• Title/Summary/Keyword: mirror

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Passive Mode Locking of Figure '8' Type Erbium-doped Fiber Ring Laser Using Nonlinear Loop Mirror (비선형 Loop Mirror 방식을 이용한 '8'자 고리형 Erbium 광섬유 레이저의 수동형 모드 록킹)

  • 박희갑
    • Korean Journal of Optics and Photonics
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    • v.4 no.3
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    • pp.330-337
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    • 1993
  • Figure '8' type, passively-mode-locked erbium-doped-fiber ring laser was developed, incorporating a nonlinear loop mirror. Transmittance of the loop mirror was found to be dependent on the incident light intensity due to the non-reciprocal nonlinear phase shift, which enables the passive mode locking of the laser. Self-starting of stable mode locking was possible with only controlling the polarization controllers inside the cavity without any help of external perturbation or modulation. The mode-locked output pulse shape was discussed in relation with the transmission characteristics of nonlinear loop mirror.

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Mirror Neuron System and Stroke Rehabilitation (미러뉴런시스템과 뇌졸중 재활)

  • Kim, Sik-Hyun
    • PNF and Movement
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    • v.7 no.4
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    • pp.45-53
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    • 2009
  • Purpose : The purpose of this article was to review the literature on mirror neuron system with reference to its functional diversity in stroke rehabilitation.. Method : This review outlines scientific findings regarding different neurophysiological properties in mirror neurons, and discusses their involvement in process of stroke rehabilitation. Result & Conclusions : Mirror neurons were first discovered in macaque monkey. These neurons, like most neurons in F5 areas in premotor cortex, fired when an individual performs an action, as well as when he/she observes a similar action done by another individual, although originally fired only during action execution. Mirror neurons form a network for motor planning and initiating of motor action. Thus, in stroke rehabilitation based on the mirror neuron-action observation, motor imagery, observation with intent to imitate and imitation-may help activate mirror neuron system for improved outcome of physical therapy. These studies provide a scientific theoretical basis and discuss for the use of mirror neuron system as a complement to clinical physical therapy in stroke rehabilitation.

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BuddyMirror: A Smart Mirror Supporting Image-Making Service (BuddyMirror: 이미지 메이킹 서비스를 지원하는 스마트 미러)

  • Jo, Yeon-Jeong;Sim, Chae-Lin;Jang, Hyo-Won;Jin, Jae-Hwan;Lee, Myung-Joon
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.9 no.5
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    • pp.811-821
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    • 2019
  • Image making for a person is a way to improve various factors that can express oneself, such as appearance, impression, and confidence. In general, people use mirror or camera as a traditional method to make their own image or perform presentation exercises. Recently, as smart mirrors are widely used in various fields, attempts to use smart mirrors as image making tools instead of mirrors have been frequently made. Smart Mirror is considered as a suitable tool to provide image making service because it can attach various devices such as a camera and a microphone in addition to the main advantage of a mirror that it is easily accessible. In this paper, we present BuddyMirror - a smart mirror software that provides image-making service to users, and a dedicated mobile app for flexibly running the mirror software. BuddyMirror provides functions for presentation, mock interview, and styling service at the request of users, interworking with the dedicated mobile app. We also describe the techniques developed for implementing and activating each of the new services as a module of MagicMirror, a widely used smart mirror development platform. The developed mobile app enables users to deliver presentations to BuddyMirror or to download the recorded video for image-making services.

Measurement of Fine 6-DOF Displacement using a 3-facet Mirror (삼면반사체를 이용한 6자유도 미소 변위 측정)

  • 박원식;조형석;변용규;박노열
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.50-50
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    • 2000
  • In this paper, a new measuring system is :proposed which can measure the fine 6-DOF displacement of rigid bodies. Its measurement principle is based on detection of laser beam reflected from a specially fabricated mirror that looks like a triangular pyramid having an equilateral cross-sectional shape. The mirror has three lateral reflective surfaces inclined 45$^{\circ}$ to its bottom surface. We call this mirror 3-facet mirror. The 3-facet mirror is mounted on the object whose 6-DOF displacement is to be measured. The measurement is operated by a laser-based optical system composed of a 3-facet mirror, a laser source, three position-sensitive detectors(PSD). In the sensor system, three PSDs are located at three corner points of a triangular formation, which is an equilateral triangular formation tying parallel to the reference plane. The sensitive areas of three PSDs are oriented toward the center point of the triangular formation. The object whose 6-DOF displacement is to be measured is situated at the center with the 3-facet mirror on its top surface. A laser beam is emitted from the laser source located at the upright position and vertically incident on the top of the 3-fatcet mirror. Since each reflective facet faces toward each PSD, the laser beam is reflected at the 3-facet mirror and splits into three sub-beams, each of which is reflected from the three facets and finally arrives at three PSDs, respectively. Since each PSD is a 2-dimensional sensor, we can acquire the information on the 6-DOF displacement of the 3-facet mirror. From this principle, we can get 6-DOF displacement of any object simply by mounting the 3-facet mirror on the object. In this paper, we model the relationship between the 6-DOF displacement of the object and the outputs of three PSDs. And, a series of simulations are performed to demonstrate the effectiveness of the proposed method. The simulation results show that the proposed sensing system can be an effective means of obtaining 3-dimensional position and orientation of arbitrary objects.

