• 제목/요약/키워드: monochromatic incident light

검색결과 12건 처리시간 0.02초

Dichromatic 투사광선에 따른 나노 미터 해상도의 점접촉 유막 두께 측정 연구 (Study on the Measurement Technology of Fluid Film Thickness with Nanometer Scale by Dichromatic Incident Light)

  • 공현상;장시열
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.686-689
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    • 2003
  • Many technologies are applied to the measurement of elastohydrodynamic lubrication (EHL) film thickness. In particular, optical in-situ interferometric method has many advantages in making the actual contact behaviors realized with the experimental apparatus. Careful selection of incident lights greatly enhances the fringe resolution up to nanometer scale by using image processing technology. In this work, it is found that dichromatic incident light can provide much finer resolution of EHL film thickness than monochromatic incident light, because it has much more variables of color components to be discriminated among the wavelengths of colors according the variations of EHL film thickness. Some simulated interferometric images are shown how the film thickness is resolutionized in nanometer scale

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Monochromatic Image Analysis of Elastohydrodynamic Lubrication Film Thickness by Fringe Intensity Computation

  • Jang, Siyoul
    • Journal of Mechanical Science and Technology
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    • 제17권11호
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    • pp.1704-1713
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    • 2003
  • Point contact film thickness in elastohydrodynamic lubrication (EHL) is analyzed by image processing method for the images from an optical interferometer with monochromatic incident light. Interference between the reflected lights both on half mirror Cr coating of glass disk and on super finished ball makes circular fringes depending on the contact conditions such as sliding velocity, applied load, viscosity-pressure characteristics and viscosity of lubricant under ambient pressure. In this situation the film thickness is regarded as the difference of optical paths between those reflected lights, which make dark and bright fringes with monochromatic incident light. The film thickness is computed by numbering the dark and bright fringe orders and the intensity (gray scale image) in each fringe regime is mapped to the corresponding film thickness. In this work, we developed a measuring technique for EHL film thickness by dividing the image patterns into two typical types under the condition of monochromatic incident light. During the image processing, the captured image is converted into digitally formatted data over the contact area without any loss of the image information of interferogram and it is also interpreted with consistency regardless of the observer's experimental experience. It is expected that the developed image processing method will provide a valuable basis to develop the image processing technique for color fringes, which is generally used for the measurement of relatively thin films in higher resolution.

점접촉 탄성 유체 윤활에서의 띠 무의 강도에 의한 유막 두께 측정 (Measurement of Film Thickness by Fringe Intensity Analysis in Point Contact Elastohydrodynamic Lubrication)

  • 장시열;최언진
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1999년도 제30회 추계학술대회
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    • pp.103-113
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    • 1999
  • Point contact film thickness in elastohydrodynamic lubrication (EHL) is analyzed by the image processing method for the monochromatic incident light. Interference between the reflected lights both on Cr coating of glass disk and on super finished ball makes circular fringes, which are regarded as film thickness together with numbering of fringe order. In this study, we developed technology to measure the film thickness by analyzing dark and bright intensity waves which results from monochrome green light. Two typical fringe patterns only with intensity values 3re examined for the measurement of point contact EHL film thickness. We expect that this technology will give valuable clue to improve color image processing analysis for high resolution of EHL film thickness with white incident light.

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탄성 유체 윤활에서의 유막 두께 측정에 관한 정성적 분석 (Qualitative Analysis of Film Thickness in Elastohydrodynamic Lubrication)

  • 최언진;장시열
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1999년도 제29회 춘계학술대회
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    • pp.147-155
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    • 1999
  • The film thickness and shape of elastohydrodynamic lubrication is measured by optical interferometer, which is the most precise method for EHL film measurement. However the interpretation of the image pattern from optical viscometer is not easy for two-dimensional shape. A newly developed method of image processing makes it possible to evaluate the film thickness and shape in every point of contact region with two dimensional aspects. In this study, we captured film shape of EHL film from the monochromatic incident light with the Image processing method, which uses phase shift method, and obtained the image analysis method for gray level image in order to qualitatively evaluate film shapes.

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탄성 유체 윤활에서의 유막 두께 측정에 관한 정성적 분석 (Qualitative Analysis of Film Thickness in Elastohydrodynamic Lubrication)

  • 최언진;박경근;장시열
    • Tribology and Lubricants
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    • 제16권5호
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    • pp.317-323
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    • 2000
  • The film thickness and shape of elastohydrodynamic lubrication is measured by optical interferometer, which is the most precise method for EHL film measurement. However, the interpretation of the image pattern from optical viscometer is not simple for two-dimensional shape. A newly developed method of image processing makes it possible to evaluate the film thickness and shape in every point of contact region with two dimensional aspects. In this study, we captured the film shape of EHL film by the monochromatic incident light and analyzed the film thickness with the image processing method, which uses phase shift method. From the values of intensity in fringes, the qualitative feature of film thickness in the contact area are obtained by using Zernike polynomial

