• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.710-713
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• 2008

LED Scanning Backlight Stereoscopic Display with Shutter Glasses is provided to realize stereoscopic image viewing even in a liquid crystal display. The eye shutter signal is alternately switched from the left eye to the right eye with 120Hz of LCD Vertical synchronization (V-sync).

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.93-99
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• 2011

This paper presents a new type of optical silicon accelerometer using deep reactive ion etching (DRIE) and micro-stereolithography technology. Optical silicon accelerometer is based on a mass suspended by four vertical beams. A vertical shutter at the end of the mass can only moves along the sensing axis in the optical path between two single-mode optical fibers. The shutter modulates intensity of light from a laser diode reaching a photo detector. With the DRIE technique for (100) silicon, it is possible to etch a vertical shutter and beam. This ensures low sensitivity to accelerations that are not along the sensing axis. The microstructure for sensor packaging and optical fiber fixing was fabricated using micro stereolithography technology. Designed sensors are two types and each resonant frequency is about 15 kHz and 5 kHz.

• Current Optics and Photonics
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• v.2 no.5
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• pp.422-430
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• 2018

Rolling shutter operation of CMOS cameras can be utilized in optical camera communications in order to transmit data from an LED to mobile devices such as smart-phones. From temporally modulated light, a spatial flicker pattern is obtained in the captured image, and this is used for signal recovery. Due to the degradation of rolling shutter images caused by light smear, motion blur, and focus blur, the conventional decoding schemes for rolling shutter cameras based on the pattern width for 'OFF' and 'ON' cannot guarantee robust communications performance for practical uses. Aside from conventional techniques, such as polynomial fitting, histogram equalization can be used for blurry light mitigation, but it requires additional computation abilities resulting in burdens on mobile devices. This paper proposes a transition-based decoding scheme for rolling shutter cameras in order to offer simple and robust data decoding in the presence of image degradation. Based on the designed synchronization pulse and modulated data symbols according to the LED dimming level, the decoding process is conducted by observing the transition patterns of two sequential symbol pulses. For this, the extended symbol pulse caused by consecutive symbol pulses with the same level determines whether the second pulse should be included for the next bit decoding or not. The proposed method simply identifies the transition patterns of sequential symbol pulses other than the pattern width of 'OFF' and 'ON' for data decoding, and thus, it is simpler and more accurate. Experimental results ensured that the transition-based decoding scheme is robust even in the presence of blurry lights in the captured image at various dimming levels

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.4
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• pp.454-460
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• 2016

Unlike conventional visible light communications (VLC) adopting photo detectors (PD), optical camera communications (OCC) employs cameras in detecting the transmitted data. Especially, the data rate of OCC can be enhanced by using the principle of rolling-shutter, which is the operating scheme of a CMOS image sensor. In this study, we consider a novel OCC system for high-speed real time video processing to transmit high speed data from LED and to acquire image utilizing rolling-shutter effect of CMOS image sensor. Also, we demonstrate the improved performance of proposed system using a test-bed.

• Journal of the Optical Society of Korea
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• v.15 no.4
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• pp.345-351
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• 2011

We present a novel approach to the holographic three-dimensional display using a liquid crystal shutter for binocular display applications. One of the difficult problems in implementing a binocular holographic three-dimensional display is the extremely narrow viewing angle. This problem is attributed to the spatial light modulator pixel number which restricts the maximum spatial bandwidth of the spatial light modulator. In our proposed method, a beam splitter and liquid crystal shutter are used to present two holograms of a three-dimensional scene to the corresponding eyes. The combination of holographic display and liquid crystal shutter can overcome the problem of the extremely narrow viewing angle, presenting threedimensional images to both eyes with correct accommodation depth cues.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.118-119
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• 2003

조명각 변조방식에 의한 3차원 디스플레이 모듈의 구성요소는 back light unit(BLU), stripe-patterned LC shutter, lenticular lens sheet이다. 이런 3차원 디스플레이 에서 조명각도의 올바른 변조를 위해서는 stripe-patterned LC shutter, lenticular lens sheet 상호 결합이 가장 중요하다. 그림 1 은 이러한 입체영상 module의 개념도이다. 그림과 같이 LC shutter위에 적절한 렌티큘러 렌즈 어레이를 설치할 때, 줄무늬 모양의 면 광원에서 방출된 빛이 한번은 정확히 오른쪽 눈으로 다음 번에는 왼쪽 눈으로 향하게 하여 양안 시차에 의해 3D영상이 보이도록 하는 것이 이 모듈의 핵심원리이다. (중략)

• JOURNAL OF ELECTRICAL WORLD
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• no.10 s.130
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• pp.17-25
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• 1987

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.468-471
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• 2003

We firstly report liquid crystal shutter based on plastic film and its application to 3D shutter for stereoscopic displays. Plastic liquid crystal shutters have remarkable advantages compared to conventional glass liquid crystal shutters. They are thin, light and non-breakable so that very comfortable 3D shutter eye-wear can be realized using them. The concepts, optical performances and reliability test results of plastic film liquid crystal shutters are presented.

• Journal of the Semiconductor & Display Technology
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• v.10 no.2
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• pp.83-89
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• 2011

In this study, we investigated the effects of shutter control by Reactive Magnetron Sputtering using Inductively-Coupled Plasma(ICP) for obtaining ZnO thin films with high purity. The surface morphologies and structure of deposited ZnO thin films were characterized using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X-ray Diffractometer (XRD). Also, optical and chemical properties of ZnO thin films were analyzed by Spectroscopic Ellipsometer (SE) and X-ray Photoelectron spectroscopy (XPS). As a result, it observed that ZnO thin films grown at reactive sputtering using shutter control and ICP were higher density, lower surface roughness, better crystallinity than other conventional sputtering deposition methods. For obtaining better quality deposition ZnO thin films, we will investigate the effects of substrate temperature and RF power on shutter control by a reactive magnetron sputtering using inductively-coupled plasma.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.8-13
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• 2017

Compare with other communication system based RF technology, Optical Camera Communication (OCC) has limitation on data rate due to the low frame rate of camera. The limitation on data rate can be solved with multiple-input and multiple-output (MIMO) technology; and it is the final target of all researches on OCC. The MIMO topology can be implemented easily without breaking out the architecture of image sensor. For image sensor classification, there are two architectures have been developed: rolling shutter and global shutter. The operation of two techniques is different so the performance is also different. In this paper we analyze and evaluate the performance of the MIMO architecture for OCC.