• Title/Summary/Keyword: degree of alignment

Search Result 194, Processing Time 0.022 seconds

A Study on Alignment of Nematic Liquid Crystal by Using Slanted Non-polarized Ultraviolet Light Irradiation on Polyimide Film (폴리이미드막표면위에 경사진 자외선 조사를 이용한 네마틱 액정의 배향에 관한 연구)

  • 서대식;황율연;이보호
    • Electrical & Electronic Materials
    • /
    • v.10 no.5
    • /
    • pp.461-466
    • /
    • 1997
  • In this paper, we developed the new non-rubbing liquid crystal (LC) alignment techniques in the cell with slanted non-polarized ultraviolet (UV) light irradiation on polyimide (PI) film. It is shown that the uniform alignment for nematic (N) LC is obtained by using slanted non-polarized UV light irradiation on PI surface. We successfully obtained that the pretilt angle of NLC is generated about 3.3 degree in the cell with slanted non-polarized UV light irradiation with 70 degree on PI surface, for the first time. It is considered that the pretilt angle generation in NLC is attributed to interaction between the LC molecular and the PI, which is broken the polymer by slanted non-polarized UV irradiation. Therefore, we concluded that the uniform LC alignment is attributed to anisotropic dispersion force due to photo depolymerization with slanted non-polarized UV light irradiation on PI surface.

  • PDF

Development of an Optical Alignment Control Module with High Speed and Accuracy for Optics-Based Products (광학제품을 위한 고속.고정밀 광정렬 제어 모듈 개발)

  • Kim Seung-Chul;Kim Gyung-Bum
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.23 no.5 s.182
    • /
    • pp.103-110
    • /
    • 2006
  • Automatic optical alignment modules are a key technology in optical communication system. However, the optic component assembly depends highly on manual or semi-automated alignment process. In this paper, a novel alignment mechanism with minimum degree-of-freedom has been designed and theoretical models are derived from geometric optical characteristics on collimators, optical filters and optical ray alignment. The automatic alignment control algorithm has been newly developed based on the mechanism and models, and then we make fast, precise and reliable alignment through the algorithm. The reliability of developed modules has been verified with various simulations and performance evaluations.

Effect of Polyimide on the Liquid Crystal Alignment for the Photo-Alignment Layers of Coumarin based Photopolymer/Polyimide Blends

  • Sung, Shi-Joon;Cho, Ki-Yun;Park, Jung-Ki
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2002.08a
    • /
    • pp.1083-1084
    • /
    • 2002
  • We prepared the blend alignment layers made from coumarin based photopolymer and polyimides for liquid crystal(LC) alignment using linearly polarized ultraviolet(UV) exposure. The alignment properties of LC were found to depend on the type of polyimide in the blend alignment layers. The degree of photereaction of polyimide was important factor for LC alignment direction on the blend alignment layers.

  • PDF

The liquid crystal alignment effect of in-cell retarder using homogeneous alignment layer (수평 배향막을 이용한 내장형 위상지연 박막의 액정 배향 효과)

  • Choi, Min-Oh;Lim, Young-Jin;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2005.07a
    • /
    • pp.449-450
    • /
    • 2005
  • Alignment characteristic of liquid crystal (LC) on in-cell retarder which is composed of reactive mesogens has been tested. The in-cell retarder which is polymerized on top of the homogeneous alignment layer (AL) has an optic axis along the rubbing direction of the homeogenous AL and does show good alignment effect of the LC without showing any defects, which possibly allows a skip of another AL on the in-cell retarder that was required conventionally to control alignment of the LC. However, the measured pretilt angle is only 0.04 degree so that disclination lines are generated for a cell that uses the in-cell retarder as an AL when the LC is tilted upward by a vertical electric field.

  • PDF

A Wafer Pre-Alignment System Using a High-Order Polynomial Transformation Based Camera Calibration (고차 다항식 변환 기반 카메라 캘리브레이션을 이용한 웨이퍼 Pre-Alignment 시스템)

  • Lee, Nam-Hee;Cho, Tai-Hoon
    • Journal of the Semiconductor & Display Technology
    • /
    • v.9 no.1
    • /
    • pp.11-16
    • /
    • 2010
  • Wafer Pre-Alignment is to find the center and the orientation of a wafer and to move the wafer to the desired position and orientation. In this paper, an area camera based pre-aligning method is presented that captures 8 wafer images regularly during 360 degrees rotation. From the images, wafer edge positions are extracted and used to estimate the wafer's center and orientation using least squares circle fitting. These data are utilized for the proper alignment of the wafer. For accurate alignments, camera calibration methods using high order polynomials are used for converting pixel coordinates into real-world coordinates. A complete pre-alignment system was constructed using mechanical and optical components and tested. Experimental results show that alignment of wafer center and orientation can be done with the standard deviation of 0.002 mm and 0.028 degree, respectively.

