• Title/Summary/Keyword: fresnel lens

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Circular Fresnel POF(Plastic Optical Fiber) Daylighting System Performance Evaluation Study (원형 프레넬 집광형 POF 주광 조명시스템 성능 평가 연구)

  • Kang, Eun-Chul;Choi, Yong-Jun;Yoon, Kwang-Sik;Lee, Euy-Joon
    • Journal of the Korean Solar Energy Society
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    • v.31 no.1
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    • pp.31-36
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    • 2011
  • CF(Circular Fresnel) POF(Plastic Optical Fiber) daylighting system is a beam daylighting system utilizing solar direct beam radiation. In this study, a CF POF daylighting system has been introduced, developed and applied to KIER test buildings. The CF POF daylighting system consists of three parts: light collector, light transmitter and light diffuser. The light collector includes a Circular Fresnel lens focusing solar direct illuminance by sun tracking. The light transmitter contains the POF cable which has light transmission loss of 4.5% per meter. The light diffuser has about 80% diffuser efficiency. This study aims to evaluate of POF daylighting system performance. At the results of a CFPOF system performance evaluation, the theoretical CFPOF system efficiency was 41.9% and the actual CFPOF system efficiency at the KIER test building was 37.5%. The difference was due partly to the connecting efficiency.

A study of burr formation on microgrooving for fresnel lens mould (프레넬렌즈 금형용 미세홈 가공에 있어서 버 발생 경향에 관한 연구)

  • 임한석;안중환
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.3
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    • pp.28-34
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    • 1997
  • The side burrs and shape distortion resulting from the micromachining of an array of V-shape microgrooves in fresnel lens mould were experimentally invesigated. The focus of this study is on the influence of depth of cut and prism angle on the burr growing rate. The main experiments were con- ducted on the single prism cutting for the convinient of measuring the burr shape and cutting force. From the observation of the burr shape and burr growing rate, it was found that there exits a critical depth of cut below which the burrs are more or less irregular and weak. But above that critical value, the burrs are re- latively clear and stiff.

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Unambiguous 3D Surface Measurement Method for a Micro-Fresnel Lens-Shaped Lenticular Lens Based on a Transmissive Interferometer

  • Yoon, Do-Young;Kim, Tai-Wook;Kim, Minsu;Pahk, Heui-Jae
    • Journal of the Optical Society of Korea
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    • v.18 no.1
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    • pp.37-44
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    • 2014
  • The use of a laser interferometer as a metrological tool in micro-optics measurement is demonstrated. A transmissive interferometer is effective in measuring an optical specimen having a high angle slope. A configuration that consists of an optical resolution of 0.62 micron is adapted to measure a specimen, which is a micro-Fresnel lens-shaped lenticular lens. The measurement result shows a good repeatability at each fraction of facets, however, a reconstruction of the lens shape profile is disturbed by a known problem of $2{\pi}$-ambiguity. To solve this $2{\pi}$-ambiguity problem, we propose a two-step phase unwrapping method. In the first step, an unwrapped phase map is obtained by using a conventional unwrapping method. Then, a proposed unwrapping method based on the shape modeling is applied to correct the wrongly unwrapped phase. A measured height of each facet is compared with a profile result measured by AFM.

Analysis of Power Degradation and Distortion in Coherent-Beam Combining with Lens Aberration (렌즈 수차에 의한 타일형 빔 결합 출력 감쇠와 왜곡 현상 분석)

  • Kim, Byungho;Na, Jeongkyun;Jeong, Yoonchan
    • Korean Journal of Optics and Photonics
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    • v.31 no.6
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    • pp.290-294
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    • 2020
  • In this paper, we quantitatively analyze the effect of lens aberration on the degradation of beam-coupling efficiency of a tiled coherent-beam combining system. The Zernike polynomial is used to quantify the aberration of the lens, and Fresnel diffraction is applied to numerically simulate the change in the peak light intensity when combined at a distance. The results of this paper will be useful for quantitative prediction of the beam-combining efficiency that is degraded by aberration of the lens, and it is expected to be helpful for the optimal design of a practical tiled coherent beam-combining system.

Three-dimensional Dynamic Display System Based on Integral Imaging

  • Jung, Sung-Yong;Min, Sung-Wook;Park, Jae-Hyeung;Lee, Byoung-Ho
    • Journal of Information Display
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    • v.3 no.1
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    • pp.22-26
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    • 2002
  • Three-dimensional dynamic display system based on computer-generated integral imaging is discussed and its feasibility is verified via some basic experiments. Integrated images observed from different viewing points are seen to have full parallax and the animated 3D image was implemented successfully. Moreover, using large size Fresnel lens array was found to helps widen viewing angle and to make the system more practical.

