• Title/Summary/Keyword: Fringe-electric field

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Electro-Optic Characteristics according to Distance between Pixel Electrodes in Fringe In-plane field Switching mode (화소 전극 간 거리가 Fringe In-plane field Switching mode의 전기 광학 특성에 미치는 영향)

  • Kim, Min-Su;Park, Ji-Woong;Jung, Jun-Ho;Ha, Kyung-Su;Lim, Young-Jin;Lee, Myong-Hoon;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.337-338
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    • 2008
  • We have studied electro-optic characteristics of a high performance liquid crystal display using Fringe In-plane field Switching (FIS) mode. The strong electric fields cause more liquid crystals to reorient almost in plane above and between the pixel electrodes. As a result, the operation voltage is lower and transmittance is higher than those of Fringe Field Switching (FFS) and In-Plane Switching (IPS) modes. Apparently, the transmittance depends on voltage applied at the configurations of FIS mode which are proposed. Therefore, we have studied certain length of between electrodes for maximum transmittance and light intensity.

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Liquid Crystal Device associated with Fringe-Field Driven Optically Compensated Splay

  • Jung, B.S.;Kim, S.J.;Oh, S.M.;Lee, S.H.;Kim, H.Y.;Kim, S.Y.;Lim, Y.J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.1197-1199
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    • 2004
  • We have studied an optically compensated splay (OCS) mode driven by fringe electric field. The OCS configuration obtained by applying voltage to vertically aligned LCs shows a dark state when an optic axis of the OCS cell coincides with one of crossed polarizer axis. When the fringe electric field is applied, the LC director rotates in plane above whole electrode surface, giving rise to the high transmittance, the low operating voltage and wide viewing angle simultaneously.

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Study on the Quantitativity of Image Sticking in the Fringe-field Switching(FFS) Mode (Fringe-Field Switching (FFS) 모드에서 잔상 정량화에 관한 연구)

  • Seen, Seung-Min;Kim, Mn-Sook;Jung, Yeon-Hak;Kim, Hyang-Yul;Kim, Seo-Yoon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.8
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    • pp.720-723
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    • 2005
  • We studied the quantitativity of the image sticking which is occured by the resicual DC in the fringe-electric field switching (FFS) mode. Actually, in the FFS mode driven by the strong fringe electric field, the asymmetric residual DC was formed in the bottom substrate. It made the impurity ion stick to the alignment layer such as polyimde layer. Thus, the differnece of the luminance existes after the stress check pattern is applied to the panel so that we can see the image sticking. This image sticking decreases as the residual DC value between specific patterns decreases. Therefore, it is necessary to control the residual DC for the FFS mode with the high image quality. It is possible to eliminate the image stiking when the extra pixel voltage is applied through the circuit tunning for reducing the difference of residual DC accroding to the panel position.

Wide Viewing Angle Transflective Liquid Crystal Display using Fringe-Field Switching Mode (FFS 모드를 이용한 광시야각 반투과형 액정 디스플레이)

  • Song, Je-Hoon;Lim, Young-Jin;Park, Chi-Hyuk;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.567-570
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    • 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.

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Study on Electro-Optic Characteristics Dependent on Passivation Layer Thickness in the FFS mode using a Liquid Crystal with Positive Dielectric Anisotropy (유전율 이방성이 양인 액정을 이용한 FFS모드의 절연층 두께에 따른 전기 광학 특성 연구)

  • Lee, Ji-Youn;Park, Sang-Hyun;Oh, Sang-Min;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.485-486
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    • 2005
  • Fringe-field switching mode which has a horizontal and vertical electric field exhibits high transmittance and wide viewing angle characteristics. In the FFS mode, a passivation layer between common and pixel electrodes exists, which functions as preventing current leakage of fringe-field. In this paper, we have studied LC behavior, transmittance and operating voltage characteristics with applied voltage as a function of the passivation layer thickness and defined optimal value of the layer to be about $0.5{\mu}m$.

