• Title/Summary/Keyword: CCFL backlight

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Developing the High Efficient Inverter Using Piezo Electronic Transformer (압전트랜스를 이용한 고효율 CCFL 인버터 시스템 설계)

  • Lee, Young-Kyu;Joo, Sung-Jun;Lee, Byung-Hoon;Hong, Soon-Gil
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.1199-1201
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    • 2002
  • Today, the ceramic transformer becomes widely used for the TFT LCD backlight inverter system thanks to its high efficiency and small size. In this paper, a high efficient inverter system for cold cathode flourescent lamp (CCFL) including PLL controller for tuning the PWM frequency to the frequency that the efficiency of the inverter system becomes maximum is proposed. The control IC implementing this feature will be released by Interpion Co. Ltd. in May 2002.

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A New Buck-Boost Half Bridge Inverter for Low Temperature Driving of EEFL (외부전극 형광램프의 저온구동을 위한 새로운 벅부스트 하프브리지 인버터)

  • Cho Kyu-Min;Oh Won-Sik;Moon Gun-Woo;Park Mun-Soo;Lee Sang-Gil
    • Proceedings of the KIPE Conference
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    • 2006.06a
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    • pp.387-389
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    • 2006
  • The LCD TV has many variable functions for consumer. Low temperature driving below minus 20 degree is also one of key functions. Since LCD is not self-luminance device, it is needed backlight system. Recently EEFL(External Electrode Fluorescent Lamp) widely substitutes for CCFL(Cold Cathode Fluorescent Lamp). It is more cheaper, higher efficiency, and easy to drive parallel connection compared to CCFL. In this paper, several conditions for low temperature driving of EEFL are investigated and a new boost-half bridge inverter for low temperature driving is proposed. Mode analysis is described and experimental results is represented to verify validity of the proposed inverter.

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A Study on the CCFL Backlight Inverter for 37' LCD TV (37인치 LCD TV를 위한 CCFL 백라이트 인버터에 관한 연구)

  • Cho, Hyun-Chang;Lim, Young-Cheol;Yang, Seung-Hak;Park, Yun-Do
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.746-749
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    • 2005
  • LCD 디스플레이의 대형화에 따라 백라이트용 냉음극 방전램프(Cold Cathode Fluorescent Lamp)는 길어지고 있으며, 하나의 램프를 이용한 백라이트는 휘도의 한계가 있어 대형 디스플레이에서는 램프를 병렬로 사용하여 필요한 휘도를 만들고 있다. 본 논문에서는 냉음극 방전램프 16개를 사용하는 37인치 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 채택하므로서 램프간의 휘도편차를 개선하였고 향후에 상용화가 가능함을 보였다.

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Electrical characteristics of Piezoelectric Transformer for PDA using PNW-PMN-PZT Ceramics (PNW-PNM-PZT 세라믹스 이용한 PDA용 압전 트랜스포머의 전기적특성)

  • Lee, Sang-Ho;Oh, Dong-On;Yoo, Ju-Hyun;Lyu, Sung-Lim;Park, Chang-Yub
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05c
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    • pp.228-231
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    • 2003
  • In this sturdy, piezoelectric transformer using PNW-PMN-PZT ceramics was fabricated with the size of $1{\times}16{\times}5mm^3$ for LCD backlight inverter application of PDA. And its electrical characteristics were investigated with load resistance and driving frequency. At the frequency of 212.6kHz, CCFL for PDA was driven stably, and input voltage of 8.83V and output voltage of 305V were shown.

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Design and manufacture of Inverter for Driving Electrode Fluorescent Lamp (외부전극 형광램프 구동용 인버터 설계 및 제작)

  • Yoon, Dong-han
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.6 no.2
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    • pp.76-80
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    • 2013
  • In this paper, a external electrode fluorescent lamp driving inverter for LCD backlight is designed. AC input from a lamp-driven system to process up to two inverter system for the existing configuration of power-efficient than the system as well as to increase the volume and weight reduction, Furthermore low-cost advantage. AC power input in order to drive EEFL stable and AC 85V ~ 265V power factor increase in the PFC Block can be used for running the Inverter Block EEFL and composed.

