• Transactions on Electrical and Electronic Materials
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• 제8권5호
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• pp.215-217
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• 2007

Recently, color reproduction properties have attracted lots of attention with mass production of LCD especially corresponding to TV application and achievement of color reproduction properties such as CRT have been considered one of technical goals for high quality display. However, revision of the color reproduction properties only with CF(color filter) have fundamental limitations and resultant decrease in the transmittance of panel causes demand on high brightness of BL(Back Light). In this paper, we present such a method in which by optimization of original light spectrum from the BL source will improves the color reproduction properties corresponding to them of the CRT. When the intensity of RED and Green-Blue from ramp is revised densely, the characteristics different from CCFL(Cold Cathode Fluorescent Lamp) used before become added so that about 11 % of the color reproduction properties is improved compare to the existing LCD panel.

• 한국분말재료학회지
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• 제22권1호
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• pp.27-31
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• 2015

Flat panel display devices are mainly used as information display devices in the 21st century. The worldwide waste flat panel displays are expected at 2-3 million units but most of them are land-filled for want of a proper recycling technology More specifically, rare earth metals of La and Eu are used as fluorescent materials of Cold Cathode Flourscent Lamp(CCFL)s in the waste flat panel displays and they are critically vulnerable and irreplaceable strategic mineral resources. At present, most of the waste CCFLs are disposed of by land-filling and incineration and proper recovery of 80-plus tons per annum of the rare earth fluorescent materials will significantly contribute to steady supply of them. A dearth of Korean domestic research results on recovery and recycling of rare earth elements in the CCFLs prompts to initiate this status report on overseas research trends and noteworthy research results in related fields.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.149-151
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• 2008

This paper presents an architecture for driving multiple parallel cold cathode fluorescent lamps (CCFLs) for back lighting applications. The key to the architecture is a proposed capacitive coupling approach for lamp ignition. This system is consist of a flyback converter, a single inverter to drive multiple lamps and conductive floating reflector. The topology is capable of driving a number of parallel lamps with independent accurate lamp, current regulation and improving cost effectiveness with significant reduction in size and weight, compared to typical high frequency ac ballast. Experimental demonstration results for ten of parallel CCFLs with simultaneous ignition.

• 대한전자공학회논문지SD
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• 제39권12호
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• pp.1016-1021
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• 2002

LCD backlight용 형광램프(fluorescent lamp, FL)의 전극구조에 따른 발광특성을 평가하였다. 동일한 조건에서 제작된 cold cathode fluorescent lamp(CCFL) 및 EEFL에 대하여 인가전압과 EEFL의 전극 폭에 따른 휘도와 발광효율을 측정, 평가하였다. 12 V에서 측정된 CCFL의 휘도와 발광효율은 각각 27600 cd/㎡ 및 35.3 lm/w를 나타내었다 EEFL의 휘도는 전극면적을 증가시킬수록 증가되었고, 발광효율은 전극 면적이 증가되면서 증가되었다가 전극 폭 20 mm에서 최대값을 나타낸 다음 다시 감소하였다. 20 mm의 전극 폭을 갖는 EEFL에 대하여 12 V와 14 V에서 측정된 휘도와 발광효율은 각각 21600 cd/㎡, 26500 cd/㎡ 및 35.6 lm/w, 34.8 lm/w였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.123-127
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• 2004

Cold cathode fluorescent lamp (CCFL) has been used as a light source for direct type backlights for LCD monitors or TV. One inverter for one CCFL was necessary for maintaining the lamp current so that many inverters were used to drive as many CCFLs of direct type backlight for LCD TV. An inverter for driving 16 CCFLs was developed to reduce the backlight cost. The length and diameter of CCFL were 450mm and 4mm, respectively. Backlight including 16 CCFLs for 26" LCD TV was assembled by using one inverter. The uniformities of the assembled backlight operated by the conventional inverter and the newly developed inverter were 75% and 88%, respectively.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.81-83
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• 2006

The conventional cold cathode fluorescent lamp (CCFL) driver for LCD TV has a transformer for each lamp to step up the high sinusoidal waveform from the low input voltage. The transformer used in the conventional topology causes the driver to have bulky size and high cost. This paper proposes a new transformer-less CCFL driver for LCD backlight that is based on the parallel-loaded resonant inverter topology. This resonant topology enables the circuit to supply enough high voltage for CCFL without a transformer. Also, with current-balancing technique, this transformer-less inverter drives 16 CCFL lamps.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.197-199
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• 2005

The Cold cathode fluorescent lamp (CCFL) are widely used to illuminate the liquid crystal display(LCD). Ballasts are required for CCFL because the lamp need high starting voltage and behave negative dynamic resistant characteristics in the desired region of operation. Dimming methods of CCFL are used to pulse frequency modulation(PFM) or pulse width modulation(PWM). In this paper, CCFL driving and control circuit is designed by half-bridge type series and parallel resonant inverter that variable frequency modulation method to control the output voltage current. The validity of this study is confirmed from the simulation and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1181-1183
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• 2003

Cold cathode fluorescent lamp(CCFL) are widely used to illuminate the liquid crystal display(LCD). Usually, CCFL dimming methods are used to lamp current regulation or average current adjust feeding the CCFL inverter. Switching frequency of inverter is higher than resonant frequency at stabile states. In this study, design of CCFL driving circuit by half-bridge type series and parallel resonant inverter that variable frequency modulation method to control the output power. This method has advantages such as low EMI and reduced harmonics. And it is easy to dimming control use microprocessor. The validity of this study is confirmed from the simulation and experimental results.

• 전력전자학회논문지
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• 제10권2호
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• pp.130-137
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• 2005

LCD는 광변조기능을 가지는 수광 소자로서 발광원인 백라이트를 필요로 하는데 일반적으로 냉음극 방전램프(CCFL: Cold Cathode Fluorescent Lamp)가 사용된다. 기존의 권선형 변압기를 이용한 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 압전 변압기를 병렬로 연결하는 방식을 이용하였고, 또한 전류 부담이 적은 외관 전극 형광 램프(EEFL: External Electrode Fluorescent Lamp)를 이용한 멀티램프 구동 방법이 압전 인버터에 적용 가능한지를 확인하였다.

• 전력전자학회논문지
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• 제11권6호
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• pp.502-507
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• 2006

LCD의 대형화에 따라 백라이트용 냉음극 방전램프(Cold Cathode Fluorescent Lamp)는 길어지고 있으며, 하나의 램프를 이용한 백라이트는 휘도의 한계가 있어 대형 디스플레이에서는 여러 개의 램프를 사용하여 필요한 휘도를 만들고 있다. 본 논문에서는 냉음극 방전램프 20개를 사용하는 42인치 LCD TV용 대형 백라이트 구동을 위한 인버터를 각각의 램프들이 입력조건에 대해 동일한 출력을 갖도록 설계하였다. 기존의 냉음극 방전램프의 구동방식인 하이-로우(H-L) 방식에서의 문제점을 보완하여 하이-하이(H-H) 방식을 채택하여 램프 좌우측의 휘도 차이를 개선하였다. 또한 램프간의 휘도 편차를 개선하기 위해 램프와 직렬로 커패시터를 연결하는 방식을 사용하였다. 제안된 시스템을 실험을 통해 검증하였다.