• 한국정보디스플레이학회:학술대회논문집
• /
• 2002.08a
• /
• pp.511-513
• /
• 2002

Electro-optical characteristics of new multi-domain vertical-alignment (MVA) liquid crystal displays (LCDs) with negative dielectric anisotropy on a homeotropic photopolymer were studied. Good voltage-transmittance (V-T) curves by the new MVA-LCD on the homeotropic photo-polymer were obtained. Also, the stable response time of MVA-LCD on the homeotropic photopolymer can be achieved. The viewing angle of the new MVA-LCD could be improved by the grating groove with UV exposure and development on the photo-polymer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.11a
• /
• pp.567-570
• /
• 2004

We have designed a single gap transflective liquid crystal display (LCD) driven by a fringe electric field, in which the LCs are homogeneously aligned in the initial state. In the reflective and transmissive areas, the degrees of the rotation of the LC director are $22.5^{\circ}$ and $45^{\circ}$, respectively. Utilizing this mechanism and an in-cell retarder with a quarter-wave plate that is used below the LC layer, the transflective LCD using fringe-field switching (FFS) mode is realized.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.792-795
• /
• 2006

In-plane-switching (IPS)-mode LCD is one of the most useful technologies for a broad range of viewing angles. To apply for IPS-LCDs, we synthesized novel homogeneous alignment materials, changing dianhydrides (BTDA and BPDA) and bridged diamines (ODA and PACM). We measured their pre-tilt angles using the crystal rotation method with positive LC and their surface properties.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.571-574
• /
• 2003

Three ring type liquid crystalline compounds having 4-alklycyclohexyl group, 1,2-difluorobenzene and phenylisothiocyanate moieties as main skeleton were designed to have negative dielectricity. However, the compounds with 2,3,2'-trifluoro-3'-isothiocyanated biphenylcyclohexane core did not exhibit the nematic liquid crystalline phase because of two conformers by interaction of isothiocyanate and adjacent fluorine atoms. Also, 4-alkyl-2,2',3'-trifluoro-3-isothiocyanated biphenylcyclohexane core was designed expecting to have uniform conformers of isothiocyanate group. In the course of developing polyimides for VA mode LCD, we synthesized alkyl-3,5-diaminobenzene efficiently with various length of alkyl chains from commercially available di-t-butyl malonate and 3,5-dinitrobenzoyl chloride as starting material.

• Korean Journal of Optics and Photonics
• /
• v.8 no.3
• /
• pp.223-229
• /
• 1997

A source code is developed on the basis of Berreman's 4$\times$4 matrix formalism for the analysis of polarization transmission characteristics of twisted nematic liquid crystal display. By using the program, the polarization transmission characteristics of liquid crystal cells and polarizers are analyzed. For a normally white twisted nematic liquid crystal cell, we obtained a family of iso-contrast contours which helps to understand the viewing angle characteristics of the liquid crystal display device by using the cell. The program also help us to understand the variation of the degree of polarization as well as the deviation of the state of polarization of the light transmitted through the polarizer commonly used in the LCD according to the change in incidence angle. This result suggests the contrast of the images appearing on the LCD can be limited by the characteristics of the polarizer in addition to the liquid crystal cell.

• Journal of the Semiconductor & Display Technology
• /
• v.7 no.2
• /
• pp.29-33
• /
• 2008

LCD panels are increasingly used to show moving image material, for example in LCD television sets. However, moving images become blurred on LCD panels. One of the causes of motion blur is the slow reaction of LC(liquid crystal) cell to change in the pixel value. Another cause of motion blur is the hold-type characteristic of the LCD panel, during the frame time the image is shown continuously. This type of motion blur can be reduced with a scanning backlight. We have designed and fabricated a scanning backlight system that solves the hold-type characteristic problem in a way that Flat fluorescent lamp divided 6 blocks was scanned 60Hz.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.460-463
• /
• 2005

We studied the nematic liquid crystal (NLC) alignment capability by the Ultraviolet (UV) alignment method on a a-C:H thin -film , and investigated electro-optical performances of the UV aligned twisted nematic (TN)- liquid crystal display (LCD) with the UV exposure on a-C:H thin film surface. A good LC alignment by UV irradiation on a a-C:H thin -film surface was achieved. Monodomain alignment of the UV aligned TN-LCD can be observed. The good electro-optical (EO)characteristics of the UV aligned TN-LCD was observed with oblique UV exposure on the a-C:H thin film surface for 1min.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.432-433
• /
• 2006

Electro-optical (EO) characteristics of twisted nematic (TN) - liquid crystal display (LCD) on the NDLC thin film using obliquely ion beam (IB) exposure as new ion beam (IB) type system (DuoPIGatrion ion source). A good uniform alignment of the nematic liquid crystal (NLC) alignment with the ion beam exposure on the NDLC thin film was observed. In addition, it can be achieved the good EO properties of the ion-beam-aligned TN-cell on polyimide surface ; the stable VT curve in the ion-beam-aligned TN cell on the NDLC thin film with ion beam exposure using new type IB equipment was obtained. and the fast response time in the ion-beam-aligned TN cell on the NDLC thin film with ion beam exposure using new type IB equipment was obtained.

• 한국경영정보학회:학술대회논문집
• /
• 2008.06a
• /
• pp.557-562
• /
• 2008

FPD(Flat Panel Display) 시장은 디지털 기술의 발전으로 급속하게 성장하고 있으며, 이는 TV 시장에서도 마찬가지이다. 많은 전문가들은 LCD(Liquid Crystal Display)와 PDP(Plasma Display Panel)의 기술적 차이로 인해 LCD는 소형 크기의 TV에 적합하고, PDP는 대형 TV에 적합할 것이라 예상하고, 이에 따라 FPD TV 시장에 적용되는 기술이 목표시장(target market)에 따라 양분할 것으로 전망하였다. 그러나 LCD 생산기술상의 예상치 못한 급속한 진전은 PDP가 목표로 하는 대화면 TV 시장에서 LCD가 독자적인 틈새시장을 형성하고 이를 점차 확대할 수 있도록 하였다. 이러한 시장 전개 양상은 LCD와 PDP의 경쟁을 심화시키고, 현재 앞에서 전망한 바와 같은 현상은 발견되지 않고 있으며, 오히려 대화면 TV 시장에서조차 LCD가 우위에 있음을 보여주는 사례가 많다. 본 연구에서는 LCD가 PDP와의 기술적 격차를 줄이고, 결과적으로 LCD와 PDP간 경계를 무너뜨린 보다 근원적인 원인을 분석한다. 특히 이러한 잠재적 메커니즘을 시스템 다이나믹스 방법론을 도입하여 분석한다. 특히 PDP에 대하여 점진적으로 LCD가 우위를 확보하게 되는 피드백 루프들을 밝혀 내고자 한다. 그리고 이러한 피드백 루프 중에서 가장 효과가 큰 메커니즘을 찾아낸다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.1168-1171
• /
• 2009

We propose a low cost, high performance, effective overdrive implementation method for liquid crystal display systems. The technique can calculate all overdrive values using higher order approximation algorithm by only three measurements. We find that our technique can be applied regardless of LCD panels. Due to its simplicity, we can also tune motion performance of the LCD systems without measurements.