Analysis of Illumination Nonuniformity in Optical Imaging System

Abstract

In order to study the influence by non-uniformity of illumination on testing performance of optical measurement system, the causes of non-uniformity were analyzed. We constructed the relationship model between interval distance of LED light source and illumination. The distribution of illumination with different intervals of LED were simulated. Then relationship model between viewing-field angle at object plane of optical system and illumination was established. Influence of viewing-field angle at object plane on distribution of illumination was studied. The experimental results indicate that non-uniform light source and wide viewing-field angle are two main causes for non-uniformity in optical imaging system. Larger interval distance of LED or viewing-field angle will result in non-uniformity of illumination.