• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1306-1310
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• 2006

We conducted visual perception experiments to determine the perception limits of motion blur based on human visual system at LCD TV's moving pictures. The motion blur can be expressed Blurred Edge Width (BEW). The results showed that the BEW of moving pictures should be below 3.4pixels (visual angle 4.2') at 3H distance in a living room environment.

• Design & Manufacturing
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• v.6 no.1
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• pp.63-66
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• 2012

In the manufacturing of a LCD TV bottom chassis, the distortion after forming should be suppressed below pre-defined amount to avoid contact with electric components. Finite element analysis procedure of forming and springback of a LCD TV bottom chassis is developed to investigate the distortion behaviour. It is shown that after the first forming large distortion occur due to uneven metal flow induced by various embossings. In the second forming, distortion is decreased by introducing bead that absorbs the excessive metal flow. It is proved that analysis method could describe these behaviour effectively. The developed analysis method can be used to find the proper location and shape of bead more quickly and effectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.8
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• pp.1394-1400
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• 2010

This paper introduces a newly improved Ultra-FRFET that has much better reverse recovery characteristic than that of the typical MOSFET and presents its effectiveness in the HV-BLU system of LCD TVs. The reverse recovery time, $T_{rr}$ of Ultra-FRFET is shorter than 40nsec and the peak value of reverse current, $i_{rr}$ is also much smaller compared to the typical MOSFET's, which are sufficient to prevent the MOSFET’s failures without additional FRDs and diodes in HV-BLU system with a half-bridge resonant inverter topology worked by PWM method. In order to verify the validity, the loss analysis and the implementation results in cases when both the conventional solution using typical MOSFETs with additional FRDs and a new solution using Ultra-FRFETs are applied to a HV-BLU of 40" LCD TV are presented. As a result, the effectiveness of Ultra-FRFET was verified and the results are presented in this paper.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.631-632
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• 2010

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1164-1167
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• 2009

Motion-image-quality of LCD-TVs is discussed by dynamic spatial frequency response. Smaller temporal aperture or higher frame rate can improve dynamic response, but an increase of motion velocity easily cancels the improvement. A guideline for deciding the desirable temporal aperture and frame rate of LCD-TVs is described, under the condition that camera and display have the same parameters. Two candidates of the desirable parameter sets will be (240 or 300 Hz, 50 to 100% aperture) and (120Hz, 25 to 50% aperture), from the viewpoint of "limit of acceptance" on motion-imagequality-deterioration for critical picture materials.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.2
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• pp.111-118
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• 2010

Recently, LCD TV using LED backlight has a great attention due to its low power consumption, slim construction, mercury free, wide color gamut and fast response. For the uniform brightness of the LCD panel, multi channel LEDs and DC/DC converter for each LED are required in conventional system. Therefore energy conversion efficiency is poor, the system size bulky and the cost of production high. To overcome these above mentioned drawbacks, a new current-balancing multi-channel LED driver is proposed in this paper. It can not only drive multi-channel LEDs with one DC/DC converter but also provide all LEDs with constant balanced current. To confirm the validity of the proposed driver, its operation and performance are verified on a prototype for 46" LCD TV.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.995-998
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• 2008

Lamp mura has become a challenge for slim LCD-TV backlight design. The aim of this paper is to apply a novel diffuser plate to improve lamp mura issue instead of increasing lamps or optical films. The results are positive and contribute to the design of slimmer TV without cost up.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1155-1156
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• 2008

현재 에너지 소비를 줄이기 위한 연구들이 활발히 진행되고 있다. 그 중 대형 LCD TV 분야는 전체 소비전력의 약 70%이상이 백라이트에 의한 소비이므로, 대형 LCD TV의 전력 절감을 위해서는 효율적인 백라이트 설계에 대한 연구가 매우 중요한 부분이다. 따라서 본 연구에서는 백라이트의 효율적인 전력 소비를 위해 다채널 영상 분할 LED백라이트 밝기 제어를 통한 저전력 BLU 설계하였다. 본 연구를 통한 실험을 한 결과 60%이상의 전력 절감효과를 측정하여 연구의 유효함을 입증하였다.

• Information Display
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• v.2 no.1
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• pp.25-29
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• 2001

TFT-LCD는 그 상업화의 역사가 이제 겨우 10여년으로 일천함에도 불구하고 괄목할만한 시장성장과 더불어 우리 생활에 많은 변화를 야기했고, 그 변화의 정도는 앞으로 더욱 더 심화 될 것으로 예상된다 . 요즘 유행처럼 이야기되어지는 정보화 기술 (IT: Information Technology), 디지털 기술이란 의미도 궁극적으로 따져보면 영상정보의 효율적 전달을 의미하며, 그 정보의 실체를 사람의 눈으로 보는 것은 결국 디스플레이 인 것이다. 여러 가지의 디스플레이 가운데 특히 TFT-LCD는 노트북 컴퓨터를 시발점으로 모니터 등 그 웅용분야를 점차 넓혀 가고 있으며, 디스플레이 산업의 시장을 주도하고 있다. 현재 디스플레이의 가장 큰 부분을 차지하고 있는 TV 시장에 대한 접근도 활발히 하고 있어 그 동안 CRT 를 사용한 TV 시장에도 향후 각 디스플레 이간의 주도권 및 영역 다툼이 더욱 심화 되리라고 예상된다. 본고(本稿)에서는 TFT-LCD를 중심으로 TV 에 응용 되기 위한 기술적 요구 사항과 현재 LCD maker들의 개발 현황 및 향후 전망 등 에 대해 정리해 보고자 한다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1126-1127
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• 2007

This paper presents One Cycle Control type PFC converter for power system Unit of LCD TV. A control technique known as One Cycle Control contends reductions in complexity, cost, design time, and PCB real estate, without a sacrifice in performance. In this paper, design and experiment on 300W One Cycle Control type PFC Converter for Power System Unit of LCD TV.