Design of The Bicycle LED Head Light Using Variable-Focus-Parabolic Surface

• Main Authors: Chia-Ming Chang, 張家銘
• Other Authors: 蔡忠佑
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/8hkv9d

碩士 === 國立虎尾科技大學 === 機械與電腦輔助工程系碩士班 === 101 === A LED projection system is proposed comprising a LED chip and a variable-focus-parabolic (VFP) reflector in which the focal length varies as a function of the vertical displacement of the incidence point relative to the horizontal centerline of the LED chip. The light ray paths within the projection system are analyzed using a skew-ray tracing approach. A method is then proposed for optimizing the geometry of the projector in such a way as to optimize the uniformity of the illuminance distribution on the target region of image plane, and simultaneously avoid the glare effect. The validity of the proposed optimization method is demonstrated by means of ZEMAX simulation. It is shown that the optimized VFP projector yields a significant improvement the illuminance uniformity and avoids the glare effect compared to conventional spherical and parabolic projectors.