• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.117-118
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• 2008

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.325-328
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• 2005

EEFLs are mostly driven by sinusoidal wave driving method although EEFLs (External Electrode Fluorescent Lamps) are driven by both sinusoidal wave and square wave. The sinusoidal driving method reduces the cost and allows more power efficiency since this driving method can reduce the voltage stress of EEFL inverter switches and achieve the soft switching of the switches. And a transformer should be used in the inverter since the high voltage should be applied to the both ends of EEFL to turn on the lamp. However, the power loss mainly occurs at the transformer in the sinusoidal wave driving method. In order to remove the transformer which makes the power loss, a new method is presented. In this paper, the square wave is applied directly to the both ends of EEFL by a proposed two-stage inverter. Moreover, the luminance and power efficiency will be compared between the common sinusoidal wave driving method and square wave driving method.

• Journal of the Korean Vacuum Society
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• v.16 no.5
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• pp.330-337
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• 2007

Influence of glass dielectric property (dielectric constant K, dielectric loss) on the external electrode fluorescent lamps of the dielectric barrier discharge has been investigated with 4-different glasses. Conventional borosilicate glass tubes with $K=5.6{\sim}5.9$ and tan ${\delta}=5.0{\times}10^{-3}{\sim}6.0{\times}10^{-3}$ and aluminosilicate glass tubes with high K=6.6 and low tan ${\delta}=1{\times}10^{-4}$ and soda-lime glass tribes with K=7.7 and tan ${\delta}=1.37{\times}10^{-2}$ have been compared. The high value of dielectric constant K makes the capacitance of external electrode fluorescent lamps intensity and enhances the discharge efficiency. The dielectric loss of tan ${\delta}$ shows the factor of power consumption in the external electrode to induce heats and to be weak in pinhole stability. The aluminosilicate glass tubes of high K and low tan ${\delta}$ have been enhanced by $14{\sim}18%$ in luminance and efficiency in comparison with the conventional borosilicate glass tubes and the aluminosilicate external electrode fluorescent lamps are strong against the pinhole formation. Soda-lime glass tubes with high K and high tan ${\delta}$ are a little favorable in luminance and efficiency and they are very weak in pinhole occurrence.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.465-469
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• 2004

액정 디스플레이의 백라이트 광원으로 냉음극 방전램프(CCFL: Cold Cathode Fluorescent Lamp)가 일반적으로 사용된다 최근 LCD 모니터의 두께는 갈수록 얇아지며, 화면은 넓어지고 있는 대형화 추세이다. 기존의 권선형 변압기를 이용 인버터를 구성하여 멀티램프를 구동하고 있지만 이는 코어나 권선 손실에 의한 효율 저하와 부피나 중량의 증가, 그리고 과열에 의한 화재의 위험성을 가지고 있다. 이러한 문제들을 해결하기 위해 본 논문에서는 압전 변압기를 이용한 멀티램프 구동용 인버터를 설계 지침에 따라 구성하였다. 인버터 하나로 압전변압기를 병렬로 연결하는 방식을 이용하였고, 또한 전류 부담이 적은 외관 전극 형광 램프(EEFL: External Electrode Fluorescent Lamp)를 이용한 멀티램프 구동 방법을 압전 인버터에 적용 가능한지 고찰하였다. 적용한 방식으로는 풀-브리지 (Full-Bridge)회로를 응용하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1135-1138
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• 2003

A direct light type backlight for large-area LCD-TVs using External Electrode Fluorescent Lamps (EEFLs) has been developed. The brightness was $450cd/m^{2}$(nit) and the luminous uniformity (max/min) was 1.3. The mechanical design of backlight was optimized and the reliability of lamps was secured. As a result, the possibility of backlight with EEFLs for large area LCD-TVs was sufficiently proved.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.504-507
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• 2006

