• 대한기계학회논문집A
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• 제24권11호
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• pp.2732-2741
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• 2000

Combination of magnetic recording technology and optical recording technology such as Near Field Optical Recording is watched recently. In order to accomplish this technology, the development of an electromagnetic driven mm-sized mirror shifting laser beam in track direction have to needed. In Near Field Optical Recording System, shifting laser beam in track direction mean as fine tracking and means as coarse tracking. Therefore in Near Field Optical Recording, 2-stage actuator is composed of servo controller in reading or recording information on disc layer. In our research, through design and simulation process of driven mm-sized mirror, we arrange systematically design process of driven mm-sized mirror having good frequency transfer characteristics. Design and simulation processes included modal analysis of spring, calculation of magnetic moment according to the number of turns and geometric configuration of coil and magnetic circuit analysis meaning that calculation of magnetic flux density in air gap of magnetic circuit. After that we design and make parts of driven mm-sized mirror, assemble and evaluate our electriomagnetic driven mm-sized mirror. we compared design values with actual characteristic values and present solution scheme. Through these processes we performed manufacturing of an electromagnetic driven mm-sized mirror having good frequency-domain characteristics and high sensitivity characteristics.

• Journal of the Optical Society of Korea
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• 제13권1호
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• pp.15-21
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• 2009

High-order harmonic generation from a solid surface affected by the contrast of a laser pulse was studied using an oscillating mirror model. High-order harmonics generated from solid surfaces have unusual properties such as spectral redshift, and an intensity difference between even- and odd-order harmonics which is not reported for high-order harmonics generated by a gas medium. We confirmed that high-order harmonics from solid surfaces have selectivity of polarization as well as cut-off extension and the enhancement of conversion efficiency proportional to laser intensity. And the principle of operation and the characteristics of a plasma mirror system developed for achieving high contrast laser pulses to pursue the experimental realization of high-harmonic generation from solid surfaces are reported. Energy fluence on the plasma mirrors is tunable between $10\;J/cm^2$ and $1000\;J/cm^2$ and around 1000 shots are available before the plasma mirrors require replacement.

• 천문학회보
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• 제46권1호
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• pp.38.3-38.3
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• 2021

We are developing an optomechanical design of infrared telescope for the CubeSat and Unmanned Aerial Vehicle (UAV) which adapts the Linear Astigmatism Free- Three Mirror System in the confocal off-axis condition. The small entrance pupil (diameter of 40 mm) and the fast telescope (f-number of 1.9) can survey large areas. The telescope structure consists of three mirror modules and a sensor module, which are assembled on the base frame. The mirror structure has duplex layers to minimize a surface deformation and physical size of a mirror mount. All the optomechanical parts and three freeform mirrors are made from the same material, i.e., aluminum 6061-T6. The Coefficient of Thermal Expansion matching single material structure makes the imaging performance to be independent of the thermal expansion. We investigated structural characteristics against external loads through Finite Element Analysis. We confirmed the mirror surface distortion by the gravity and screw tightening, and the overall contraction/expansion following the external temperature environment change (from -30℃ to +30℃).

• 한국통신학회논문지
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• 제34권10B호
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• pp.1117-1123
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• 2009

DMD(Digital Micro-mirror Device)와 갈바노 스캐너를 이용한 두부 고정형 다초점 디스플레이 시스템은 초점조절이 가능하여 스테레오스코픽 디스플레이에서 발생하는 양안의 수렴작용과 단안의 초점조절 작용의 불일치에 의한 눈의 피로 문제를 해결할 수 있는 디스플레이 시스템이다. 이 시스템은 레이저 스캐닝 방법으로 각 시점에 대한 영상의 수렴점을 형성하여 관찰자 동공에 제공함으로 초점조절이 가능토록 한다. 본 논문에서는 이 다초점 디스플레이 시스템의 레이저 스캐닝 방법을 수학적으로 분석하였고, 이러한 분석에 기반 한 다초점 시스템을 제작하여 비디오카메라를 통하여 초점조절이 가능함을 보였고, 결과적으로 레이저 스캐닝 방법에 의한 다초점 시스템의 시점 형성원리가 검증되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.971-972
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• 2008

• 제어로봇시스템학회논문지
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• 제11권12호
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• pp.1020-1026
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• 2005

