High speed optical read-out of data stored in an array

Abstract

Data is stored in frames of fixed format at successive intervals along a ribbon or photographic film. Synchronizing marks on the storage medium indicate the location of each data frame and detection of each successive synchronizing mark triggers a light source which illuminates the film with successively different wavelengths of radiant energy. Successive data frames of the successive wavelengths or colors are imaged on successive detector arrays, each detector array having its elements arranged in a pattern similar to the format of the data. When all the detector arrays have been used, the cycle of colors and of detector arrays is repeated. The detector arrays consist of photodiodes operated in the charge storage mode. After exposure, the elements of the arrays are sampled in a predetermined sequence based on the format of the data, to produce the desired high speed output data signal. Thus, the limited read-out speed of the detector arrays is not a limitation on the present system because such read-out is carried out in parallel by use of a number of arrays into which the data has been optically demultiplexed. The stored data may be in either amplitude modulated or holographic form.