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Study on Viewing angle controllable Liquid Crystal Display with High Aperture Ratio (시야각 조절이 가능한 고개구율 액정 디스플레이 연구)

  • Shin, Suck-Jae;Her, Jung-Hwa;Lim, Young-Jin;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.173-173
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    • 2010
  • We proposed viewing angle switchable liquid crystal display(LCD) associated with fringe-field switching (FFS) mode with high aperture ratio characteristic. In the device, single pixel is separated into two regions, named as main pixel for displaying images and sub pixel for viewing angle control. In sub pixel region, add the common electrode on the top substrate and the initial alignment of liquid crystal is Hybrid Alignment Nematic (HAN) state. In conclusion, we suggested that the device has high aperture ratio characteristic because the LC directors are rotated in which viewing angle control region are generated fringe electric field.

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Dynamic Stability Depending on the Dielectric Anisotropy of the LC in the Fringe-Field Switching (FFS) mode (Fringe-Field Switching (FFS) 모드에서 액정의 유전율 이방성에 따른 동력학 안정성에 관한 연구)

  • 김미숙;김향율;이승희
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.3
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    • pp.224-230
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    • 2003
  • The voltage-dependent transmittance curve of a homogeneously aligned liquid crystal (LC) cell driven by fringe-electric field(named FFS mode) was studied, while changing dielectric anisotropy of a LC. The results show that for a LC with positive dielectric anisotropy while positioning at initial position. Therefore, we conclude that the dynamic stability is strongly dependent on the types of the LCs and voltage-dependent dynamics of the LC with negative dielectric anisotropy is staler than that of the LC with positive dielectric anisotropy in the FFS mode.

Viewing angle controllable liquid crystal display using fringe-field switching mode with high aperture ratio characteristic (고투과율 특성을 갖는 FFS 모드의 시야각 스위칭)

  • Kim, Jin-Ho;Her, Jung-Hwa;Chin, Mi-Hyung;Lim, Young-Jin;Jin, Hyun-Suk;Kim, Byeong-Koo;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.32-33
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    • 2009
  • We propose viewing angle switchable liquid crystal display(LCD) associated with fringe-field switching (FFS) mode with high aperture ratio characteristic. This device is composed of R(red), G(green), B(blue), pixel and W(white) pixel in which R,G,B pixel shows image and white pixel for both viewing angle control and image. Conventional viewing angle controllable liquid crystal display has not transmittance because the liquid crystal only tilts up without rotates in viewing angle control region. In this paper, we suggested that the device has high transmittance characteristic because the LC directors are rotated in which viewing angle control region are generated fringe electric field.

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Study on Electro-optic Characteristics and Dynamic Stability Depending on the Pretilt Angle for the Twisted Nematic(TN) and Fringe-field Switching(FFS) Mode (TN 모드와 FFS 모드에서 Pretilt Angle이 전기 광학 특성 및 동력학 안정성에 미치는 영향에 관한 연구)

  • Kim, M.S.;Jung, Y.H.;Kim, H.Y.;Kim, S.Y.;Lee, S.H.
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.11
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    • pp.1234-1240
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    • 2004
  • We studied on the electro-optic characteristics and dynamic stability according to an undesirably defined pretilt angle induced in high step coverage of pixel area for the Twisted Nematic (TN) / Fringe-Field Switching (FFS) mode. In case of the TN mode, LC directors twist reversely near the edges of thin-film-transistor and black matrix where the pretilt angle of the LC is not well defined. Therefore, the voltage-dependent dynamics of the LC in TN mode is unstable and shows the bad electro-optic characteristics. On the other hand, in case of the FFS mode, the LCs are twisted parallel to the bottom substrate by fringe electric field and the electro-optic characteristic is not influenced by the pretilt angle of the LC which is not well defined.

Study on electro-optic characteristics of fringe electric field driven single gap transflective liquid crystal display (단일갭 반투과 FFS 액정 표시 장치의 전기 광학 특성 연구)

  • Chin, Mi-Hyung;Jeong, Eun;Lim, Young-Jin;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.421-422
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    • 2007
  • The fringe electric field driven transflective liquid crystal display with dual orientation has a problem that the voltage-dependent transmittance and reflectance curves do not match each other, requiring a dual driving circuit to achieve a high electro-optic performance. Optimizations of the electrode structure in the array substrate and rubbing direction solve this problem so that the transflective display with a single gap and a single gamma curve for reflective and transmissive region is possible.

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