• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.2-6
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• 2009

This presentation reviews the current progress in the technology of Light Emitting Diode (LED) as it relates to the LED backlight for Liquid Crystal Display (LCD). A vivid description is given about the performance of LED that is still on the rise and certain limitations of LED that is on the decline.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.115-122
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• 2005

As the digital TV markets rapidly growing, many manufacturers introduce large size flat screen TV units. There are two different display types available to large size models which are plasma and TFT-LCD. Since both are constructed with thin large panels that are mostly fragile to even moderate mechanical shock inputs. Some large size panels are severely resonated by the acoustic sound generated TV which deteriorates video quality. Recognizing the potential problems of large displays, accurate measurement of the panels is to be an essential task for the reliable design. Measurement of mechanical properties of a thin large crystallized panel such as TFT-LCD display with traditional material testing equipments is challenging. Since TFT-LCDs are constructed with combination of brittle glass panels, polymer sheets, and liquid crystal, their properties are not only anisotropic but also usually non-linear. Accurate measurement of the properties often requires very expensive facilities. Especially when the size of the test sample is as large as 40-inch or wider, direct measurement cost is prohibitive. Even worse, machining of the large TFT-LCD to make a smaller size specimen that could be fit into a material tester is not possible because of liquid crystal leakage. A new method fer the measurement of elastic modulus of large TFT-LCD panel is presented in this article. The suggested method provides a simple, economic, and user-friendly way fer measuring the elastic modulus of large panels with considerable level of accuracy.

• Journal of Information Display
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• v.3 no.4
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• pp.4-7
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• 2002

A recently developed phase separated composite film method has been employed to fabricate a liquid crystal (LC) based electro-optical device using a single glass substrate. The resulting device is made of adjacent parallel layers of LC and polymer maded by phase separation. The LC layer is confined between the solidified polymer layer on one side and the glass substrate on the other. The electro-optical properties of these devices demonstrate their technological potential in light weight and hand-held electronic products.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1715-1718
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• 2006

Evaluating method of the device parameters of liquid crystal display (LCD) by means of the renormalized transmission spectroscopic ellipsometry is demonstrated. Dielectric and elastic constant, threshold voltage, pretilt angle, cell gap and Anchoring strength coefficients can be evaluated from the measurement of ellipsometric parameters measured by the symmetrically oblique incidence transmission ellipsometry (SOITE). Furthermore, rapid evaluating method for rubbed polyimide film is also demonstrated.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.219-222
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• 2003

The Capacitor DAC with gamma correction is proposed for TFT-LCD (Liquid Crystal Display) driver application. It is based on two ideas. First, 6bit digital code is converted 8bit digital code by memory circuit (Look Up Table) for gamma correction. second, weighted voltage ratio DAC is proposed for reducing area and power consumption.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.408-411
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• 2004

Color filter is a fundamental and necessary component to make a full-color TFT-LCD, its quality intensively influence the performance of TFT-LCD in the application of Notebook Computer, Monitor and Television. Color filter in chromaticity also make an effect for human visual system and video enjoyment. Recently, mother glass size is enlarged for demand of large-size panels and new generation color .filter technology for large-size liquid crystal cell panels is also developed. Here, latest generation color filter technology in TFT-LCD will be discussed.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.921-924
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• 1999

By controlling the pixels of a liquid crystal display (LCD) electronically, we fabricated a real-time moving window on a LCD, through which light passes. Using the moving window and hi-focusing lens, we suggested a non-mechanical spatio-angular multiplexed holographic memory system and demonstrated its feasibility through optical experiments. The principle of the proposed method and optical experimental results are also presented.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.136-137
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• 2001

LCD(Liquid Crystal Display)는 크게 투과형과 반사형으로 나눌 수 있으며 투과형 LCD의 전력소모중 약 70％를 차지하는 부분이 백라이트 유닛이다. 다른 차세대 도광판 연구와는 달리 경사면을 이용한 방법이 아니라 도광판 속에서의 산란을 조절하는 방식이다. 기존 도광판은 그림 1-(b)처럼 밑면에 dot pattern을 인쇄하여 dot의 크기, 001의 간격을 이용한 것이다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.234-235
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• 2000

최근에 많이 사용되는 휴대용 기기의 표시장치인 액정표시장치(LCD)에는 반사형이 많이 사용되고 있다. 반사형 LCD는 전력소모의 많은 부분을 차지하는 backlight를 주변광원으로 대체하여 전력소모를 줄일 수 있는 표시장치로 많이 연구되고 있다. 특히, 반사형 LCD는 밝기면에서 우수한 single-polarizer mode가 적합하다$^{1.3}$ . 그러나 single-polarizer mode는 two-polarizer mode와 비교해서 dark 상태에서의 누설광이 많이 발생하여 대비비가 저하되는 단점이 있다. 이 점을 보완하기 위하여 전 파장 영역에서 편광판에 의해 반사광이 차단될 수 있도록 설계를 했다. (중략)

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.602-606
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• 2008

LCD is supplied light by BLU(Back Light Unit) and the light represents color by each color filter. Also LCD adjusts the amount of light by controlling liquid crystal between the glass of upper plate and one of lower. However, it is impossible to completely exclude light due to the structural and physical characteristic of liquid crystal. Therefore, on transfering light through optical sheet and liquid crystal, many problems are generated. They are related with energy efficiency and get effective for the contrast of LCD to have lower contrast ratio than other display devices. To solve the problems, many techniques have been studied and developed but don't exist keys to solution for them. Among methods, local dimming is one example to be applied to LCD. In this paper we propose image processing algorithm for local dimming of BLU of LED used as light source. The proposed algorithm extracts maximum luminance signal and lights using each extracted signal on segmented region of BLU. Also the proposed algorithm generates image signal in corresponding to luminance of the segmented region and supplies them with LCD panel to represent image with improving luminance ratio.