• Title/Summary/Keyword: 재귀 반사

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Analysis of the Reflection Characteristics of a Rectangular Corner Cube Retro-Reflector (사각면 코너 큐브 재귀 반사체의 반사출력광 특성 및 응용)

  • Jeong, Yong-Beom;Kim, Young-Hoon;O, Beom-Hoan
    • Korean Journal of Optics and Photonics
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    • v.26 no.1
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    • pp.17-22
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    • 2015
  • The applications for retro-reflectors, with their unique reflection characteristics, have been expanding, to include venetian blind slats, displays, traffic safety mark, etc. We propose expandable structures of inclined corner cube retro-reflectors and analyze their corresponding reflection characteristics. Various traffic safety structures with retro-reflectors may be designed more quantitatively using the chart of characteristics we have presented.

Analysis of Quality Improvement of a Floating Image Using a Hybrid Retroreflective Mirror Array Sheet (혼성-병풍형 구조의 재귀반사 거울 배열판을 이용한 부양영상 개선 분석)

  • Yu, Dong Il;Baek, Young Jae;Yong, Hyeon Joong;O, Beom Hoan
    • Korean Journal of Optics and Photonics
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    • v.30 no.4
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    • pp.142-145
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    • 2019
  • Normally, a corner cube retroreflector (CCRR) sheet is used as a retroreflective mirror array (RRMA) in a volumetric display. Each CCRR unit reflects light in the retroreflective direction, which is parallel to the incident light, and it makes a blurred image, as it shifts the position of light within its dimensions. Adopting a "curved planar wall" and "parabolic focusing" (x-axis), a hybrid-t(transverse direction)-RRMA is proposed, to improve the image quality and brightness. The improvement of image contrast is achieved by tuning a "linear v-shaped groove" structure to a "parabolic v-shaped groove". Also, the system has been simplified and the brightness enhanced 4 times by removing the half mirror.

High Performance Glass Beads for Traffic Marking in Wet Weather (차선의 우천시 야간 시인성 향상을 위한 그라스 비드 적용 연구)

  • Lee, Chang-Geun;Lee, Hyun-Seock;Oh, Heung-Un
    • International Journal of Highway Engineering
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    • v.14 no.1
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    • pp.9-16
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    • 2012
  • The performance of road markings is classified into the visibility at daytime, night time, wet condition and rainy conditions. The objective of this study is to obtain the driving safety of drivers under conditions of unstable weather condition such as the rain. The visibility of road markings is closely related to the preview time and detection distances and the ways to improve road marking materials and increase the dry retroreflectivity and wet retroreflectivity, which are the measures of daytime and nighttime visibility is researched to decrease the traffic accidents. For this purpose, Road marking glass beads with the refraction rate of 1.5 and 2.2 are introduced to raise the retroreflectivity. After investigating the minimum threshold retroreflectivity and Install Minimum retroreflectivity at home and abroad, minimum control values for the roadmarking visibility and improvement of nightime rainy retroreflectivity are suggested by physical properties and retroreflectivity experiments.

Analysis and Application of the Reflection Characteristics of a Simple Retro-reflector (1차원적 단순배열구조 재귀반사체의 반사출력광 특성 및 응용)

  • Jeong, Yong-Beom;Hong, Sung-Hoon;Lee, Seung-Gol;O, Beom-Hoan
    • Korean Journal of Optics and Photonics
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    • v.25 no.5
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    • pp.239-244
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    • 2014
  • Retro-reflectors have been used for a wide range of applications such as traffic safety, special blinds, optical devices, etc. We analyzed the characteristics of the reflected light of a strap retro-reflector as a function of incidence angle. It is expected that various solar control structures may be designed more quantitatively using the characteristic chart we have prepared.

Development of a Measuring Instrument for the Coefficient of Luminous Intensity of Retro-Reflection of Miniature Telecentric Cameras (소형 텔레센트릭 카메라 광학계의 재귀반사 측정 방법 연구 및 측정 장치 개발)

  • Yeo, TaeWoon;Karasik, V.E.;Kim, Young Il
    • Korean Journal of Optics and Photonics
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    • v.25 no.6
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    • pp.334-339
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    • 2014
  • In this paper, the optical properties of a miniature telecentric camera are studied analytically and experimentally. By means of optical properties, the luminous intensity of retro-reflection of a miniature telecentric optical system is investigated. First, from a simulation the theoretical value of the coefficient of luminous intensity of retro-reflection of a miniature telecentric system is estimated. Second, a miniature telecentric camera device is designed, and the value of the coefficient of luminous intensity of retro-reflection of the actual device is measured through experiment. From simulation and experiment, we found that both the estimated and observed values of the coefficient of luminous intensity of retro-reflection range from 0.002 to $0.03m^2/sr$ (P384200CPH: $0.0042-0.018m^2/sr$, P285200CPH: $0.0045-0.0297m^2/sr$, P321450S: $0.0021-0.00963m^2/sr$) at 1.4 to 4.9 arcminute. The results prove the significance of the mechanisms used to design the miniature telecentric camera, and the experimental method. Accordingly, with these significant results, this study contributes to the development of theory and practice in optical engineering science.

