• Journal of Information Display
• /
• v.5 no.3
• /
• pp.18-24
• /
• 2004

Voltage-dependent transmittance characteristics associated with various cell parameters have been studied in-plane switching liquid crystal display when both common and pixel electrodes are transparent. When both electrodes are opaque, the transmittance is related to only the distance (I) between electrodes. However, where transparent electrode is used, it is influenced not only the 1but also an electrode width (w) and rubbing angle. In addition, these factors are related to operating voltage which shows maximal transmittance. To maximize the light efficiency of the cell and obtain low operating voltage, the above-mentioned cell parameters need to be optimized.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1605-1608
• /
• 2006

The contrast ratio, brightness, and uniformity of S-IPS panel, whose alignment process was employed by ion-beam-alignment (IBA) technology, were improved significantly compared with the convention rubbing's panel, because the light leakage has been reduced in dark state effectively. The IBA technology could generate a panel whose pretilt angle was stable and low after post-treatment process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.12
• /
• pp.1144-1148
• /
• 2006

We have investigated liquid crystal (LC) aligning capabilities and electro-optical (EO) characteristics of transparent electrodes as Al-doped ZnO (AZO) substituting indium tin oxide (ITO). The experiment results show that a uniform vertical LC alignment on AZO electrodes based on a rubbed polyimide (PI) surface were achieved. A high pretilt angle of about $88^{\circ}$ was obtained. EO performances of the VA cell on rubbed PI surfaces with AZO electrodes are almost the same as that of the VA cell with ITO electrodes. These results appeared that AZO electrodes as transparent electrodes of LCDs could substitute ITO electrodes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.05a
• /
• pp.202-205
• /
• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.171-171
• /
• 2010

Electro-optic characteristics of liquid crystal display using fringe field switching(FFS) device depend on many parameters such as cell retardation, electrode structure, rubbing angle, cell gap and dielectric anisotropy. In this paper, the light efficiency of FFS mode will be analyzed to confirm the electro-optic characteristics according to positive dielectric anisotropy such as transmittance, operating voltage and response time.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.05a
• /
• pp.820-825
• /
• 2004

The floating ring seal is used in an oxidizer and a fuel pump of the turbo pump unit in the liquid rocket engine to optimize a leakage without rubbing phenomenon. The damper floating ring seal, one of the floating ring seals, is with round hole pattern surfaces. It can reduce the leakage by increased friction factor that obtained from experimental data. In this paper, the leakage test about floating ring seal and damper floating ring seal was conducted. The test result showed the leakage performance of damper floating ring seal was better than the leakage performance of floating ring seal. With the leakage test the lock-up and rotation test about seal was conducted and that position is measured. The relatively large lock-up eccentric ratio was obtained from the test result of damping floating ring seal. The attitude angle of seal increases with increasing of shaft rotation

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.10
• /
• pp.1095-1099
• /
• 2004

We investigated the electro-optica](EO) performances of the super twisted nematic liquid crystal display(STN-LCD) on the polyimide(PI) surface using polymer film. The NLC(Nematic Liquid Crystal) 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.437-438
• /
• 2008

The Conventional patterned vertical alignment (PVA) device shows a very high contrast ratio at normal direction and does not require rubbing process. However it has a disclination area in which the liquid crystal can be collision in the boundary domain region. In this paper, we studied PVA(Z-shape) device in which the liquid crystal can be tilted down in multiple directions stably because the surface pretilt angle is controlled by photopolymerization of the UV - curable reactive mesogen (RM) under a proper condition. Consequently, the device shows improved electro optical properties as compared to conventional PVA mode.

• Polymer(Korea)
• /
• v.27 no.5
• /
• pp.484-492
• /
• 2003

How the characteristics and stability of the rubbing-induced alignment of nematic liquid crystals (LCs) relate to the interfacial characteristics of LC-polyimide has been studied. The characteristics of the LC alignment (such as the LC texture, the pretilt angle, and the anchoring energy) and their thermal stability have been investigated for 5 polyimides synthesized for this work. The work showed that the rubbed polyimide alignment layer induces the strong LC anchoring and that the characteristics and stability of LC alignment are determined by the short-ranged interactions between LC and polyimide molecules at the alignment layer surface. The increased flexibility of the polyimide accelerates thermal imidization, increases the pretilt angle, and improves the alignment stability. It also turned out that fluorination of the polyimide tends to deteriorate the alignment uniformity and stability. No distinct differences in the alignment characteristics were shown for the aromatic- and alicyclic-dianhydride polyimides.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.11a
• /
• pp.124-127
• /
• 2002

LC aligning capabilities and the variation of pretilt angles with ion beam irradiation on the a-C:H thin films, and electro-optical (EO) performances of the ion beam aligned twisted nematic (TN)-liquid crystal display (LCD) with oblique ion beam exposure on the a-C:H thin film were studied. A high pretilt angle of $3.5{^{\circ}}$ via ion beam irradiation on the a-C:H thin film was measured. Also, the LC pretilt angle decreased due to the increase in surface roughness at over 2 min of IB exposure time. It is considered that this roughness increase due to increasing IB exposure time that generated destroy of oriented rings of atoms related to LC alignment. An excellent voltage-transmittance (V-T) curve of the ion beam aligned TN-LCD was observed with oblique ion beam exposure on the a-C:H thin film for 1 min. Also, a faster response time for the ion beam aligned TN-LCD with oblique ion beam exposure on the a-C:H thin film for 1 min can be achieved. Finally, the residual DC property of the ion beam aligned TN-LCD with ion beam exposure of 1 min on the a-C:H thin film is almost same as that of the rubbing aligned TN-LCD on a PI surface.