Browsing by Author "Lee, Hsiao-Wen"

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Color Quality Improvement of Micro LED Display Image by TMP LED Design
(2018-01-01)
Lee, Hsiao-Wen
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Wang, Ting-Jay
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Lin, Bor-Shyh
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交大名義發表
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光電系統研究所
In recent years, Micro LED technology has been popularly developed. How to improve the issue of color stability in Micro LED technology is an important and also a difficult research topic. Here, the brightness decay and color displacement in high chip temperature are the two major factors in the color quality of Micro LED display image. In this paper, the technique of thin metal package is applied in the LED package to effectively improve the material thermal resistance of the LED package. By improving the material thermal resistance of the LED package, it could improve the brightness decay 5% in LED high junction temperature. The proposed method could reduce 0.01 of Cx displacement in LED high junction temperature and control Cy displacement less than 0.005 in chip junction temperature 45 degrees to 110 degrees. From the experimental results, the proposed method could exactly improve the color quality of quantum well Micro LED display image in high temperature.
Improvement of illumination uniformity for LED flat panel light by using micro-secondary lens array
(2012-11-05)
Lee, Hsiao-Wen
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Lin, Bor-Shyh
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光電系統研究所
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影像與生醫光電研究所
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生醫電子轉譯研究中心
LED flat panel light is an innovative lighting product in recent years. However, current flat panel light products still contain some drawbacks, such as narrow lighting areas and hot spots. In this study, a micro-secondary lens array technique was proposed and applied for the design of the light guide surface to improve the illumination uniformity. By using the micro-secondary lens array, the candela distribution of the LED flat panel light can be adjusted to similar to batwing distribution to improve the illumination uniformity. The experimental results show that the enhancement of the floor illumination uniformity is about 61%, and that of the wall illumination uniformity is about 20.5%. (C) 2012 Optical Society of America
Micro-lens array design on a flexible light-emitting diode package for indoor lighting
(2015-10-01)
Lee, Hsiao-Wen
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Lin, Bor-Shyh
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光電系統研究所
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光電工程學系
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Institute of Photonic System
An advanced, ultra-thin, flexible LED (FLED) package technique is first proposed in this study, where a polyimide substrate was used as the lead frame package material due to its physical stability in thermal processing. The experimental results showed that the thickness of the mockup sample measured by a vernier caliper was 260 mu m and 35% thinner than the Panasonic organic LED lighting panel announced on 4 March 2014 in Tokyo. Moreover, the flexible angle of the ultra-thin LED package was 200.54 degrees when it surrounded a disk with a 1 cm radius. A design of a micro-lens array manufactured by silicone molding on the FLED is also proposed in this study. Finally, different types of micro-lenses were applied to different lighting regions to investigate their lighting effects. (C) 2015 Optical Society of America
The Surveillance Transceiver Module Design for Improvement of Irradiance Coverage and Image Grayscale Quality
(2019-02-01)
Lee, Hsiao-Wen
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Lin, Bor-Shyh
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光電系統研究所
;
影像與生醫光電研究所
;
Institute of Photonic System
Night image quality is gradually emphasized in surveillance industry in past years, and the requirement for the night image definition standards is enhanced. A traditional flashlight-like circularly symmetric light is gradually not suitable for the industry, and the optical design equipped secondary optical elements also encounters the difficulty in space restriction. Package lenses are used for the optical design in this study, mainly replacing the functions of secondary optics and solve the restriction of inadequate internal space of a camera. Meanwhile, the light design of a light-emitting module is proceeded to match the characteristic of a camera image capturing 4:3 or 16:9. Radiant coverage and irradiance efficiency are two parameters to judge the light quality. A new design, under the irradiance efficiency 100%, could enhance the original radiant coverage from 0.366 to 0.825, increasing up to 2.25 times. Besides, the image irradiance uniformity also increases from 0.47 to 0.714, with the increase up to 1.52 times. The package lens design is gradually accepted by international surveillance manufacturers.