• Journal of Information Display
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• v.10 no.1
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• pp.33-36
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• 2009

A new hybrid silicon thin-film transistor (TFT) fabrication process using the DPSS laser crystallization technique was developed in this study to realize low-temperature poly-Si (LTPS) and a-Si:H TFTs on the same substrate as a backplane of the active-matrix liquid crystal flat-panel display (AMLCD). LTPS TFTs were integrated into the peripheral area of the activematrix LCD panel for the gate driver circuit, and a-Si:H TFTs were used as a switching device of the pixel electrode in the active area. The technology was developed based on the current a-Si:H TFT fabrication process in the bottom-gate, back-channel etch-type configuration. The ion-doping and activation processes, which are required in the conventional LTPS technology, were thus not introduced, and the field effect mobility values of $4\sim5cm^2/V{\cdot}s$ and $0.5cm^2/V{\cdot}s$ for the LTPS and a-Si:H TFTs, respectively, were obtained. The application of this technology was demonstrated on the 14.1" WXGA+(1440$\times$900) AMLCD panel, and a smaller area, lower power consumption, higher reliability, and lower photosensitivity were realized in the gate driver circuit that was fabricated in this process compared with the a-Si:H TFT gate driver integration circuit

• Industrial Engineering and Management Systems
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• v.8 no.3
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• pp.148-154
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• 2009

In recent days, large-sized flat-panel display (FPD) has been increasingly applied to computer monitors and TVs. Mura defects, appearing as low contrast or non-uniform brightness region, sometimes occur in manufacturing of the Thin-Film Transistor Liquid-Crystal Displays (TFT-LCD). Implementation of automatic Mura inspection methods is necessary for TFT-LCD production. Various existing Mura detection methods based on regression diagnostics, surface fitting and data transformation have been presented with good performance. This paper proposes an efficient Mura detection method that is based on a regression diagnostics using studentized residuals for automatic Mura inspection of FPD. The input image is estimated by a linear model and then the studentized residuals are calculated for filtering Mura regions. After image dilation, the proposed threshold is determined for detecting the non-uniform brightness region in TFT-LCD by means of monitoring the every pixel in the image. The experimental results obtained from several test images are used to illustrate the effectiveness and efficiency of the proposed method for Mura detection.

• Journal of Information Display
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• v.7 no.3
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• pp.1-4
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• 2006

2.22-inch qVGA $(240{\times}320)$ amorphous silicon thin film transistor liquid active matrix crystal display (a-Si TFT-AMLCD) panel has been successfully demonstrated employing a 2.5 um fine-patterning technology by a wet etch process. Higher resolution 2.22-inch qVGA LCD panel with an aperture ratio of 58% can be fabricated as the 2.5 um fine pattern formation technique is integrated with high thermal photo-resist (PR) development. In addition, a novel concept of unique a-Si TFT process architecture, which is advantageous in terms of reliability, was proposed in the fabrication of 2.22-inch qVGA LCD panel. Overall results show that the 2.5 um fine-patterning is a considerably significant technology to obtain higher aperture ratio for higher resolution a-Si TFT-LCD panel realization.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.3
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• pp.39-46
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• 1994

CMOS LCD driving circuits using poly-Si TFT have been designed and basic blocks including test patterns have been fabricated. Column driver drives the pixels by block because polu-Si TFT can not operate at the speed of video signal. Row driver has mode selection circuit which can select a mode between interlacing mode and non-interlacing mode. Experimental results show shift register can operate at 1MHz colck frequency with 4pF load.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.320-323
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• 2000

In the resent years, the Thin Film Transistor Liquid Crystal Display(TFT-LCD) have trend toward larger panel sizes and higher spatial and/or gray-scale resolution. In this trend, Because of its low field effect mobility, a-Si TFT is change to poly-Si TFT. In this paper, both effective-medium model of poly-Si TFTs and empirical capacitance model are applied to Pixel Design Array Simulation Tool (PDAST) and the pixel characteristics of TFT-LCD array were simulated, which were compared with the results calculated by Aim-Spice.

