• Proceedings of the KIEE Conference
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1603-1605
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• 2002

TFT-LCD is widely used for flat panel display. The large-size TFT-LCD panel requires a high speed driving and various driving methods because of signal delay, which is responsible for the shading effects. In this work, the floating and double driving methods are applied to Pixel Design Array Simulation Tool(PDAST) and the pixel characteristics of TFT-LCD array is simulated. Also, we have implemented the semi-empirical TFT model to PDAST, which makes to obtain a more accurate pixel characteristics.

• Proceedings of the KIEE Conference
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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.

• Journal of the Korean Magnetics Society
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• 제22권3호
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• pp.91-96
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• 2012

In this paper, a three-dimensional finite element model based on the multi-pixel was constructed to accurately predict electric field distributions including an interference phenomenon between adjacent pixels in the liquid crystal of a complicated TFT-LCD panel. Utilizing the elaborate numerical model, the characteristics of spatial electric field distributions depending on various fault-electrode conditions are thoroughly examined on the basis of the field distribution of a normal electrode condition. The validity of the proposed model is proved by comparing the simulation results with those of the existing optical inspection equipments.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.841-844
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• 2007

In this paper, a vertical block mura, which massively occurred in the LCD products, was investigated extensively by various methods, source drain (SD) line shift is found out to be one of the key reasons. This work to some extent, establishes theoretic hypothesis for further research and solutions similar issues.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.673-674
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• 2003

The reliability of TFT, crystallized by sequential lateral solidification (SLS) technology, has been studied High current damage is characterized by high gate bias (-20V) and drain bias (-10V). It is found that performance of SLS TFTs is enhanced by high current stress up to 300 sec of stress time for 20/8 (W/L) N-TFT. After that, TFT performance is degraded with the increase of the stress time. It is speculated from the experimental data that SLS TFTs initially contain a number of unstable defect states. Then, the defect states seem to be cured by high current stress.

• Journal of Information Display
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• 제10권1호
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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

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2008년도 춘계종합학술대회 A
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• pp.734-737
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• 2008

This paper presents a new automatic TFT-LCD image quality optimization system. We also have developed new algorithms using 6-point programmable matching technique with reference gamma curve, and automatic power setting sequence. It optimizes automatically gamma adjustment and power setting registers in mobile TFT-LCD driver IC to reduce gamma correction error, adjusting time, and flicker. Developed algorithms and programs are generally applicable for most of the TFT-LCD modules. The proposed optimization system contains module-under-test (MUT, TFT-LCD module), control program, multimedia display tester for measuring luminance and flicker, and control board for interface between PC and TFT-LCD module. The control board is designed with DSP, and it supports various interfaces such as RGB and CPU. Developed automatic image quality optimization system showed significantly reduced gamma adjusting time, reduced flicker, and much less average gamma error than competing system. We believe that the proposed system is very useful to provide high image quality TFT-LCD and to reduce developing process time using optimized gamma-curve setting and automatic power setting.

• Journal of Information Display
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• 제2권2호
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• pp.1-6
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• 2001

A $1"{\times}l"$, $512{\times}512$ poly-Si TFT-LCD with a new integrated 8-bit parallel-serial digital data driver was proposed and designed. For high resolution, the proposed parallel-serial digital driver used serial video data rather than parallel ones. Thus, digital circuits for driving one column line could be integrated within very small width. The parallel-serial digital data driver comprised of shift registers, latches, and serial digital-to-analog converters (DAC's). We designed a $1"{\times}l"$, $512{\times}512$ poly-Si TFT-LCD with integrated 8-bit parallel-serial digital data drivers by a circuit simulator which has physical-based analytical model of poly-Si TFT's. The fabricated shift register well operated at 2 MHz and $V_{DD}$=10V and the fabricated poly-Si TFT serial DAC's, which converts serial digital data to an analog signal, could convert one bit within $2.8{\mu}s$. The driver circuits for one data line occupied $8100{\times}50{\mu}m^2$ with $4{\mu}m$ design rule.

• Proceedings of the KIEE Conference
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1255-1261
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• 1995

The development of LCD Simulation program has been targeted to the design and estimation of LCD in an efficient, reasonable and proper method. In developing this program, we have got the theoretical construction for analysis of LCD. Moreover, we've applied CAE to the field of LCD, and thus we could help finding the optimal condition of LCD design or new type of LCD. This software can be applied for the modes such as TN, mono-STN, B/W STN(DSTN, FSTN), color STN, TFT, reflective modes and the program can be developed for other modes.

• Information Display
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• 제12권6호
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• pp.30-37
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• 2011