AUTOMATIC ADVANCE MECHANISM FOR MICROFICHE READER

摘要

A microfiche reader keyed to a tape recorder includes a platen receiving a microfiche having a series of images or frames arranged in successive parallel rows and columns. The platen is mounted slidably on a carriage for movement laterally of the reader in the direction of a row or X axis of the microfiche and the carriage is in turn mounted slidably on a chassis for movement front-to-back in the direction of a column or X axis of the microfiche. The platen and carriage are each spring-biased in one direction of their travel into end positions placing one of the images in the beam of a light source. A track in a face of the platen of a grid formation has parallel track sections for the respective columns interconnected at the ends. A guide pin on the chassis engages this track and a pawl-rack mechanism is operable to step the carriage against the force of its return spring by successive images. When the guide pin has reached the end of a track section the pawl is disengaged and the carriage is spring returned and the platen spring shifted sidewise to place the first image of the next column into the light beam, and so on until all images have been scanned. When the end of the microfiche is reached the guide pin is disengaged causing the carriage to be spring returned home and the platen is shifted manually against its spring bias to start position after which the guide pin is reengaged with the track. The microfiche may then be replayed or be replaced by another.