• Title/Summary/Keyword: vertical alignment

Search Result 335, Processing Time 0.037 seconds

Electro-optical Characteristics of in the Vertical-Alignment 1/4$\pi$ Cell Using Homeotroopic Photopolymer (수직 광폴리머를 이용한 VA-1/4$\pi$셀의 전기 광학 특성)

  • 황정연;서대식;김재형
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.14 no.8
    • /
    • pp.670-674
    • /
    • 2001
  • The electro-optical (EO) performance in the vertical-alignment (VA) - 1/4$\pi$ cell photoaligned with polarized UV exposure on a homeotropic photopolymer surfaces was investigated. Excellent voltage-transmittance curve in the VA - 1/4$\pi$ cell photoaligned with polarized UV exposure for 3 min on the photopolymer containing cholesteryl group of 8% can be achieved. The V-T characteristics in the VA-1/4$\pi$ cell photoaligned on the photopolymer surface can be improved by increasing cholesteryl group. For response time measurement, the transmittance characteristics of the VA-1/4$\pi$ cell photopolymer surface was better than that of the VA-1/4$\pi$ cell rubbingaligned on a polyimide(PI) surface.

  • PDF

High-transmittance Multi-domain Vertical Alignment Liquid Crystal Device with Protrusion Structure

  • Kim, Ki-Han;Jeon, Eun-Young;Park, Byung Wok;Choi, Sun-Wook;Song, Dong Han;Kim, Hoon;Shin, Ki-Chul;Kim, Hee Seop;Yoon, Tae-Hoon
    • Journal of the Optical Society of Korea
    • /
    • v.16 no.2
    • /
    • pp.166-169
    • /
    • 2012
  • We propose a high-transmittance multi-domain vertical alignment liquid crystal device with a protrusion structure. Disclination lines, which inevitably appear at the boundaries of domains in a multi-domain structure, can be reduced by adding a protrusion structure on the top substrate. The transmittance was improved by 11% using the proposed structure with no change of either the dark state or the operating voltage.

Formation of Dual Threshold in a Vertical Alignment Liquid Crystal Device

  • Choi, Sun-Wook;Jin, Huilian;Kim, Ki-Han;Lee, Ji-Hoon;Kim, Hoon;Shin, Ki-Chul;Kim, Hee Seop;Yoon, Tae-Hoon
    • Journal of the Optical Society of Korea
    • /
    • v.16 no.2
    • /
    • pp.170-173
    • /
    • 2012
  • We present a method that enables dual threshold voltages in a vertical alignment liquid crystal device, through which the gamma shift can be reduced with no subsequent decrease in the contrast ratio. By forming polymer layers, the threshold voltage shift is accomplished through the utilization of the voltage drop effect. We expect that the proposed method can be applied to the conventional 4-domain mode in order to achieve an 8-domain mode without the need for complex driving schemes.

Vertical Alignment Effects of Liquid Crystals by an Octadecyltrichlorosilane Self-Assembled-Monolayer prepared on an Anisotropic $SiO_2$ Surface

  • Seok, Keun-Yeong;Han, Yeon-Jeong;Kim, Hak-Rin
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.645-647
    • /
    • 2009
  • We investigated vertical liquid crystal (LC) alignment effects of a self-assembled-monolayer (SAM) prepared on an anisotropic $SiO_2$ surface where the field-induced LC reorientation produced a uniform single domain texture. We compared the results with the homeotropic-to-random planar reorientation results shown in LCs aligned on a SAM surface prepared on an isotropic $SiO_2$ surface.

  • PDF

Optimized electrode design to improve transmittance in the Patterned Vertical Alignment Liquid Crystal Display

  • Hwang, Seong-Jin;Kim, Youn-Sik;Lee, Seung-Hee;Lyu, Jae-Jin;Kim, Kyeong-Hyeon
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2007.08a
    • /
    • pp.549-552
    • /
    • 2007
  • Patterned vertical alignment (PVA) mode requires multi-domain to exhibit wide viewing angle whereas the transmittance is sacrificed. To overcome the demerit, a fine pattern was formed at folded region in PVA Z-shape electrode structure. In the present work fine patterns were formed near domain boundary regions where the unwanted field direction which causes the LC to tilt down in unwanted direction exists. Thereby transmittance is improved near those fine patterns. This method is very simple and more cost-effective process than the other methods. In this article, we show the method of fine pattern formation and its influence on LC molecule in PVA mode with Z-shape electrode structure.

  • PDF

Wide Viewing Angle Characteristics Using Novel Vertical-Alignment 1/6$\pi$ Cell Mode (새로운 VA-1/6$\pi$셀 모드를 이용한 광시야각 특성)

  • 황정연;서대식;한은주;김재형
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.13 no.10
    • /
    • pp.883-886
    • /
    • 2000
  • We have developed a novel vertical-alignment(VA) - 1/6$\pi$ mode that provides a wide viewing angle for nematic liquid crystal (NLC) with negative dielectric anisotropy on a homeotropic polyimide (PI) surfaces. Good voltage-transmittance curves were achieved with the new VA - 1/6$\pi$ cell model without a negative compensation film. The viewing angle of a new VA -1/6$\pi$ cell without a negative compensation film was wider than that of a conventional VA cell. Finally, the wide viewing angle using the new VA-1/6$\pi$ cell mode can be achieved.

