Study on the Highway Tunnel Lighting with Spectrum Superposition

2012 ◽  
Vol 512-515 ◽  
pp. 2713-2717
Author(s):  
Yong Yang ◽  
Wen Yuan Han ◽  
Lei Wang
Keyword(s):  
Luminous Efficiency ◽  
Light Sources ◽  
White Led ◽  
Peak Wavelength ◽  
Mesopic Vision ◽  
Photopic Vision ◽  
Highway Tunnel ◽  
Vision Condition ◽  
The Difference

The lighting level of highway tunnel is usually under mesopic vision condition, but the traditional luminance and illuminance test are corrected by photopic vision spectral luminous efficiency. According to the difference of spectral luminous efficiency between photopic and mesopic, the lighting with different peak wavelength would provide various ratios of radiation / photometric flux. Four kinds of narrowband light sources with the same tested flux were stacked up in white LED and HPS respectively, through equivalent brightness calculation, the most efficient spectral wavelength were obtained under mesopic condition.

Highway Tunnel Lighting Research Based on Mesopic Vision

2011 ◽  
Vol 71-78 ◽  
pp. 4061-4064
Author(s):  
Yong Yang ◽  
Chuan Zheng Zhu ◽  
Lei Wang
Keyword(s):  
Reaction Time ◽  
Design Method ◽  
B Value ◽  
Light Sources ◽  
White Led ◽  
Mesopic Vision ◽  
Highway Tunnel ◽  
Function Fitting ◽  
Sodium Lamp ◽  
High Pressure Sodium Lamp

The white LED and high-pressure sodium lamp (HPS) are used to simulate highway tunnel lighting under different background brightness (abbreviated as B) conditions, from a series of reaction time tests, the result shows that white LED can provide shorter reaction time for observers compared with HPS, further research suggests under the mesopic vision, different kinds of light sources maybe have unlike brightness, although which is identical under the photopic vision. From the luminous spectrum test and mesopic vision spectral luminous efficiency function fitting calculation, the mesopic equivalent brightness can be determined with certain light source and B value. This conclusion would provide a more accurate and lower energy consumption lighting design method for highway tunnel.

Properties of Light Sources under Mesopic Vision

2011 ◽  
Vol 308-310 ◽  
pp. 228-231
Author(s):  
Yong Yang ◽  
Lei Wang ◽  
Wei Li
Keyword(s):  
Visual Perception ◽  
Luminous Efficiency ◽  
Light Sources ◽  
Human Visual Perception ◽  
Efficiency Function ◽  
White Leds ◽  
Mesopic Vision ◽  
Vision Condition ◽  
Background Brightness

The mesopic vision theory is used to study illumination properties of series of light sources, through the test of luminous spectrum and derivation based on the MOVE model, the results show that spectral luminous efficiency function Vmes(λ) is between traditional V(λ) and V′(λ) when the background brightness under mesopic vision condition, and the function of Vmes(λ) is changed with the different of light sources and background brightness. Based on human visual perception, the mesopic vision equivalent brightness can be calculated, which of HPS is lower than test brightness corrected by V(λ), but white LEDs and FL show opposite phenomena, and the different value between mesopic and photopic brightness presents reduce trend with rising of background brightness.

Equivalent Brightness Fitting Calculation Method about White LEDs

2011 ◽  
Vol 121-126 ◽  
pp. 2721-2725
Author(s):  
Yong Yang ◽  
Lei Wang ◽  
Chuan Zheng Zhu
Keyword(s):  
Relative Strength ◽  
Luminous Efficiency ◽  
Color Temperature ◽  
Light Sources ◽  
White Led ◽  
Excellent Correlation ◽  
Efficiency Function ◽  
White Leds ◽  
Mesopic Vision ◽  
Brightness Curve

White LEDs can show different correlated color temperature (abbreviated as CCT) by adjusting the luminous spectrum peak distribution and relative strength. Recent research results indicate that spectral luminous efficiency function of mesopic vision Vmes(λ) and equivalent brightness are associated with luminous spectra of light sources. A series of white LEDs with different CCT are tested and calculated, it shows white LED with higher CCT has higher mesopic vision equivalent brightness, although the brightness are identical when the tester corrected by traditional photopic vision spectral luminous efficiency V(λ). From the equivalent brightness curve fitting, the curve can be described as a polynomial function, for it excellent correlation, the more value of equivalent brightness could be calculated without complex derivation.