In the era of ubiquitous computing, human-friendly man-machine interface is getting more attention due to its possibility to offer convenient services. For this, in this paper, we introduce a 'Half-Mirror Interface System (HMIS)' as a novel type of human-friendly man-machine interfaces. Basically, HMIS consists of half-mirror, USB-Webcam, microphone, 2ch-speaker, and high-speed processing unit. In our HMIS, two principal operation modes are selected by the existence of the user in front of it. The first one, 'mirror-mode', is activated when the user's face is detected via USB-Webcam. In this mode, HMIS provides three basic functions such as 1) make-up assistance by magnifying an interested facial component and TTS (Text-To-Speech) guide for appropriate make-up, 2) Daily weather information provider via WWW service, 3) Health monitoring/diagnosis service using Chinese medicine knowledge. The second one, 'display-mode' is designed to show decorative pictures, family photos, art paintings and so on. This mode is activated when the user's face is not detected for a time being. In display-mode, we also added a 'healing-window' function and 'healing-music player' function for user's psychological comfort and/or relaxation. All these functions are accessible by commercially available voice synthesis/recognition package.

• 제어로봇시스템학회논문지
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• 제20권6호
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• pp.606-611
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• 2014

The understanding of another's behavior is a fundamental cognitive ability for primates including humans. Recent neuro-physiological studies suggested that there is a direct matching algorithm from visual observation onto an individual's own motor repertories for interpreting cognitive ability. The mirror neurons are known as core regions and are handled as a functionality of intent recognition on the basis of imitative learning of an observed action which is acquired from visual-information of a goal-directed action. In this paper, we addressed previous works used to model the function and mechanisms of mirror neurons and proposed a computational model of a mirror neuron system which can be used in human-robot interaction environments. The major focus of the computation model is the reproduction of an individual's motor repertory with different embodiments. The model's aim is the design of a continuous process which combines sensory evidence, prior task knowledge and a goal-directed matching of action observation and execution. We also propose a biologically inspired plausible equation model.

• 인터넷정보학회논문지
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• 제6권6호
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• pp.149-161
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• 2005

전방위 렌즈의 단점은 균일하지 않은 해상도에 있다. 등거리 전방위 렌즈는 이러한 단점을 해결하기 위한 새로운 대안으로 볼 수 있으며, 등거리 스테레오 전방위 렌즈는 한 개의 카메라를 통해 스테레오 영상을 획득할 수 있다는 점에서 매우 효율적인 시스템이라 말할 수 있다. 그러나 등거리 스테레오 전방위 렌즈는 단일 등거리 전방위 렌즈에 비해 획득 영상의 크기가 상대적으로 작게 되어 해상도가 낮아진다는 단점이 있다. 정확한 거울의 위치, 카메라 축과 거울 중심과의 정확한 정렬등의 문제는 정밀도를 높여 해결할 수 있지만, 영상 획득 시 필수적으로 필요한 렌즈의 초점 거리 변화는 피할 수 없게 된다. 본 논문에서는 먼저 초점 거리 변화가 물체의 거리 측정에 미치는 영향을 고찰한 후 스테레오 영상에서 보이는 물체의 시야 각은 두 영상에서 거의 일정하다는 가정하에 실제 초점 거리를 계산하는 방법을 제시한다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.47-50
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• 2005

In this study, micro mirror array for small form factor optical pick-up was replicated by micro UV-molding. First, mold for micro mirror array was fabricated using micromachining. Also, to analyze the characteristics of the surface quality, flatness of replicated mirror surface were measured by white light scanning inteferometry system. The results show that the micro mirror array with a sufficient surface quality can be obtained by polymer replication process.

• 한국정밀공학회지
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• 제16권8호
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• pp.113-121
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• 1999

It is necessary to calibrate measurement systems to enhance its measurement accuracy. The visual sensing system that is presented in our previous work has to be calibrated, too. It is a multiple mirror system for three-dimensional measurement, which is composed of a camera and a series of mirrors. It is important to calibrate the positions and orientations of the mirrors relative to the camera because they have direct influence on the relationship between the image plane and the task space. This paper presents the calibration method for the visual sensing system. To confirm the measurement performance of the implemented system. its measurement accuracy in measuring the locations in three-dimensional space is investigated. A series of experiments for measuring the locations of the circle-shaped marks are performed. Experimental results show that the sensing system can be effectively used for three-dimensional measurement.