• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1405-1408
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• 2008

Synchronization signal circuit system for low cross-talk stereoscopic display. We proposed the employment of the scanning beams of any adjacent scanning regions gradually scan from upper to down direction of the LED backlight panel.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1584-1587
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• 2005

Although the picture quality of today's displays is very good already, a continuous improvement is desirable as the new larger display sizes increase the visibility of artifacts. A contributing factor for picture quality enhancement through smart video processing and algorithm design is the information gathered from video statistics. Interesting parameters gathered from video statistics are e.g. the image- and display load, the usage of the color gamut, the estimated power consumption and the occurrence of static image parts. Examples of applications that can benefit from video statistics are power calculations, color gamut mapping algorithms, dynamic backlight control for LCD panels and LED backlights for LCD panels.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.368-369
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• 2003

The recent development of InGaN-based white light emitting diodes (LEDs) has expanded their potential applications in areas such as white electric home appliances, backlight for mobile phone or notebook PC, and indoor lightings. In this lecture, recent researches related to the phosphors for LEDs applications and their luminescent properties were reviewed. PDPs are considered as the most potential flat panel displays with a large-screen size. Phosphors in PDPs directly affect the brightness and lifetime. So, many researchers have tried to improve the luminescence characteristics of the phosphors especially under vacuum ultraviolet (VUV) excitation. We overviewed recent research trends and conclusive achievements for the PDP phosphors.

• Journal of Power Electronics
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• 제11권3호
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• pp.271-278
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• 2011

This paper presents a LLC resonant controller IC for secondary side control without external active devices to achieve low profile and low cost LED back light units. A gate driving transformer is adopted to isolate the primary side and the secondary side instead of an opto-coupler. A new integrated dimming circuitry is proposed to improve the dynamic current control characteristic and the current density of a LED for the brightness modulation of a large screen LCD. A dual-slope clock generator is proposed to overcome the frequency error due to the under shoot in conventional approaches. This chip is fabricated using 0.35 ${\mu}m$ BCD technology and the die size is $2{\times}2\;mm^2$. The frequency range of the clock generator is from 50 kHz to 500 kHz and the range of the dead time is from 50 ns to 2.2 ${\mu}s$. The efficiency of the LED driving circuit is 97 % and the current consumption is 40 mA for a 100 kHz operation frequency from a 15 V supply voltage.

• 융합신호처리학회논문지
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• 제11권4호
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• pp.326-331
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• 2010

본 논문은 LED와 아크릴을 이용한 새로운 BLU을 제안하고 그 가능성을 실험적으로 검증했으며, 특히 LED에 의한 아크릴의 빛 산란 및 가이딩에 관한 연구에 초점을 맞췄다. 기존 형광 램프를 이용한 BLU는 현재 많이 개발되어 있는 상황이나, 이러한 BLU 제품은 구입 가격이 높고 수명이 짧으며, 벽에 부착할 경우 두꺼워 부착하기가 쉽지 않다. 또한, 실외에서 사용하기 위해서는 외부의 환경으로부터 보호될 수 있는 별도의 패키징이 필요하다. 본 논문에서는 저렴한 비용으로 옥외 간판의 BLU로 활용될 수 있는 새로운 BLU 시스템을 제안하고 검증한다. 장치의 구성은 매우 저렴하게 구입할 수 있는 아크릴과 LED로 이루어지며, 빛의 산란 효과를 이용하기 위하여 아크릴 표면에 다양한 스크래치를 시도하였다. 또한, 인터넷을 통하여 BLU의 색상, 조도를 다이나믹하게 원격 조정할 수 있도록 임베디드 시스템을 구현 하였다. 모의실험의 결과를 바탕으로 간판용 BLU를 실제 구현하였고, 모의실험의 경우 2,673Lux, 실제 제작한 광고용 BLU는 2,554Lux의 평균 밝기가 측정되었다. 모의실험 결과와 실제 제작된 BLU의 실험 결과가 유사하게 나타남을 확인 할 수 있었다.