Green Innovation Design Based on TRIZ Theory

2011 ◽  
Vol 308-310 ◽  
pp. 373-379 ◽  
Author(s):  
Zhi Feng Liu ◽  
Yang Gao ◽  
Lei Zhang ◽  
Di Hu
Keyword(s):  
Visual Perception ◽  
Luminous Efficiency ◽  
Light Sources ◽  
Green Innovation ◽  
Human Visual Perception ◽  
Efficiency Function ◽  
White Leds ◽  
Mesopic Vision ◽  
Vision Condition ◽  
Background Brightness

The mesopic vision theory is used to study illumination properties of series of light sources, through the test of luminous spectrum and derivation based on the MOVE model, the results show that spectral luminous efficiency function Vmes(λ) is between traditional V(λ) and V′(λ) when the background brightness under mesopic vision condition, and the function of Vmes(λ) is changed with the different of light sources and background brightness. Based on human visual perception, the mesopic vision equivalent brightness can be calculated, which of HPS is lower than test brightness corrected by V(λ), but white LEDs and FL show opposite phenomena, and the different value between mesopic and photopic brightness presents reduce trend with rising of background brightness.

Road Luminaire’ Mesoptic Luminous Efficiency Analysis

2011 ◽  
Vol 71-78 ◽  
pp. 4918-4922
Author(s):  
Ke Huang ◽  
Ji Weng ◽  
Ying Kui Hu
Keyword(s):  
Luminance Level ◽  
Efficiency Analysis ◽  
Luminous Efficiency ◽  
Light Sources ◽  
Efficiency Function ◽  
Photopic Vision

Four kinds of traffic lighting sources HPS, MH, LED and EDL are widely used in roads and tunnels, the luminance at this place almost in the range of 1-10 cd/m2, which is the mesoptic vision. The mesoptic luminous efficiency can be calculated from photopic vision spectral luminous efficiency function. The results indicate that HPS’s luminous efficiency increased with improve of adaptation brightness, while the rest three kinds of light sources’ luminous efficiency reduced. At the same luminance level, HPS, MH, LED and EDL’s mesoptic luminous efficiency reduced in turn.

The Study of Retroreflective Material Based on Mesopic Vision Theory

2012 ◽  
Vol 236-237 ◽  
pp. 67-71
Author(s):  
Chuan Zheng Zhu ◽  
Yong Yang ◽  
Lei Wang
Keyword(s):  
Luminous Efficiency ◽  
Mesopic Vision ◽  
Vision Condition ◽  
Result Show ◽  
Spectrum Distribution

The coefficient of retroreflection is considered as the most important parameter of retroreflective material, the value of which is tested by photopic detector now. In fact this material were usually used under mesopic vision condition, and through the test of retroreflective spectra, the mesopic spectral luminous efficiency Vmes(λ) and equivalent brightness were calculated. The result show that at different brightness the retroreflective light present unlike spectrum distribution, and white, blue material with higher retroreflection value under mesopic vision, red material own lower value, this phenomenon is more apparent with the decrease of brightness.

Manufacture and Evaluation of Light Emitting Diode Package Substrate Using Flexible Printed Circuit Board

2015 ◽  
Vol 15 (10) ◽  
pp. 7578-7581
Author(s):  
Jung-Kab Park ◽  
Jin-Ha Shin ◽  
Mun-Gi Jung ◽  
Tomabechi Shigehisa ◽  
Hwa-Sun Park ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Light Emitting Diode ◽  
Thermal Conductance ◽  
Polyimide Film ◽  
Luminous Efficiency ◽  
Circuit Board ◽  
Light Sources ◽  
Thermal Shock Test ◽  
Light Emitting ◽  
Au Electrode

Unlike other light sources such as fluorescent lamps and incandescent bulbs, light-emitting diodes (LED) convert 70∼80% of energy into heat. If the heat produced an LED chip is not effectively released, its luminous efficiency and lifespan are reduced. Therefore, as a method effectively release heat, an LED PKG substrate containing a heat-releasing material with excellent thermal conductance was fabricated, and its thermal resistance and luminous efficiency were analyzed. In this experiment, a thin polyimide film with excellent ductility was used to fabricate the LED PKG substrate. A 35-μm-thick Cu foil with excellent thermal conductance was subjected to high temperature and pressure and attached to both sides of the polyimide film. By electroplating Ag or Au, which has excellent thermal conductance, for us as the electrode and heat-releasing material, LED PKG substrate was fabricated with a thickness of approximately 170 μm. (−40 °C → RT → 120 °C). The results revealed that the LED PKG substrate having a Ag electrode with excellent thermal conductance had an excellent thermal resistance of approximately 4.2 °C/W (Au electrode: 5.6 °C/W). The luminous flux after 100 cycles in the thermal shock test was reduced by approximately 0.09% (Au electrode: 2.77%), indicating that the LED PKG substrate had excellent thermal resistance without any mechanical and material defects in a rapid-temperature-changing environment. The advantages and excellent thermal resistance can be exploited in cellular phones and LCD panels, and heat-releasing problems in thin panels be solved.

The Chromaticity Shift of White-LED Light Sources Passing through Fog

2013 ◽  
Author(s):  
Chiu-Chung Yang ◽  
Chien-Sheng Huang ◽  
Ching-Huang Lin ◽  
Chien-Yue Chen ◽  
Shao-Ciang Gan
Keyword(s):  
Light Sources ◽  
White Led ◽  
Led Light
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