Plano-Convex Lens Fabrication for Distance Sensor based on Single Vision

Abstract

A real-time distance sensing system based on single vision is necessary to obtain distance information and the image at the same time for Advanced Driver Assistance System (ADAS). The sensor system developed in my laboratory uses barrel with three lenses. By simulation of CodeV software for the lens barrel, combination of two plano-convex lenses and one concave-convex lens was optimized for converging to CIS with 90.6% at 17lp/mm and 37.6% at 51lp/mm for f/14 in Modulation Transfer Function (MTF). This paper reports the fabrication of plano-convex lens using only one mask by microfabrication. Diameter and plane surface of lens was determined by using cavity on silicon substrate. The height of glass cylinder depends on Chemical-Mechanical Polishing (CMP) and the glass cylinder transforms to lens with spherical surface in thermal reflow process at 850.. Whole system including lens barrel has a few cubic centimeter size favorably compared with Lidar and stereo vision.