• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.41-44
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• 2001

본 논문은 액정 Driver IC에 사용되a는 내부 기준 clock 발생 및 Voltage Converter에 boosting을 하기 위한 clock을 제공하는 Oscillator 설계 및 구현 하였다 LCD Driver IC에서 발생되는 Oscillator clock 은 고속의 clock신호는 필요로 하지 않으나 LCD display에 관련된 frame 주파수에 직접적인 영향을 주므로 중심 주파수 결정 및 duty비에 따른 주파수 제어가 매우 중요하다. 본 논문에서는 가변 duty를 적용하는 LCD system에 적용할 수 있는 가변 duty oscillator를 소개한다. Process는 0.35um, 12V공정을 사용하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.3
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• pp.264-268
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• 2005

A 2.2-inch QCIF+(176${\times}$RGB${\times}$220) TFT-LCD with integrated row driver was developed using a standard amorphous silicon TFT technology. At low temperature, the integrated row driver operation is dramatically effected by the electron drift mobility reduction(■50 %) and the threshold voltage shift (■1V) of the a-Si TFT. We studied the dependency of circuit design and found that higher on-current circuit is important to guarantee good operation in wide temperature range.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.559-562
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• 2004

A 2.2-inch QCIF+ $(176{\times}RGB{\times}220)$ TFT-LCD with integrated row driver was developed using a standard amorphous silicon TFT technology. At low temperature $({\sim}-20^{\circ}C)$, the integrated row driver operation is dramatically effected by the electron drift mobility variation $({\sim}50%)$ and the threshold voltage shift $({\sim}1V)$ of the a-Si TFT. We studied the temperature dependency of the circuit design and found that higher on-current circuit is important to guarantee good operation in wide temperature range.

• Journal of Information Display
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• v.2 no.2
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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.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.531-534
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• 2005

This paper presents a new data line sharing technique for TFT-LCD panels. This technique reduces the number of data driver IC's to half by having two adjacent pixels share the same data line. This in turn doubles the number of gate lines, which are integrated directly on the glass substrate of amorphous silicon for further cost reduction and more compactness. The proposed technique with new pixel array structure was applied to 15.4 inch WXGA TFT-LCD panels and has proven that the number of driver IC's were halved with nearly 41% circuit cost reduction and 5.3% reduction in power consumption without degrading the image quality.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1251-1254
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• 2006

A novel a-Si TFT integrated gate driver circuit using multi-thread driving has been developed. The circuit consists of two independent shift registers alternating between the two mode, "wake" and "sleep". The degradation of the circuit is retarded since the bias stress is removed during the sleep mode. It has been successfully integrated in 14.1-in. XGA LCD Panel, showing enhanced stability.

• Journal of Power Electronics
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• v.10 no.4
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• pp.351-356
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• 2010

A new current-balancing multi-channel LED driver is proposed in this paper. The conventional LED driver system consists of three cascaded power conversion stages and its driver stage has the same number of expensive boost converters as those of the LED channels. On the other hand, the proposed LED driver system consists of two cascaded power stages and its driver stage requires only passive devices instead of expensive boost converters. Nevertheless, all of the currents through multi-channel LEDs can be well balanced. Therefore, it features a smaller system size, improved efficiency, and lower cost. To confirm the validity of the proposed driver, its operation and performance are verified on a prototype for a 46" LCD TV.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1176-1178
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• 2007

A novel integrated a-Si:H gate driver with high reliability has been designed and simulated. Since the a-Si:H TFT is easily degraded by gate bias stress, we should optimize the circuit considering the threshold voltage shift. The conventional circuit shows voltage drop at the input stage by threshold voltage of the TFT, however, the proposed circuit dose not shows voltage drop and keeps constant regardless of threshold voltage shift of the TFT.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.481-487
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• 2016

A new two-line based inversion driving method is introduced for low power display-driver ICs. By inserting a timing offset between the chopper stabilization and the alternation of LCD polarity, we can reduce power consumption without noticeable degradation in the display quality. By applying the proposed scheme to 12" LCD applications, we achieved 7.5% and 27% power saving in the display-driver IC with white and black patterns, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.592-595
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• 2008

This paper presents development of automatic image quality register optimization system using mobile TFT-LCD (Thin Film Transistor-Liquid Crystal Display) driver IC and embedded software. It optimizes automatically gamma adjustment and voltage setting registers in mobile TFT-LCD driver IC to improve gamma correction error, adjusting time, flicker noise and contrast ratio. Developed algorithms and embedded software 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, flicker noise and contrast ratio, and control board for interface between PC and TFT-LCD module. The control board is designed with DSP and FPGA, and it supports various interfaces such as RGB and CPU.