• Title, Summary, Keyword: Wide angle lens

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The Research of the 2nd Lens Design for Wide Angle Distribution (광 확산용 2차 렌즈 설계 기술 연구)

  • Joo, Won-Don;Oh, Sang-Hyeon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.6
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    • pp.1-7
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    • 2012
  • Recently an optical diffusion of LED lamps has been studied actively. In this paper, the second lens applied to a cover of the LED lamp was analytically designed to having a wide angle distribution of light without diffuser characteristic by dispersing agent. In this process, We found a major factors that can help improve the performance of the lens. It is the refractive power of the lens, the Mie particle density of phosphor, and the arrangement of the LED. Through the final simulation, we can see the LED lamp is possible to get wide angle light distribution by proper source modeling and second lens designing. Also, we can see this simulated results are entirely consistent with measured data for light distribution. In this research, we present the shape of the second lens with wide angle distribution and derive the important factors for the second lens design.

The Research for the Wide-Angle Lens Distortion Correction by Photogrammetry Techniques (사진측량 기법을 사용한 광각렌즈 왜곡보정에 관한 연구)

  • Kang, Jin-A;Park, Jae-Min;Kim, Byung-Guk
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.2
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    • pp.103-110
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    • 2008
  • General lens, widely using in Photogrammetry, has narrow view, and have to adjust "Image-Registration Method" after obtain images and it need cost; economic, period of time. Recent days, there is various study that use wide-angle lens, usually for robotics field, put to practical use in photogrammetry instead of general lens. In this studies, distortion tendency of wide-angle lens and utilize the correction techniques suitable to wide-angle lens by the existing photographic survey methods. After carrying out the calibration of the wide-angle lens, we calculated the correction parameters, and then developed the method that convert the original image-point to new image-point correcting distortion. For authorization the developed algorithm, we had inspection about shape and position; there are approximately 2D RMSE of 3 pixel, cx = 2, and cy = 3 different.

Design of Off-axis Wide Angle Lens for the Automobile Application

  • Kim, Tae Young;Shin, Min-Ho;Kim, Young-Joo
    • Journal of the Optical Society of Korea
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    • v.17 no.4
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    • pp.336-343
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    • 2013
  • Recently various types of driver assistance systems have been used for automobiles. In 2008, the U.S Congress passed a law which required that most cars be equipped with devices to warn objects behind the vehicle. Because of that, market of rear view cameras is expected to rise dramatically. Therefore many suppliers try to provide a wide angle camera for car makers. But a high distortion is caused by the wide angle might result in lower image quality. In order to improve the image quality, normally we use an algorithm to correct a distortion. Though we can improve the distorted image by correction algorithm, we must pay more cost to use it. In this paper, we propose a new optical system reducing a distortion in contrast to a conventional lens without cost. In other words, we can see only an area of interest. That is similar to reducing a field of view. Using a new optical system, we can get a less distorted image. In order to view an area of interest, we introduce an off axis optical system having refractive surfaces and reflective surfaces. In this paper, we describe the results of design and, evaluation of an off axis wide angle compact imaging system. In comparison to conventional wide angle lens, we can get the improvement of MTF, distortion, and lateral color aberrations. And we also can reduce a total cost because we don't need the outer apparatus or bracket to mount on the car.

3D Visualization of Partially Occluded Objects Using Axially Distributed Image Sensing With a Wide-Angle Lens

  • Kim, Nam-Woo;Hong, Seok-Min;Lee, Hoon Jae;Lee, Byung-Gook;Lee, Joon-Jae
    • Journal of the Optical Society of Korea
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    • v.18 no.5
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    • pp.517-522
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    • 2014
  • In this paper we propose an axially distributed image-sensing method with a wide-angle lens to capture the wide-area scene of 3D objects. A lot of parallax information can be collected by translating the wide-angle camera along the optical axis. The recorded wide-area elemental images are calibrated using compensation of radial distortion. With these images we generate volumetric slice images using a computational reconstruction algorithm based on ray back-projection. To show the feasibility of the proposed method, we performed optical experiments for visualization of a partially occluded 3D object.

