• 제목/요약/키워드: reflective liquid crystal

검색결과 113건 처리시간 0.031초

빠른 응답과 높은 대비비의 반사형 LCD를 위한 HAN Cell (Hybrid Liquid Crystal Cell for a Fast-Response High-Contrast Reflective Display)

  • 문성훈;이기동;윤태훈;김재창
    • 한국광학회:학술대회논문집
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    • 한국광학회 2000년도 하계학술발표회
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    • pp.234-235
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    • 2000
  • 최근에 많이 사용되는 휴대용 기기의 표시장치인 액정표시장치(LCD)에는 반사형이 많이 사용되고 있다. 반사형 LCD는 전력소모의 많은 부분을 차지하는 backlight를 주변광원으로 대체하여 전력소모를 줄일 수 있는 표시장치로 많이 연구되고 있다. 특히, 반사형 LCD는 밝기면에서 우수한 single-polarizer mode가 적합하다$^{1.3}$ . 그러나 single-polarizer mode는 two-polarizer mode와 비교해서 dark 상태에서의 누설광이 많이 발생하여 대비비가 저하되는 단점이 있다. 이 점을 보완하기 위하여 전 파장 영역에서 편광판에 의해 반사광이 차단될 수 있도록 설계를 했다. (중략)

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Design and testing large FOV retinal displays on the basis holographic combiner

  • Gan, Mikhail A.;Gan, Iacov M.;Tchertkov, Alexander S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.442-445
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    • 2004
  • We report principles and results of design large FOV retinal display systems by software WinDEMOS and software for computer testing display systems TEDiS. We discuss results design head mounted and head up display. As combiner we are used volume interference recorded or synthetic HOE, and as the sours of the image high resolution transmitting or reflective liquid crystal matrixes on silicon (LCOS) or CRT.

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Optical Configuration of a HAN Cell for Reflective Displays

  • Lee, Seo-Hern;Jang, Mi-Kyoung;Jeong, Jin-Kwan;Han, Kwan-Young;Yoon, Tae-Hoon;Kim, Jae-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.957-960
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    • 2002
  • We propose an optical configuration of a hybrid-aligned nematic liquid crystal cell for reflective displays by which we can achieve wide viewing angle and uniform reflection spectrum.

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고휘도 마이크로 광부품 / 모듈의 신뢰성 분석 시험 (Reliability analysis test of high brightness micro optical component and module)

  • 이낙규;이혜진;최석우;최두선
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.535-536
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    • 2006
  • Researches about micro technology travel lively in these days. Such many researches are concentrated in the field of materials and a process field. But properties of micro materials should be known to give results of research developed into still more. In these various material properties, reliability data such as mechanical, optical, thermal property, etc is the basic property. In this paper, it is measured that is material properties of main BLU(Back Light Unit) components in LCD(Liquid Crystal Display). The pattern shape of prism sheet, diffuser film and reflective plate are measured by variable 3D scanning equipments. It is researched which is the method to measure an optimal 3D pattern shape in each components.

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반사형 쌍안정 TN LC 셀의 설계 및 제작 (Design and Fabrication of a Reflective Bistable TN LCD)

  • 백흠일;장기철;이기동;윤태훈;김재창
    • 한국광학회지
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    • 제10권4호
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    • pp.279-282
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    • 1999
  • 본 논문에서는 LCD의 어두운 상태의 특성을 보완하기 위해 광대역 λ/4 보상판을 사용하여 단일 편광판 모드 반사형 쌍안정 TN LCD를 설계·제작하였다. 단일 편광판 모드에서 광대역 λ/4 보상판의 필요성을 이론적인 계산과 실험을 통해 확인하였고, 시험적ㅇ로 제작한 단일 편광판 모드 반사형 쌍안정 TN LCD는 기존 구조의 반사형 쌍안정 TN LCD와의 비교에서 더욱 밝은 디스플레이 특성을 나타내었다. 본 실험에서 우리는 10:1의 콘트라스트를 얻었다.

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Experimental and Simulation Study of the Optical Performances of a Wide Grid Polarizer as a Luminance Enhancement Film for LCD Backlight Applications

  • Seo, Jae Seok;Yeom, Tae Eun;Ko, Jae-Hyeon
    • Journal of the Optical Society of Korea
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    • 제16권2호
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    • pp.151-156
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    • 2012
  • Reflective polarizers can be used as luminance enhancement films for LCD backlights via the polarization recycling process. The optical performances of a wire grid polarizer (WGP) as a reflective polarizer adopted in edge-lit backlights were investigated by luminance evaluation and a time-domain simulation technique. The results were compared to those of a commercial dielectric multilayer film. The luminance gain factor of WGP was smaller than that of the multilayer film by 18%. This was attributed to a much larger internal loss of WGP due to light absorption by metal wires. The internal losses of both reflective polarizers and the polarization conversion efficiency of the backlight were obtained numerically based on a phenomenological model. The optical performances of WGP were optimized by using a time-domain simulation technique. The luminance gain increased and was found to become comparable to, but slightly less than the case of the dielectric multilayer film with decreasing line width.

