• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1155-1158
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• 2007

To reduce acoustic noise level of an AV projector, primary noise sources of AV projector were analyzed. Based on the analyzed result, methods to control each source are presented and tried. Structure-borne noise can be controlled by anti vibration design of mounting system, and air-borne noise by reducing flow resisitvity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.132-137
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• 2003

For the evaluation of acoustic noise of a DLP projector, vibration and sound characteristics of a DLP projector were studied. The acoustic noise of DLP projector could be classified into three categories, that is, the direct noise from a body of rotation, the air-bone noise generated from turbulence or vortex occurred during cooling process and the structural born noise produced by vibrating elements. Cooling fans and color filter wheel which rotates at 9000 rpm are main causes of acoustic noise induced in DLP projector. Since the structure of an optical module in a DLP projector can be excited by the excessive vibration of a color filter wheel, the structural design for anti-vibration should be considered. To make a reduction of overall acoustic noise, the anti-vibration design and the enclosing structure have been studied and applied to a color filter wheel.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.9 s.90
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• pp.861-867
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• 2004

For the evaluation of acoustic noise of a DLP projector, vibration and sound characteristics of a DLP projector were studied. The acoustic noise of DLP projector could be classified into three categories, that is, the direct noise from a body of rotation, the air-bone noise generated from turbulence or vortex occurred during cooling process and the structural born noise produced by vibrating elements. Cooling fans and color filter wheel which rotates at 9000 rpm are main causes of acoustic noise induced in DLP projector. Since the structure of an optical module in a DLP projector can be excited by the excessive vibration of a color filter wheel, the structural design for anti-vibration should be considered. To make a reduction of overall acoustic noise, the anti-vibration design and the enclosing structure have been studied and applied to a color filter wheel.

• Journal of Information Display
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• v.11 no.2
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• pp.76-83
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• 2010

This paper presents the multi-user autostereoscopic 3D display system constructed and operated by the authors using the time-multiplexing approach. This prototype has three main advantages over the previous versions developed by the authors: its hardware was simplified as only one optical array is used to create viewing regions in space, a lenticular multiplexing screen is not necessary as images can be produced sequentially on a fast 120Hz LCD with full resolution, and the holographic projector was replaced with a high-frame-rate digital micromirror device (DMD) projector. The whole system in this prototype consists of four major parts: a 120Hz high-frame-rate DMD projector, a 49-element optical array, a 120Hz screen assembly, and a multi-user head tracker. The display images for the left/right eyes are produced alternatively on a 120Hz direct-view LCD and are synchronized with the output of the projector, which acts as a backlight of the LCD. The novel steering optics controlled by the multiuser head tracker system directs the projector output to regions referred to as exit pupils, which are located in the viewers’eyes. The display can be developed in the "hang-on-the-wall"form.

• International Journal of Contents
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• v.12 no.2
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• pp.1-5
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• 2016

Extensible 3D (X3D) is the ISO standard for defining 3D interactive web- and broadcast-based 3D content integrated with multimedia. With the advent of this integration of interactive 3D graphics into the web, users can easily produce 3D scenes within web contents. Even though there are diverse texture nodes in X3D, projective textures are not provided. We enable X3D to provide SingularProjectiveTexture and MultiProjectiveTexture nodes by materializing independent nodes of projector nodes for a singular projector and multi-projector. Our approach takes the creation of an independent projective texture node instead of Kamburelis's method, which requires inconvenient and duplicated specifications of two nodes, ImageTexture and Texture Coordinate.

• 전자공학회논문지 IE
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• v.48 no.4
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• pp.19-24
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• 2011

Advances in mobile communications, portable computing and personal electronics have led consumers to demand large viewing area, bright, high resolution, compact and long life portable displays. Pico projectors are the latest technology to prove that big things often do come in small packages. Our goal in this paper was to implement a portable, low power, and highly adaptable miniature pico projector system. The pico projector is designed many functions of the pico projector solutions, multimedia, and T-DMB broadcasting.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1427-1429
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• 2008

In this paper, an illumination system design using two lamps was proposed to improve the brightness of the projector. The proposal is based on the results from optical simulation. The prism array was applied to maintain the same optical properties, such as brightness distribution for the divergence angle and the composed beam size of the system. These were compared to those of the one UHP lamp system. The brightness of the two-lamp system, having a panel size of 0.74" and an f/2.9, increased by a factor of 1.7 when compared to the brightness of one UHP lamp system.

• 전기의세계
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• v.45 no.9
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• pp.37-41
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• 1996

MEMS 기술에 의해 개발되고 있는 많은 제품들 가운데 가장 잠재력 있고 큰 시장을 가진 대형 projector의 개발은 핵심 chip이 현재 DMD(Digital Micromirror Device), AMA(Actuated Mirror Array), 그리고 GLV(Grating Light Valve) 방식으로 진행되고 있으며 TI사가 개발 중인 DMD projector가 상품화에 근접해 있으며 고화질의 시제품을 SID(Society for Information Display) 국제 전시회에 출품하여 전세계 연구원들의 이목을 끌었으며 앞으로 어떻게 수율을 높이고 광학계의 단순화를 이루어 제작비를 낮추는 가가 관심의 초점이다. MEMS 연구를 하는 한 사람으로서의 사견으로도 이 제품이 성공하여야 범세계적으로 일어나고 있는 MEMS 기술이 더욱 확실한 신기술로서의 지위를 갖고 연구되리라 믿는다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.292-295
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• 2003

Moire topography method is a well-known non-contacting 3-D measurement method. the automatic 3-D measurement by moire topography has been required since the method was frequently applied to the engineering and medical fields. 3-D measurement using digital projection moire topography is very attractive because of its high measuring speed and high sensitivity. In this study, digital two-wavelength phase shilling moire is applied to the entertainment fields. recently. as promoting the growth of the VR-Game, display devices which attract public attention such as HMD or Projector are being appeared in order to deliver effectively the absorption sense. this study realized the Auto-calibrating system for arbitrary display surface using digital moire method which satisfied the shape measurement of display surface and the request of FOV(Field of View) output. also when large screen wasn't prepared, this auto-calibrating system was applied to enjoy games or movies at home with a projector and walls

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.39-44
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• 2008

This paper proposes a real-time geometric correction system based on a projector to project digital images onto deformable surface. Markers use to trace lots of corresponding points would spoil the projected image when the projector projects a digital image onto the surface because they leave marks on the surface. In addition, it is difficult to build a real-time geometric correction system since bottlenecks occur through the process of the geometric correction for projecting images. In this paper, we use invisible infrared markers and a vertex shader of GPU using Cg TookKit of NVIDIA in order to eliminate disadvantage and bottlenecks in the process of markers recognition so that it is possible to project natural correction images in real-time. As a result, this system overlays an interactive virtual texture onto the real paper by using the geometric transformation. Therefore, it is possible to develop variation of AR(Augmented Reality) based on digital contents systems.