• 제목/요약/키워드: ferroelectric liquid crystal

검색결과 54건 처리시간 0.024초

Dielecrtric and Voltage Holding Properties of the Half-V-shaped Switching Ferroelectric Liquid Crystal Mode Driven by Active Matrix

  • Choi, Suk-Won;Kim, Hong-Chul;Jeong, Woo-Nam;Seo, Chang-Ryong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.1121-1124
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    • 2003
  • For high quality displays, analog responding liquid crystals with spontaneous polarization ($P_{s}$) need to be coupled with active matrix driving schemes. We have characterized the half-V-shaped switching ferroelectric liquid crystal mode (half-V FLC mode) in terms of dielectiric and voltage holding properties. Research on these switching properties provided us with the technology for switching half-V FLC mode FLCs by using amorphous silicon TFTs.

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Effect of the polymer wall boundary condition on the dynamic and memory behavior of the ferroelectric liquid crystal

  • Lee, Ji-Hoon;Lim, Tong-Kun;Park, Seo-Kyu;Kwon, Soon-Bum
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1132-1134
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    • 2006
  • In this research, we examined the correlation between the polymer wall boundary condition and the dynamic/ memory behavior of the ferroelectric liquid crystal (FLC) molecules. It was shown that the polymer wall perpendicular to the rubbing direction induces asymmetric switching to the rubbing direction and induce smaller cone angle angle of LC. On the contrary, in the cell with polymer wall parallel to the rubbing direction, the FLC molecules are oriented in the rubbing direction and shows symmetric switching and has larger cone angle. Memory behavior of each cell has strong correlation with the dynamic state of the FLC molecules. Response time of each cell was also examined.

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FLC SLM을 이용한 편광의존형 2×2 광스위치 (Polarization dependent 2×2 optical switch using ferroelectric liquid crystal (FLC) Spatial Light Modulator(SLM))

  • 김인태;유연석
    • 한국광학회지
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    • 제13권5호
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    • pp.408-413
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    • 2002
  • We demonstrated a polarization dependent type 2$\times$2 optical switch, using a binary reflection type SLM. Reflection type FLC was used as a half wave retardation plate. Two inputs were controlled by each SLM for the desired output direction. In conclusion, in the "1" state the average optical loss was 6.6 ㏈, and in the "0" state the average optical loss was 14.6 ㏈, and measured the switching speed as 75 $mutextrm{s}$. By using this method, a polarization dependent type 2$\times$2 optical switch can be demonstrated and the possibility of a 4-port WDM optical switch also verified.

강유전정 액정 디스플레이의 배향을 위한 액정성 고분자 (Liquid Crystalline Polymer for the Alignment of Ferroelectric Liquid Crystal Display)

  • 진성호;전영재;이종천;김강
    • 한국재료학회지
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    • 제10권5호
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    • pp.350-353
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    • 2000
  • 강유전성 액정 분자 배향을 위해 열방성 고분자 액정물질을 배향막으로 사용하고 그표면 morphology를 AFM(Atomic Forced Microscope)으로 관찰한 결과 잘 배향된 sample cell에서도 microgroove 구조가 나타나지 않았음을 관찰하였다. 잘 배향된 sample cell 23:1의 contrast ratio를 보이면서 memory 효과를 나타내었다. 또한 20V의 AC field로 안정화시키자 전형적인 stripe-shaped 무늬가 나타났다.

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1H Nuclear Magnetic Resonance of a Ferroelectric Liquid Crystalline System

  • Cha, J.K.;Lee, K.W.;Oh, I.H.;Han, J.H.;Lee, Cheol-Eui;Jin, J.I.;Choi, J.Y.
    • Journal of Magnetics
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    • 제15권2호
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    • pp.61-63
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    • 2010
  • We used $^1H$ nuclear magnetic resonance (NMR) to study the phase transitions and molecular dynamics in a characteristic ferroelectric liquid crystal with a carbon number n = 7, S-2-methylbutyl 4-n-heptyloxybiphenyl-4'-carboxylate (C7). The results were compared with those of our recent work on S-2-methylbutyl 4-n-octanoyloxybiphenyl-4'-carboxylate (C8), with a carbon number n = 8. While the recrystallization and isotropic phase transitions exhibited a first-order nature in the $^1H$ NMR spin-lattice and spin-spin relaxation measurements, a second-order nature was shown at the Sm-A - Sm-$C^*$ liquid crystalline phase transition. A soft-mode anomaly arising from the tilt angle amplitude fluctuation of the director, of which only a hint had been noticed in the C8 system, was manifested in the C7 system at this transition.

Titanium oxide nanoparticle hybridized liquid crystal display in vertical alignment

  • 이원규;오병윤;임지훈;박홍규;김병용;나현재;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.160-160
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    • 2009
  • In recent years, the merging of nanomaterials and nano-technology into electro-optic (EO) device technology such as liquid crystal displays (LCDs) has attracted much attention because of their unique electro- and magneto-optic properties and novel display applications. One example of hybrid LC-inorganic systems is semiconductor nanorods added to LC for their strong reorientation effect and tunable refractive index. Doping of nanoparticles in LC or polymers can lead to changes in performance characteristics such as electro-optical, dielectric, memory effect, phase behavior, etc. Due to the tunability of LCDs with mixed inorganic materials, low voltage operation of a LC system can also be achieved using the significant electro-optical effect achieved through suspension of ferroelectric nanoparticles in NLC.

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