• 제목/요약/키워드: Electro-Optical

검색결과 1,068건 처리시간 0.035초

폴리머 분산 액정의 전기 광학적 스위칭 특성에 대한 액정방울 크기의 효과 (Effect of droplet size on electro-optical switching properties of polymer dispersed liquid crystals)

  • 김인태;유연석
    • 한국광학회지
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    • 제17권1호
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    • pp.23-30
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    • 2006
  • 폴리머 분산 액정의 전기광학 스위칭 특성에 대한 액정 방울 크기의 효과를 실험적으로 연구하였다. 액정 방울의 크기는 상 분리를 위해 조사하는 레이저 광원의 세기와 LC/oligomer의 혼합 비율에 따라 변화되었다. 전기 광학적 스위칭 전압은 LC/oligomer의 혼합비율과 액정의 방울 크기에 크게 의존하였다. 실험 결과를 보면 상 분리용 조사 레이저광의 세기가 클 때 액정방울의 크기는 작아졌고 포화투과도 전압은 상승했지만 rise time은 짧아 졌다.

Electro-hydrodynamic 프로세스를 이용한 PMMA 마이크로 비드 제조방법에 대한 연구 (Research for fabricating micro-size PMMA beads using Electro-hydrodynamic process)

  • 박종하;이준희;김완두
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1509-1514
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    • 2008
  • To fabricate microsized poly(methyl methacrylate)(PMMA) beads of uniform size and density on poly(ethylene terephthalate) (PET) fis, we introduce an electro spraying technique that uses a target electrode applied with an ac electric fid. Using the apparatus and various material properties, we could obtain uniform size PMMA beads which were deposited on the thin PET film. The optical properties, transmittance and light diffusivity of the fis electro sprayed with the PMMA were characterized. The results show that the sprayed beads appear to act as a good optical diffuser, like microlenses. To understand the effect of process variables, applied field conditions and rheological properties, the morphological pictures of the deposited particles were investigated through the optical and scanning electron microscope.

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LED 패키지를 위한 사각 형상의 마이크로 렌즈 (Rectangular Microlens array for Multi Chip LED Packaing)

  • 임창현;정원규;최석문;오용수
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 추계학술대회 논문집
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    • pp.882-884
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    • 2005
  • A new rectangular shape microlens array having high sag for solid-state lighting is presented. Proposed microlens, which has high sag, over $375{\mu}m$ and large diameter, over 3 mm can enormously enhance output optical extraction efficiency. Rectangular shape of microlens can maximize the fill factor of light-emitting-diode (LED) package and minimize the optical loss at the same time. This wafer level microlens array is fabricated on LED package. It has many advantages in optical properties, low cost, high aligning accuracy, and mass production.

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Design and Analysis of Color Separation Grating by Using Fresnel Diffraction Theory

  • Chen, Chien-Hung;Lin, Hoang-Yan
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1505-1509
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    • 2006
  • We use the color separation grating (CSG) to split colored light into the sub-pixel of LCD to enhance the optical efficiency as compared with that of using color filter. Based on the Fresenl diffraction theory, the theoretical optical efficiency can reach 66-81%, ranging almost from 2 to 2.5 times of that using color filters.

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Macroscopic Nonlinear Optical Properties of Tricyanopyrrolidene Chromophore Containing Amorphous Polycarbonate: Effect of Molecular Lateral Moiety in the Conjugative Structure

  • Cho, Min-Ju;Lee, Sang-Kyu;Jin, Jung-Il;Choi, Dong-Hoon
    • Macromolecular Research
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    • 제14권6호
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    • pp.603-609
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    • 2006
  • Tricyanopyrrolidene chromophores were prepared in order to compare their macroscopic nonlinear optical (NLO) properties with a conjugated structure through the long molecular axis. A thiophene or phenyl ring was tethered to an ethylenic bond; it may act as a lateral moiety to disrupt the planarity of a chromophore and lessen the electrostatic interaction. Thin film composites of these chromophores dissolved in amorphous polycarbonate (APC) were fabricated. Real time pole and probe method was employed to investigate the change of electro-optic (EO) signal during poling. The EO properties and their relaxation behaviors of the guest-host systems containing newly synthesized chromophores were investigated in detail.

