• 제목/요약/키워드: Voltage-transmittance

검색결과 281건 처리시간 0.025초

Flexible audible display(VizDio$^{TM}$) using polymer dispersed liquid crystal on film speaker

  • Bae, Byeong-Taek;Park, Dong-Hee;Jeong, Kwang-Ho;Choi, Won-Kook
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.877-878
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    • 2009
  • To realize the flexible audible display (FAD), polymer dispersed liquid crystal(PDLC) is deposited on PVDF(Poly-vinylidene fluoride) film with piezoelectric property. With applied audio signal, it makes sound more than 70 dB in 700 Hz-10kHz. In case of transparency it is opaque and transmittance is less than 10% at 550nm wavelength without bias voltage. It is turned to be transparent and show transmittance of 66% with driving voltage of 60V.

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수직 광폴리머 표면에 사진식각을 이용한 다중도메인 수직배향셀의 광시야각 특성 (Wide-Viewing Angle Characteristics of MVA Cell using Photolithograph with Homeotropic Photopolymer Surface)

  • 황정연;이경준;이재호;김태호;이상극;서대식
    • 한국전기전자재료학회논문지
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    • 제16권3호
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    • pp.219-223
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    • 2003
  • The electro-optical (EO) performances of a multidomain verticial-alignment (MYA) cell on a homeotropic photopolymer have been investigated. In the absence of an electric field, the WVA cell achieved black state as LC alignment is homeotropic An electric field created by interdigitated electrodes and rib made after photolithograph using the photopolymer on both substrates causes a director deformation of a multidomain type. Good voltage transmittance curves for a MVA cell on the homeotropic photopolymer were observed. Also, the stable response time of MYA cell on the homeotropic photopolymer can be achieved.

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

  • 황정연;서대식;한은주;김재형
    • 한국전기전자재료학회논문지
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    • 제13권10호
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    • pp.883-886
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    • 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.

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비편광 UV조사에 의한 광배향 VA-LCD의 전기광학특성 (Electro-optical properties of photo-aligned VA-LCD by irradiation of unpolarized UV light.)

  • 박두석;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
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    • pp.545-548
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    • 1999
  • The electro-optical characteristics of photo-aligned vertical-alignment (VA)-liquid crystal display (LCD) with non-polarized ultraviolet (UV) light irradiation of 45\`on homeotropic polyimide (Pl) surface were investigated. LC alignment on photo-aligned VA-LCD is attributed to photo-depolymerized reaction of the polymer with non-polarized UV light irradiation on PI surface. We had good voltage-transmittance (V-T) characteristics of photo-aligned VA-LCD. The response time of photo-aligned VA-LCD was slower than that of the rubbing-aligned VA-LCD. Finally, we suggest that the slow response time of photo-aligned VA-LCD depends on the LC domain.

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VA-1/6$\pi$셀을 이용한 시야각 특성의 개선 (Improvement of viewing angle characteristics using a VA-1/6$\pi$ cell)

  • 황정연;서대식;한은주;김재형
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.515-518
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    • 2000
  • We studied the viewing angle characteristics of a negative dielectric anisotropy nematic liquid crystal (NLC) using the new vertical-alignment (VA)-1/6 cell on a rubbed polyimide (PI) surface. Good voltage-transmittance (V-T)characteristics using the new VA-1/6 cell without a negative compensation film were obtained. The iso-viewing angle characteristics using the new VA-1/6 cell without the negative compensation film can be achieved.

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고내열성을 가진 감광성 폴리이미드의 액정배향 특성에 관한 연구 (Study on characteristics of liquid crystal alignment on photosensitive polyimide having thermal stability)

  • 이상민;황정연;남기형;서대식;서동학
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.502-505
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    • 2003
  • We synthesized high thermal photoalignment material with hydroxyl aromatic polyimide, and studied the liquid crystal (LC) aligning capabilities on the photopolymer layers. Also, electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photoaligned with linearly polarized UV exposure were investigated. A good LC alignment with UV exposure on the photopolymer surface can be obtained. However, the low pretilt angles were obtained below $1^{\circ}$. The Voltage-transmittance (V-T) curve without backflow bounce in the photoaligned TN cell with UV exposure was observed. The response time of photoaligned TN cell was measured about 24 ms.

