• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.7
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• pp.1275-1281
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• 2007

The discharge phenomena in a flat fluorescent lamp for the backlight unit of liquid crystal displays are simulated by sung a two-dimensional fluid model. The numerical methods for the calculation of plasma dynamics and the radiation transport are introduced for the discharge simulation and for the transmission of the vacuum ultraviolet lights. The simulation results are presented to compare the luminance and the luminance efficacy with the variation of gas pressure, gas mixture ratio, driving voltage, and frequency.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.17-18
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• 2006

Flat Panel Displays (FPDs) have made a revolution in the display industry. TFT-LCD (Thin Film Transistor Liquid Crystal Display) has been the main player of FPD for last two decades. As the industry continuously develops the technology for better performance with lower cost is constantly demanded where several post LCD technologies are being developed. One of the prime candidates of post LCD technology is AMOLED (Active Matrix Organic Light Emitting Diode) that is considered to be an ideal FPD due to its extraordinary display performance and potentially low cost display structure. This technology has been accepted to small size display applications, such as cellular phone, PDA and PMP, etc. In this paper it is discussed that how this technology can be extended to large size display applications, such as TV. The technical issues and solutions of TFT backplane and color patterning of OLED materials are discussed and proposed

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.509-512
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• 2008

In this study, colorimetric characteristics of a 2.2-inch iriver MP4 based upon OLED was evaluated and compared with another MP4 based upon Liquid Crystal Display (LCD). According to IEC61966-4, the two displays were tested in terms of spectral power distribution, tone reproduction curve (TRC), luminance, contrast, correlated color temperature, 2D color gamut and spatial uniformity. Consequently, the OLED showed better performance for the first four aspects but a similar quality was observed for the rest.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.699-702
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• 2006

We have developed twist nematic liquid crystal displays (TN-LCDs), of which the viewing angle can be controlled. The TN-LCDs have the function of switching between the wide viewing mode and narrow viewing angle mode using two tilted LC layers. Tilt angles of the two LC layers, $14^{\circ}$ and $60^{\circ}$ were required in both wide viewing angle and narrow viewing angle modes, respectively. In this way, the viewing angle range in terms of contrast ratio 5:1 can be switched from $120^{\circ}$ to $60^{\circ}$.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.928-931
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• 2003

In order to realize full color display, two approaches were used. The first method is the patterning of red, green, and blue emitters using a selective deposition. Another approach is based on a white-emitting diode, from which the three primary colors could be obtained by micro-patterned color filters. White-light-emitting organic light emitting devices (OLEDs) are attracting much attention recently due to potential applications such as backlights in liquid crystal displays (LCDs) or other illumination purposes. In order for the white OLEDs to be used as backlights in LCDs, the light emission should be bright and have Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (0.33, 0.33). For obtaining white emission from OLEDs, different colours should be mixed with proper balances even though there are a few different methods for mixing colors. In this study, we will report a white organic electroluminescent device using exciton diffusion length concept.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.711-714
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• 2006

Properties of silicon nitride ($SiN_x$) film including physical and electrical characteristics have been studied for improving the stability of hydrogenated amorphous silicon thin-film transistors (a-Si TFTs) in active-matrix liquid-crystal displays (AMLCDs). The instability of a-Si:H TFTs is estimated by accelerated stress test of both bias-temperature stress and bias-illumination stress. The results show that the deposition conditions of $SiN_x$ films with higher power and lower pressure are the best choice for improving the on-current and stability of TFTs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.36-39
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• 2002

Polycrystalline silicon (poly-Si) thin film transistor (TFT) technology is emerging as a key technology for active matrix liquid crystal displays (AMLCD), allowing the integration of both active matrix and driving circuit on the same substrate (normally glass). As high temperature process is not used for glass substrate because of the low softening points below 450$^{\circ}C$. However, high temperature process is required for getting high crystallization volume fraction (i.e. crystallinity). A poly-Si thin film transistor has been fabricated to investigate the effect of high temperature process on the molybdenum (Mo) substrate. Improve of the crystallinity over 75% has been noticed. The properties of structural and electrical at high temperature poly-Si thin film transistor on Mo substrate have been also analyzed using a sputtering method

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.739-742
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• 2003

본 연구에서는 정전계 에너지를 이용하여 IPS-LCD의 화소와 각 전극간 정전용량을 엄정한 방법으로 계산하였다. 정전계 에너지는 전극의 유한한 크기로 인해 발생하는 측면 전장효과를 고려한 3차원 방향자와 전위분포를 시뮬레이션 함으로써 얻을 수 있었다. 수치해석 방법으로는 유한차분법을 사용하였다. 그 결과 IPS-LCD의 화소 정전용량과 게이트-공통전극간 정전용량은 구조적 특성으로 인해 기존의 TN-LCD와 비교하여 1/16배 가량으로 훨씬 더 작은 값을 나타냄이 확인되었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.4
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• pp.282-285
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• 2012

It is well known that Zinc Oxide (ZnO) is an attractive material for its various applications. ZnO has been mostly used as a transparent conducting oxide in liquid crystal displays, solar cells due to its advantages of low cost, high productivity, and excellent electrical conductivity. Notably, flexible-dye-sensitized solar cells (DSSCs) based on polyethylene terephthalate (PET) substrates require low temperature sintering processing conditions. Therefore, low temperature processing conditions have been strongly required for transparent conducting film applications. In this paper, we prepared low temperature-sintered ZnO ceramics employing Li as a sintering aid.

• Korean Journal of Materials Research
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• v.17 no.7
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• pp.352-357
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• 2007

Since a pattern defects "repair" system using a diode pumped solid state laser for Flat Panel Display (FPD) was suggested, a lot of laser systems have been explored and developed for mass-production microfabrication process. A maskless lithography system using 405 nm violet laser and Digital Micromirror Device (DMD) has been developed for PDP and Liquid Crystal Display (LCD) Thin Film Transistor (TFT) photolithography process. In addition, a "Laser Direct Patterning" system for Indium Tin Oxide (ITO) for Plasma Display Panel(PDP) has been evaluated one of the best successful examples for laser application system which is applied for mass-production lines. The "heat" and "solvent" free laser microfabrications process will be widely used because the next-generation flat panel displays, Flexible Display and Organic Light Emitting Diode (OLED) should use plastic substrates and organic materials which are very difficult to process using traditional fabrication methods.