Analysis and Test results for the EOS(Electro Optical Subsystem) geometric mapping of the KOMPSAT2 Telescope

  • Jung Dae-Jun;Jang Hong-Sul;Lee Seung-Hoon
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.489-492
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    • 2005
  • As a former level of MSC(Multi Spectral Camera) telescope of the KOMPSA T2satellite, the several performance tests of EOS(Electro Optical Subsystem) were performed in the EOS level. By these tests, not only the design requirement of payload can be verified but also the test result can be the important criterion to estimate the performance of payload in the launch and space orbit environment. The EOS Geometric Mapping test is to verify the accuracy of the alignment & assembly on the Subsystem of the MSC by measurement like these; LOS(Line of Sight), LOD(Line of Detector), Band to Band Registration, Optical Distortion and Reference Cube. This paper describes the test results and the analysis for the EOS Geometric Mapping.

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도프형 유기 EL 소자의 전기-광 변환소자 응용 (Application to the Electro-Optical Conversion Device of OLEDs)

  • 김주승;민용기;구할본
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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    • pp.114-118
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    • 2006
  • We investigated the transient electroluminescence (EL) and modulation characteristics of red organic light-emitting diodes (OLEDs), which consist with 4-(dicyanomethylene)-2-i -propyl-6-(1,1,7,7-tetramethyljulolidyl-9-cnyl)-4H-pyran (DCJTI) and rubrene doped into tris(8-hydroxyquinoline)aluminum ($Alq_3$). The transient EL waveforms showed two components, the overshooting peak and constant component, indicating that the excess amount of accumulated charges simultaneously recombine at the onset moment. This overshooting effect reduced the rise time of transient EL and enhanced the optical output of OLEDs when the pulse voltage applied to the device. We demonstrated that the red OLEDs could be use for the high-speed switching application by driving at more than 100 MHz and transmitting the video signals utilized as the electro-optical conversion device

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Image Quality Evaluation and Tolerance Analysis for Camera Lenses with Diffractive Element

  • Lee, Sang-Hyuck;Jeong, Ho-Seop;Jin, Young-Su;Song, Seok-Ho;Park, Woo-Je
    • Journal of the Optical Society of Korea
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    • 제10권3호
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    • pp.105-111
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    • 2006
  • A novel image quality evaluation method, which is based on combination of the rigorous grating diffraction theory and the ray-optic method, is proposed. It is applied for design optimization and, tolerance analysis of optical imaging systems implementing diffractive optical elements (DOE). The evaluation method can predict the quality and resolution of the image on the image sensor plane through the optical imaging system. Especially, we can simulate the effect of diffraction efficiencies of DOE in the camera lenses module, which is very effective for predicting different color sense and MTF performance. Using this method, we can effectively determine the fabrication tolerances of diffractive and refractive optical elements such as the variations' in profile thickness, and the shoulder of the DOE, as well as conventional parameters such as decenter and tilt in optical-surface alignments. A DOE-based 2M-resolution camera lens module designed by the optimization process based on the proposed image quality evaluation method shows ${\sim}15%$ MTF improvement compared with a design without such an optimization.

전기장에 의한 Bi12SiO20 단결정의 변화된 광행로길이 계산 (Calculation of Changed Optical Path Length of Bi12SiO20Single Crystal by the Electric Field)

  • 이수대
    • 한국전기전자재료학회논문지
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    • 제18권11호
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    • pp.1048-1055
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    • 2005
  • The formula to calculate a variation of optical path length of single crystal by the electric field was derived by this study. The formula was applied to $Bi_{12}SiO_{20}$ single crystal. The results are as follows. In case of the applied electric field in the body diagonal direction and the passing light along the same direction, the variation of optical path length had the largest value. The symmetry of the space distribution of optical path length satisfied $E3C_2\;8C_3$, the set of elements of the symmetry of $Bi_{12}SiO_{20}$ single crystal. The property which gave the largest influence to the variation of optical path length is the strain of length by the Inverse piezoelectric effect. The second influence, is the variation of the refractive index by the electro-optic effect. The variation of optical path length by the inverse piezoelectric effect and by the electro-optic effect have a reverse sign each other.