetime characteristics and real life curve of the LED light source are obtained eventually.

scholarly journals Application of color temperature controllability in LED lighting environment of highway tunnel

2021 ◽  
Vol 233 ◽  
pp. 01101
Author(s):  
Zhiqiang Liu ◽  
Peifeng Li ◽  
Haifeng Jiang ◽  
Dan Wang
Keyword(s):  
Light Source ◽  
Visual Recognition ◽  
Control Function ◽  
Light Environment ◽  
Color Temperature ◽  
Led Lighting ◽  
Led Light ◽  
Dimming Control ◽  
Lighting Environment ◽  
Light Color

In recent years, tunnel LED lighting has been widely used in tunnel lighting engineering because of its advantages such as fast start, low energy consumption and good light color controllability. However, at present, the tunnel LED lighting mostly adopts the single dimming control function of light brightness, which does not give full play to the technical advantages of the tunnel LED lighting with two indicators of light brightness and light color temperature control, and does not consider the influence of the color temperature and spectral distribution of the LED light source on the safety and comfort of the tunnel LED lighting environment. Therefore, this paper studies the relationship between the color temperature of tunnel LED lighting source and the visual comfort and visual recognition distance, analyzes the actual impact of the color temperature of LED light source on the tunnel lighting light environment, and puts forward the color temperature index applicable to the entrance and exit sections of tunnel LED lighting, which provides a theoretical basis for building a safe and comfortable "two types" tunnel LED lighting light environment.

scholarly journals Analysis on High-Power Seaport LED Luminaire with Uniform Light Distribution Based on Optimized Lens and Heatsink

2021 ◽  
Vol 11 (9) ◽  
pp. 4035
Author(s):  
Jinsheon Kim ◽  
Jeungmo Kang ◽  
Woojin Jang
Keyword(s):  
Light Source ◽  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Light Distribution ◽  
Light Sources ◽  
Led Light ◽  
High Power Led ◽  
Distribution Requirement ◽  
Lighting Application

In the case of light-emitting diode (LED) seaport luminaires, they should be designed in consideration of glare, average illuminance, and overall uniformity. Although it is possible to implement light distribution through auxiliary devices such as reflectors, it means increasing the weight and size of the luminaire, which reduces the feasibility. Considering the special environment of seaport luminaires, which are installed at a height of 30 m or more, it is necessary to reduce the weight of the device, facilitate replacement, and secure a light source with a long life. In this paper, an optimized lens design was investigated to provide uniform light distribution to meet the requirement in the seaport lighting application. Four types of lens were designed and fabricated to verify the uniform light distribution requirement for the seaport lighting application. Using numerical analysis, we optimized the lens that provides the required minimum overall uniformity for the seaport lighting application. A theoretical analysis for the heatsink structure and shape were conducted to reduce the heat from the high-power LED light sources up to 250 W. As a result of these analyses on the heat dissipation characteristics of the high-power LED light source used in the LED seaport luminaire, the heatsink with hexagonal-shape fins shows the best heat dissipation effect. Finally, a prototype LED seaport luminaire with an optimized lens and heat sink was fabricated and tested in a real seaport environment. The light distribution characteristics of this prototype LED seaport luminaire were compared with a commercial high-pressure sodium luminaire and metal halide luminaire.

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