Circularly polarized vision system for attenuation of reflection and glare

The paper presents the use of applying circular polarization in a vision system. It describes how reflections and glare are reduced when illuminating a reflecting surface with circularly polarized light and collecting scattered light through the same circular polarizer. Even if usage of linear polarizers in vision systems is common, the use of circularly polarized light offers advantages due to the simplicity of the setup, which is composed of a single polarizing plate, without any need for accurate angular alignment, enhancing the contrast without significant loss of illumination due to the absence of dark field regions. Reduction of glare reduces image saturation, therefore allowing for a better contrast in images acquired from highly reflective surfaces