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Claim 1

A RAPID ACCESS HIGH DENSITY DATA STORAGE DEVICE INCLUDING IN COMBINATION A PLURALITY OF PLATES OF SOLID IMPRESSIONABLE THERMOPLASTIC FILM EACH HAVING DATA BEARING LIGHT MODIFYING MARKS FORMED THEREON, SAID MARKS BEING FORMED ON EACH OF SAID PLATES IN A RECTANGULAR ARRAY OF RECTANGULAR SUB-BLOCKS WHICH DEFINE RELATIVELY WIDE INTERSECTING AVENUES AND STREETS TO PROVIDE QUICK ACCESS TO THE DATA CONTAINED IN ANY ONE SELECTED SUB-BLOCK, AND WITH THE DATA IN EACH OF THE SUB-BLOCKS BEING ARRANGED IN LINES IN THE ORDER OF ONE MIL APART WITH THE DATA IN EACH LINE BEING FORMED IN WORDS SPACED IN THE ORDER OF ONE MIL APART AND EACH WORD BEING FORMED FROM BITS OF INFORMATION LIKEWISE SPACED IN THE ORDER OF ONE MIL APART, A RAPID SCANNING LIGHT SOURCE COMPRISING A FLYING SPOT SCANNER HAVING A WIDE ANGLE OF DEFLECTION IN TWO TRANSVERSE DIRECTIONS POSISTIONED TO VIEW THE PLURALITY OF PLATES AND CAPABLE OF RAPIDLY INDEXING A BEAM OF LIGHT TO A SELECTED ONE OF THE PLATES TO THE INTERSECTION OF A STREET AND AVENUE BORDERING A DESIRED SUB-BLOCK OF DATA, A RESPECTIVE SET OF PHOTOMULTIPLIER DEVICES POSITIONED TO VIEW EACH OF SAID PLURALITY OF PLATES OF THERMOPLASTIC FILM, ONE PAIR OF PHOTOMULTIPLIERS IN EACH SET BEING ARRANGED TRANSVERSE TO THE REMAINING PAIR OF PHOTOMULTIPLIERS AND TO THE LINES OF DATA IN THE SUB-BLOCK, MEANS INCLUDING A FIRST ADDRESS REGISTER FOR SELECTING ONE SET OF PHOTOMULTIPLIERS ADJACENT A DESIRED PLATE OF THERMOPLASTIC FILM, SWITCHING MEANS CONTROLLED BY SAID FIRST ADDRESS REGISTER FOR SWITCHING THE SELECTED SET OF PHOTOMULTIPLIERS TO TWO DIFFERENCE AMPLIFIERS AND TO A