• Title/Summary/Keyword: Flat Fluorescent Lamp(FFL)

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Analysis of flat fluorescent lamp discharges for LCD backlight unit by using two-dimensional fluid simulation code

  • Yoon, Hyun-Jin;Ha, Chang-Seung;Lee, Hae-June
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1569-1572
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    • 2007
  • A two-dimensional fluid simulation code has been developed in order to investigate discharge phenomena and to improve plasma luminous efficiency in a Hg flat fluorescent lamp (FFL) for an LCD backlight unit. In this study, the method of a two-dimensional fluid simulation for FFL is explained and the simulation results of Hg-Ar-Ne mixture gas are presented for the enhancement of the luminance efficiency. The effects of various parameters, such as driving voltage, frequency, and gas mixture ratio, are investigated. The luminance efficiency increased with increasing fraction of mercury but the increasing fraction of argon did not affect the efficiency much.

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Fabrication and properties of Xe plasma flat fluorescent lamp (LCD Backlight용 FFL(Flat Fluorescent Lamp)의 제작 및 특성 연구)

  • Kang, Jong-Hyun;Lee, Yang-Kyu;Heo, Sung-Taek;Oh, Myung-Hoon;Lee, Dong-Gu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.431-432
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    • 2007
  • In this study, we used screen printing on the rear glass with silver electrodes, phosphor and a dielectric which is on the silver electrodes, and carried out firing in the temperature of $550^{\circ}C$, $570^{\circ}C$, $450^{\circ}C$ each. To seal the rear and top glass together, we used crystalline frit paste as a sealing material with dispenser and carried out firing up to $450^{\circ}C$. As using this panel, we focused on optimizing the condition which influences characteristics of discharging by the distance between electrodes, electrode structure, type and pressure of gases for FFL.

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Discharge characteristics of FFL as the variation of cell structure (셀 구조 변화에 따른 FFL(Flat Fluorescent Lamp)의 방전특성)

  • 윤성현;박철현;조민정;임민수;권순석;임기조
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.600-603
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    • 2000
  • Recently, Display devices have become important in the information-oriented society and flat display devices are greatly demanded. Liquid crystal display(LCD) represents one of the most promising devices for large size desk-top monitors, notebook PC and car navigation system. However LCD cannot give forth light itself and must have backlight system. The most popular backlighting system is composed of a lighting-guide plate and CCFL as a lighting source. The number of CCFL must increase up if the area of display is increased. So a new backlighting source with high luminance is needed for large LCDs. In this paper, we proposed a surface discharge FFL with the new electrode structure like the needle shaped electrode as the variation of cell structure to high luminance and low power consumption. In comparison with different electrode structure it has low discharge voltage and current and good optical characteristics. So it has better discharge characteristics than different surface discharge FFL and can be fungible for a backlight as a lighting source in LCDs.

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Electrooptic characteristics of flat fluorescent lamps depending on the driving conditions

  • Kim, Young-Youb;Choi, Jae-Young;Ko, Jae-Hyeon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.944-947
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    • 2007
  • The electrooptic characteristics of 32-inch multichannel-structured, mercury-type flat fluorescent lamps have been investigated in detail. The luminance and the lamp current/voltage have been monitored by changing the driving conditions such as duty ratio, backlight conditions. It was found that the efficiency became the maximum at the duty ratio of 50 % with a nearby metal plate.

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Electrical and Optical Characteristics of Flat Fluorescent Lamp for LCD Back-lighting (LCD 후면 광원용 FEL의 전기적 및 광학적 특성)

  • 김명녕;권순석
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.4
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    • pp.725-729
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    • 2003
  • In this paper, a mercury-free flat discharge lamp with opposite electrode structure, a couple of phosphor layer and discharge vessel has been studied for LCD back-lighting. When the drive voltage conditions were set properly, a uniform discharge generates over entires emitting surface. The firing voltage was increased with increasing the discharge gas pressure. It was considered that this tendency was resulted from the decrease of mean free paths due to the increase of discharge gas pressure. The maximum luminance of 2700[cd/m2] was obtained in the green emitting FFL.