광학활성 동축 이중 원통을 수직하게 비추는 단색 빛의 산란 : II. 수치 계산 결과 (Scattering of a Normally Incident Monochromatic Light by Optically Active Concentric Double Cylinders: II. Numerical Result)

  • 김현우;김진승
    • 한국광학회지
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    • 제20권6호
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    • pp.375-380
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    • 2009
  • 광학활성 동축 이중층 원통에 수직 입사하는 전자기 파동의 산란을 수치 계산 법을 써서 살펴 보았다. 앞의 논문에서 얻은 해석적인 해를 바탕으로 수치계산 프로그램을 개발했고, 산란광의 밝기와 편광 상태의 각도에 따른 분포를 몇 가지 예에 대해서 계산하였다. 이러한 수치계산 프로그램은 산란광의 밝기와 편광상태의 각분포를 재어 원통의 크기, 구조, 조성을 비파괴적으로 정확히 결정하는데 쓸 수 있다.

광학활성 동축 이중 원통을 수직하게 비추는 단색 빛의 산란 : I. 해석적 이론 (Scattering of a Normally Incident Monochromatic Light by Optically Active Concentric Double Cylinders: I. Analytic Theory)

  • 김현우;김진승
    • 한국광학회지
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    • 제20권6호
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    • pp.366-374
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    • 2009
  • 광학활성 동축 이중 원통의 산란 문제에 대한 해석적인 해를 구하였다. 얻은 해의 타당성을 점검하고자 해를 이미 알고 있는 특수한 경우와 비교하였다. 이 해는 둥근 막대모양의 생물 세포를 광학적으로 분석하는데 쓸 수 있는데, 세포핵에는 나선형으로 꼬인 염색체가 들어 있으므로 광학활성이 있을 수 있다.

Subjective appraisal of the appearance on monochromatic light differenced by the eyeball's pigment

  • Muraoka, Tetsuya;Ikeda, Hiroaki
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.1009-1013
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    • 1990
  • In the Orient, most references are made on the visual perception of the eye having the blue iris, even in the case where the reference should be made on the perception by the eye having the dark iris. In order to clarify the difference in the visual perceptions of a monochromatic light, an objective boundary wavelength between hues incident on the dark eyes was obtained and the correlation between the valuesalready reported as having been obtained with the blue eyes was examined. A significant difference was found in the subjective boundary wavelengths of hues depending on the difference in the visual sensitivity distribution on the dark and blue eyes.

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Multi-spectral Mueller Matrix Imaging for Wheat Stripe Rust

  • Yang Feng;Tianyu He;Wenyi Ren;Dan Wu;Rui Zhang;Yingge Xie
    • Current Optics and Photonics
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    • 제8권2호
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    • pp.192-200
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    • 2024
  • Wheat stripe rust, caused by Puccinia striiformis, has reduced winter wheat yield globally for ages. In this work, multi-spectral Mueller matrix imaging with 37 measurements using the method of double rotatable quarter-wave plates was used to investigate wheat stripe rust. Individual Mueller matrix measurements were performed on incident monochromatic light with nine bands in the range of 430 to 690 nm. As a result, it was found that the infected area absorbed linearly polarized light and was sensitive to circularly polarized light in the spectral domain. Both linear depolarization and linear diattenuation images distinguished between wheat stripe rust and healthy tissue. The responsiveness of stripe rust to polarized light reveals the potential of using polarization imaging to detect plant diseases. This further suggests that the multi-spectral Mueller matrix imaging system provides us with an alternative approach to agricultural disease detection.

Design and Fabrication of an Off-axis Elliptical Zone Plate in Visible Light

  • Anh, Nguyen Nu Hoang;Rhee, Hyug-Gyo;Kang, Pilseong;Ghim, Young-Sik
    • Current Optics and Photonics
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    • 제6권1호
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    • pp.44-50
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    • 2022
  • An off-axis zone plate is able to focus on a single order while neglecting the zeroth order in a visible imaging system. This allows one to enhance the contrast quality in diffractive images, which is the major advantage of this type of zone plate. However, most previous reflection zone plates are used in focusing X-rays with a small grazing incident angle and are intricately designed with the use of a local grating period. In this study, we suggest the design of an off-axis elliptical zone plate (EZP) that is used to focus a monochromatic light beam with separation between the first and unfocused orders under a large grazing incident angle of 45°. An assumption using the total grating period, which depends on the average and constant grating period, is proposed to calculate the desired distance between the first and zeroth order and to simplify the construction of a novel model off-center EZP. Four diffractive optical elements (DOEs) with different parameters were subsequently fabricated by direct laser lithography and then verified using a performance evaluation system to compare the results from the assumption with the experimental results.