中大機構典藏-NCU Institutional Repository-提供博碩士論文、考古題、期刊論文、研究計畫等下載:Item 987654321/81035
English  |  正體中文  |  简体中文  |  Items with full text/Total items : 76531/76531 (100%)
Visitors : 29756793      Online Users : 364
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version

    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/81035

    Title: 點矩陣式LED交通標誌之光學元件設計與評估;Optical Lens Design and Evaluation of LED Traffic Signs of Dot Matrix Type
    Authors: 方俊皓;Fang, Jiun-Hau
    Contributors: 照明與顯示科技研究所
    Keywords: LED交通標誌;套件;背向照明;概化估計方程式;LED traffic signs;Lens;Backward lighting;Generalized estimating equation
    Date: 2019-08-12
    Issue Date: 2019-09-03 15:26:25 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 現今LED技術日新月異,在生活中各處皆可見到LED產品的應用,LED的低耗電、高流明、使用壽命長等優點使得LED儼然成為照明等相關應用的主流,在交通標誌上也是如此,為了增加夜間行駛的安全性,LED交通標誌也在逐漸增加,但LED標誌優劣仍是需要評估的。在先前研究之四種LED交通標誌結果中,針對各個標誌進行了舒適度、判別度與喜好度三個面向進行主觀感受問卷分析,但分析數據僅在各個面向獨立比較,而本研究利用概化估計方程式,將此三種面向的數據同時納入考量計算出一整合三者之邊際均值作為評估之綜合得分,隨後以各個LED交通標誌進行事後成對比較,其比較結果與先前研究結果相似,且利用這種估計方法可得單一得分作為指標,能更直觀的評估LED交通標誌不同設計的優劣,後續相關實驗可改採用此種方式進行評估。
    ;LED technology is changing with each passing day. LEDs have been widely used in lighting applications, including traffic signs. In order to improve the safety of night driving, more and more traffic signs have utilized LEDs. But these traffic signs need to be evaluated. Our previous studies have evaluated four custom-made LED highway traffic signs with different designs in three aspects, including the legibility, visual comfort and preferences. Each aspect was evaluated independently at the time. The current study uses the generalized estimating equations to calculate the marginal mean as the evaluation score for each sign’s messages when legibility, visual comfort and preferences across all signs are controlled.
      The other study in this thesis is modifying the lens design with partial backward lighting in our previous studies to be used on LED traffic signs of dot matrix type. We designed a total of 11 lenses back then, and among them two lenses were more effective and applicable. The lens that we selected for the ergonomic experiment is based on a thin plastic sleeve with one end coated with 90 % highly reflective coating. The lens was designed to be fitted on bullet-shaped LEDs, but the LEDs used on the signs have silicone on the outer layer for waterproof and dustproof. So the lens is larger than the original design. In order to be durable, the lens material is changed from acrylic to polycarbonate. The influence of the above factors increases the illumination area of the backward light, and the intensity decreases. As a result, the power ratio of front-facing light to backward light is 10.38:1, which is still within the acceptable range although it is different from the original expectation.
      The ergonomic experiments evaluate the legibility, visual comfort and preferences of each part of the traffic sign at the distance of 75 m and 30 m. The experimental data are estimated by the method of generalized estimation equations described in the previous paragraph. Then the pairwise comparisons on the mean evaluation scores are tested in three ways, including the data of Wan word, Li word and both of them. The results show that the lens with partial backward lighting has no benefit in improving the visual quality of LED traffic signs of the dot matrix type. Nevertheless, future experiments can still try some other lenses and tune the optical design to control the illumination area and intensity of backward lighting, in order to achieve better visual quality of LED traffic signs of dot matrix type.
    Appears in Collections:[Institute of Lighting and Display Science ] Electronic Thesis & Dissertation

    Files in This Item:

    File Description SizeFormat

    All items in NCUIR are protected by copyright, with all rights reserved.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - 隱私權政策聲明