Design of Light Guide Plate for Photobioreactor (광생물 반응기를 위한 도광판 설계)

  • Park, Gi-Chan;Kim, Hun;Kim, Jong-Tye;Park, Jeong-Woo;Jeong, Sang-Hwa;Park, Jong-Rak
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.2
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    • pp.133-139
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    • 2011
  • We have performed optical design of light guide plates (LGPs) for a photobioreactor by using an illumination design tool. An LGP having light emitting diodes (LEDs) as a light source on the four sides was designed by optimizing the distribution of LGP patterns and design of another LGP, on top of which sunlight was focused by a Fresnel lens, was executed. Finally, a hybrid-solar-and-LED-lighting scheme was described. Detailed design process and optical performances of the designed LGPs are presented.

Scattering characteristic analysis of Fresnel zone plate lens using TLM (TLM법을 이용한 프레넬 존 플레이트 렌즈 산란특성 해석)

  • 김태용
    • Proceedings of the Korea Society for Simulation Conference
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    • 2003.06a
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    • pp.15-18
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    • 2003
  • Most numerical techniques such as FEM, BEM, and MOM are able to analize electromagnetic scattering problems from arbitrary shapes. Although these methods could be applied to compute electromagnetic scattering problems in frequency domain, it was limited for electrodynamic problem in time domain. In this paper, electromagnetic scattering problem from Fresnel zone plate lens are considered. Some numerical results computed by TLM are compared with Kirchhoff's approximation and PO method.

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Analysis of Soret-type Fresnel Zone Plate Lens Antenna using TLM method (TLM법을 이용한 Soret 타입 프레넬 존 플레이트 렌즈 안테나 해석)

  • Kim, Tae-Yong;Jo, Heung-Kuk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.6
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    • pp.1221-1226
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    • 2011
  • In order to analyze the receiver gain characteristic of the Soret-type FZPL lens antenna which is operated at 12GHz, TLM method can be applied. The application of the FZPL lens antenna is often use the receiver for satellite TV system, radio telescope, and Geodetic System. Some numerical results computed by TLM method are compared with Kirchhoff's approximation and PO method. The focal characteristic of receiver gain on main axis of the FZPL is mostly shown at the front side, which means that the position of the receiver should be properly calibrated.

On-orbit Analysis of Power Generation Efficiency of Concentrating Photovoltaic System Using Commercial Fresnel Lens for Pico Satellite Applications (상용 프레넬렌즈를 이용한 극초소형 위성용 집광형 태양전력 시스템의 궤도 전력생성효율 분석)

  • Park, Tae-Yong;Chae, Bong-Geon;Oh, Hyun-Ung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.4
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    • pp.318-325
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    • 2015
  • Pico satellite has limited surface to install the solar cells due to its extremely limited size. Also, the sun incidence angle with respect to the solar panel continuously varies according to the attitude control strategy and its important parameter for the power generation. In this study, a concentrating photovoltaic system for pico satellite application has been proposed that can enhance the power generation efficiency in case of the unfavorable condition of the sun incidence angle with respect to the solar panel of the satellite using the fresnel lens. To prove the possibility of maximizing the power generation efficiency of the proposed concentrating power system, we have performed the power measurement test using a solar simulator and commercial fresnel lens. And on-orbit analysis of the power generation efficiency using the STK which is a commercial S/W has also been performed based on the test results.

A Design of Standing Human Body Sensing System Using Rotation of a PIR Sensor (초전형 적외선 센서 회전방식을 이용한 정지 인체 감지 시스템에 관한 연구)

  • Cha, Hyeong-Woo;Cho, Min-Yyeong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.1
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    • pp.129-136
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    • 2016
  • A novel sensing system for standing and moving human body using PIR(pyroelectric infrared) sensor was development. The system consists of power supply, interface circuit of PIR sensor, small stepping motor, and digital control. The detecting principle for stop human body is detecting the human body when the stepping motor sticking the PIR sensor and the fresnel lens has rotated by 180 degree at six second and has stopped the motor for no detecting signal of human body. We developed control algorism for proposed the detection system. The experimentation shows that the detector system had detected length and angle were 6m and 30 degree against as standing and moving human body with $37^{\circ}C$.