• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.85-86
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• 2007

As the manufacturing capacity needs for large size LCD TV shifts very fast into next generation, equipment manufactures face more challenges in development of the systems which can accommodate productivity, reliability and high process quality requirements from the panel makers. AKT committed to continue its contribution to the growth of the LCD market by providing excellent PECVD products. The cost containment and performance improvement are key challenges for large size processing equipment development and this presentation discusses various challenges and AKT's solutions in developing large size PECVD equipment beyond Gen. 8.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1287-1290
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• 2006

A high speed analog buffer using polycrystalline silicon (poly-Si) thin film transistors (TFT) is proposed for 2.2-inch quarter video graphic adapter (qVGA) TFT-LCD panel. Simulation results show that the settling time of the proposed circuit is $10{\mu}sec$ in 2.2-inch qVGA and the power consumption of proposed analog buffer is $25{\mu}W$.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.260-260
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• 2010

현대 사회가 고도의 정보화 사회로 변화하는 가운데 능동행렬 액정 표시 소자(AMLCD : Active Matrix Liquid Crystal Display)는 정보 디스플레이 분야에서 없어서는 안될 중요한 위치를 차지하게 됐다. AMOLED는 자체발광형이므로 LCD에 비해 시야각, contrast, 시인성이 우수하며, 화소를 낮은 전류 밀도로 구동시킨다는 장점이 있다. OLED 소자는 각 화소를 구동할 수 있는 박막 트랜지스타가 필요하며, OLED 소자와 결합된 TFT의 연구도 진행되고 있다. 더욱이 모바일 소자에서 낮은 구동 전압과 비용의 절감을 위해 System On Panels (SOP)에 대한 연구가 또한 진행되고 있다. LCD 패널위에 콘트롤러와 메모리와 같은 소자를 직접화시킴으로써 액정 표시 장치를 소형화시킬 수 있으며 신뢰성을 향상시킬 수가 있다. 본 연구에서는 SOP를 위한 ELA 방법을 통하여 결정화한 poly-Si TFT memory를 제작하여 전기적 특성을 조사하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1103-1107
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• 2004

Last year, we introduced a TFT-LCD with RGBW color system. The primary advantage of the RGBW system is that its optical efficiency is at least 50% higher than the RGB system. However, it is not a simple task to incorporate the new color system into the infrastructure of the RGB system: the driving circuitry, fabrication of color filter, and color conversion. In this report, the practical hurdles are discussed and the solutions are presented.

• Information Display
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• v.21 no.6
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• pp.46-56
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• 2020

액정 모드 기술은 TFT-LCD의 화질, 공정, 비용을 결정짓는 핵심 기술로 당시 일본에 의해 새로운 개념의 광시야각 액정 모드들이 먼저 개발되었지만 한국의 엔지어들의 노력으로 순수 우리 기술을 개발해 상품화한 것은 돌이켜보면 대단한 일이었다고 본다. 당시 후발 주자인 국내 업계와 학연은 일본의 기술을 배우고 따라잡기 위해 일본어 공부를 하면서 일본어로 된 전문서적을 읽고 학회에서 일본 연구자들에 자존심을 버리고 끊임없는 질문으로 기술을 배웠다. 이러한 상황에서도 삼성의 연구자들은 당시 MTA보다 한 단계 향상된 PVA 모드를 개발해 세계 최초의 30인치 TV에 적용시켜 상용화했을 뿐만 아니라 엘지디스플레이의 연구자들은 IPS 기술을 발전시켜 대형 IPS TV의 세계시장을 주도하였다. 당시 제일 후발주자였던 하이디스 엔지니어들은 FFS란 액정 모드를 개발해 현재 일본 뿐만 아니라 세계의 모든 TFT-LCD 업체가 이 기술을 이용하여 제품을 양산하고 있고 향후에도 미니 LED 기술과 접목하여 고화질 LCD 기술을 주도할 것으로 보인다. 이러한 기술 개발로 액정 기술 분야에서 한국 연구자들이 세계적으로 인정받고 있다고 감히 말할 수 있다. 현재 신개념의 디스플레이 분야에서도 한국이 리드를 하고 있다고 보는데 많은 후배 연구자들이 디스플레이 역사의 한 페이지를 장식할 혁신 기술을 개발하고 있는 것을 응원한다. 마지막으로 필자의 경험을 바탕으로 평가한 각 기술들에 대해 다른 전문가들과 이견이 있을 수도 있음을 명시하며, IPS와 PVA 기술을 직접 개발하지 않은 관계로 더 많은 내용을 세밀하게 기술하지 못한 점 송구하게 생각한다. 위 액정 기술들을 우리나라 디스플레이 기술 20선에 선정해 주신 "한국 디스플레이 기술 20선 선정위원회"에 감사드립니다.