The Effects of MAIS Strategic Alignment on Production Performance: The Consideration of AMT (생산기술 첨단화에 따른 관리회계정보시스템 전략적 연계가 생산성과에 미치는 영향)

  • Choe, Jong-Min
    • The Journal of Information Systems
    • /
    • v.26 no.2
    • /
    • pp.25-42
    • /
    • 2017
  • Purpose This study empirically examined the causal relationships among the level of advanced manufacturing technology(AMT), facilitation of alignment, the degrees of strategic alignment of management accounting information systems(MAIS), and the improvement of production performance. Design/methodology/approach Data for this study were drawn from a survey of the current status of AMT used in Korean manufacturing firms. At the beginning, 131 organizations responded to the request for information. However, during the survey, 5 firms withdrew from the survey, and as a result, 126 manufacturing firms were included in the research. In order to collect data, this study administered questionnaires with the participating firms. The survey was conducted during a 4-month period between November 2015 and March 2016. Findings The results showed that the level of AMT has a significant impact on alignment facilitation. A significant causal relationship between alignment facilitation and MAIS strategic alignment was also found. It was shown that under high degrees of MAIS strategic alignment, MAIS must provide broad-scope and integrated types of information. The causal relationships between MAIS strategic alignment and organizational performance were significant and positive. Thus, it is concluded that under high levels of AMT, a high degree of MAIS strategic alignment positively contributes to the improvement of a firm's production performance.

Generation of high pretilt angle in nematic liquid crystal by using photo-alignment techniques on polyimide surfaces (광배향 기술을 이용한 액정의 고프리틸트각 발생)

  • 한정민;황율연;이창훈;서대식
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1997.11a
    • /
    • pp.198-201
    • /
    • 1997
  • We investigated the generation of pretilt angle for nematic liquid crystal (NLC) in a cell with slanted non-polarized ultraviolet (UV) light irradiation on mixtured polyimide (PI) surfaces. It was found that the monodomain alignment of NLC is obtained in a cell with an angle of incidence of 75∼85 degrees on PI surface. We consider that the monodomain alignment of NLC is attributed to anisotropic dispersion force effect due to photo-depolymerization of polymer on Pl surfaces. We successfully observed that the pretilt angle of NLC is generated above 5 degree with an angle of incidence of 75∼85 degree. It is considered that the pretilt angle generation in NLC is attributed to interaction between the LC molecules and the Polymer surfaces.

  • PDF

A Study on the How IT Governance Decision Making Knowledge Sharing between CEO and CIO Influences the Effectiveness of the Information Systems (IT 거버넌스 의사결정 영역에 대한 CEO와 CIO의 지식공유 정도가 정보시스템 효과성에 미치는 영향에 관한 연구)

  • Kim, Min-Sun;Hong, Shin-Hye;Lee, Jae-Bum
    • The Journal of Information Systems
    • /
    • v.17 no.4
    • /
    • pp.129-156
    • /
    • 2008
  • This study empirically tested a research model and hypothesis extracted and based on IT governance and knowledge sharing theories. In this study we targeted CIO and IS managers to find the effects of the degree of knowledge sharing between CEO and CIO regarding five areas of IT governance decision-making: IT principles, IT architecture, IT infrastructure, business application needs, and IT investment and prioritization, on IT and business alignment. Additionally we studied the effects of business alignment on the effectiveness of information systems. Results showed that the degree of knowledge sharing in CEO and CIO on IT principles, IT infrastructure, IT investment and prioritization had a positive influence on IT and business alignment, ultimately showing a positive influence on the effectiveness of information systems. This research has shown that fording the preferable relationship between IT and business affected by performing high quality decision making based on knowledge sharing and consequently it also is a basis to provide a positive influence to the effectiveness of the information system.

Tracing the evolution of massive galaxies; Alignment of elliptical galaxies in the Virgo cluster

  • Kim, Suk;Jeong, Hyunjin;Lee, Jaehyun;Lee, Youngdae;Joo, Seok-joo;kim, Hak-Sub;Rey, Soo-Chang
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.42 no.2
    • /
    • pp.47.1-47.1
    • /
    • 2017
  • We study the alignment of kinematic position angles (PAkin) of early-type galaxies in the Virgo cluster using Atlas3D data. The PAkin represent the direction of the angular momentum of the galaxies better than the photometric position angles. Therefore, the alignment of their PA$_{kin}$ is a useful tool to trace the momentum direction. The early-type galaxies in the Virgo cluster have been known to be distributed as filamentary structures inside the cluster. We found that their PAkin are aligned to two directions of 20degree and -80degree. This fact is confirmed using the bootstrap test, and that is, the two alignment angles are statistically significant. Besides, these two angles are surprisingly aligned parallel to the filamentary structures inside the cluster. These results suggest that early-type galaxies were formed by major merging in the filament structures and then fall into the Virgo cluster while maintaining their position angles.

  • PDF

Investigation of High Pretilt Angle Generation in Nematic Liquid Crtstal by Using Transcription alignment Techniques (전사배향기술을 이용한 네마틱액정의 고프리틸트각 발생에 관한 연구)

  • Seo, Dae-Shik;Han, Jeong-Min;Kim, Jin-Ho;Lee, Bo-Ho
    • Proceedings of the KIEE Conference
    • /
    • 1997.07d
    • /
    • pp.1582-1584
    • /
    • 1997
  • We investigated the transcription of liquid crystal (LC) alignment method by using memory effect of nematic (N) LC on polyimide (PI) surface with side chain as for non-rubbing alignment techniques. That the monodomain alignment of aligned NLC is observed by polarizing microscope textures in the cells on PI surface with side chain, We obtained that the pretilt angle of NLC are generated about 3.7 degree on PI surface. We suggest that the LC alignment by using transcription aligngnment method is attributed to memory effect of NLC on PI surface.

  • PDF