METHOD OF FILM INSPECTION WITH A MICROSCOPICAL IMAGE ANALYZER

摘要

TITLE METHOD OF FILM INSPECTION WITH A MICROSCOPICAL IMAGE ANALYZER An automated system is used for the inspection of a transparent film which has been metallized by vaporizing a metal so that it impacts the film's surface at a preselected angle, wherein the metallized film sample is illuminated with a light source, and the transmitted light is passed through a microscope to a video camera, which produces a videoscan. The videoscan is digitized, stored in a computer memory, and processed pixel by pixel by the computer which calculates asperity height distribution from the number and lengths of metallizing shadows caused by asperities on the film surface. This method is especially useful for inspecting film to be used for recording devices, especially for video tapes, where accurate information on the asperity height distribution is required.