碩士 / 國立交通大學 / 工學院精密與自動化工程學程 / 105 / Fisheye lens are the ultra wide-angle lens with the view angle larger than 180 degrees. By applying non-similar imaging principle, fisheye lens could introduce negative distortion to have ultra wide view angle imaging onto a limited image plane. To design proper fisheye lens with 0.3M pixel sensor for the vehicle camera, the current study utilizes reverse telephoto lens as the foundation, combining with optical design software to deal with the aberration comes with the negative distortion. After structural analysis and aberration convergence simulation, the proposed lens were composed by a four-piece compound material lens, including one piece of glass and triplet aspheric plastic lens. The total length of the proposed lens is 11.9mm, which is significantly reduced from the current five-piece lens with 16.5mm in length. In addition, the lesser relative distortion could be achieved by adopting the ultra-short focus design concept. The 0.8mm effective focal length makes a relative distortion of only -50% at 150 degree view angle, while the current lens with effective focal length of 1.34mm would cause a relative distortion of -70%. When the proposed fisheye lens are functioned with 1/4" CMOS image sensor, the 192 degree of horizontal field view angle could be achieved to ensure the coverage of panorama images. The Modulation Transfer Function at the maximum field reaches 0.347 when the cutoff frequency of system is 90lp/mm, which ensures the image quality at the edges of the panorama image.
Identifer | oai:union.ndltd.org:TW/105NCTU5146006 |
Date | January 2016 |
Creators | Tsai, Chen-Shuo, 蔡鎮碩 |
Contributors | Tsai, Jia-Lin, 蔡佳霖 |
Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
Language | zh-TW |
Detected Language | English |
Type | 學位論文 ; thesis |
Format | 70 |
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