Rapidly accessible optically stored information

Claim 1

An optical information retrieval system comprising: a film having a series of frames which has recorded at each frame thereof a first hologram of an information object, and a second hologram of the Fraunhofer form over a majority of the area of said frame of a binary encoded index object said first hologram being recorded with a first reference beam and said second hologram being recorded with a second reference beam, said first and second reference beams each having a unique and different angle of incidence upon said film; means for continuously driving said film; means for applying first and second coherent light beams to the moving film at incident angles substantially identical to the incident angles of said first and second reference beams respectively, so as to reconstruct an image of said information objects and of said binary encoded index objects; a viewing screen and means for projecting said image of said information objects upon the viewing screen; an array of light sensing elements disposed at the position of said image of said binary encoded index objects for detecting the binary code of said index objects during movement of said film and for producing a binary output signal indicative thereof, the image of each said index object from a particular frame remaining stationary and superimposed over said array of light sensing elements during the entire time that any portion thereof is in the second coherent light beam; and comparator means adapted to receive a binary address signal associated with a frame of recorded information object and connected to receive the array binary output signal, said comparator means having an output signal connected to said film driving means for stopping said film when the received signals correspond.