• Title/Summary/Keyword: Edge-lit

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Analysis of CCFL blackening in edge-lit LCD modules

  • Lee, Yong-Woo;Seo, Dong-Jin;Noh, Cheol-Yong;Choi, Seong-Sik
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.803-805
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    • 2008
  • For the life estimation of CCFLs in edge-lit LCD modules has been required CCFL blackening test, which is executed in the state of low current and long-time operation under the high temperature condition. We investigated the reason why CCFL blackening happened more easily in the above test conditions and the way how mechanical parts had influence upon CCFL blackening in the edge-lit LCD modules.

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Design of Light Guide Plate to Improve Optical Characteristics for Large-Area Edge-lit LED Display (대면적 엣지형 LED 디스플레이의 광특성 향상을 위한 도광판설계)

  • Lee, Jae-Yong;Shin, Min-Ho;Kim, Jong-Sub;Kim, Young-Joo
    • Transactions of the Society of Information Storage Systems
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    • v.9 no.1
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    • pp.10-16
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    • 2013
  • Through the rapid development of LED TV, a large-area edge-lit backlight unit is widely researched in the display industry for enhancing the optical efficiency, luminous uniformity and slim design. In addition, an edge-lit backlight unit includes many optical sheets such as reflection sheet, prism sheet and diffuser sheet. However the function can be replaced by the carefully patterned light guide plate (LGP). Micro patterns which located on the top and bottom surface of light guide plate was designed by ray-tracing optical simulation. The designed patterns improved the light characteristics of LGP, including optical extraction efficiency and intensity distribution uniformity. These results suggest that it is very effective method to design edge-lit LGP with micro-patterns on both sides for large-area display and to reduce the fabrication cost.

Improvement of on-axis luminance by optimization of edge-lit backlight optic (LCD 에지형 백라이트 광학계의 휘도집광 효율 향상에 관한 연구)

  • Joo, Byung-Yun;Hong, Joo-Pyo
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.10a
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    • pp.95-98
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    • 2009
  • This paper dealt with the design guide of the conventional edge-lit backlight optic with which the on-axis luminance could be increased by trying to improve the light condensing efficiency of a bright enhancement film (BEF). First, the general design guide concerned with the backlight optic was proposed, and then its validness was experimentally proved by conducting design examples with haze controls of both diffuse film and microdot material printed on the backside of the light guide plate. Experimental results showed that the variation range of the on-axis luminance by the present approach was about $5{\sim}9%$, which would be by no means negligible in the practical application.

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Ultra-slim LCD TV module using edge-lit LED backlight system

  • Kim, Woo-Jun;Cho, Joo-Woan;Yeo, Dong-Min;Ye, Byoung-Dae;Seo, Dong-Jin;Choi, Jin-Sung;Jang, Tae-Seok
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.214-217
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    • 2008
  • We present an ultra-slim LCD module for 40-inch FHD TV. By employing edge-lit backlight system, module thickness of 10mm is achieved. To satisfy the luminance spec of 450 nits in FHD resolution, it is critical to adopt high efficient LED and optical components.

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Simulation Study on the Optimization of Hybrid Light Guide Plates for Edge-lit Backlight Applications

  • Lee, Jeong-Ho;Nahm, Kie-Bong;Ko, Jae-Hyeon;Kim, Joong-Hyun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.693-696
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    • 2009
  • The ray-tracing technique was used to optimize the light guide plate for the purpose of improving the on-axis luminance on the edge-lit backlights. One-dimensional prisms and engraved V-shaped patterns were applied to the upper and the lower surfaces of the light guide plate, respectively. By optimizing the apex angles of these micro-structures, as well as the shape of the reverseprism film put over the light guide plate, highly-collimated light-output distribution could be obtained on the backlight, which may contribute to the development of mobile LCD's with low power consumption.

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Study on the Simulation Model for the Optimization of Optical Structures of Edge-lit Backlight for LCD Applications

  • Ju, Young-Hyun;Park, Ji-Hee;Lee, Jeong-Ho;Lee, Ji-Young;Nahm, Kie-Bong;Ko, Jae-Hyeon;Kim, Joong-Hyun
    • Journal of the Optical Society of Korea
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    • v.12 no.1
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    • pp.25-30
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    • 2008
  • The optical performances of 15-inch edge-lit backlight were simulated by using a Monte Carlo ray-tracing technique. The backlight model was built by combining a wedge-type light guide plate, a diffuser sheet, a tubular fluorescent lamp with a lamp reflector, and two crossed prism sheets. Angular distributions of the luminance on each optical component obtained from simulation were consistent with those obtained from experiments on a real 15-inch backlight. The constructed backlight model was used to evaluate the optical performances of a micro-pyramid film. It was found that the on-axis luminance gain on the pyramid film is higher than that on one prism film but much lower than that on the two crossed prism films. These results suggest that a reliable simulation model can be used to develop new hybrid films and to optimize the optical structure of edge-lit backlight in order to reduce the developmental period.

Optical Characteristics of LED Backlight and CCFL Backlight for LCD-TV Applications (LCD TV용 LED백라이트와 CCFL백라이트의 광학 특성 평가 및 비교)

  • Ryu, Jin-Sun;Yu, Mi-Yeon;Park, Seung-Mi;Kim, Su-Jin;Ko, Jae-Hyeon
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.10a
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    • pp.69-72
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    • 2009
  • Recently, LED(Light Emitting Diode) TV has attracted greate attention due to its super-slim form factore as well as low power consumption. LED TV is actually an LCD(Liquid Crystal Display) TV in which edge-lit LED backlight is adopted. In the presente study, we report on the comparison of optical characteristics 55-inch edge-lit LED backlight and CCFL(Cold Cathode Fluorescent Lam)backlight. The angular distribution of the luminance and the on-axis luminance gain on each optical component were investigated and compared. The effect of the backlight structure on the performance of the optical films was studied and discussed.

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Improvement of Color and Luminance Uniformity of the Edge-Lit Backlight Using the RGB LEDs

  • Son, Chang-Gyun;Yi, Jong-Hoon;Gwag, Jin-Seog;Kwon, Jin-Hyuk;Park, Gyeung-Ju
    • Journal of the Optical Society of Korea
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    • v.15 no.3
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    • pp.272-277
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    • 2011
  • The effect of the M-window color mixing bar on the characteristics of color mixing and hot spots in the edge-lit backlight employing red (R), green (G), blue (G) light emitting diodes (LED) were studied in terms of the structure of the M-window color mixing bar. The rays from RGB LEDs entering the M-window bar were mixed by internal reflection and scattering inside the M-window bar so that the hot spots and color separation were minimized. The M-window bar was designed and fabricated and the simulation results are matched quite well to experimental data.

A Novel Light Guide Plate with Micro-prisms for an Edge-lit LED Backlight

  • Kwon, Jae-Joong;Kim, Hyoung-Joo;Shim, Sung-Kyu;Baek, Seung-In;Hwang, In-Sun;Jang, Tae-Seok
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1193-1195
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    • 2008
  • We propose a novel light guide plate for an edge-lit LED backlight. Properly designed micro-prisms enable light to go out of the LGP in near vertical direction and luminance fluctuations in front of the LEDs to be invisible.

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