Fringe-Field 구동형 반사형 Hybrid Aligned Nematic 액정 디스플레이의 전기-광학 특성 (Electro-Optic Characteristics of the Fringe-Field driven Reflective Hybrid Aligned Nematic Liquid Crystal Display)

  • 정태봉;박지혁;손정석;송제훈;이승희
    • 한국전기전자재료학회논문지
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    • 제17권2호
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    • pp.201-206
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    • 2004
  • We have performed computer simulation and experiment to obtain electro-optic characteristics of reflective hybrid aligned nematic (R-HAN) cell driven by fringe field, in which the cell consists of polarizer, optical compensation film, LC layer and reflector. Conventional R-HAN cell driven by fringe field using only the LC layer shows high wavelength dispersion at dark-state and thus viewing angle characteristic is strongly wavelength-dependent. In order to improve this demerit, we added one optical compensation film to conventional R-HAN cell. The display with optimized cell parameters shows low wavelength dispersion at dark-state and exhibits a wide viewing angle without the occurrence of grey scale inversion over a wide range of viewing angles and the contrast ratio greater than 5 over exists about 120$^{\circ}$ in vortical direction and 160$^{\circ}$in horizontal direction. Experimental results show good agreements with theoretical results and fast response time.

Anti-Reflective coating for External Efficiency of Organic Light Emitting Diode

  • Kim, Byoung-Yong;Han, Jin-Woo;Kim, Jong-Yeon;Han, Jeong-Min;Moon, Hyun-Chan;Park, Kwang-Bum;Seo, Oae-Shik
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.449-449
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    • 2007
  • OLED has many advantages of low voltage operation, self radiation, light weight, thin thickness, wide view angle and fast response time to overcome existing liquid crystal display (LCD)'s weakness. Therefore, It draws attention as promising display and has already developed for manufactured goods. Also, OLED is regarded as a only substitute of flexible display with a thin display. A considerable portion of the light originating film emissive centers buried in a solid film never escapes due to internal reflection at the air-film interface and is scattered as edge emission or dissipated within the solid film This is one of the major reasons why the luminous power efficiency of OLED remains low, in spite of research progress in OLED. Although several ways of overcoming this difficulty have been reported, no comprehensive method has been proposed yet. In this paper, we propose that use of anti-reflective coating layers.

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광경화성 고분자를 이용한 반투과형 액정디스플레이 (Transfelctive Liquid Crystal Display using UV Curable Reactive Mesogen)

  • 임영진;정은;진미형;김진호;김성수;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 춘계학술대회 및 기술 세미나 논문집 디스플레이 광소자
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    • pp.51-52
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    • 2008
  • A single gap transflective liquid crystal display(LCD) driven by fringe electric field in the transmissive(T) region and vertical electric field in the reflective(R) region was designed. Because the pretilt angle is formed in $53^{\circ}$ through polymerization of an UV curable reactive mesogen(RM) monomer at the surface, the effective cell retardation $(d{\Delta}n_{eff})$ value of the R region becomes half of that in the T region where the LCs are homogenously aligned. Consequently, a transflective display driven by a vertical and fringe electric field with a single cell gap and single gamma curves is realized.

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Single cell gap polymer-stabilized blue-phase transflective LCDs using internal nanowire grid polarizer

  • Cui, Hong-Qing;Ye, Zhi-Cheng;Hu, Wei;Lin, Xiao Wen;Chung, T.C.;Jen, Tean-Sen;Lu, Yan-Qing
    • Journal of Information Display
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    • 제12권3호
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    • pp.115-119
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    • 2011
  • Optically isotropic liquid crystal (LC) mixture such as blue-phase LC and nanostructured LC composites exhibit the advantages of fast response time, high contrast ratio and wide-viewing angle due to the induced birefringence along the horizontal electric field. Utilizing this mixture, a novel single cell gap in-plane switching-type polymer-stabilized blue-phase transflective liquid crystal display by embedding the nanowire grid polarizer as a polarization-dependent reflective polarizer in the R region is proposed. This device can be used as a normal black mode without any quarter-wave plate or patterned in-cell phase retarder. Moreover, the transmittance is identical to the reflectance so that it will be suitable for single gamma driving. Detailed electro-optic performances, such as voltage-dependent light efficiency and viewing angle of the proposed device configuration, are investigated.