Random access large-capacity memories

Claim 2

A random access system for information storage and retrieval comprising: a radiation-responsive medium; a source of frequency-modulated carrier signal, the frequency modulations of which represent information to be stored; recording means for recording on said radiation-responsive medium the frequency-modulated carrier signal from said source as an optical diffraction grating wherein the spacing between adjacent parallel lines varies in accordance with said frequency modulations; and optical means for selectively reading out the line space variations of said grating and, hence, the stored information.

Claim 3

The random access system for data storage and retrieval of claim 1 wherein said optical means comprises: a source of substantially monochromatic collimated light; means for selectively directing said monochromatic collimated light onto any one of said recorded gratings; photodetecting means; and means for focusing light emanating from said one of said gratings onto said photodetecting means so as to produce electrical output signals from said photodetecting means in accordance with the data stored in said one of said gratings.

Claim 4

A random access system for data storage and retrieval as set forth in claim 2 wherein said recording means comprises: means for producing an electron beam; first deflection means for progressively deflecting said electron beam in a first direction across said radiation responsive medium; second deflection means for deflecting said electron beam in a second direction, orthogonal to said first direction.

Claim 5

A random access system for data storage and retrieval as set forth in claim 3 wherein said source of frequency-modulated carrier signal comprises: a carrier signal source coupled to said second deflection means; a plurality of oscillators, each oscillator having a different frequency of operation, wherein each frequency of operation represents data to be stored; and modulating means, coupling said plurality of oscillators to said carrier signal source, for modulating the output frequency of said carrier frequency source.

Claim 6

The random access system for data storage and retrieval of claim 2 wherein said radiation-responsive medium comprises a thermoplastic film.

Claim 7

The random access system for data storage and retrieval of claim 3 wherein said radiation-responsive medium comprises a thermoplastic film.

Claim 8

The random access system for data storage and retrieval of claim 4 wherein said radiation-responsive medium comprises a thermoplastic film.

Claim 9

The random access system for data storage and retrieval of claim 6 including means for accelerating said electrons with constant voltage so that said electrons strike said thermoplastic film with uniform intensity.

Claim 10

The random access system for data storage and retrieval of claim 7 including means for accelerating said electrons with constant voltage so that said electrons strike said thermoplastic film with uniform intensity, said means for accelerating said electrons being rendered operative by said carrier signal source only when amplitude of the carrier signal produced by said carrier signal source is between predetermined constant values.

Claim 11

A random access system for data storage and retrieval as set forth in claim 1 wherein said recording means produces a plurality of said optical diffraction gratings and said plurality of optical diffraction gratings are arranged in a matrix of rows and columns.

Claim 12

The random access date storage and retrieval system of claim 10 wherein said optical means for selectively retrieving stored date from said matrix of optical diffraction gratings comprises: a source of substantially monochromatic collimated light; means for selectively directing said monochromatic collimated light onto any one of said gratings in said matrix; photodetecting means; and means for focusing light emanating from said one of said gratings onto said photodetecting means so as to produce electrical output signals from said photodetecting means in accordance with the data stored in said one of said gratings.

Claim 13

The random access data storage and retrieval system of claim 10 wherein said each of said gratings comprises parallel grooves formed of substantially uniform depth in a recording medium.

Claim 14

The random access data storage and retrieval system of claim 11 wherein said each of said gratings comprises parallel grooves formed of substantially uniform depth in a recording medium.

Claim 15

The random access data storage and retrieval system of claim 10 wherein said each of said gratings comprises parallel grooves formed of substantially uniform length and depth in a recording medium.

Claim 16

The random access data storage and retrieval system of claim 11 wherein said each of said gratings comprises parallel grooves formed substantially uniform length and depth in a recording medium.

Claim 17

The random access data storage and retrieval system of claim 10 wherein said optical means for selectively retrieving stored data from said matrix of optical diffraction gratings comprises: at least one beam of laser light; means for selectively directing each beam of said laser light onto any respective one of said gratings in said matrix; at least one photosensitive apparatus; and means for focusing light emanating from said respective one of said gratings onto a respective photosensitive apparatus so as to produce electrical output signals from said respective photosensitive apparatus in accordance with the data stored in said respective one of said gratings.

Claim 18

The random access data storage and retrieval system of claim 16 wherein said focusing means comprises optically aligned cylindrical and spherical lens units disposed between said gratings and said photosensitive apparatus.

Claim 19

Apparatus for recording on a radiation-responsive medium optical diffraction gratings wherein spacing between lines of each of the gratings is controllably variable in accordance with signals representing data to be stored, said apparatus comprising: an evacuated recording chamber; an electron source situated within said chamber; means for positioning said medium within said chamber to permit electrons from said electron source to impinge upon said medium; means for directing said electrons toward positions progressing horizontally across said recording medium; electron deflection means for deflecting said electrons vertically; signal-generating means for producing a constant frequency AC waveform; means for generating a plurality of diverse waveforms each having at least one characteristic representative of data to be stored; means coupled to said signal-generating means for frequency modulating the output signal from said signal-generating means with selected ones of said plurality of diverse waveforms dependent upon data to be stored in a selected diffraction grating; and means coupling said frequency-modulated waveform to said electron deflection means to produce diffraction gratings in said radiation-responsive medium at locations determined by a threshold level in said frequency-modulated AC waveform.

Claim 20

Apparatus for recording on a radiation-responsive medium optical diffraction gratings wherein spacing between lines of each of the gratings is controllably variable in accordance with signals representing data to be stored, said apparatus comprising: an evacuated recording chamber; an electron source situated within said chamber; means for positioning said medium within said chamber to permit electrons from said electron source to impinge upon said medium; means for directing said electrons toward positions progressing horizontally across said recording medium; electron deflection means for deflecting said electrons vertically; signal-generating means for producing a constant frequency AC waveform; means for generating a plurality of diverse waveforms each having at least one characteristic representative of data to be stored; means coupled to said signal-generating means for frequency modulating the output signal from said signal-generating means with selected ones of said plurality of diverse waveforms dependent upon data to be stored in a selected diffraction grating; and means coupling said frequency-modulated waveform to said electron deflection means to produce diffraction gratings in said radiation-responsive medium at locations determined by a threshold level in said frequency-modulated AC waveform.

Claim 21

The apparatus of claim 18 including half-wave rectifying means coupling said signal-generating means to saiD electron deflection means.

Claim 22

The apparatus of claim 18 including electron-accelerating means, and switching means coupling said signal-generating means to said electron-accelerating means, said switching means applying an electron-accelerating potential to said electron-accelerating means only when the amplitude of signal produced by said frequency modulating means is between predetermined constant values.

Claim 23

The apparatus of claim 19 including electron-accelerating means, and switching means coupling said half-wave rectifying means to said electron-accelerating means, said switching means applying an electron-accelerating potential to said electron-accelerating means only when the amplitude of signal produced by said frequency-modulating means is between predetermined constant values.