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 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.

The Research of LED Light Source System for Hybrid Cymbidium

2015 ◽  
Vol 734 ◽  
pp. 947-951
Author(s):  
Jing Yue Li ◽  
Fei Long Wu ◽  
Hong Zhou ◽  
Xu Ke Li
Keyword(s):  
Control System ◽  
Light Source ◽  
Economic Benefit ◽  
Ornamental Plant ◽  
Light Environment ◽  
Artificial Light ◽  
Light Control ◽  
Led Light ◽  
Special Environment ◽  
Environment Condition

Hybrid Cymbidium is a kind of highly ornamental plant, which can bring much economic benefit.However, this plant need a special environment condition of good temperature and light.As a result, it costs too much to plant the Hybrid Cymbidium.In this paper we present an intelligent light control system which can provide a good light environment condition for Hybrid Cymbidium and it can reduce much of the cost.By using this light control system,we can get good economic benefit .Moreover this system can be used in most of the plant which need artificial light.

Reliability of Low Color Temperature Phosphor-free LED Light Source

2020 ◽  
Vol 41 (3) ◽  
pp. 323-330
Author(s):  
李嘉祥 LI Jia-xiang ◽  
潘 拴 PAN Shuan ◽  
刘军林 LIU Jun-lin ◽  
吴小明 WU Xiao-ming
Keyword(s):  
Light Source ◽  
Color Temperature ◽  
Led Light

scholarly journals Research on adjustable correlated color temperature COB-LED light source based on flip chips and screen printing technology

2021 ◽  
Author(s):  
Rongrong Zhang ◽  
Zuojie Wen ◽  
Bingqian Li ◽  
Shenghua Liang ◽  
Mingde Yang ◽  
...  
Keyword(s):  
Light Source ◽  
White Light ◽  
Screen Printing ◽  
Light Emitting Diode ◽  
Luminous Flux ◽  
Color Temperature ◽  
Current Ratio ◽  
Led Light ◽  
Driving Current ◽  
Screen Printing Technology

Abstract Using the characteristic of flip light emitting diode (LED) chips without front-side welding wires, before applying fluorescent glue throughout the luminous surface, a part of the chips are directionally and quantitatively coated fluorescent glue by screen printing process, a chip on board (COB) white LED light source is developed with adjustable correlated color temperature (CCT). A part of the blue LED chips in the light source excites the fluorescent glue to produce a warm white light (CCT = 2631K), and the other part produces cool white light (CCT = 6181K). When changing the driving current ratio of the two parts of the chips, the CCT of COB LED light source can be continuously adjusted between warm and cool white light. According to the measured data, the relationship between the CCT and the driving current ratio of the two parts is obtained by fitting. Within the adjustable range of the CCT (2631 K to 6181 K), the color rendering index (CRI) is about 90. The minimum is 89.3 and the maximum is 93.1. While achieving adjustable CCT and high CRI, the LED light source has a luminous flux of 1938.76 lm on a circular surface with a diameter of 11 mm. The overall luminous efficiency is close to 100 lm/W.

Study on Tunable Color Temperature White LED Light Source with Ultra-High Color Rendering Index

2015 ◽  
Vol 35 (10) ◽  
pp. 1023002
Author(s):  
谌江波 Chen Jiangbo ◽  
余建华 Yu Jianhua ◽  
高亚飞 Gao Yafei ◽  
张翼扬 Zhang Yiyang ◽  
陆秀炎 Lu Xiuyan
Keyword(s):  
Light Source ◽  
Color Temperature ◽  
White Led ◽  
Led Light ◽  
Color Rendering Index ◽  
Color Rendering

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.

Development and effect analysis of circadian rhythm-assisted LED lighting for reproducing short-wavelength ratio characteristics of natural light

2021 ◽  
pp. 002072092098848
Author(s):  
Seung-Taek Oh ◽  
Jae-Hyun Lim
Keyword(s):  
Circadian Rhythm ◽  
Short Wavelength ◽  
Animal Experiment ◽  
Color Temperature ◽  
Natural Light ◽  
Effect Analysis ◽  
Led Lighting ◽  
Artificial Lighting ◽  
Lighting Control ◽  
Lighting Environment

The short-wavelength ratio of natural light that changes a day cycle helps maintain the circadian rhythm. The circadian rhythm is a phenomenon in which the flow of physical activity is repeated every 24 hours and is synchronized mainly by natural light. However, since people's exposure time to artificial lighting has increased recently, the issue of circadian rhythm imbalance has been raised, and lighting techniques for reproducing the color temperature or wavelength characteristics of natural light have been proposed. There has not been any case for the short-wavelength ratio cycle reproduction of natural light close to the circadian rhythm; thus, a circadian rhythm-assisted LED light that reproduces the short-wavelength ratio of natural light for one day is presented in this paper, and its effect is confirmed through animal experiment. After the lighting control standard is derived through the analysis of natural light characteristics, its periodic short-wavelength ratio is realized through the control of each LED lighting channel. Subsequently, rat-based animal experiment is conducted to analyze the amount of melatonin, a major factor in circadian rhythm. The results confirm that the proposed lighting environment has higher melatonin levels by about 17% (day7) and 24% (day14) compared with the general lighting environment.

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