• Asian Journal of Innovation and Policy
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• 제1권2호
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• pp.200-218
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• 2012

Estimating the economic life of a technology is the first important prerequisite step in the feasibility analysis of technology-based business. Many empirical studies have concentrated on patents data to estimate the time period for a technology. However, it is recommended to estimate it along with qualitative considerations of future technological and market conditions. In this regard, little is known about how approaches are applied. This paper aims to establish a structural framework of estimating the lifetime of a technology by integrating the outputs of an analysis of the determinants in each transition of a product life cycle. We describe an illustrative case about a light emitting diode (LED) backlight unit (BLU) technology for the liquid crystal display (LCD) TV. The framework allows valuators and experts to estimate a technology lifetime by using multidimensional factors.

• Journal of Information Display
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• 제11권2호
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• pp.39-44
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• 2010

The time dependences of the luminance properties of 55-inch CCFL and LED backlights and 32-inch FFL backlights with LCD panels were investigated during the warm-up time from the cold start. The long-term luminance maintenance curve of a standard CCFL was examined in a time window up to 5000 hours. These two time dependences are important characteristics from the viewpoint of initial picture quality and lifetime reliability, respectively. Empirical equations were suggested for the analysis of the time dependence of these luminance data. These approaches are expected to be helpful in predicting the luminance properties of backlights based on the luminance data obtained in a limited time window.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1519-1522
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• 2009

We describe a 32" liquid-crystal display (LCD) with multi-touch sensing capability by integrating IR detector arrays onto the LED backlight plate. A transparent light guide is placed in front of the display screen, with IR LEDs disposed at its edges and emitting IR light into the light guide, the light is trapped by total internal reflection within the light guide to be as touch-sensing light. A physical contact with the acrylic plate surface will stimulate some trapped light to be escaped from the light guide and pass through LCD panel to be detected by the IR detectors. The touch-sensing LCD with this configuration can locate simultaneous multiple touche points on the touchable surface.

• 한국인쇄학회지
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• 제29권3호
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• pp.105-124
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• 2011

TFT-LCD consists of LCD panel on the top, circuit unit on the side and BLU on the bottom. The recent development issues of BLU-dependent TFT-LCD have been power consumption minimization, slimmerization and size maximization. As a result of this trend, LED is adopted as BLU instead of CCFL to increase brightness and to reduce thickness. In liquid crystal displays, the light efficiency is below 10% due to the loss of light in the path from a light source to an LCD panel and presence of absorptive polarizer. This low efficiency results in low brightness and high power consumption. One way to circumvent this situation is to use a reflective polarizer between backlight units and LCD panels. Since a nano-wire grid polarizer has been known as a reflective polarizer, an idea was proposed that it can be used for the enhancement of the brightness of LCD. The use of reflective polarizing film is increasing as edge type LED TV and 3D TV markets are growing. This study has been carried out to fabrication of the nano-wire grid polarizer(NWGP) and investigated the brightness enhancement of LCD through polarization recycling by placing a NWGP between an c and a backlight unit. NWGPs with a pitch of 200nm were fabricated using laser interference lithography and aluminum sputtering and wet etching. And The NWGP fabrication process was using by the UV imprinting and was applied to plastic PET film. In this case, the brightness of an LCD with NWGPs was 1.21 times higher than that without NWGPs due to polarization recycling.

• 한국인터넷방송통신학회논문지
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• 제15권1호
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• pp.245-251
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• 2015

이 논문에서 LED로 구동되는 LCD 표시판의 백라이트 전체 화면의 밝기를 균일하게 제어할 수 있고, 필요에 따라 전체 화면 중 각 부분의 휘도 및 색의 특성을 정밀하게 제어할 수 있는 LED 백라이트용 제어 장치 및 백라이트 용 구동 장치를 제시한다. 백라이트 제어 장치는 clock 신호에 따라 직렬 데이터를 시프트 시키면서 병렬 데이터로 변환하여 출력하는 직렬-병렬 변환 시프트 레지스터, 복수의 레지스터들, 카운터, 복수의 비교기들, 그리고 PWM 제어 신호를 출력하는 복수의 동기화 게이트들을 포함한다. 이 논문에서 백 라이트 제어 장치 및 백라이트 구동 장치는 clock 주파수를 높이지 않으면서도 높은 분해능을 갖는 PWM 제어 신호를 생성할 수 있고 양자화 잡음을 분산하여 희석시킬 수 있는 PWM 제어 회로, 백라이트 제어 장치 장치를 제시한다.