Discharge and Characteristic of Hg-free Flat Fluorescent Lamp (무수은 평판형 형광램프의 제작 및 방전특성)

  • Lee, Myoung-Ho;Lim, Min-Su;Lee, Mun-Ju;Lim, Kee-Joe
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.624-627
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    • 2004
  • 본 논문은 LCD Backlight로 사용되고 있는 CCFL의 문제점을 해결하기 위해 간단한 구조를 가지는 mercury-free, Xe 평판형 형광램프에 대한 연구를 하였다. 일반적으로, 수은을 포함한 형광램프는 낮은 온도에서의 휘도문제와 상대적으로 긴 점등시간, 수명과 특히, 환경 문제가 있다. 본 논문에는 화학적으로 안정한 불활성 가스인 Xe을 사용함으로써 기존의 백라이트가 가지고 있는 문제점을 해결하였다. 제작된 8인치$(200{\times}156{\times}10mm)$ 램프는 AC 펄스 전압에 의해 높은 균일도, 안정한 방전, 우수한 전기적 및 광학적 특성을 가진다. 또한 본 연구에서, 무수은 Xe 평판형 형광램프의 전극폭에 대한 전기적 및 광학적 실험을 통하여 90[%]의 균일도에서 $7,000[cd/m^2]$의 휘도와 30[lm/W]의 효율을 얻었다.

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An Aanlysis of LCD backlight unit using 2-Dimensional Simulation (2차원 수치해석을 통한 LCD 백라이트 분석)

  • Song, In-Cheol;Choi, Won-Young;Lee, Don-Kyu;Yoon, Hyun-Jin;Choi, Joon-Young;Lee, Hae-Jun;Lee, Ho-Jun
    • Proceedings of the KIEE Conference
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    • 2006.10a
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    • pp.204-205
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    • 2006
  • 기존의 3${\sim}$4mm 간격을 가진 냉음극 형광램프(CCFL)나 외부전극형광램프(EEFL)는 휘도의 균일성과 응답속도가 열등하기 때문에 42인치보다 큰 크기를 가지는 LCD TV에 적합하지 않다. 그래서 대면적 BLU(backlight unit)에 적합한 평면형광램프(FFL)에 대한 관심이 높아지고 있다. 본 논문에서는 FFL의 발광 효율을 향샹시키기 위하여, 가스 혼합비를 변화시키면서, 2차원 유체코드를 이용한 수치해석을 통하여 방전효율에 영향을 미치는 요소가 Hg임을 확인 하였다.

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The improvement of moving picture quality in TFT-LCD with Blinking Backlight System and Liquid Crystal Overdriving Methode (Blinking Backlight System과 Liquid Crystal Overdriving Methode를 사용한 TFT-LCD의 동영상 화질개선을 위한 연구)

  • Han, Jung-Min;Kim, Jong-Hwan;Kim, Young-Hwan;Kim, Gwi-Yeol;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.05a
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    • pp.146-149
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    • 2005
  • In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. LCD is different from CRT in the sense that it's continuous passive device, whichholds images in entire frame period, while impulsetype device generate image in very short time. We realized articulate image generation similar to CRT by CCFL blinking drive and TN-LCD overdriving. As a result, reduced image sticking phenomenon was validated by naked eye and response time measureme.

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Design of the backlight inverter for multi-lamp driving

  • Han Jae Hyun;Lim Young Cheol;Yang Seung Hak;Kweon Gie Hyoun
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.80-83
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    • 2001
  • As a LCD monitor is larger and thinner, a Cold Cathode Fluorescent Lamp (CCFL) for backlight in LCD monitor gradually becomes longer and thinner. The backlight of a large LCD monitor, however, has a limitation in its brightness. In this study, a parallel multi-lamp is used in order to supply enough brightness. Though the CCFLs are made through a detail and equal manufacturing process, they don't have exactly the same features individually in their brightness, frequency, voltage and current. Consequently, it is difficult to have equal brightness at an early lighting condition or during lighting time. In this paper, a parallel multi-lamp which can have the same output under the same condition is designed. For this, 18 inch LCD monitor with four lamps is used. An inverter for multi-lamp driving is also used in this study. The newly designed inverter shows more than $90\%$ efficiency in its brightness input and output. Besides, it is also available for a multi-drive of other lamps.

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Development of Inverter for Improvement of Low Temperature Operation of LCD Backlight using Flat Fluorescent Lamp (FFL) (면광원을 이용한 LCD 백라이트의 저온구동특성 향상을 위한 인버터 개발)

  • Hur, Jeong-Wook;Lim, Sung-Kyoo
    • Journal of the Microelectronics and Packaging Society
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    • v.14 no.1
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    • pp.11-17
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    • 2007
  • The CCFLs, EEFLs and FFLs use mercury and the operating conditions are different at warm or cold temperature. At start of operation, there may exist a possibility of inhomogeneous operation of lamps or channels of FFL to the very low vapor pressure of mercury at low temperature. In this paper, an inverter with level control block (LCB) was developed to drive LCD backlight using FFL stably at low temperature range. The operation of FFL backlight at $-20^{\circ}C$ was successfully demonstrated by developing inverter with LCB under 130 Watt of power consumption.

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