• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.294-295
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• 2006

Field sequential liquid crystal display (FSLCD) has advantages such as a high transmittance due to no use of color filter and high color reproductivity because of LED backlight for a luminance source. However, to realize FSLCD response time of the LCD must be below 5ms. In this paper, we have chosen electrically controlled birefringence (ECB) mode for this application and studied film compensation to improve the operating voltage and viewing angle and to achieve a fast response time optimizing the condition of the discotic film and TAC film, operating voltage decreases to 5V, and viewing angle range is $160^{\circ}$ at horizontal and vertical direction, respectively and $120^{\circ}$ in diagonal direction. (contrast ratio > 10:1) and optimized cell exhibits a fast response time of 4ms in most grey levels.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05a
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• pp.109-113
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• 2005

We have studied a field sequential liquid crystal display (FSLCD) with electrically controlled birefringence (ECB). 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. Because $K_{11}$ value out of the elastic coefficient of LC is also larger than $K_{22}$ value, decay time of VA-ECB is advantage. However, the transmittance & response time reduced with decreasing the cell gap. This drawback can be overcome by using LC with high ${\Delta}n$ but VA-ECB is occured loss of light efficiency because the $\gamma$ value increased by high ${\Delta}n$ of LC. Consequently, the HA-ECB mode is one of strongest candidate for FSLCD application.

• Transactions on Electrical and Electronic Materials
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• v.17 no.2
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• pp.109-112
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• 2016

We demonstrated an alternative electrically controlled birefringence liquid crystal (ECB-LC) system with ion beam (IB)-irradiated yttrium gallium oxide (YGaO) alignment films using a sol-gel process. The surface roughness of the films was dependent on the annealing temperature; aggregated particles on surface were observed at lower annealing temperatures, whereas a smooth surface could be obtained with higher annealing temperatures. Higher transmittance in the visible region was observed at higher annealing temperatures. The film had an amorphous crystallographic state irrespective of the annealing temperature. Furthermore, ECB-LC cell with our IB-irradiated YGaO film yielded faster response time when compared to ECB-LC cell with rubbed polyimide. Considering the fast response time and high transmittance, the IB-irradiated YGaO-base LC system is a powerful alternative application for the liquid crystal display industry.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.800-802
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• 2006

A simple wide-viewing-angle solution of electrically controlled birefringence (ECB) LCD is proposed, which is based on a single discotic compensation film. The use of a single discotic film instead of two leads to a considerable reduction in cost while high performance is maintained.

• Korean Journal of Optics and Photonics
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• v.20 no.1
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• pp.48-52
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• 2009

We make a simple electrically controllable linear polarization rotator over $360^{\circ}$ without loss by using a thick ECB(electrically controlled birefringence) liquid crystal cell and a quarter wave plate at 514.5 nm wavelength. Its operating principle can be analyzed and explained by using simple polarization analysis and experimental data. We demonstrate that the degree of polarization of the rotator is 0.964 and the temporal variation for 1 week lies within ${\pm}1$ degree. We can easily solve the problem of nonlinearity of the dependence of the rotational angle of linear polarization on the applied voltage by changing the utilized voltage range or its fitting curve.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.483-484
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• 2005

The field sequential liquid crystal display (FSLCD) does not need a color filter so that it is suitable for high resolution display. However, FSLCD has a drawback which requires a fast response time of sub-5 ms. We have studied the FSLCD with electrically controlled birefringence (ECB) mode. The ECB mode exhibits fast response time, high transmittance, low operating voltage and adequate viewing angle with a help of optical compensation films. In this paper, we present electro-optic characteristics of the ECB mode using a discotic film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.397-398
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• 2008

We have studied the electrically controlled birefringence (ECB) mode using reactive mesogen (RM) monomer to control pretilt angle and improve electrical characteristics. The measure of capacitance confirmed new pretilt angle by RM monomer, and Voltage Holding Ratio (VHR) was increased more than normal ECB cell.