Distortion Calibration and Image Analysis of Megapixel Ultrawide-angle Lens (메가픽셀급 초광각 렌즈의 왜곡영상 보정과 화질분석)

  • Kang, Min-Goo;Lee, Jae-Son;Lee, Ou-Seob
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.3
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    • pp.597-602
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    • 2013
  • In this paper, the lens module of mega pixel type was designed for barrel distortion calibration due to the barrel distortion of ultra wide angle. And the performance of this camera module was improved with the images from wide dynamic range 2 megapixel CMOS image sensor.

Fisheye Lens for Image Processing Applications

  • Kweon, Gyeong-Il;Choi, Young-Ho;Laikin, Milton
    • Journal of the Optical Society of Korea
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    • v.12 no.2
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    • pp.79-87
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    • 2008
  • We have developed a miniature fisheye lens with $190^{\circ}$ field of view operating simultaneously in the visible and the near infrared wavelengths. The modulation transfer function characteristic for the visible wavelength is sufficient for a mega-pixel-grade image sensor. The lens also has a fair resolution in the infrared wavelength region. The calibrated $f-{\theta}$ distortion is less than 5%, and the relative illumination is over 90%. In consequence, a sharp wide-angle image can be obtained which is uniform in brightness over the entire range of field angles. The real image heights for the visible and the near infrared wavelengths have been fitted to polynomial functions of incidence angle with sub-pixel accuracies. Combined with the near equidistance projection scheme of the lens, this lens can be advantageously employed in various image-processing applications requiring a wide-angle lens.

Wide Viewing Angle Screen Design of High Definition LCD Projection System

  • Na, Man-Ho;Moon, Hee-Jong;Lee, Han-Bae;Park, Man-Hyo;Park, Myung-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.161-162
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    • 2000
  • We propose multi-layer aspheric lenticular lens for rear projection screen to provide wide viewing angle. Each pitch of lenticular lens sheet is divided by three region and image light from projection optical system is propagated widely on each region due to different focal point. Besides, to improve vertical viewing angle of screen, we propose glass bead embedded screen on observer side of lenticular lens.

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Design of High-resolution Wide-angle Lenz Module, and Image Distortion Compensation for Smart NUX (스마트 NUX용 고해상도 광각렌즈모듈 및 영상왜곡보정 설계)

  • Lee, Jae-Gon;Kang, Min-Goo;Kim, Won-Kyu;Lee, Kyung-Taek
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.5
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    • pp.999-1004
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    • 2012
  • In this paper, camera modules and lens's images were analyzed for the compensation of distortion image by wide angle lens based WDR(Wide Dynamic Range) with high resolution sensor(2-Mega CMOS Image sensor). Due to wide angle ($176^{\circ}$) of designed wide angle camera modules, the compensation result of distorted image was analyzed, and the application of these modules was proposed for smart NUX(Natural User eXprience).

Neural network based distortion correction of wide angle lens (신경회로망을 이용한 광각렌즈의 왜곡보정)

  • 정규원
    • 제어로봇시스템학회:학술대회논문집
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    • pp.299-301
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    • 1996
  • Since a standard lens has small sight angle, a fish-eye lens can be used in order to obtain wide sight angle for the robot vision system. In spite of the advantage, the image through the lens has variable resolution; the central information of the lens is of high resolution, but the peripheral information is of low resolution. Owing to this difference of resolution, the variable resolution image should be transformed to a uniform resolution image in order to determine the positions of the objects in the image. In this work, the correction method for the distorted image is presented and the performance is analyzed. Furthermore, the camera with a fish eye lens can be used to determine the real world coordinates. The performance is shown through experiments.

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A Compact Rotman Lens with Wide Angle Steering Characteristics (광각 빔조향 특성을 갖는 소형 로트만 렌즈)

  • 이광일;김인선;오승엽
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.5
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    • pp.500-506
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    • 2002
  • This paper presents a design of wide angle steering microstrip Rotman lens operating over broadband frequency range for Electronic Warfare equipments. It has a compact and simple structure which it is easy to manufacture repetitively. The lens is modelled as a 2-dimension planar circuit, the contour integral method is performed over entire lens contour and the transmission coefficients from 8 beam ports to 8 array ports are found. The measured results are well agreed with those of analysis. Prediction of the multibeam array pattern fed by linear array antenna shows $\pm$65$^{\circ}$ of beam steering and $\pm$5 dB insertion loss deviation over 3:1 frequency range.