Light Sources For Special Application - Metal Halide Lamps

Metal halide lamps are very efficient light sources based on a Hg plasma arc with metal halide salt additions. In spite of their high efficiency, the lamps suffer from several problems, such as color separation and instabilities, which currently hinder large-scale use. These phenomena are caused by a complex interaction of convection and diffusion flows in the plasma. In order to unravel the various contributions, experiments under microgravity have been performed where convection is absent. The experiments confirm the previously held qualitative views, but also provide absolute data on densities and temperatures that will be used to validate numerical models of these lamps.

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Application of LED in Marine Fishery

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.765-767.213 ◽

2013 ◽

Vol 765-767 ◽

pp. 213-216

Author(s):

Wen Qing Shi ◽

Zheng Ye Xiong ◽

Yong Qiang Li ◽

Cun You Huang

Keyword(s):

High Energy ◽

Economic Benefits ◽

Metal Halide ◽

Light Sources ◽

Market Demand ◽

Led Light ◽

Marine Fishery ◽

Incandescent Lamps ◽

Metal Halide Lamps ◽

Chinese Marine

Aiming at the high energy-consuming characteristics of Chinese marine fishery, the application of LED in Chinese marine fishery is analyzed. It has remarkable energy-saving effect if the fishing style of trawling is replaced by light-seine fishing, and the gathering-fish lamps of metal halide lamps or incandescent lamps are replaced by LED light sources. The conversion of the trawlers to light-seine vessel and widespread use of LED light sources will lead to cut down energy consumption and increase the economic benefits. Based on rough calculation, it can make Chinese fisherfolk increase income about hundreds of millions of dollars and reduce more than millions of tons CO2 emission if the conversion of the trawlers to light-seine vessel and the replacement of metal halide lamps or incandescent lamps to LED light sources can reach 20% of all. Moreover, LED light source can use for general lighting purpose in marine fishery. All of these will cause the development of the correlative industries. For instance, the market demand of LED is very vast.

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Effectiveness of Light Source on Detecting Thin Film Transistor

Crystals ◽

10.3390/cryst8100394 ◽

2018 ◽

Vol 8 (10) ◽

pp. 394 ◽

Cited By ~ 1

Author(s):

Fu-Ming Tzu ◽

Jung-Hua Chou

Keyword(s):

Thin Film ◽

Light Source ◽

Thin Film Transistor ◽

Metal Halide ◽

Light Sources ◽

Blue Led ◽

Optical Inspection ◽

Metal Halide Lamps ◽

Better Than ◽

Halogen Lamps

Light sources tend to affect images captured in any automatic optical inspection (AOI) system. In this study, the effectiveness of metal-halide lamps, quartz-halogen lamps, and LEDs as the light sources in AOI systems for the detection of the third and fourth layers electrodes of thin-film-transistor liquid crystal displays (TFT-LCDs) is examined experimentally. The results show that the performance of LEDs is generally comparable or better than that of metal-halide and quartz-halogen lamps. The best optical performance is by the blue LED due to its spectrum compatibility with the time-delay-integration charged-coupled device (TDI CCD) sensor and its better spatial resolution. The images revealed by the blue LED are sharper and more distinctive. Since current LEDs are more energy efficient and environmentally friendly, using LEDs as the light source for AOI is very beneficial. As the blue LED performs the best, it should be adopted for AOI using TDI CCD sensors.

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Electrical consequences of large-scale replacement of metal halide by LED luminaires

Lighting Research and Technology ◽

10.1177/1477153516645647 ◽

2016 ◽

Vol 50 (2) ◽

pp. 282-293 ◽

Cited By ~ 9

Author(s):

MJ Hermoso-Orzáez ◽

JI Rojas-Sola ◽

A Gago-Calderón

Keyword(s):

Large Scale ◽

Thermal Protection ◽

Metal Halide ◽

Light Sources ◽

Electrical Parameters ◽

Large Power ◽

Start Up ◽

Before And After ◽

Inrush Currents ◽

Metal Halide Lamps

The recent trend for large-scale replacement of luminaires using discharge light sources with LED luminaires without any significant adjustments to the electrical installation has generated controversy. This study examines the main electrical measures in a large outdoor lighting installation before and after the replacement of a large number of metal halide floodlights with LED luminaires. The electrical parameters of both technologies are discussed in detail and compared, with special attention given to the odd-numbered harmonics of voltage and current, the generated wave deformation, currents in the neutral conductor, the wattless reactive volt amps and the peak inrush currents. At cold start-up, the LED luminaires generate large power-on currents, much larger than those generated by the metal halide lamps, despite requiring 36% less real installed power. This is a basic problem to be solved when planning a public lighting renovation with LED luminaires as the rest of electrical parameters are reduced. To address this problem, it is proposed to energise the luminaires using magneto-thermal protection circuits with slow trip curves that will tolerate the large short-term inrush currents.

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Effectiveness of Light Source on Detecting Thin Film Transistor

10.20944/preprints201809.0175.v1 ◽

2018 ◽

Author(s):

Fuming Tzu ◽

Jung-Hua Chou

Keyword(s):

Thin Film ◽

Light Source ◽

Thin Film Transistor ◽

Metal Halide ◽

Light Sources ◽

Blue Led ◽

Optical Inspection ◽

Metal Halide Lamps ◽

Better Than ◽

Halogen Lamps

Light sources tend to affect images captured in any automatic optical inspection (AOI) system. In this study, the effectiveness of metal-halide lamps, quartz-halogen lamps, and LEDs as the light sources in AOI systems for the detection of the 3rd and 4th layers electrodes of thin-film-transistor liquid crystal displays (TFT-LCDs) is examined experimentally. The results show that the performance of LEDs is generally comparable or better than that of metal-halide and quartz-halogen lamps. The best optical performance is by the blue LED due to its spectrum compatibility with the time-delay-integration charged-coupled device (TDI CCD) sensor and its better spatial resolution. The images revealed by the blue LED are sharper and more distinctive. Since current LEDs are more energy efficient and environmentally friendly, using LEDs as the light source for AOI is very beneficial. As the blue LED performs the best, it should be adopted for AOI using TDI CCD sensors.

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