Apparatus for electronically mapping frames on an updatable microfiche

Abstract From the Canadian patent

An apparatus for electronically mapping an updatable microfiche includes a microprocessor-based analyzer programmed to control and evaluate optical scanning of the imaging frame areas arranged in generally parallel rows and columns across, the entire microfiche. Optical photosensors are used to detect the presence of a frame mark within an expected region of an imaged area. An electronic data mask retrievably stored in a mask table memory array is used to screen the output data from the sensors. The mask table is derived from relative sensor position data collected during a scanning operation on a calibrated microfiche. The calibration routine also determines average sensitivity levels of …