  • PDF

Effects of Vertical Alignment of LCs on Rubbed Polymer Surfaces using Low Resistive Transparent Electrodes

  • Han, Jin-Woo;Kim, Young-Hwan;Kim, Byoung-Yong;Han, Jeong-Min;Moon, Hyun-Chan;Park, Kwang-Bum;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.06a
    • /
    • pp.396-396
    • /
    • 2007
  • We investigated the liquid crystal (LC) aligning capabilities and electrooptical characteristics of semi-transparent silver paste electrodes substituting indium tin oxide (ITO) electrodes. Experimental results show that a uniform vertical LC alignment and a large pretilt angle were achieved using the semi-transparent silver paste. The vertical alignment mode based on the semi-transparent silver paste electrodes showed appropriate electro-optical characteristics and a high transparency in comparison with that based on the ITO electrodes. These results indicate that the semi-transparent silver paste electrodes of liquid crystal displays could substitute the ITO electrodes.

  • PDF

삼성의 LCD-SPVA 및 -PSVA모드 개발사(開發史)와 액정주입 ODF 공정

  • Yu, Jae-Jin;Sin, Seong-Tae
    • Information Display
    • /
    • v.22 no.4
    • /
    • pp.34-44
    • /
    • 2021
  • 90년대 초 LCD (Liquid Crystal Display)는 연관된 반도체 산업과 함께 제2산업의 쌀로 불리며 정부와 관련업계의 높은 관심 속에 큰 성장을 이루었다. 삼성은 일본 기업에 비해 LCD 개발을 늦게 시작했지만 패널 대형화와 넓은 광시야각을 구현한 PVA (Patterned Vertical Alignment) 모드 (mode)를 실현하고, 여기에 더하여 측면 시인성 문제까지 해결한 공정이 단순하며 높은 대비비를 구현하는 SPVA (Super Patterned Vertical Alignment) 및 PSVA (Polymer-Stabilized Vertical Alignment) 모드를 개발하였다. 이와 동시에 새로운 액정 주입 방식인 ODF (One Drop Filling) 기술을 최초로 양산에 접목함으로써 LCD 산업에서 경쟁사들이 따라올 수 없는 훨씬 앞선 제1 주자가 되었다. 이 보고서는 삼성이 SPVA와 PSVA 모드를 역경 속에서 타사들과 어떻게 경쟁하며 발전시켜 왔는가에 대한 내용과 ODF 기술에 대해 삼성의 고유 자산권을 침해하지 않는 범위 내에서 서술하고자 한다. ※ 대비비: 화면의 백색상태 (white state)와 암흑 상태 (black state)의 광비 (光比)

An Analysis of the Attitude Estimation Errors Caused by the Deflection of Vertical in the Initial Alignment (초기정렬에서 수직편향으로 인한 자세 추정 오차 분석)

  • Kim, Hyun-seok;Park, Chan-sik
    • Journal of Advanced Navigation Technology
    • /
    • v.26 no.4
    • /
    • pp.235-243
    • /
    • 2022
  • In this paper, in the case of an inertial navigation system, the posture estimation error in the initial alignment due to vertical deflection is analyzed. Posture estimation error due to DOV was theoretically analyzed based on the speed and posture error of INS. Simulations were performed to verify the theoretical grinding, and the results were in good agreement. For example, in the case of η=20", an alignment error of ϕN=0.00287°, ϕU=0.00196° occurred, and in the case of 𝜉=20", an error of ϕE= -0.00286° occurred. Through this, it was confirmed that the vertical posture error caused by the DOV occurred as a coupling characteristic of the INS posture error. It has been shown that an additional posture error may occur due to the DOV, which was not considered in the existing INS alignment, which means that correction for the DOV must be considered when applying high-precision INS.

Study on Mechanism and Electro-Optical Characteristics of Liquid Crystal Alignment Employing ZnO:Al Electrode

  • Kim, Mi-Jung;Oh, Byeong-Yun;Kim, Byoung-Yong;Kang, Dong-Hun;Park, Hong-Gyu;Lee, Kang-Min;Moon, Hyun-Chan;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.11a
    • /
    • pp.433-433
    • /
    • 2007
  • In this paper, we investigated the feasibility of applying ZnO:Al films to display devices as transparent electrodes, and reported the electro-optical (EO) characteristics of VA cells using ZnO:Al electrodes and compared them with those of VA cells using ITO electrodes. The experiment results show that a uniform vertical LC alignment and a large pretilt angle were achieved. Also, the good voltage-transmittance curve, response time, and capacitance-voltage characteristics were observed for the rubbing aligned VA-LCD using ZnO:Al electrodes m comparison with ITO electrodes. In other words, the vertical alignment mode based on the ZnO:Al electrodes showed appropriate electro-optical characteristics and high transparency in comparison with that based on the ITO electrodes. These results indicated that the transparent ZnO:Al electrodes of the liquid crystal displays could substitute the ITO electrodes.

  • PDF