• 한국레이저가공학회지
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• 제10권1호
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• pp.29-34
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• 2007

We propose a novel application of laser engraving to patterning of light guide panel (LGP) for backlight. The feasibility of three-dimensional engraved pattern in the LGP was verified by measuring brightness and uniformity. To improve the overall uniformity, we have modified proposed patterns and found improved design for patterns. The tailoring of pattern by using laser engraving method could endow the controllability of uniformity. The proposed LGPs are more efficient in both average brightness and uniformity of illumination than the conventional LGPs which have surface pattern on the panel.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1048-1052
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• 2008

Difficulties in developing process of Liquid Crystal Display(LCD) products such as frequent design modifications, various design requirements, and short-term development period bring on the need of integrated design approach that is efficient and easy to handle. Back Light Unit(BLU) of the LCD, which drastically affects the optical performance of LCD products, is divided into in-coupling part and out-coupling part. Serration of the in-coupling part flattens the light received from point light sources and dot pattern of the out-coupling part regularizes the light sent to screen. Therefore, the optical performance of a LCD product is largely influenced by the shape of serration and the arrangement of dot pattern. In this research, a new design approach which enables to improve the optical performance of LCD products and overcome the prementioned difficulties in developing process of LCD products is proposed. The shape of serration is parameterized to 3 parameters and out-coupling part is partitioned into 10 partitions to apply the optimization technique to this problem. 3 parameters for the shape of serration and densities of 10 partitions are used as design variables in the design optimization. Optical simulation tool named SPEOS is used to evaluate the optical performance of the LCD product. Since the optical simulation uses the random ray tracing technique, numerical noise may possibly be included in the simulation process. To solve the problem caused by numerical noise, the PQRSM which can stably find the solution of the noise problem is used in this research.

• 반도체디스플레이기술학회지
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• 제18권4호
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• pp.25-29
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• 2019

Microstructure pattern generation on light guides in backlight unit (BLU) is an essential process for designing flat panel display, but efficient designing algorithm is still limited to achieve uniform luminescence while maintaining fully random distribution to avoid interference effects. In this study, a molecular dynamics model based pattern generation algorithm has been developed. The proposed algorithm allows a fast and efficient distribution of patterns at specified density within the user-defined computational cells, and its efficiency and performance has been demonstrated with sample cases.

• 소성∙가공
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• 제20권1호
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• pp.60-63
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• 2011

BLU(back light unit) is one of kernel parts of LCD(liquid crystal display) unit. New 3-D micro-lens pattern for LGP(light guide plate), one of the most important parts of LCD-BLU, had been researched. Instead of dot pattern made by chemical etching or laser ablation, SCS(slanted curved surface) micro-lens pattern was designed with optical CAE simulation. This study introduce the method of design using optical CAE simulation for SCS micro-lens, the new fabrication method of micro-mold with SCS micro-lens pattern.

• 조명전기설비학회논문지
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• 제26권5호
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• pp.13-20
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• 2012

The light transmittance of optical device is one of the important conditions to improve the product performance and it has researched through the various methods. One of these methods to improve the optical transmittance is to use a pattern on optical surface. The advantages of this method are to simplify the manufacturing process and to easy mass production. If a surface of glass has with the proper patterns, we can expect a great effect on optical transmittance. The purpose of this research is to derive a pattern to get high transmittance from a theoretical approach and to analyze the transmittance through the simulation. And then, we made a sample with a pattern and compared with the results from simulation and experiment.

• 센서학회지
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• 제26권3호
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• pp.173-178
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• 2017

In this paper, we newly developed an omnidirectional receiver for visible light communication (VLC). The omnidirectional receiver was composed of a flexible solar cell attached on a cylindrical surface with its axis in vertical direction. The solar cell surface was symmetrical and showed an almost uniform receiving pattern in a horizontal plane. The maximum difference in a receiving pattern was within 7% of its peak value in a horizontal plane. This configuration is very easy to fabricate and useful in constructing wireless sensor networks in which one receiver needs to detect multiple LED signals in different directions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.728-731
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• 2005

A light guide panel (LGP) is an element of the LCD back light unit, which is used for display devices. In this study, a laser marking process is applied to the fabrication of light guide panels as the new fabrication process. In order to obtain a light guide panel which has high luminance and uniformity, four principal parameters such as power, scanning speed, ratio of line gap, and number of line were selected as important factors. A Web-based design tool was developed to generate patterns of light guide panel, and the tool may assist the designer to develop optimized patterns. Topcon-BM7 was used for luminance measurement of each specimen 100mm$\times$100mm area. By Taguchi method optimized levels of each parameters such as 40W of power, 30mm/s of scanning speed, 100:50 ratio of pattern gap, and 90 line of pattern were found by Taguchi method.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.414-415
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• 2007

PMMA light guiding plate with nano pattern was fabricated by nano imprinting technology. Silicon mold was fabricated by conventional photolithography. A nickel stamper was fabricated by electroplating process using silicon mold. Nano imprinting was performed on PMMA plate at $140^{\circ}C$ under pressure of 20kN. The nano pattern on PMMA plate was investigated using FE-SEM.

• 제어로봇시스템학회논문지
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• 제14권10호
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• pp.1005-1013
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• 2008

This paper describes a new sensor system for 3D range measurement using the structured infrared light. Environment and obstacle sensing is the key issue for mobile robot localization and navigation. Laser scanners and infrared scanners cover $180^{\circ}$ and are accurate but too expensive. Those sensors use rotating light beams so that the range measurements are constrained on a plane. 3D measurements are much more useful in many ways for obstacle detection, map building and localization. Stereo vision is very common way of getting the depth information of 3D environment. However, it requires that the correspondence should be clearly identified and it also heavily depends on the light condition of the environment. Instead of using stereo camera, monocular camera and the projected infrared light are used in order to reduce the effects of the ambient light while getting 3D depth map. Modeling of the projected light pattern enabled precise estimation of the range. Identification of the cells from the pattern is the key issue in the proposed method. Several methods of correctly identifying the cells are discussed and verified with experiments.

• 전기학회논문지P
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• 제66권4호
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• pp.242-246
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• 2017

In this study, it was investigated about optical simulation in high brightness and high uniformity general lighting using glass light guide plate. And we adopt edge-light emission type light plate. Edge-light type lighting has been used LCD application, especially note PC or smart phone backlight unit. Because it had the good properties such as slim shape and light weight. We thought this type was suitable for general lighting application such as wall attached type or ceiling mount type. But many of edge-light type lighting had problems. It called slanted output light rays. That was main key parameter how could control the direction of output light rays. We investigated the solution of this problems, using ray tracing method, we recognized the major fact of the solution relied on the geometric structure of diffusing dot shape. We set the conditions of aspect ratio in diffusing dot shape such as 0.5 to 1. And, at first, we designed diffusing dots shape based on the results of optical simulation and made specimen. as above condition, and acquired good result in confirming dots shape such as the value of the output rays's peak angle was around 75 degrees. And good light distribution characteristics were measured by slated spectro-radiometer. It was shown that the effective ways of designing light distribution characteristics using optical simulation such as ray tracing linear method for making general lighting using glass light guide plate.