• Journal of IKEEE
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• v.14 no.2
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• pp.51-57
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• 2010

A CMOS rail-to-rail high voltage buffer amplifier is proposed to drive the gamma correction reference voltage of large TFT LCD panels. It is operating by a single supply and only shows current consumption of 0.5mA at 18V power supply voltage. The circuit is designed to drive the gamma correction voltage of 8-bit or 10-bit high resolution TFT LCD panels. The buffer has high slew rate, 0.5mA static current and 1k$\Omega$ resistive and capacitive load driving capability. Also, it offers wide supply range, offset voltages below 50mV at 5mA constant output current, and below 2.5mV input referred offset voltage. To achieve wide-swing input and output dynamic range, current mirrored n-channel differential amplifier, p-channel differential amplifier, a class-AB push-pull output stage and a input level detector using hysteresis comparator are applied. The proposed circuit is realized in a high voltage 0.18um 18V CMOS process technology for display driver IC. The circuit operates at supply voltages from 8V to 18V.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3080-3086
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• 2009

We have analyzed the output characteristics of a LGP with pyramid shaped pattern by using a 3-D simulation tool. The influences on the LGP output of various parameters such as the pattern shape, pattern occupation ratio, pattern size, and etching angle were investigated. Comparing the pyramid shaped pattern with hemispherical patterns, little difference was observed. And, it was proved that the pattern occupation ratio and etching angle have relatively large effects on LGP output characteristics, while the pattern size has no effect. Therefore, we can improve the LGP characteristics by optimizing pattern structure and distribution.

• Transactions on Electrical and Electronic Materials
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• v.8 no.4
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• pp.166-169
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• 2007

In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. LCD is different from CRT in the sense that it's continuous passive device, which holds images in entire frame period, while impulse type device generate image in very short time. To reduce image sticking problem related to hold type display mode, we made an experiment to drive TN-LCD like CRT. We made articulate images by turn on-off backlight, and we realized the ratio of Back Light on-off time by counting between on time and off time for video signal input during 1 frame (16.7 ms). Conventional CCFL (cold cathode fluorescent lamp) cannot follow fast on-off speed, so we evaluated new fluorescent substances of light source to improve residual light characteristic of CCFL. We realized articulate image generation similar to CRT by CCFL blinking drive and TN-LCD overdriving. As a result, reduced image sticking phenomenon was validated by naked eye and response time measurement.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.694-697
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• 2003

In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. LCD is different from CRT in the sense that it's continuous passive device, which holds images in entire frame period, while impulse type device generate image in very short time. To reduce image sticking problem related to hold type display mode, we made an experiment to drive LCD like CRT. We made articulate images by turn on-off backlight, and we realized the ratio of Back Light on-off time by adjusting between on time and off time for video signal input during 1 frame (16.7ms). Conventional CCFL (cold cathode fluorescent lamp) cannot follow fast on-off speed, so we evaluated new fluorescent substances of light source to improve residual light characteristic of CCFL. We realized articulate image generation similar to CRT by blinking drive. As a result, reduced image sticking phenomenon was validated by naked eye and response time measurement.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04b
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• pp.121-123
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• 2002

Fast response characteristics of twisted nematic liquid crystal display (TN-LCD) cell with different nematic liquid crystals (NLCs) and cell gap on a rubbed polyimide (PI) surface were studied. High transmittance and fast response time of the TN-LCD on the rubbed PI surface were achieved by using high birefringence ($\Delta$ n) and low cell gap. It is considered that the transmittance and response time of the TN-LCD on the rubbed PI surface decreased as $\Delta$ nd decrease.