• Title/Summary/Keyword: Back light unit (BLU)

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Field Emission-Back Light Unit Fabricated Using Carbon Nanotube Emitter

  • Kim, H.S.;Lee, J.W.;Lee, S.K.;Lee, C.S.;Jung, K.W.;Lim, J.H.;Moon, J.W.;Hwang, M.I.;Kim, I.H.;Kim, Y.H.;Lee, B.G.;Choi, Y.C.;Seon, H.R.;Lee, S.J.;Park, J.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.277-280
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    • 2007
  • Field emission-back light unit (FE-BLU) was fabricated using carbon nanotube (CNT) emitter. Local dimming and local brightening techniques were achieved, which results in very high contrast ratio. In addition, the motion blur phenomenon, one of the serious problems of liquid crystal display (LCD) with cold cathode fluorescent lamp (CCFL)-BLU, was removed from LCD-TV by using FE-BLU.

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Development of a LED BLU Tester Detecting the Errors of LCD Panels (LCD 패널의 불량을 검출하는 검사용 LED BLU 개발)

  • Kouh, Hoon-Joon;Jang, Kyung-Soo;Oh, Ju-Young
    • The Journal of the Korea Contents Association
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    • v.10 no.5
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    • pp.62-69
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    • 2010
  • LCD panel need BLU(Back Light Unit) that is outside source of light because can not emit light voluntarily. BLU is used in LCD module and is used in tester that examine LCD panel's badness. Lately, BLU had changed from CCFL(Cold Cathode Fluorescent Lamp) to LED(Light-Emitting Diode) fast. CCFL need extra-high tension power and produce much heat and is difficult to keep fixed brightness. LED is few electric power wastage and keeps fixed brightness. But, BLU that is used to detector that examine the LCD module is using CCFL until recently. This paper develops LED BLU that can examine LCD panel's badness. Also, this manufactures LED BLU to 24 inch size to examine all LCD panels(12~24 inch), and develops so that LED BLU may operate according to LCD panel's size.

Driving Current Control for Time-Stable RGB LED Backlighting Using Time-Varying Transform Matrix (시변 변환 행렬을 이용한 시간에 안정된 RGB LED Backlighting 구동 전류 제어)

  • Park, Kee-Hyon;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.4
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    • pp.42-49
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    • 2009
  • This paper proposes a driving current control method for a back light unit (BLU), consisting of red, green, and blue (RGB) light-emitting diodes (LEDs), whereby an RGB optical sensor is used to check the output color stimulus variation to enable a time-stable color stimulus for light emission by the RGB LED BLU. First, to obtain the present color stimulus information of the RGB LED BLU, an RGB to XYZ transform matrix is derived to enable CIEXYZ values to be calculated for the RGB LED BLU from the output values of an RGB optical sensor. The elements of the RGB to XYZ transform matrix are polynomial coefficients resulting from a polynomial regression. Next, to obtain the proper duty control values for the current supplied to the RGB LEDs, an XYZ to Duty transform matrix is derived to calculate the duty control values for the RGB LEDs from the target CIEXYZ values. The data used to derive the XYZ to Duty transform matrix are the CIEXYZ values for the RGB LED BLU estimated from the output values of the RGB optical sensor and corresponding duty control values applied to the RGB LEDs for the present, first preceding, and second preceding sequential check points. With every fixed-interval check of the color stimulus of the RGB LED BLU, the XYZ to Duty transform matrix changes adaptively according to the present lighting condition of the RGB LED BLU, thereby allowing the RGB LED BLU to emit the target color stimulus in a time-stable format regardless of changes in the lighting condition of the RGB LEDs.

LIGA-reflow Micro-lens Pattern 적용 도광판의 미세사출성형

  • 황철진;허영무;하수용;이규현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.05a
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    • pp.134-134
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    • 2004
  • LCD-BLU의 고효율 광특성을 유도하기 위한 도광판의 초미세패턴 형상가공기술, 미세사출성형기술과 미세형상패턴 광학해석기술 및 전광특성 측정 및 보완기술이 요구된다. 이러한 기술들을 바탕으로 LCD-BLU의 고단가의 주요요인인 기능성 광학 sheet(prism sheet 등)를 연차적으로 제거 및 도광판에 기능을 결합하는 기술개발이 본 연구의 목적이다.(중략)

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Study on the gate cutting of light guiding plate for mobile using quenching element (박형 도광판의 음각, 양각 마이크로 패턴 성형성에 관한 연구)

  • Hwang, Chul-Jin;Kim, Jong-Sun;Min, In-Gi;Kim, Jong-Dug;Yoon, Kyung-Hwan
    • Design & Manufacturing
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    • v.2 no.5
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    • pp.1-4
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    • 2008
  • LCD-BLU (Liquid Crystal Display - Back Light Unit) is one of kernel parts of LCD unit and it consists of several optical sheets(such as prism, diffuser and protector sheets), LCP (Light Guide Plate), light source (CCFL or LED) and mold frame. The LGP of LCD-BLU is usually manufactured by forming numerous dots with $50-200{\mu}m$ in diameter on it by erosion method. But the surface of the erosion dots of LGP is very rough due to the characteristics of the erosion process during the mold fabrication, so that its light loss is high along with the dispersion of light into the surface. Accordingly, there is a limit in raising the luminance of LCD-BLU. Especially, the negative and positive micro-lens pattern fabricated by modified LiGA with thermal reflow process was applied to the optical design of LGP.

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Cost effective CNT-BLU

  • Han, In-Taek;Kim, Yong-Cheol;Kim, Ha-Jin;Kim, Young-Whan;Kim, Jong-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.145-147
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    • 2009
  • The cost effective structures and materials for the carbon nanotube (CNT) back light unit (BLU) are proposed. Simplified device structures and related electron emitter materials are prepared. CNT emitters were screen printed or remotely mounted on the back plate, and this enabled less than two photo patterning steps. Besides the cost benefits, operating voltage was dramatically decreased and higher current density was obtained

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A Simulation on The BLU Assembly Line (시뮬레이션을 이용한 백라이트유닛의 생산공정예측)

  • Kim, Seung-Nam;Moon, Je-Chang;Rim, Suk-Chul
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.05a
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    • pp.1047-1051
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    • 2005
  • Many corporation invest in LCD industry because of The growth of it. Back Light Unit(BLU), LCDs' main part take 20% of its product costs. In this paper we proposed simulation model that is in the process of introducing an equipment, We try to apply a simulation model in the BLU Assembly line by using ARENA. We make BLU Assembly line with various part storage, product strorage. etc. We evaluate Logistics in Assembly Line, and forecast bottleneck and throughput

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BLU (Back Light Unit) 기술 동향

  • Kim, Cha-Yeon
    • Proceedings of the Optical Society of Korea Conference
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    • 2008.07a
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    • pp.347-348
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    • 2008
  • 언급한 바와 같이 사이즈별로 시장의 규모, 특징, 개발의 방향이 약간씩 달리하고 있으나 분명한 것은 공정단순화 및 광효율향상 포함한 원가절감을 위하여 기능성 시트들을 개발을 위한 활동이 활발하게 진행하고 있다. 광원은 중형이상의 경우 CCFL, EEFL이 주류를 이루고 있으나 초대형화, 고색재현, Local Dimming을 위한 LED 광원을 채택한 LED-BLU 개발을 활발히 진행 중이다.

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