• 전기학회논문지
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• 제57권7호
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• pp.1295-1297
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• 2008

Large-sized flat-panel displays are widely used for PC monitors and TV displays. In this paper, frequency domain pre-filter algorithms are presented for detection of defects in large-sized Thin Film Transistor-Liquid Crystal Display(TFT-LCD) panel surfaces. Frequency analysis with 1-D, 2-D FFT methods for extract the periodic patterns of lattice structures in TFT-LCD is performed. To remove this patterns, frequency domain band-stop filters were used for eliminating specific frequency components. In order to acquire only defected images, 2-D inverse FFT methods to inverse transform of frequency domain images were used.

• 반도체디스플레이기술학회지
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• 제10권4호
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• pp.15-20
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• 2011

The lithography system installed inside precision industry's (e.g. TFT-LCD) production factories are increasing in size, thereby increasing its dynamic load along with it. Such condition causes vibration within the area where the system is installed, which then negatively affects the production line to produce defective products. To prevent this type of situation, the facilities should adopt dynamic design that considers the lithography system's dynamic load. This study predicts the maximum value allowed for dynamic stiffness (which is a ratio of vibration response against a single unit of the dynamic load) of the lithography system and explains the result of its application on actual structures inside the facilities.

• 한국광학회지
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• 제19권1호
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• pp.43-47
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• 2008

현재 TFT-LCD(Thin Film Transistor Liquid Crystal Display)에 사용되는 BLU(Back Light Unit) 패턴 크기는 수 십 ${\mu}m$인데 반해, 최근에는 BLU 패턴의 크기를 수 ${\mu}m$ 또는 그 이하로 조절함으로써 출력광의 휘도를 증가시키고 균일도를 향상시키고자 하는 연구가 진행되고 있다. 본 연구에서는 패턴의 크기, 분포 및 점유 면적이 출력광의 분포에 미치는 영향을 조사하였다.

• 한국산학기술학회논문지
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• 제15권6호
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• pp.3429-3434
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• 2014

TFT-LCD 패널 제조 산업에서 삼성전자는 후발기업으로써 선발기업인 일본의 샤프를 추월하여 선도하고 있다. 트리즈 시스템 분석을 활용하여 디스플레이 산업은 노트, 모니터, TV & 모바일 제품 시장으로 변화를 하였으며 시장(고객)의 요구속성도 변화를 함을 제시하였다. 또한 삼성의 TFT-LCD 기술 중 빠른 응답 기술 혁신 사례를 제시하였다. 예를 들면, 응답속도 개선을 위해 기존 사용하고 있는 액정 혼합물에 트리즈의 모순성, 물질-장 방법 등을 활용하여 개발된 고복굴절률 액정물질을 첨가하여 광시야 각, 빠른응답 특성을 갖는 신규 액정 혼합물을 개발하였다. 새로운 액정혼합물의 응답속도는 60%정도로 단축 개선되었다(기존 액정 사용 시 16 ms, 새로운 액정혼합물 사용 시 10ms).

• 한국재료학회지
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• 제19권1호
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• pp.7-12
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• 2009

TFT-LCD is the most popular type of flat display panel in the information technology field. The back light unit is a main part of the structure of a TFT-LCD panel. Occasionally, studies have shown that failures of the CCFL of the BLU occur due to the poor weld characteristics of these materials. The aim of this study was to prepare some technical data and to characterize a microjoined electrode for the CCFL. Microstructure examinations, microhardness measurements, resistance measurements and microtensile tests of the microjoined electrode were carried out. The result indicates that a large amount of grain coarsening exists in the heat-affected zone (HAZ) of the weld between the cup and the pin. This grain coarsening of the HAZ between the cup and pin is caused by the welding cycle, which may have an influence on the lowest microhardness values. Fracturing of the microjoined electrode also occurred at the HAZ close to the cup between the weld holding the cup and the pin. Additionally, no specific changes of the electrical resistance among the cup, pin, and lead wire themselves or in the microjoined electrode were observed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
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• pp.225-228
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• 2001

We simulated and analyzed the flicker phenomena in the poly-Si TFT-LCD using PSpice for the development of wide-area and high-quality LCD display We define the electric quantity of flicker in the TFT-LCD, which is the ratio of half frame frequency (30Hz) to DC (0 Hz) frequency. We compared two different types of TFTs, excimer laser annealed (ELA) poly-Si TFT and silicide mediated crystallization (SMC) poly-Si TFT, and found that the ELA and SMC TFTs show different flicker characteristics because of their mobility and leakage current. In addition, we showed that the gate voltage should be chosen carefully at the minimum flicker because of the larger leakage current of poly-Si Tn as compared with a-Si TFT

• 전자공학회논문지A
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• 제32A권12호
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• pp.149-158
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• 1995

This paper describes the development of a software tool LCD FRAME that may guide the analyzing process for the electrical characteristics and the design procedure for constructing the thin film transistor liquid crystal display(TFT/LCD) packages. LCD FRAME can analyze its electrical characteristics from the TFT/LCD system package configuration, and provide the design variables to meet the user's requirements. These analysis and design procedure can be done in real time according to the model at simplified package level of TFT/LCD. LCD_FRAME is an object-oriented expert system which considers package elements as objects. With this LCD_FRAME software tool, we analyzed the I-V characteristics of a-Si TFT and its signal distortion which has maximum 1.58 $\mu$s delay along the panel scan line of the package containing 480 ${\times}$ 240 pixels. We designed the package structure of maximum 6.35 $\mu$s signal delays and 3360 ${\times}$ 780 pixels, and as a result we showed that the proper structure of 20 $\mu$m scan line width, 60$\mu$m panel TFT gate width and 8 $\mu$m gate length. This LCD_FRAME software tool provides results of the analysis and the design in the form of input files of the SPICE program, text data files, and graphic charts.

• 한국정밀공학회지
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• 제22권3호
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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.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1040-1043
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• 2004

As time goes by, the market demand increases and each LCD panel manufacturing company makes every effort to produce more panels in a limited time. It is necessary to reduce the cost and time of production for the improvement of productivity in manufacturing companies. The increased speed of thin films growth used in the TFT process brings improvement of productivity but it is also accompanied by a drop in display quality due to a characteristic change of the thin film. So in our dissertation, we deal with the increased speed of a-Si layer growth and the proportioned a drop in characteristic quality. We discuss a drop in display quality by a characteristic change of a-Si layer and we propose a counter-plan through panel design improvement. We have already applied our plan to the 15" XGA panel and confirmed the improved result.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.457-459
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• 2005

Low viscosity LCs have been developed for fast response time improvement of the TFT-LCD Monitors based on TN mode. This low viscosity characteristic s cause the pretilt angle to be changed and the uniformity to degrade. We have studied on the pretilt angle effect by the various components used for low viscosity LCs. We prepared the panels by using these various components and measured pretilt angle for this research. As a result of this research, we have found out that each low viscosity component has the different pretilt angle level and uniformity. For good display quality, it is important to keep the stable pretilt angle. The low viscosity LCs with this stable pretilt angle make it possible to prepare the high performance TFT-LCD Monitor with both fast response time characteristics and good display quality