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

  • 이지연;박상현;오상민;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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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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Improve the Transparency of Liquid Crystal Display Using Hybrid Conductive Films Based on Carbon Nanomaterials

  • Shin, Seung Won;Kim, Ki-Beom;Jung, Yong Un;Hur, Sung-Taek;Choi, Suk-Won;Kang, Seong Jun
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.241.2-241.2
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    • 2014
  • We present highly transparent liquid crystal displays (LCDs) using hybrid films based on carbon nanomaterials, metal grid, and indium-tin-oxide (ITO) grid. Carbon based nanomaterials are used as transparent electrodes because of high transmittance. Despite of their high transmittance they have relatively high sheet resistance. To solve this problem, we applied grid and made hybrid conductive films based on carbon nanomaterials. Conventional photolithography processes were used to make a grid pattern of metal and ITO. To fabricate transparent conductive films, carbon nanotube (CNT) ink was spin coated on the grid pattern. The transparency of the conductive film was controlled by shape and size of the grid pattern and the thickness of CNT films. The optical transmittance of CNT-based hybrid films is 92.2% and sheet resistance is also reduced to $168{\Omega}/square$. These substrates were used for the fabrication of typical twisted nematic (TN) LCD cells. From the characteristics of LCD devices such as transmittance, operating voltage, voltage holding ratio our devices were comparable to those of pristine ITO substrates. The result shows that the hybrid conductive films based on carbon nanomaterials could be alternative of ITO for the highly transparent LCDs.

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다결정 실리콘 박막 위에 P이온 샤워 도핑 후 열처리 방법에 따르는 도펀트 활성화 및 결함 회복에 관한 효과 (The Effect of Annealing Methods on Dopant Activation and Damage Recovery of Phosphorous ion Shower Doped Poly-Si)

  • 김동민;노재상;이기용
    • 전기화학회지
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    • 제8권1호
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    • pp.24-31
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    • 2005
  • Ion-Shower-Doping장비 및 $PH_/3M_2$혼합 가스를 사용하여 Phosphorous를 ELA방법으로 제조된 Poly-Si에 가속 전압 및 조사량을 변수로 이온 주입하였다. As-implanted된 시편의 결정도는 UV-transmittance spectroscopy를 사용하여 측정하였다. 이 때 UV-transmittance를 이용하여 측정한 값은 Raman spectroscopy를 이용해서 측정한 값과 서로 관련되어 있음을 알았다. 면 저항은 가속전압이 1kV에서 15kV까지 증가함에 따라 감소한다 그러나 가혹한 도핑조건하에서는 가속전압의 증가 시 면 저항이 증가한다. 이는 활성화 열처리 후 치유되지 않은 결함에 의해 전자가 포획되며 이에 따라 전하 운반자의 농도가 감소하는 때문이다. 활성화 열처리는 로열처리, RTA 열처리, ELA 열처리 등의 방법으로 수행하였고 열처리 방법에 따르는 도펀트의 활성화 및 결함의 회복의 거동을 연구하였다

Poly[N-(phenyl)maleimide]계 광폴리머를 이용한 액정배향효과 (Effects of Liquid Crystal Alignment on the Photopolymer based Poly[N-(phenyl)maleimide])

  • 황정연;서대식;김준영;이재호;김태호
    • 한국전기전자재료학회논문지
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    • 제14권10호
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    • pp.845-849
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    • 2001
  • The new phto-alignment material PMI5CA, poly{N-(phenyl)maleimide-co-3-[4-(pentyloxy) cinamate]porpyl-2-hydroxy-1-methacrylate}, was synthesized and the electro-optical (EO)characteristics in the vertical-aligned(VA) liquid crystal display (LCD) photo-aligned on the photopolymer surface were studied. Excellent Voltage-transmittance(V-T) characteristics in the VA-LCD photoaligned with polarized UV exposure of oblique direction on the pohotopolymer surface for 1 min can be achieve. The transmittance of the VA-LCD photoaligned on the photopolymer surface decreased with increasing UV exposure time. We suggest that decrease of transmittance in the VA-LCD photoaligned on the photopolymer surface is attributed to the dissociation of the ester linkage in the photodimerized cinnamate structure with increasing UV exposure time.

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