Research and design of projection objective of automobile pixel headlight

摘要

This article has designed a wide-angle digital micro-projection lens suitable for a 0.55" DMD chip with an aspect ratio of 1∶2 using ZEMAX optical software. The structure of the lens consists of 3 aspherical lenses. It adopts "negative-positive-positive" type reversed telephoto structure, and the lens material is optical plastic PMMA. It can well solve the problems of the off-axis aberration correction and image surface illumination uniformity for wide-angle lens. It has the characteristics of simple structure, small size, easy processing, low cost and large rear working distance. The effective focal length of the lens is 11.163mm, the relative aperture is 1/1.8, the full field of view is 64°, the maximum aperture is less than 32mm, and the total optical length is controlled at 103.6mm. For car lighting, the lens has good imaging quality. At a resolution of 16.5lp/mm, the modulation transfer function (MTF) value of all fields of view is greater than 0.45. The lens is imported into the professional car light distribution software LucidShape to simulate, using a million rays to traces, the result of light distribution meets the current only ADB light distribution regulations, and can achieve various pattern projections.