Nam-deog Kim

46.1: Invited Paper: Integrated a‐Si:H TFT Gate Driver Circuits on Large Area TFT‐LCDs

Integrated a-Si:H TFT gate driver circuits on large area TFT-LCDs are reviewed. A novel AC-biased holding circuit to stabilize the floating node of the shift register on the gate drivers is proposed to improve the driver reliability. Experimental confirmation validates that the new a-Si:H TFT gate drivers are highly reliable

70.1: Invited Paper: Large‐Sized Full Color AMOLED TV: Advancements and Issues

We have demonstrated a 40-inch diagonal, full color WXGA AMOLED TV. It was based on the technologies of amorphous silicon (a-Si) TFT backplane and white OLED with color filter. Despite of recent technology advancement enabling high color purity, large-sized AMOLED, a lot of problems to solve still exist to enter the large-sized display market. Here, Samsung will discuss how far the technologies need to go for the marketplace of large-sized display.

P-66: Ink Jet Printed Full Color Polymer LED Displays

We have developed polymer LED displays using ink jet printing without visible swathe marks which can be observed during display operation. In addition, we have also developed a single-pass printing technology for hole-conduction layer deposition to significantly reduce the complexity of interlacing printing across the panel which is known as an alternative to remove the swathe mark.

A Touch-sensitive Display with Embedded Hydrogenated Amorphous-silicon Photodetector Arrays

Abstract - A new touch-sensitive hydrogenated amorphous silicon(a-Si:H) display with embedded optical sensor arrays is presented. The touch-sensitive panel operation was successfully demonstrated on a prototype of 16-in. active-matrix liquid crystal display (AMLCD). The proposed system provides the finger touched point without the real-time image processing of information of the captured images. Due to the simple architecture of the system, we expect the introduction of large-area touch-sensitive display panels.Key Words : Flat-panel displays, Touch screen panel*정 회 원 : 서울대 전기컴퓨터공학부 박사과정**펠로우회원 : 서울대 전기컴퓨터공학부 교수†교신저자, 준회원 : 서울대 전기컴퓨터공학부 석사과정E-mail : xcloverx@emlab.snu.ac.kr 접수일자 : 2009년 8월 21일 최종완료 : 2009년 9월 7일※본 논문은 본 학회 2009년 하계학술대회 학술위원회에서 우수논문으로 선정되어 편집위원회 심사 후 본 논문지에 게재 되었음. 1. 서 론 터치 디스플레이는 다양한 사용자들에게 간단한 인터페이스를 제공하고 키보드를 제거함으로써 장치의 공간을 절약할 수 있다[1]. 하지만, 대면적 디스플레이를 구현함에 있어서 기존의 기술로는 부가적인 구성요소와 무게 및 부피를 추가해야하고 생산비용이 높아지는 문제점을 가진다[2]. 근래에 소개된 광센서를 이용한 방법[6]-[12]에 쓰이는 저온 다결정 실리콘 기술은 균일성의 문제와 높은 비용이 문제가 되므로 수소화된 비정질 실리콘 박막 트랜지스터(a-Si:H TFT)의 이용이 필요하다[13]. 본 논문에서는 a-Si:H TFT 기반의 광센서가 내장된 새로운 터치 AMLCD를 제시하였다. 제안된 시스템은 이미지 정보 수집과 실시간 이미지 처리 방식을 따르지 않고 수평 방향 출력과 수직 방향 출력 정보의 교차점으로부터 터치 포인트 정보를 제공한다. 이로써 터치 디스플레이의 대면적 구현이 가능해 진다.

16.4: A 14.1″ WXGA Solution Processed OLED Display with a‐Si TFT

We have developed the worlds largest a-Si TFT based solution processed AMOLED full color display. In our 14.1″ WXGA demonstrator, we have realized the worlds best performance for solution-processed OLED materials in an active matrix display, while setting a higher standard for uniformity and image quality.

P-88: Active Local Dimming System for Low Power and Motion Blur Enhancement

Recently, as the light-emitting diodes (LEDs) technology has improved, especially LED brightness is remarkable increased, the brightness of LCD panel is enough even if LED sources are located in only short edge sides (left and right) of the LCD module. As a result, the smart local dimming system is needed to use the invented LED back light unit (BLU) efficiently. In this paper, we proposed the new local dimming system to reduce power consumption and enhance motion picture quality for a new edge LED BLU. The proposed system is applied to active 2D local dimming algorithm and scanning technique at the same time. Our local dimming system has 3 advantages, 25% power saving, 1:100,000 contrast ratio and average MPRT 3.9ms with 240Hz panel. We verified performances by measurement. Finally, our 2D dimming technique was developed as AISC IP type which was merged in timing controller (TCON), so we can apply our system for mass product in 2011 year.

A study for grounding effect to improve performance of WWAN

Electromagnetic interference (EMI) from a LCD panel deteriorates the performance of wireless network system (with wireless network cards: Wireless Wide Area Network (WWAN) card) in a notebook. One of the main EMI noise factor, for the wireless network system, is the grounding effect of the antenna in the system. In this paper, the approach to solve the EMI noise of the system is introduced; by using the grounding methods of the system. In order to measure the EMI noise of the WWAN itself, the standard JIG system is developed. Most grounding effects are confirmed experimentally. Because the EMI noise of the WWAN system is difficult to reduce, it is important to know the antenna (with the coaxial cable) itself.

An improved LC filter for reduction of WWAN noise

A common-mode (CM) filter is usually used to remove CM currents on differential-mode (DM) signal lines [1]. However, in this paper we propose the application of an improved LC filter to reduce EMI noise of DM signal lines. The most important points of applying the LC filter are the consideration of the timing skew and notch points. It has been difficult to find the proper LC filter for DM signal lines, so a new LC filter was developed only for the LCD panel. Three factors are studied for our new LC filter: (1) DC resistance, (2) shape of capacitor, and (3) dielectric constant. Because the LC filter is much cheaper than the CM filter and has advanced properties, the new LC filter is very useful and promising for LCD panels. The new LC filter can be used to reduce EMI of the LCD panel for wireless network systems.

P-78: A Thermally Adaptive Response Time Compensation System for LCD Panels

This paper presents thermally adaptive driving (TAD) technology for response time compensation (RTC) of an LCD with an integrated sensor. The TAD is comprised of analog sensor signal conditioning and a digital feedback algorithm. The integrated thermal sensor provides accurate temperature measurement of the liquid crystal layer. The TAD controller has an 8-step look-up-table (LUT), and compensates response time based on the panel temperature. The TAD system reduces response time by nearly 50% over the temperature range 0 ° −; 60 °C.

P-177: A 14.1-in. Full-Color Polymer-LED Display with a-Si TFT Backplane by Ink-Jet Printing

We have developed a 14.1 inch full color polymer LED display, based on an a-Si TFT backplane, using ink jet printing, which does not show visible swathe marks during display operation. To remove the swathe marks, we have developed the single path printing technology for the hole-conduction layer deposition to significantly reduce the complexity of interlacing printing across the panel, which is known as an alternative to remove the swathe marks. In addition, we have adopted the interlayer process to increase the lifetime of ink jet printed displays. These technologies will enable the scale-up of the ink jet printed AMOLED applications to larger size displays, such as desktop monitors and TVs.