Automatic contactless optical evaluation of reflecting surface quality - using photoelectric transducers and point or laser illumination source

摘要

An arrangement for automatic contactless evaluation of the quality of reflecting surfaces enables the quality factors to be converted into electrical signals by photoelectric transducers such as phototransistors, photomultipliers, or imaging tubes. They provide practical, reliable, and economical evaluation of large surfaces. An optically reflected light field is created by point or parallel light illumination from a laser or point source. The field is scanned by the photoelectric transducers whose signals are evaluated to derive the quality factors. An image of the intensity distribution of the reflected light may be formed on a ground glass plate to enable direct visual evaluation instead of automatic sensing and signal evaluation. The quality characteristic may be the variance of the measured signal divided by its square.