• Journal of Information Display
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• v.12 no.3
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• pp.121-124
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• 2011

The mechanism for lattice-shaped mura defects was proposed by characterizing the electro-optic properties of liquid crystal (LC), which showed different transmission properties between the normal and mura defect areas. An increase in the mura defect rate was observed when the dotted LC in the one drop filling (ODF) was exposed for a longer time. The dotted LC droplet at the edge evaporated more rapidly than that in the center. This resulted in a higher concentration of polar singles at the edge of the dotted LC droplet, leading to a higher ${\Delta}n$ value and higher transmittance. This implies that the reductio of the exposure time of the dotted LC to air plays a critical role in decreasing the occurrence of lattice-shaped mura defects in ODF.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.54-64
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• 2004

본격적인 디지털 방송 시대를 앞두고 대형 TV 스크린에 대한 기술 개발 경쟁이 치열하게 전개되고 있다. 대형 디스플레이 소자로서 대표 주자인 Plasma Display Panel(PDP)의 양산에 한국, 일본 및 대만의 전자 업체들의 경쟁이 시작되었고, 이제는 30 인치 이상 대형 디스플레이로 상업화 가능성이 없었던 TFT(Thin Film Transistor) LCD(Liquid Crystal Display)가 40인치 이상의 TV 시장을 공략하기 위해서 대규모의 투자를 진행하고 있어서 PDP의 아성을 위협하기 시작했다〔1〕∼〔3〕. (중략)

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.158-163
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• 2002

최근 전자통신기기의 급속화된 발전과 함께 전자부품에 대한 초소형화, 고성능화가 요구되고 있다. 특히 노트북 컴퓨터나, PDA, LCD 모니터와 같이 박막 액정 표시장치(Thin Film Transistor Liquid Crystal Display, TFT-LCD)가 대표적인 예라 볼 수 있다. 이러한 박막 액정 표시장치는 그 내부에 냉음극 형광램프(Cold Cathode Fluroscent Lamp)가 있어서 백라이트의 역할을 하는데 냉음극 형광램프의 특성상 초기 고압의 구동전압을 인가시킬 수 있는 인버터가 필수적이라 하겠다. 본 논문에서는 18인치(4_CCFL), 20인치(6_CCFL) TFT-LCD 모니터용, 멀티램프 구동 인버터를 설계 제작하여 90%에 가까운 효율을 얻었다. 코일손실 및 전자유도의 장애가 없고 불연성의 장점을 가지고, 소형화가 가능한 적층형 압전 변압기를 제작하고 이 제작된 적층형 압전 변압기의 전기적 특성분석을 통한 방전램프 구동용 인버터의 승압용 변압기로써 적용이 가능함을 확인하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.489-493
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• 2005

TFT-LCD(Thin Film Transistor Liquid Crystal Display) module is representative commercial product of FPD(Flat Panel Display). Thickness of TFT-LCD module is very thin. It is adopted for major display unit for IT devices such as Cellular Phone, Camcorder, Digital camera and etc. Due to the harsh user environment of mobile IT devices, it requires complicated structure and tight assembly. And user requirements for the mechanical functionalities of TFT-LCD module become more strict. However, TFT-LCD module is normally weak to high level transient mechanical shock. Since it uses thin crystallized panel. Therefore, anti-shock performance is classified as one of the most important design specifications. Traditionally, the product reliability against mechanical shock is confirmed by empirical method in the design-prototype-drop/impact testredesign paradigm. The method is time-consuming and expensive process. It lacks scientific insight and quantitative evaluation. In this article, a systematic design evaluation of TFT-LCD module for mobile IT devices is presented with combinations of FEA and testing to support the optimal shock proof display design procedure.

• Journal of the Korean Vacuum Society
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• v.9 no.3
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• pp.233-236
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• 2000

The structural, electrical and chemical characteristics of Al alloy thin film with low impurity concentrations AlW deposited by using dc magnetron sputtering deposition are investigated for the applications as data bus line in the TFT-LCD panel. The deposited thin films show the decrease of resistivity and the increase of grain size after the RTA at $300^{\circ}C$ for 20 min.. Moreover, the resistivity of AlW does not show appreciable grain size dependence after RTA. It is concluded that the decrease of resistivity after RTA is due to the increase of grain size. The annealed AlW is found to be hillock free. And for investigating chemical attack in TFT-LCD etching processing the electric potential of AlW alloy for Ag/AgCl were investigated by cyclic voltammetry. When W wt.% of AlW alloy was higher than about 3%, the electric potential of AlW was more positive than ITO's. Therefore AlW alloy thin film can be propose to use for data bus line.