• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.4
• /
• pp.54-64
• /
• 2004

본격적인 디지털 방송 시대를 앞두고 대형 TV 스크린에 대한 기술 개발 경쟁이 치열하게 전개되고 있다. 대형 디스플레이 소자로서 대표 주자인 Plasma Display Panel(PDP)의 양산에 한국, 일본 및 대만의 전자 업체들의 경쟁이 시작되었고, 이제는 30 인치 이상 대형 디스플레이로 상업화 가능성이 없었던 TFT(Thin Film Transistor) LCD(Liquid Crystal Display)가 40인치 이상의 TV 시장을 공략하기 위해서 대규모의 투자를 진행하고 있어서 PDP의 아성을 위협하기 시작했다〔1〕∼〔3〕. (중략)

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.292-294
• /
• 2008

We have developed new reflective LCD for Mixed twist nematic LC mode with high quality image. We have found out an optimal twist angle of LC and optical film's axis by simulation. Also we measured electro-optic characteristics for new design panel. As a result, high reflectance and wide viewing angle characteristics were achieved.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1247-1250
• /
• 2006

A new liquid crystal display (LCD) Data identified Time Extension (DiTEX) driving scheme with a high charged voltage is proposed. The different charged voltage owing to the differential charging time and various initial pixel-potential can be eliminated or diminished under this method. It is compatible with a 2-row inversion and can be realized into the commercial dual-sided gate circuits.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.293-296
• /
• 2007

Gamma curve is one of the most important optical performance characteristics of a liquid crystal display. we present investigations on the relationship between gamma and polarizer. The gamma curve is affected by the angle of the polarizer absorption axis. When the crossed angle between the two polarizers turns larger, gamma values will decrease. The gamma variation caused from each polarizer variation could be improved by monitoring and controlling the axial direction of the polarizers.

• Journal of Information Display
• /
• v.8 no.3
• /
• pp.17-21
• /
• 2007

We introduce a new electrode structure for the patterned vertical alignment (PVA) mode, which has a lower color-shift at large viewing angle than the one-domain VA mode. By manipulating the period of electrode structure, we can make more multi-domains and use the existing fabrication processes without having to use additional materials.

• Korean Journal of Optics and Photonics
• /
• v.19 no.1
• /
• pp.48-53
• /
• 2008

We propose an optical configuration to compensate dispersion characteristics in the dark state of normally black twisted nematic (NB-TN) liquid crystal display (LCD). We employed a half-wave plate (HWP) and a +A plate to achieve the superior dark state. By using the parameter space diagram (PSD) method, we could obtain the optimum values of parameters and the high contrast-ratio over 500 : 1 could be obtained. Furthermore, excellent dispersion characteristics were also obtained in the bright state. We could confirm the performance of the proposed structure using both the numerical calculations and the experiments.

• Applied Chemistry for Engineering
• /
• v.21 no.6
• /
• pp.616-620
• /
• 2010

This study was performed to recycle Propylene Glycol Monomethyl Ether Acetate (PGMEA) from Liquid Crystal Display (LCD) industry emission as a waste organic solvent by using a multistage distillation column and tried to decide optimum reflux ratio. From the final experiment result, it was confirmed ; in case the sample A, the PGMEA purity is more than 98% and the moisture is less than 0.05%, on the other hand, in case the sample B, the PGMEA purity is more than 95% when the reflux ratio is 6 and the moisture is less than 0.01% (Refer to Table 1 for the contents of sample A and B). These values means fine level which can be adapted in the LCD manufacture, requiring more than 90% common purity of recycling level.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.6
• /
• pp.111-118
• /
• 2008

In this paper, novel latch-up prevention method that employs power-up sequential switches has been proposed to relieve latch-up problem in liquid crystal display (LCD) driver ICs. These sequential switches are inserted in the 2'nd and 3'rd boosting stages, and are used to short the emitter-base terminals of parasitic p-n-p-n circuit before relevant boosting stages are activated during power-up sequence. To verily the performance of the proposed method, test chips were designed and fabricated in a 0.13-um CMOS process technology. The measurement results indicated that, while the conventional LCD driver If entered latch-up mode at $50^{\circ}C$ accompanying a significant amount of excess current, the driver IC adopting the proposed method showed no latch-up phenomenon up to $100^{\circ}C$ and maintained normal current level of 0.9mA.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.10
• /
• pp.61-66
• /
• 2007

A gain enhancement rail-to-rail buffer amplifier for liquid crystal display (LCD) source driver is proposed. An op-amp with extremely high gain is needed to decrease the offset voltage of the buffer amplifier. Cascoded floating current source and class-AB control block in the op-amp achieve a high voltage gain by reducing the channel length modulation effect in high voltage technologies. HSPICE simulation in $1\;{\mu}V$ 15 V CMOS process demonstrates that voltage gain is increased by 30 dB. The offset voltage is improved from 6.84 mV to $400\;{\mu}V$. Proposed op-amp is fabricated in an LCD source driver IC and overall system offset voltage is decreased by 2 mV.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1179-1181
• /
• 2004

We have studied a single gap transflective liquid crystal display (LCD) associated with in-plane switching (IPS) mode. In the transmissive IPS cell, the transmittance of electrodes and above electrodes is different, that is, the degree of rotation of the LC director between electrodes and above electrodes is 45 $^{\circ}$ and 22.5 $^{\circ}$ , respectively. Utilizing the different rotating angle of the LC director and in-cell retarder with a quarter-wave plate used below the LC layer, the IPS transflective LCD is realized such that the area between electrodes is used as a transmissive part and the area above electrodes is used as a reflective part.