• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.51-54
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• 2007

Top-emission 3.5 inch qVGA IOD (Inverted AMOLED) was fabricated with inverted EL structure driven by a-Si TFT backplane. In order to get stable driving TFT, we used FCP(Field Control Plate) layer which was connected with the source of the driving TFT. And we developed planarization process to planarize the cathode layer which was the bottom layer of inverted OLED. Our unique IOD structure is “a-Si TFT/ Al(Cathode)/ LiF/ LG-201(ETL)/ EML(RGB)/ HTL/ LG-101(HIL & Buffer layer)/ IZO(Anode)”. LG-201(ETL) layer was studied for more efficient electron injection from cathode to EML, and LG-101(HIL & Buffer layer) covered by IZO anode was also explored for decreasing the EL surface damage.

• 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.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.205-207
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• 2008

The new process for hybrid silicon thin film transistor (TFT) using DPSS laser has been developed for realizing both low-temperature poly-Si (LTPS) TFT and a-Si:H TFT on the same substrate as a backplane of active matrix liquid crystal display. LTPS TFTs are integrated on the peripheral area of the panel for gate driver integrated circuit and a-Si:H TFTs are used as a switching device for pixel in the active area. The technology has been developed based on the current a-Si:H TFT fabrication process without introducing ion-doping and activation process and the field effect mobility of $4{\sim}5\;cm^2/V{\cdot}s$ and $0.5\;cm^2/V{\cdot}s$ for each TFT was obtained. The low power consumption, high reliability, and low photosensitivity are realized compared with amorphous silicon gate driver circuit and are demonstrated on the 14.1 inch WXGA+ ($1440{\times}900$) LCD Panel.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.10
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• pp.945-954
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• 2004

Recently, specifications of flat display module is going to be higher definition, brightness and more wide viewing angle. On the other hand, physical thickness of those modules is forced to be slimmer and lighter. The flat display modules such as plasma or TFT-LCD employ thin crystallized panels that are normally weak to high level transient mechanical energy inputs. As a result, anti-shock performance is one of the most important design specifications of TFT-LCD modules. TFT-LCD module manufacturers and their customers like PC or TV makers perform a series of strict impact/drop test for the modules. However most of the large display module designs are generated based on engineer's own trial-error experiences. Those designs may result in disqualification from the drop/impact test during final product evaluation. A rigorous study on the impact failure of the displays is of course necessitated in order to avoid the problems. In this article, a systematic design evaluation is presented with combinations of FEM modeling and testing to support the optimal shock proof display design procedure.

• 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.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1809-1811
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• 1999

In recent years, attempts have been made to greatly improve the display quality of active-matrix liquid crystal display devices, and many techniques have been proposed to solve such problems as gate delay, feed-through voltage and image sticking. Gate delay is one of the biggest limiting factors for large-screen-size, high-resolution thin-film transistor liquid crystal display (TFT/LCD) design. Many driving method proposed for TFT/LCD progress. Thus we developed gate driving signal generator. Since Pixel-Design Array Simulation Tool (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 driving signals of gate lines on the pixel operations can be effectively analyzed.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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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.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.988-990
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• 2005

A 5.0-inch plastic TFT-LCD with the resolution of $400{\times}3{\times}300$ lines (120ppi) was developed. The device is a transmissive type with the transparent PES plastic substrates. The PES films with one side barrier coating were used for the device. In order to produce the high resolution display device, the alignments between all the layers for the TFT and CF are essential. The fundamental shrinkage effect and the thermal expansion behavior of the plastic substrates with and without the barrier coatings were studied. The proper annealing processes followed by immediate second bar-rier coating processes provide the optimal alignment between all the layers of the TFT and CF..

• Journal of Information Display
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• v.2 no.3
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• pp.32-38
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• 2001

The most important parameter for TV application of LCD is a fast switching time for the display of moving image. To achieve faster switching time, the novel LC single materials with large dielectric anisotropies ($16{\sim}20$), high clearing temperatures ($195.5{\sim}237.4^{\circ}C$), broad nematic ranges (up to 169.9 $^{\circ}C$) and high birefringence ($0.254{\sim}0.2200$) were developed. KUR-series LC mixtures blended these single materials having significantly higher clearing temperatures and dielectric anisotropy values compared with conventional LC mixture. Especially, their clearing temperatures are $10{\sim}30^{\circ}C$ higher than their host mixture. These LC mixtures showing about lOms of high-speed switching time in Tv/Monitor of TFT LCD, is short enough to be addressed in a single time frame of 60Hz (16.7 ms). The threshold voltage $V_{th}$ was low enough to operate at a driving voltage of 5 V. The VHR values were found to be high enough for TFT-LCD in wide temperature range. Our novel LC mixtures are suitable materials for the inclusion in to LC mixtures for TV application of TN-LCD

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.597-600
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• 2006

The silver gate and source/drain electrodes for an a-Si thin film transistor were fabricated by the selective electroless plating (SELP) process. Relevant physical properties including taper angle, uniformity and resistivity are investigated. The Ag layer was about 150nm to 250nm thick, the resistivity less than $3{\times}10^{-6}$ Ohm-cm and the taper angle 45'-60' and the nonuniformity less than 10% on G2 substrates. The transfer characteristics with the Ag gate, and source/drain electrodes respectively possessed good field effect mobility similar to conventionally fabricated a-Si TFTs. This process provided low resistivity, low cost and ease of processing.