PROCEDE POUR MEMORISER DES INFORMATIONS SE PRESENTANT SOUS LA FORME DE SIGNAUX ELECTRIQUES

摘要

The present invention is directed to a method of recording information, which is in the form of electrical signals, on a storage medium by simultaneously exposing the light sensitive storage medium with a light beam which is modulated with the electric signals to be recorded and a reference light beam to form a track of information in the form of holograms on the storage medium. The method further includes retrieving the information contained in the holograms of the track of information by projecting a light beam on the track of holograms to form a reconstructed image and detecting the information from the images with a photoelectric transducer which converts the information in the reconstructed images into electrical signals. In one embodiment of the invention, sound signals are recorded in a sound groove adjacent to the information track of holograms and are retrieved simultaneously with retrieving information from the hologram track of information. To retrieve information from this embodiment, a retrieval apparatus having a needle for retrieving information in the sound groove on an information retrieval head which includes a device for projecting the reading light beam and a photodetector for detecting information retrieved by the reading light beam. The needle of the sound head also functions to guide the reading light beam along the information track as the needle moves in the sound groove. The invention also relates to a storage medium having a sound groove for storing sound signals and an information track of holograms formed on a light sensitive surface thereof.