• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.185-189
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• 2002

Flexible displays such as plastic based LCDs and organic light-emitting diodes for mobile communication devices have been researched and developed at KETI in KOREA since 1997. The Plastic film substrate has so poor thermal tolerance and non-rigidness that the fabrication of active devices and panel assembly have to perform at low temperature and pressure. In addition, high thermal expansion of the substrate is also a serious problem for reliable metallic film deposition. In this paper, we investigated particularly on the fundamental characteristics of various plastic substrates and then, suggested novel methods that improve the fabrication processes of plastic LCD panel. In order to maintain stable substrate surface and uniform cell gap during panel assembly, we utilized newly-invented iii and vacuum chuck. Electro-optical characteristics of fabricated plastic LCD are better than or equivalent to those of typical glass based LCDs though it is thinner, lighter-weight and more robust.

• 한국전기전자재료학회논문지
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• 제16권12호
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• pp.1115-1120
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• 2003

In this paper, we investigated the position dependent stress distribution of indium-tin-oxide (ITO) film on Polycarbonate (PC) substrate by external bending force. It was found that there are the maximum crack density at the center position and decreasing crack density as goes to the edge, In accordance with crack distribution, it was observed that the change of electrical resistivity of ITO islands is maximum at the center and decrease as goes to the edge. From the result that crack density is increasing at same island position as face plate distance (L) decreases, it is evident that the more stress is imposed on same island position as L decreases.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.563-566
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• 2004

We have studied a electrically controlled birefringence (ECB) mode for field sequential liquid crystal display (FSLCD). We measured response time of the ECB mode. The ECB mode exhibiting fast response time, high transmittance, low operating voltage and adequate viewing angle. The positive liquid crystal (LC) is better than negative LC on dielectric anisotropy, birefringence and rotational viscosity. So that, the ECB mode is one of strongest candidate for FSLCD application.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.1086-1089
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• 2003

We investigated the electro-optical (EO) performances of the super twisted nematic liquid crystal display (STN-LCD) on the polyimide (PI) surface using polymer film. Monodomain alignment of the plastic STN-LCD can be observed. A stable voltage-transmittance (V-T) curve of the plastic STN-LCD was observed on the polyimide (PI) surfaces using polymer film. Also, a faster response time for the plastic STN-LCD on the polyimide (PI) surfaces using polymer film can be achieved. Therefore, the EO performances of the plastic STN-LCD on the polyimide (PI) surfaces using polymer film is almost the same as that of the glass STN-LCD on a polyimide (PI) surface.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1007-1009
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• 2004

We investigated the electro-optical(EO) performances of the super twisted nematic liquid crystal display(STN-LCD) on the polyimide(PI) surface with polymer film using rubbing and photoalignment method. Monodomain alignment of the plastic STN-LCD can be observed. A faster response time for the photoaligned plastic STN-LCD on the polyimide(PI) surfaces can be achieved than rubbingaligned plastic STN-LCD.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.514-517
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• 2004

We have studied motion of micro-particle immersed in liquid crystal (LC) controlled by in-plane field, which is an important technology in the electro-phoretic display (EPD). In the EPD on and off states are decided by movement of these charged particles and response time is influenced by moving velocity of charged particles. In addition, the velocity can be controlled by intensity of applied voltage such that the higher the applied voltage, the faster velocity of particles become. In this study, we investigated particles's motion as functions of applied voltage, temperature of LC, rubbing direction,

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 디스플레이 광소자 분야
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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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.128-130
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• 2000

A new type ac plasma display panels(PDPs) cells are designed and tested electrically and optically. One cells have the structure of sin discharge path shape and small electrode area. The other cells have the non-symmetric structure with a same electrode area. They show a higher luminous efficienccy and a lower power consumption about 30% improvement than the conventional standard ac PDP cells.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.202-205
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• 2004

We investigated the electro-optical(EO) performances of the super twisted nematic liquid crystal display(STN-LCD) on the polyimide(PI) surface using polymer film. The NLC pretilt angles generated are about $18^{\circ}$ by the rubbing alignment method on thin plastic substrates. However, the pretilt angle are at about $13^{\circ}$ lower on the glass substrate than on thin plastic substrate. Monodomain alignment of the plastic STN-LCD can be observed. A stable voltage-transmittance(V-T) curve of the plastic STN-LCD was observed on the polyimide(PI) surfaces using polymer film. Also, a faster response time for the plastic STN-LCD on the polyimide(PI) surfaces using polymer film can be achieved.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.150-152
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• 2004

We have studied contrast ratio of a homogeneously aligned nematic liquid crystal (LC) display as a function of the angle between the polarizer axis and LC director. The results show that a cell configuration in which a polarizer axis facing a light source coincides with a short LC axis has a better process margin in terms of high contrast ratio than that of the cell coinciding with a long LC axis.