Structural and Physical Properties of Reflective Sheets Prepared by Using Glass Beads (유리구슬을 사용하여 제조된 재귀반사시트의 구조 및 재귀반사 특성 연구)

  • Lim, Du-Hyun;Lee, Min-Ho;Heo, Min-Yeong;Ahn, Jou-Hyeon;Park, Jin-Woo;Yu, Ji-Hyun;Kim, Jong-Seon;Ryu, Ho-Suk;Ahn, Hyo-Jun;Kim, Ik-Hwan
    • Elastomers and Composites
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    • v.46 no.4
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    • pp.277-283
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    • 2011
  • In this study, engineering grade and high intensity reflective sheets were prepared with glass beads and their reflection performance and physical properties were investigated. The reflective sheets prepared by using glass beads are divided into enclosed or encapsulated lens type, depending on whether the glass beads are open in air or not. Because of an extra layer on the glass bead surface, the enclosed lens type reflective sheets show very little change in the properties by bad weather conditions, compared to encapsulated lens type reflective sheets. Optimization of the amount of glass beads on the surface was carried out, which determines the retroreflective properties. Enclosed and encapsulated lens type reflective sheets with various colors were prepared and their coefficients of retroreflection were determined. The encapsulated type reflective sheet with white color shows a coefficient of retroreflection of $210.4cd/1x{\cdot}m^2$, which is higher than the enclosed type ($74cd/1x{\cdot}m^2$). Effect of washing on the reflective property and adhesive power of the reflective sheets was investigated, and it is found that the number of glass beads decreased with washing and the aluminum layer deposited was damaged extensively in the encapsulated lens type reflective sheets.

Measurement of the 3-Dimensional Shapes of Specular Objects by Using Double Pass Retroreflection (재귀반사 특성을 이용한 경면물체의 3차원 형상 측정)

  • Park, W.S.;Ryu, Y.K.;Cho, H.S.
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.11
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    • pp.64-72
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    • 1996
  • This paper is aimed to develop an optical method for measuring 3-dimensional shapes of specular objects having curved surfaces. The existing methods measuring the shapes of specular objects have several common disadvantages: they may not work properly if the surface is highly specular like mirror surface or if the reflectance property is not uniform over the surface. And, they often require the a priori knowledege about the surface reflectance. To overcome these disadvantages, the measurement using double pass retroreflection method is proposed in this paper. For this measurement principle, an experimental measuring system is designed and prepared which is composed of a galvanometer scanner, a beam splitter, a laser source, a CCD camera, and a reflector made of retroreflective material. To verify the effectiveness of the measurement system a series of experiments are performaed for various specular objects. The results observed from the experiments show that the developed optical sensing system can be an effective mean of measuring the 3-D shapes of specular objects.

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Preparation and Physical Properties of Diamond Grade Reflective Sheets Using Microprism (마이크로프리즘을 사용한 초고휘도 재귀반사시트의 제조 및 특성)

  • Lee, Min-Ho;Lim, Du-Hyun;Heo, Min-Yeong;Ahn, Jou-Hyeon;Park, Jin-Woo;Yu, Ji-Hyun;Kim, Jong-Seon;Ryu, Ho-Suk;Ahn, Hyo-Jun;Kim, Ik-Hwan
    • Elastomers and Composites
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    • v.46 no.4
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    • pp.284-289
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    • 2011
  • Prismatic reflective sheets were prepared using microprisms, and their retroreflection and structural properties were investigated and compared with encapsulated lens type reflective sheets based on glass beads. As prepared, the prismatic reflective sheets show well arranged array of microprisms. The arrangement of glass beads in encapsulated lens type reflective sheets is also found to be uniform without any cracks. However, during the coating process of the PET layer, the beads are coming out and the gaps are formed due to the application of high pressure. Even though the preparation method for reflective sheets based on microprisms is similar to that of reflective sheets based on glass beads, the method is relatively simple and cost effective, and also needs less time. Prismatic reflective sheets show higher coefficient of retroreflection from all entrance angles compared to reflective sheets based on glass beads. The results prove that the prismatic reflective sheets can be used for preparing the traffic sign boards to secure a clear view.

A Methodology Development for Estimating the Retroreflectivity of Pavement Markings and Traffic Guide Signs Using Digital Images (디지털 이미지를 이용한 노면표시 및 교통안내표지의 재귀반사 성능 평가 방법론 개발)

  • Choi, Keechoo;Lee, Seunghyeon;Yun, Ilsoo;Yi, Yongju
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.1
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    • pp.185-194
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    • 2014
  • This study investigates the methodology to evaluate the quantified performance of pavement markings and traffic guide signs using digital images. This methodology is significant to attempt to quantify their performance without large brightness photometer at the nighttime and bad weather. The retroreflective performance of pavement markings are evaluated through the contrast of gray levels of pavements and markings in collected digital images under the case of rain, dampness, and dryness. In addition, the appraisal of retroreflective performance of traffic guide signs are implemented through the comparison between interior illuminated and the existing retroreflective traffic guide signs using the contrast of luminance extracted from the value of RGB of backgrounds and legends in collected digital images according to geometric design, driving lanes, and the distance between the car and the sign. As a result, the retroreflective performance of pavement markings deteriorates about 3.5 times and 2 times under the case of rain and dampness respectively than dryness. Also, the performance of the existing traffic guide signs is significantly influenced by geometric design, driving lanes, and the distance, otherwise interior illuminated traffic guide signs. This methodology can be utilized to construct objective information of performance of traffic safety facilities to select appropriate position of expensive high reflective pavement markings and interior illuminated traffic guide signs considering diverse weather and geometric design.