• Title/Summary/Keyword: alignment

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Development of Multi-axis Nano Positioning Stage for Optical Alignment (광소자 정렬용 극초정밀 다축 위치 제어장치 개발)

  • 정상화;이경형;차경래;김현욱;최석봉;김광호;박준호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.304-307
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    • 2004
  • As optical fiber communication grows, the fiber alignment become the focus of industrial attention. This greatly influence the overall production rates for the opto-electric products. We proposed multi-axis nano positioning stage for optical fiber alignment. This device has 3 DOF translation and sub nanometer resolution. This nano stage consist of 3 PZT-driven flexure stages which are stacked parallel. The displacement of it is measured with capacitance gauge and is controlled by computer-embedded main controller. The design process of flexure stage using FEM is proposed and the performance evaluation of this system is verified with experiments.

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Micro Patterning Using Near-Field Coupled Nano Probe Laser Photo Patterning Of Chloromethylated Polyimide Thin Film (클로로메틸 폴리이미드(CMPI) 박막과 근접장 나노 프로브 레이저 패터닝을 이용한 미세 형상 가공 기술)

  • 최무진;장원석;김재구;조성학;황경현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.369-372
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    • 2004
  • Photo-induced surface alignment is charming as a non-contact photo-patternable alignment technology which can be used in the next generation of displays, such as large area, multi-domain. For decades, many polymer film have been investigated and developed to be used in the photo alignment. Among these photoreactive materials, recently developed polyimide, Chloromethylated Polyimide(CMPI) now became the focus of interests in this area because of its high photosensitivity and superior thermal stability. In this report, we present micro patterning method to form the nanoscale structure by Mask-Less laser patterning using this CMPI film and NSOM probe.

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If the Lower Extremity Alignment is Corrected, Will Osteochondral Lesions of the Talus Improve? (거골 골연골병변: 하지 정렬을 교정하면 거골 골연골병변이 좋아질까?)

  • Kim, Yu Mi;Kim, Kyung Il;Han, Byeol
    • Journal of Korean Foot and Ankle Society
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    • v.24 no.2
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    • pp.42-47
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    • 2020
  • Increased loading in a localized area is a possible cause of pain-related osteochondral lesions of the talus (OLT), but the reported effects of realignment surgery for OLT have been anecdotal. Moreover, no report of realignment surgery for OLT could be found in the English literature. This study reviewed previous articles on lower extremity alignment and OLT to determine if OLT can be treated with realignment surgery.

Precision Measurement for Aircraft Alignment using Industrial Photogrammetry (산업사진측량을 이용한 항공기 얼라인먼트 정밀측정)

  • Jung, Sung-Heuk;Lee, Jae-Kee
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.6
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    • pp.57-63
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    • 2005
  • According to increasing of demand for high accurate and quick measuring technology, they became to interest in industrial photogrammetry that can satisfy with this needs. This study is examined O-2A aircraft to check the application of Industrial Photogrammetry technology. To measure the aircraft alignment, the check points marked on it were used without exact aircraft design data. And to check any deformation of its external original feature, Pro-spot system has been used.

Pretilt Angle Properties of Mixture Nematic Liquid crystal for Mobile Information Device (휴대용 통신단말에 사용되는 혼합액정계에서의 프리틸트각 특성에 관한 연구)

  • Han, Jeongmin;Seo, Daeshik
    • Journal of Satellite, Information and Communications
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    • v.10 no.1
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    • pp.67-70
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    • 2015
  • We studied the state of the dual liquid crystal (LC) alignment which displays both homeotropic and homogeneous alignment on blended polyimide (PI) layer. The research was conducted using rubbing method at different imidizing temperatures and the blended PI was made using homeotropic PI having an alkyl side chain and homogeneous PI without the side chain. The uniform LC alignments were achieved, and have thermal stability. The results of contact angles were similar to that of pretilt angles.

Electro-Optical Characteristics of a-TN-LCD on Photo-alignment Films (광고분자막을 이용한 a-TN-LCD의 전기광학특성)

  • 서대식;박지호;이보호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.120-122
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    • 1997
  • In this paper, the viewing angle characteristics of amorphous (a) - twisted nematic (TN) - liquid crystal display (LCD) on poly(viny)cirmamate (PVC) alignment surfaces were investigated. It was found that the threshold voltage is increased with increasing the polymerization on PVC surfaces. We suggest that the threshold voltage is affected to the surface anchoring strength with increasing the polymerization of the alignment film. Also, we obtained that the viewing angle of a-TN-LCD is increased with increasing the polymerization on PVC surfaces. Finally, we considered that the viewing angle of a-TN-LCD on PVC surfaces is large compared to TN-LCD on rubbed polyimide (Pl) surface.

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

  • 황정연;서대식;김준영;이재호;김태호
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.10
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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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EO Characteristic of the In-plane Driven VA Cells on a Polymer Layer

  • Lee Sang-Keuk;Hwang Jeoung-Yeon;Seo Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.4
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    • pp.7-9
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    • 2003
  • Viewing angle characteristics of a nematic liquid crystal (NLC) using a in-plane driven (IPD) vertical alignment (VA) cell without a negative compensation film on a homeotropic alignment layer were studied. Good voltage-transmittance (V - T) curves were obtained using the rubbing aligned IPD- VA cell. However, instability and low transmittances of V - T characteristics in photo aligned IPD- VA cell was measured. The EO performance of a rubbingaligned IPD- VA cell without a negative compensation film was wider than that of photoaligned IPD- VA cell and conventional VA cell. Also, the fabrication processes using the rubbing aligned IPD- VA cell mode be carried out with only one-sided rubbing.

Electro-optical Characteristics in the Vortical-Alignment 1/4$\pi$ Cell by photoalignment Method (광배향법을 이용한 VA-l/4$\pi$셀의 전기 광학 특성)

  • 이윤건;황정연;서대식;김재형
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.369-372
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    • 2001
  • We studied the electro-optical (EO) performance in the vertical-alignment (VA) - l/4$\pi$ cell photoaligned with polarized UV exposure on a homeotropic photopolymer surfaces. Excellent voltage-transmittance curve in the VA - l/4$\pi$ cell photoaligned with polarized UV exposure for 3 min on the photopolymer containing cholesterol group of 8% can be achieved. The V-T characteristics in the VA-l/4$\pi$ cell photoaligned on the photopolymer surface can be improved by increasing cholesteryl group. For response time measurement, the transmittance characteristics of the VA-l/4$\pi$ cell photoaligned on the photopolymer surface was better than that of the VA-l/4$\pi$ cell rubbingaligned on a polyimide(Pl) surface.

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A study on liquid crystal alignment characteristics by the properties of hydrogenated amorphous carbon thin films (a-C:H 박막의 물성 변화에 따른 액정 배향 특성에 관한 연구)

  • Lee, Dae-Kyu;Rho, Soon-Joon;Baik, Hong-Koo;Hwang, Jeoung-Yeon;Cho, Yong-Min;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.839-844
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    • 2002
  • This letter focuses on the liquid crystal alignment characteristics according to the properties of hydrogenated amorphous carbon(a-C:H) thin film deposited by RPECVD(Remote Plasma Enhanced Chemical Vapor Deposition) method using $C_2H_2$ and He gases. The properties of the deposited thin films were controlled by the ion beam irradiation time and ion beam energy. The results show that not ion beam energy but ion beam irradiation time plays an important role in the properties of a-G:H thin films. As the ion beam irradiation time increases, not only the sp2 concentration in a-G:H thin films but also liquid crystal pretilt angle was varied.

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