현재 LCD(Liquid Crystal Display)용 광원으로서 주로 냉음극 방전램프(CCFL : Cold Cathode Fluorescent Lamp)가 사용되고 있으며, 그 외 LED를 비롯해서 외부전극 방전램프(EEFL: External Electrode Fluorescent Lamp), 면광원(FFL : Flat Fluorescent Lamp), 전계 방출램프(FEL : Field Emission Lamp)등 다른 광원에 대한 적용도 활발히 진행되고 있다. 본 논문에서는 멀티램프 구동이 유리하여 인버터 개수를 줄일 수 있는 장점을 가지고 있는 EEFL을 사용하였으며, 변압기의 자체 손실을 줄이고 소형화가 가능하며, 높은 승압 비를 갖는 압전 변압기를 병렬로 연결하여 멀티램프 구동이 가능하도록 하였다. 최적의 EEFL 구동회로를 구성하기 위해서 Push-Pull 타입의 압전 인버터를 설계하였으며, 설계된 인버터 회로에 대한 시뮬레이션 분석을 수행하고, 향후 여러 형태의 구동 방법을 적용하므로 서 압전 변압기로도 대화면 멀티 램프 구동용 인버터의 제작이 가능함을 제시하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.2
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• pp.130-137
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• 2005

LCD needs a backlight that is a light source as a photodetector that has a light modulation function and CCFL is used usually. Inverter that composes using existent winding transformer operates multi lamps, however, this efficiency falls by losses of core or winding and volume or weight increases or there is danger of fire by overheating. In order to solve these problems, a multi lamp driving Inverter using PT is composed according to the design guideline in this paper. We conformed whether the multi lamp drive method using EEFL that a current burden is less in applicable to piezoelectric inverter, and used the method that connect two piezoelectric transformers by parallel to an inverter.

• Journal of the Korean Vacuum Society
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• v.15 no.6
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• pp.576-580
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• 2006

Mercury-free lamp, external electrode fluorescent lamp (EEFL) which includes the xenon gas, is now going on the research for the replacement of mercury lamp. The densities of excited xenon atom in the $1s_4$ resonance state and the $1s_5$ metastable state are investigated in the EEFL by a laser absorption spectroscopy under various gas pressures. We have measured the absorption signals for both $1s_4$ resonance and the $1s_5$ metastable state in the EEFL by varying the discharge currents for a given pressure. This basic absorption characteristic is very important for improvement of the VUV luminous efficiency of the EEFL as well as plasma display panel.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.553-555
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• 2008

현재 사용하고 있는 LCD(Liquid Crystal Display) Backlight용 램프는 주로 CCFL(Cold Cathod Fluorescent Lamp)과 EEFL(External Electrode Fluorescent Lamp)이 사용되고 있다. 하지만 이 램프는 수은을 사용하여 RoHS(the Restriction of the use of certain Hazardous Substances in electrical and electronic equipment)규제가 점점 강화되면서 사용이 제한되고 있으며, 이에 따라 수은을 사용하지 않는 램프의 제작이 불가피해지고 있다. 또한 LCD TV는 CRT와 PDP와는 다른 LCD만의 Hold-type 특성과 LC(Liquid Crystal)의 응답속도로 인하여 Motion Blur현상이 나타나는 단점이 있다. 본 논문에서는 RoHS 규제를 만족시키는 무수은 면광원 램프를 구동하기 위한 인버터를 제안한다. 제안한 인버터는 포워드 방식을 사용하여 반도체 소자 및 자기 소자의 수를 줄여서 구동회로가 간단하다. 또한 면광원 램프를 세로방향으로 6블록으로 나누어 스캔구동을 하여 Motion Blur현상을 저감 시켰다. 끝으로 실험을 통하여 제안한 인버터의 유용성을 입증하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1531-1533
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• 2007

We made a high-efficiency lamp with same spec. as a normal lamp by improving physical constants of a lamp and then analyzed varied effects. By applying novel physical constants to an EEFL, we acquired decrease of lamp operating power and voltage.