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Uniformity Improvement of Micromirror Array for Reliable Working Performance as an Optical Modulator in the Maskless Photolithography System

  • Lee, Kook-Nyung;Kim, Yong-Kweon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.1 no.2
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    • pp.132-139
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    • 2001
  • We considered the uniformity of fabricated micromirror arrays by characterizing the fabrication process and calculating the appropriate driving voltages of micromirrors used as virtual photomask in maskless photolithography. The uniformity of the micromirror array in terms of driving voltage and optical characteristics is adversely affected by factors, such as the air gap between the bottom electrode and the mirror plate, the spring shape and the deformation of the mirror plate or torsion spring. The thickness deviation of the photoresist sacrificial layer, the misalignment between mirror plate and bottom electrode, the aluminum deposition condition used to produce the spring and the mirror plate, and initial mirror deflection were identified as key factors. Their importance lies in the fact that they are related to air gap deviations under the mirror plate, asymmetric driving voltages in left and right mirror directions, and the deformation of the Al sring or mirror plate after removal of the sacrificial layer. The plasma ashing conditions used for removing the sacrificial layer also contributed to the deformation of the mirror plate and spring. Driving voltages were calculated for the pixel operation of the micromirror array, and the non-uniform characteristics of fabricated micromirrors were taken into consideration to improve driving performance reliability.

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INTELLIGENT MIRROR ADJUSTMENT SYSTEM USING A DRIVER′S PUPILS

  • Rho, K.H.;Han, M.H.
    • International Journal of Automotive Technology
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    • v.5 no.4
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    • pp.277-285
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    • 2004
  • This paper describes an intelligent mirror adjustment system that rotates a pair of side mirrors and the room mirror of a car to the optimal position for a driver by using the location of the driver's pupils. A stereo vision system measures the three-dimensional coordinates of a pair of pupils by analyzing the input images of stereo B/W CCD cameras mounted on the instrument panel. This system determines the position angle of each mirror on the basis of information about the location of the pupils and rotates each mirror to the appropriate position by mirror actuators. The vision system can detect the driver's pupils regardless of whether it is daytime or nighttime by virtue of an infrared light source. Information about the pair of nostrils is used to improve the correctness of pupil detection. This system can adjust side mirrors and the room mirror automatically and rapidly by a simple interface regardless of driver replacement or driver's posture. Experiment has shown this to be a new mirror adjustment system that can make up for the weak points of previous mirror adjustment systems.

Depth Measurement System Using Structured Light, Rotational Plane Mirror and Mono-Camera (선형 레이저와 회전 평면경 및 단일 카메라를 이용한 거리측정 시스템)

  • Yoon Chang-Bae;Kim Hyong-Suk;Lin Chun-Shin;Son Hong-Rak;Lee Hye-Jeong
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.5
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    • pp.406-410
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    • 2005
  • A depth measurement system that consists of a single camera, a laser light source and a rotating mirror is investigated. The camera and the light source are fixed, facing the rotating mirror. The laser light is reflected by the mirror and projected to the scene objects whose locations are to be determined. The camera detects the laser light location on object surfaces through the same mirror. The scan over the area to be measured is done by mirror rotation. Advantages are 1) the image of the light stripe remains sharp while that of the background becomes blurred because of the mirror rotation and 2) the only rotating part of this system is the mirror but the mirror angle is not involved in depth computation. This minimizes the imprecision caused by a possible inaccurate angle measurement. The detail arrangement and experimental results are reported.

Fabrication of A 3-facet Mirror Using the LIGA Process (LIGA 공정을 이용한 삼면반사체 제작)

  • Oh, Dong-Young;Jung, Dong-Kwan;Park, Noh Y.;Chang, Suk-Sang;Lee, Seung-Seop
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.8
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    • pp.172-179
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    • 2000
  • In this paper a technology for the fabrication of the oblique structure using the LIGA process will be presented. The fabricated microstructure is a tetrahedral 3- facet mirror. The mirror has an equilateral triangular base of hundreds ${\mu}m$ length mirror-like three side-facets inclined to the base at 45$^{\circ}$ and knife edges. Two regular triangles of 45$^{\circ}$ and tan-12. After development the shaded part of the PMMA the tetrahedral mirror remains, The completed mirror shows excellent aspects of mirror-like facets and knife-edges. By controlling the gap between the mask and the substrate the size of mirror easily can be changed. This mirror would be used as a laser beam splitter for the feedback control of the HDD slider.

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A Study on Vibration Analysis of Vehicle Rear-view Mirror (자동차(自動車) 룸 밀러 진동에 대한 연구(硏究))

  • Lim, S.H.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.6
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    • pp.1-7
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    • 1995
  • Vehicle has two kinds of mirrors to check the rear. Especially inner rear-view mirror(room mirror) is easy to vibrate. A vibration of vehicle inner rear-view mirror affects safe driving. This study presents both of analysis of cause of mirror vibration and resolution in order to improve that throughout analysis by elasticity theory, FEM, and test.

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Wide Field-of-View Imaging Using a Combined Hyperbolic Mirror

  • Yi, Sooyeong;Ko, Youngjun
    • Current Optics and Photonics
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    • v.1 no.4
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    • pp.336-343
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    • 2017
  • A wide field-of-view (FOV) image contains more visual information than a conventional image. This study proposes a new type of hyperbolic mirror for wide FOV image acquisition. The proposed mirror consists of a hyperbolic cylindrical section and a bowl-shaped hyperbolic omnidirectional section. Using an imaging system with this mirror, it is possible to achieve a $213.8^{\circ}$ horizontal and a $126.94^{\circ}$ vertical maximum FOV. Parameters of each section of the mirror are designed to be continuous at the junction of the two parts, and the resultant image is seamless. The image-acquisition model is obtained using ray-tracing optics. To rectify the geometrical distortion of the original image due to the mirror, an image-restoration algorithm based on conformal projection is presented in this study. The performance of the proposed imaging system with the hyperbolic mirror and its image-restoration algorithm are verified by experiments.