• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.1
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• pp.20-28
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• 2003

In this paper, we present results of the comparative analysis of the flicker phenomena in the poly-Si TFT-LCD and a-Si:H TFT-LCD arrays for the development and manufacturing of wide-area and high-quality TFT-LCD displays. We used four different types of TFTs; a-Si:H TFT, excimer laser annealed (ELA) poly-Si TFT, silicide mediated crystallization (SMC) poly-Si TFT, and counter-doped lateral body terminal (LBT), poly-Si TFT. We defined the electrical quantity of the flicker so that we could compare the flickers quantitatively for four different 40" UXGA TFT-LCDs. We identify three factors contributing to the flicker, such as charging time, kickback voltage and leakage current, and analyze how much each of three factors give rise to the flincker in the different TFT-LCD arrays. In addition, we suggest and show that, in the case of the poly-Si TFT-LCD arrays, the low-level (minimum) gate voltages should be carefully chosen to minimize the flicker because of their larger leakage currents compared with a-Si TFT-LCD arrays.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.12
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• pp.25-35
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• 2001

In order to analyze the electrical characteristics of complicated thin film transistor-liquid crystal display (TFT-LCD) array circuits, it is indispensible to use simulation programs such as PSPICE and AIM-SPICE. In this paper, we present a systematic method of extracting the input parameters of poly-Si TFT for SPICE simulations. This method was applied to two different types of poly-Si TFTs, fabricated by excimer laser annealing and silicide mediated crystallization methods, and yielded good fitting results to experimental data. 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 device model to the PSPICE simulator, and analyzed easily the electrical characteristics of pixels considering the line RC delay. The results of this work would contribute to efficient simulations of poly-Si TFT-LCD arrays.

• Journal of the Korea Society of Computer and Information
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• v.12 no.4
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• pp.249-256
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• 2007

AIn this paper, a new desist of LDI controller IC for general purpose is proposed for driving the LDI(LCD Driver Interface) controller in $4{\sim}9$ inches sized portable small-medium TFT-LCD(Thin Film Transistor addressed -Liquid Crystal Display) panel module. The designed LDI controller was verified on the FPGA(Reld Programmable Gate Array) test board, and was made the interactive operation with the commercial TFT-LCD panel successfully. The purpose of design is that it is standardized the LDI controller's operation by one LDI controller for driving all TFT-LCD panel without classifying the panel vendor, and size. The main advantage for new general-purpose LDI controller is the usage for the desist of all panel's SoG(System on a Glass) module because of the design for the standard operation. And in the previous method, it used each LDI controller for every LCD vendor, and panel size, but because a new one can drive all portable small-medium sized panel, it results in reduction of LDI controller supply price, and manufacturing cost of AV(Audio Video) board and panel. In the near future, the development of SoG IC(Integrated Circuit) for manufacturing more excellent functional TFT-LCD panel module is necessary. As a result of this research, the TFT-LCD panel can make more small size, and light weight, and it results in an upturn of domestic company's share in the world market. With the suggested theory in this paper, it expects to be made use of a basic data for developing and manufacturing for the SoG chip of TFT-LCD panel module.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04a
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• pp.165-168
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• 2000

An active-matrix LCD using thin film transistors (TFT) has been widely recognized as having potential for high-quality color fiat-panel displays. Pixel-Design Array Simulation Tool (PDAST) was used to profoundly understand the gate signal distortion and pixel charging capability, which are the most critical limiting factors for high-quality TFT-LCDs. In addition, PDAST can estimate voltage distributions in common electrode which can affect pixel voltage and feed-through voltage. Since PDAST can simulate the gate, data and the pixel voltages of a certain pixel on TFT array at any time and at any location on an array, the effect of common electrode voltage can be effectively analyzed. The information obtained from this study could be utilized to design the larger area and finer image quality panel.

• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.613-616
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• 1999

An active-matrix LCD using thin film transistors (TFTs)has been widely recognized as having potential for high-quality color flat-panel displays. Pixel-Design Array Simulation Tool (PDAST) was used to profoundly understand the gate signal distortion and pixel charging capability, which are the most critical limiting factors for high-quality TFT-LCDs. Since PDAST can simulate the gate data and pixel voltages of a certain pixel on TFT array at any time and at any location on an array, the effect of the new set of capacitance models on the pixel operations can be effectively analyzed, The set of models which is adopted from VLSI interconnections calculate more precise capacitance. The information obtained from this study could be utilized to design the larger area and finer image quality panel.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.6
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• pp.416-428
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• 1999

A user-interactive pixel design tool for high-quality TFT-LCDs is realized and used to explore the sensitivity of the various array and device parameters for optimizing pixel design. In this tool, the Thompson cable equation and gradual-channel approximation were used for the gate time delay and TFT current modeling respectively. With this tool, each capacitance element, and TFT and array dimensions can be optimized under given design specifications. The electrical characteristics such ascharging ratio, gate time delay, pixel voltage level-shift, and holding ratio can be analyzed. The sensitivity analysis of those design parameters were executed and presented.

• Journal of Information Display
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• v.1 no.1
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• pp.29-31
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• 2000

A 21.6" a-Si:H TFT array for direct conversion X-ray detector with 2480 by 3072 pixels is successfully developed. To obtain X-ray image of satisfactory quality, a novel structure with a storage electrode on BCB is proposed. The structure reduces the parasitic capacitance of data line, which is one of the main sources of signal noise. Also, the structure shows greater resistance to failure than that of the conventional design.

• IE interfaces
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• v.15 no.4
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• pp.325-337
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• 2002

In this study we consider the problem of 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 schedule the production planning, and the study about automated scheduler is insufficient. In addition, the existing production method is a Push-System to raise the operation rate with expensive equipment, that has the problem to satisfy the due-date. This study presents an algorithm having a concept of Pull-System that satisfies the due-date and considers specialties of TFT-LCD production process. We make MPS(Master Production Schedule) according to the sales order, and present algorithms for scheduling about In/Out plan considering factory capacity, line balancing, material requirement, and inventory level of all Array, Cell, and Module processes. These algorithms are integrated as an automated production system, and we implement them in the actual TFT-LCD factory circumstance.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.39-39
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• 2003