• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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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

• 한국정밀공학회지
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• 제29권11호
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• pp.1164-1169
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• 2012

This paper presents a study of an integrated infrared (IR) photo sensor for display application. We fabricated hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) and hydrogenated amorphous silicon germanium thin film transistor (a-SiGe:H TFT) which were bottom gate structure. We investigated the dependence of a-SiGe:H TFT characteristics on incident wavelengths. We proposed photo sensor which responded to wavelengths of IR region. Proposed pixel circuit of photo sensor was consists of switch TFT and photo TFT, and one capacitor. We developed integrated photo sensor circuit and investigated the performance of the proposed sensor circuit according to the input wavelengths. The developed photo sensor circuit with a-SiGe:H TFT was suitable for IR.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1272-1275
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• 2008

We present the development of dry etch process for the liquid crystal display (LCD) fabrication using a dielectric barrier discharge (DBD) system at atmospheric pressure. In this experimental work, the dry etch characteristics and the electrical properties of thin film transistor are evaluated by using the scanning electron microscopy and electric probe, and TFT-LCD panel ($300\;mm\;{\times}\;400\;mm$) is manufactured with the application of the amorphous silicon etch step in the 4 mask and 5 mask processes.

• 산업공학
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• 제16권4호
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• pp.463-472
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• 2003

In this study we consider the problem of MPS(master production planning) of TFT-LCD(Thin Film Transistor - Liquid Crystal Display) production factory. Due to the complexities of the TFT-LCD production processes, it is difficult to build effective MPS. This study presents an algorithm having a concept of IDPQ(Ideal Daily Production Quantity) that considers line balancing of TFT-LCD production process. In general, the MPS building procedure does not consider line balancing in non-bottleneck processes. MPS without considering line balancing may make ineffective schedule. We present algorithms for building MPS considering factory capacity and line balancing according to the sales order.

• Current Optics and Photonics
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• 제2권1호
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• pp.69-78
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• 2018

This paper presents a precise edge detection algorithm for the critical dimension (CD) measurement of a Thin-Film Transistor Liquid-Crystal Display (TFT-LCD) pattern. The sigmoid surface function is proposed to model the blurred step edge. This model can simultaneously find the position and geometry of the edge precisely. The nonlinear least squares fitting method (Levenberg-Marquardt method) is used to model the image intensity distribution into the proposed sigmoid blurred edge model. The suggested algorithm is verified by comparing the CD measurement repeatability from high-magnified blurry and noisy TFT-LCD images with those from the previous Laplacian of Gaussian (LoG) based sub-pixel edge detection algorithm and error function fitting method. The proposed fitting-based edge detection algorithm produces more precise results than the previous method. The suggested algorithm can be applied to in-line precision CD measurement for high-resolution display devices.

• 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.

• 한국컴퓨터정보학회논문지
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• 제12권4호
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• pp.249-256
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• 2007

본 논문에서는 휴대 가능한 중소형($4{\sim}9$인치 크기)의 정보단말기에 사용되는 TFT-LCD(Thin Film Transistor addressed -Liquid Crystal Display)의 LDI(LCD Driver Interface) 제어기(controller)를 제조사와 크기에 관계없이 사용할 수 있는 표준화된 범용 TFT-LCD의 LDI를 설계하고 FPGA(Field Programmable Gate Array)로 구현하였다. 설계한 LDI 제어기는 FPGA 테스트 보드(test board)에서 검증하였으며, 상업용 TFT-LCD 패널에서 시험결과 안정적으로 상호 동작하였다. 설계한 범용 LDI 제어기의 장점은 LCD의 제조사와 크기에 관계없이 그 동작을 표준화시켜 설계하였으므로 향후 모든 패널내의 SoG(System on a Glass) 모듈 설계에 적용할 수 있는 것이다. 그리고 기존의 방식에서는 LCD 제조사별, 패널 크기별로 별개의 LDI 제어기 칩을 개발하여 사용하지만, 설계한 LDI 제어기는 모든 휴대 가능한 중소형 패널을 구동시킬 수 있어서 IC의 공급가, AV 보드와 패널의 제조 원가 하락을 가져올 수 있으며 가까운 장래에는 보다 우수한 기능의 패널을 제작하기 위한 TFT-LCD 패널 모듈의 SoG 개발이 필연적으로 요구되고 있다. 연구결과는 TFT-LCD 패널을 더욱 소형화, 경량화 그리고 저가격화가 가능하여 기술 및 시장 경쟁력을 선점할 수 있다. 또한 향후 많은 수요가 예상되는 이동형 정보단말기에 사용되는 TFT-LCD 패널 모듈의 SoG IC(Integrated Circuit) 개발과 제작을 위한 기초 자료로서 활용될 수 있다.

• 한국정밀공학회지
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• 제20권4호
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• pp.92-102
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• 2003

To detect electrical faults of a TFT (Thin Film Transistor) panel for the LCD (Liquid Crystal Display), techniques of converting electric field to an image are used One of them is the PDLC (polymer-dispersed liquid crystal) modulator which changes light transmittance under electric field. The advantage of PDLC modulator in the electric field detection is that it can be used without physically contacting the TFT panel surface. Specific pattern signals are applied to the data and gate electrodes of the panel to charge the pixel electrodes and the image sensor detects the change of transmittance of PDLC positioned in proximity distance above the pixel electrodes. The image represents the status of electric field reflected on the PDLC so that the characteristic of the PDLC itself plays an important role to accurately quantify the defects of TFT panel. In this paper, the image of the PDLC modulator caused by the change of electric field of the pixel electrodes on the TFT panel is acquired and how the characteristics of PDLC reflect the change of electric field to the image is analyzed. When the holding time of PDLC is short, better contrast of electric field image can be obtained by changing the instance of applying the driving voltage to the PDLC.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.314-317
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• 2000

In order to analyze the characteristics of complicated TFT-LCD (Thin Film Transistor-Liquid Crystal Display) circuits, it is indispensible to use simulation programs. In this study, we present a systematic method of extracting the input parameters of poly-Si TFT for Spice simulation. This method is applied to two different types of poly-Si TFTs fabricated in our group with good results. Among the Spice simulators, Pspice has the graphic user interface feature making the composition of complicated circuits easier. We added successfully a poly-Si TFT model on the Pspice simulator, which would contribute to efficient simulations of poly-Si TFT-LCD pixels and arrays.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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• pp.452-454
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• 2000

In recent years, the Thin Film Transistor Liquid Crystal Display (TFT-LCD) is used in a variety of products as an interfacing device between human and them. Since TFT-LCDs have trend toward larger Panel sizes and higher spatial and/or gray-scale resolution, pixel charging characteristic is very important for the large panel size and high resolution TFT-LCD pixel characteristics. In this paper, both data line precharging method and line time extension (LiTEX) method is applied to Pixel Design Array Simulation Tool (PDAST) and the pixel charging characteristics of TFT-LCD array were simulated, which were compared with the results calculated by both PDAST In which the conventional device model of a-Si TFTs and gate step method is implemented.