Design of Ultra Wide Angle Lens System for Car

• Main Authors: Jun-qi Wang, 王俊棋
• Other Authors: Wen-Shing Sun
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/65127159265834438546

碩士 === 國立中央大學 === 光電科學研究所 === 100 === The purpose of this study is to control the relative illumination on the image and design an ultra-wide angle lens that installed around a car. The concept of projected solid angle, that control the relative illumination on the image area and discuss how to use the F-θ distortion to estimate the deformation of image, is proposed in this study. We use its geometric relationship to reduce the sensitivity of thickness variation and element decenter, which can successfully increase the yield rate of the ultra wide angle lens. Calculating the projected solid angle by user defined function with the software is different from that by the default method. The maximum error rate between them is about 8 %, but the characteristic curves are similar. If we considered the transmittance factor, the maximum error rate between them will be reduced to 0.94 %. Besides, we estimate the variation of the real image height to avoid the defect of F-θ distortion, and set the targets for the maximum field of view. Furthermore, let the aspheric surface smoother and increase the thickness between any aspheric surfaces, which can reduce the tolerance sensitivity of the thickness variation and the element decenter. Finally, an ultra-wide angle lens with the properties of 150 degree field of view and more than 75.2 % relative illumination is successfully designed in this study.