Discharge characteristics of FFL as applied voltage variation (인가 전압의 변화에 따른 FFL(Flat Fluorescent Lamp)의 방전특성)

  • 윤성현;박철현;조민정;임민수;권순석;임기조
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.379-382
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    • 2000
  • The characteristics of Xe discharge lamp(Mercuryless lamp) are described in this paper. In this paper, FFL is operated by sine wave and pulsed source. We apply V-Q Lissajous' figure for the discharge measurements of FFL which has the electrodes covered with dielectric. When FFL is operated by sine wave source, the characteristics are similar to DBD(Dielectric Barrier Discharge) and SD(Silent Discharge). And we compared the characteristics of FFL which is operated with sine wave and pulsed discharge by using V-Q Lissajous' figure method. When FFL is operated with pulsed, the discharge current flows after the applied voltage is risen. As the duty ratio increases the electric field becomes strong and much more xenon ions are produced. And the number of metastable xenon atoms seem to increase, therefore, the phosphor radiation after the cut off of voltage increases compared with the first peak of radiation. Consequently, the 172㎚ radiation becomes strong as the duty ratio increases.

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Discharge characteristics of a Flat Fluorescent Lamp(FFL) contanining Penning gases

  • Lee, Sang-Mok;Cho, Yong;Jung, Sang-Kooun;Jeong, Byoung-Hyun;Jeong, Yun-Cheol;Kwak, Min-Gi;Sohn, Sang-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.675-678
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    • 2006
  • We developed a Flat Fluorescent Lamp(FFL) with a high luminance by using the same discharge mode as PDP. Our FFL has the simple and unique structure where the glass substrates are used as dielectric layers. The panel has a striped line shape of 7 inch diagonal size. The Xe-Ne-He mixture gas was used to generate the plasma, and the gas discharge characteristics under both total gas pressure and partial gas pressure were investigated. The panel showed a maximum high luminance $7,270cd/m^2$ under bias of 20KHz pulse of 3KV.

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Discharge characteristics of needle shaped surface discharge Flat Fluorescent Lamp (침전극구조 면방전형 FFL(Flat Fluorescent Lamp)의 방전특성)

  • Yun, Seong-Hyun;Park, Cheol-Hyun;Cho, Min-Jeong;Kwon, Sun-Suk;Lim, Min-Su;Lim, Kee-Jo
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1581-1583
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    • 2000
  • In this paper, we proposed a surface discharge FFL with the new electrode structure like the needle shaped electrode as the variation of cell structure to high luminance and low power consumption. In comparison with different electrode structure it has low discharge voltage and current and good optical characteristics. So it has better discharge characteristics than different surface discharge FFL and can be fungible of backlight as a lighting source in LCDs.

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A New Xenon Plasma Flat Fluorescent Lamp Enhanced with MgO Nano-Crystals for Liquid Crystal Display Applications

  • Lee, Yang-Kyu;Heo, Seung-Taek;Lee, You-Kook;Lee, Dong-Gu
    • Transactions on Electrical and Electronic Materials
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    • v.11 no.4
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    • pp.186-189
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    • 2010
  • Nano-sized MgO single crystal powders have recently been reported to emit ultraviolet by stimulation of electrons in a vacuum. In this study, nanocrystalline MgO powders were applied to a xenon plasma flat fluorescent lamp (FFL) for a liquid crystal display backlight to improve its emission efficiency through the extra ultraviolet from the nano-MgO crystals. For comparison, a MgO nano-thin film was applied directly on the phosphors inside a lamp panel through e-beam evaporation. Adding MgO nano-crystal powders to the phosphors improved the luminance and efficiency of FFLs by around 20% and MgO nano-crystal coverage of 40% of the phosphor provided the best FFL emission characteristics; however, application of MgO thin film to the phosphors degraded the emission characteristics, even compared to FFLs without MgO. This was due to insufficient ultraviolet stimulation of the phosphors and the crystallinity and low secondary electron coefficient of the MgO.

Design and Fabrication of Scanning Backlight Unit using Flat Fluorescent Lamp (면광원을 사용한 Scanning Backlight Unit의 설계 및 제작)

  • Chae, Hyung-Jun;Jung, Yong-Min;Hwang, Sun-Nam;Hur, Jeong-Wook;Lee, Jun-Young;Lim, Sung-Kyoo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.13 no.5
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    • pp.376-382
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    • 2008
  • In this paper, scanning backlight unit which can reduce motion blur was designed and fabricated using flat fluorescent lamp. The FFL(flat fluorescent lamp) is in the limelight as a new illuminant of next generation BLU(backlight unit), because of simple assembly and reduction of driving components. In order to control lamp brightness, lamp on-time was controlled. In this experiment, it was confirmed that lamp brightness can be dimmed linealy and in a wide range.