• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.450-452
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• 2005

The ion beam alignment technique is one of the potential and fascinating methods. However, there are merely a few reports about aligning nematic liquid crystals (NLCs) horizontally for in-plane switching mode (IPS) by means of low energy ion beam exposure on inorganic materials such as DLC. In this study, we have investigated the tilted vertical alignment of NLC by the ion beam technique on the thin films of various amorphous silicon compounds as new inorganic alignment materials. Appropriate pretilt angles of NLC with preferred orientation on these thin films were achieved. And the electro-optic property of vertically aligned single domain cells has been investigated.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.687-691
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• 2005

We demonstrated stability-enhanced liquid crystal (LC) displays using pixel-iosolated LC mode in which LC molecules are isolated in pixel by horizontal polymer layer and vertical polymer wall. The device shows good electro-optic properties with external pressure and bending due to the polymer structures. The polymer wall acts as supporting structure from mechanical pressure and maintains the cell gap from bending. Moreover, the polymer layer acts as adhesive for tight attachment of two substrates. We presented various methods to produce the polymer structures by using anisotropic phase separation from LC and polymer composites or patterned micro-structures.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.353-356
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• 2005

We have characterized the mechanical stability of the Pixel-Isolated Liquid Crystal (PILC) mode for plastic LC display applications. In our device, the LC molecules are fully isolated in the pixels by the phase-separated polymer walls. The experimental results of microscopic observation and electro-optic characterization show that our flexible PILC device has good mechanical stability against external point pressure or bending distortion due to the polymer walls in our structure.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.349-352
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• 2005

In this paper, we have investigated the hydrogen effects on Diamond-like Carbon (DLC) as an LC alignment layer of the FFS mode. By change of a Hydrogen content in the DLC sputtering process, the image sticking and electro-optic characteristics of Black-White panel with DLC / IB technology were examined.

• Journal of Information Display
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• 제5권1호
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• pp.34-40
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• 2004

Time resolved infrared IR absorption spectroscopy is carried out to investigate the dynamics of electric field induced reorientation of the biphenyl molecular core and alkyl tail sub-fragments of the nematic liquid crystal 5CB (4-pentyl-4-cyano-biphenyl). The planar to homeotropic transition for high pre-tilt planar aligned cells, is studied for switching times ranging from 200 ${\mu}sec$ down to 80 ${\mu}sec$, the latter a factor of 1000 times faster than any previous nematic IR study. The reorientation rates of the core and tail are found to be the same to within experimental error and scale inversely with applied field squared, as expected for the balance of field and viscous torques. Thus any molecular conformation change during switching must relax on a shorter time scale. A simple model shows that no substantial differences exist between the reorientational dynamics of the tails and cores on the time scales longer than on the order of 10 ${\mu}s$.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.374-377
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• 2005

We proposed a new fabrication method for stable flexible LCDs using stamping method with durable elastomer such as poly(dimethylsiloxane) (PDMS). In the device, the LC molecules are isolated in pixels where LCs are surrounded by PDMS microstructure, and two substrates are tightly attached by phase separated polymer layer. The electro-optic characteristics of our cell are comparable to those of normal sample without PDMS microstructure. We propose cost-effective roll-to-roll process for large size of plastic LCDs with our method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.213-215
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• 1987

In this paper, influences or grain size on the electro-optic properties were studied on the penferroelectric PLZT ceramics. The specimens were fabricated by the two stage sintering method. Relative permittivity was a little increased with the increment or grain size in 9,9.5/65/35 (La/Zr/Ti) PLZT specimens, and Curie temperature was decreased in the 9.5/65/35 specimens but constant in the 9.5/65/35 specimens. As the grain size was increased, field induced polarization and dP/dE were increased. Because domain walls can be easily moved by electric field. Light transmittance was increased in the 9/65/35 PLZT specimens but there was little effect on the grain size in the 9.5/65/35 PLZT specimens.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.38-40
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• 2001

Measuring technology based on the computer and software is used worldwideiy by the aids of remarkably improved digital technology and measuring devices, and the electro- magnetic interference due to high currents and high voltages is being solved by the helps of applied optic instrumentation technology. The automatic acquisition, analysis and storage system of test data is available for utilizing the numerical computation technology. The measuring accuracy and testing efficiency are thus much higher because of the developed technologies. In this paper, the construction of data acquisition system in KERI including measuring devices and its application to the short circuit test are described, and additionally the algorithm of the analyzing program for the automatic process of test data and the results of analyses are described.

• 한국세라믹학회지
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• 제36권12호
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• pp.1374-1380
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• 1999

The cause of Scond Harmonic Generation (SHG) in thermally poled silica glass is suggested basedon the electrical and dielectric relaxation measurements. The absorption currents as functions of time were measured for various types of silica glasses and analyzed by the theory of Space Charge Polarization. Space charge polarization occurs when an ionic conducting material is subjected to dc electric field with blocking electrode. Thermal poling performed to induce SHG in silica glass is basically identical to the process generating space charge polarization. Hence it was found that gene-ration removal reproduction and temperature dependence of SHG in poled silica is directly related to those of space charge polarization. It turned out that the fundamental parameters governing the SHG in poled silica are charge carrier concentration and mobility. Based on the theory of space charge polarization and experimental results of electrical rela-xation the method to increase the intensity of SHG is proposed.

• 지구물리
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• 제8권2호
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• pp.75-80
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• 2005

Optical fibre sensors have shown a potential to serve real time health monitoring of Slope and structure. They can be easily embedded or attached to the structures and are not affected by the electro-magnetic field. Furthermore, they have the flexibility of the sensor size and very highly sensitive. In this study, we conducted several laboratory on slope and field tests using a novel optical sensor based on Brillouin scattering and PVC pipe. One of the advantages of this technique is that the bare fibre itself acts as sensing element without any special fibre processing or preparation. Test results have shown that BOTDR can be a great solution for sensor systems of Slope.