Flat electron control device utilizing a uniform space-charge cloud of free electrons as a virtual cathode

Claim 2

A flat visual display device, comprising: (a) a flat face plate having a front face, an opposite back face, and means on the latter which, as a result of the impingement of electrons thereon, provides a visual image at said front face; (b) an arrangement including cathode means for establishing a uniform space-charge cloud of free electrons within a planar band parallel with and rear­ward of the back face of said display face plate; and (c) address means disposed in spaced-apart, confronting relationship with the back face of said face plate between the latter and said uniform space-charge cloud for acting on electrons within said cloud in a controlled way so as to cause the electrons acted upon to impinge on specific areas of the electrically posi­tive screen of said face plate in order to produce a desired image at the front face of said face plate.

Claim 3

A device according to Claim 1 wherein said address means includes an address plate and wherein said address plate includes: an apertured dielectric substrate having a front face confronting said face plate and a back face confronting said space-charge cloud; a first electrode array positioned on the back face of said substrate; a second electrode array positioned on the front face of said substrate; and means for voltage biasing said electrode arrays in a manner which causes the address plate to act upon electrons within said cloud in said controlled way, whereby to produce said desired image at the front face of said face plate.

Claim 4

A device according to Claim 2 wherein said cathode means serves to provide a supply of free electons behind said address plate, and wherein said arrangement for establishing said uniform space-charge cloud includes said first electrode array along with said cathode means and also a voltage biased backing elec­trode extending in a plane parallel with and behind said space charge cloud and a voltage biased grid-shaped accelerator electrode extending in a plane parallel with and between said space-charge cloud and said backing electrode, said first electrode array, backing electrode and accelerator electrode together acting on the free electrons supplied by said cathode means for establish­ing said space-charge cloud.

Claim 5

A device according to Claim 3 wherein, during the time the address means does not act on any electrons within said cloud, the voltage bias on each of said first electrode array and backing electrode is at most at or slightly negative with respect to the charges on said free electrons supplied by said cathode means so as to repel the latter and wherein the voltage bias on said accelerator electrode is positive with respect to the charge on said free electrons so as to attract the latter, whereby for any given increment of time a percentage of the electrons supplied by said cathode means will be collected by said accelerator electrode while the remainder of those electrons so supplied will oscillate between planar bands adjacent said first electrode array and said backing electrode as they are drawn back and forth to and through the accelerator electrode, thereby establishing said first-mentioned space-charge cloud within the planar band adjacent to said first electrode array and a second uniform space-­charge cloud within a planar band adjacent to said backing electrode.

Claim 6

A device according to Claim 2 wherein said cathode means includes a plurality of parallel wire-like cath­odes within a plane parallel with and behind said space-charge cloud for providing a supply of free electrons behind said cloud, and wherein said arrange­ment for establishing said uniform space-charge cloud includes said first electrode array along with said wire-like cathodes and also a voltage biased backing electrode extending in a plane parallel with and behind said wire-like cathodes and a voltage biased accelerator electrode extending in a plane parallel with and between said space-charge cloud and said wire-like cathodes, said first electrode array, backing electrode and accelerator electrode together acting on the free electrons supplied by said wire-like cathodes for establishing said space-charge cloud.

Claim 7

A device according to Claim 5 wherein, during the time the address means does not act on any electrons within said cloud, the voltage bais on each of said first electrode array and backing electrode is substan­tially always at or a slightly negative with respect to the charges on said free electrons supplied by said wire-like electrodes so as to repel the free electrons and wherein the voltage bias on said accelerator elec­trode is positive with respect to the charges on said free electrons so as to attract the latter whereby for any given increment of time a percentage of the elec­trons supplied by said cathode means will be collected by said accelerator electrode while the remainder of those electrons so supplied will oscillate between planar bands adjacent said first electrode array and said backing electrodes as they are drawn back and forth to and through the accelerator electrode, thereby establishing said first-mentioned space-charge cloud within the planar band adjacent said first electrode array and a second space-charge cloud within a planer band adjacent said backing electrode.

Claim 8

A device according to Claim 2 wherein said cathode means serves to provide a supply of free electrons behind said address plate, and wherein said arrangement for establishing said uniform space-charge cloud in­cludes said cathode means along with a voltage biased grid shaped buffer electrode extending in a plane parallel with and between said address plate and space-­charge cloud, a voltage biased backing electrode extend­ing in a plane parallel with and behind said space charge cloud and a voltage biased grid shaped accelera­tor electrode extending in a plane parallel with and between said space-charge cloud and said backing elec­trode, said buffer electrode, backing electrode and accelerator electrode together acting on the free electrons supplied by said cathode means for establish­ing said space-charge cloud.

Claim 9

A device according to Claim 7 wherein the voltage bias on each of said buffer electrode and backing electrode is at or is slightly negative with respect to the charges on said free electrons supplied by said cathode means so as to repel said free electrons and wherein the voltage bias on said accelerator electrode is positive with respect to the charges on said free electrons so as to attract the latter, whereby for any given increment of time a percentage of the electrons supplied by said cathode means will be collected by said accelerator electrode while the remainder of those electrons so supplied will oscillate between planar bands adjacent said second electrode array and said backing electrode as they are drawn back and forth to and through the accelerator electrode, thereby estab­lishing said first-mentioned space-charge cloud within the planar band adjacent to said buffer electrode and a second space-charge cloud within the planar band adja­cent said to backing electrode.

Claim 10

A device according to Claim 8 wherein said cathode means includes a plurality of parallel wire-like cathodes disposed within a plane parallel with and between said space-charge cloud and said backing elec­trode for providing said supply of free electrons.

Claim 11

A flat visual display device, comprising: (a) a flat face plate having a front face and opposite back face and electrically positive means on the latter which, as a result of impingement of elec­trons thereon, provides a visual image at said front face; (b) cathode means for providing a supply of free electrons in an area behind and spaced from said face plate; (c) address means including an apertured address plate disposed in spaced-apart, confronting relationship with the back face of said face plate between the latter and said area containing said supply of free electrons; (d) a backing electrode extending in a plane parallel with and behind said area; (e) a grid-shaped accelerator electrode extending in a plane parallel with and between said address grid and said backing electrode within said area; and (f) means for voltage biasing said address means and said backing and accelerator electrodes in a way which causes the three to act on the free electrons supplied by said cathode means within said area to establish a uniform space-charge cloud of free electrons within a planar band parallel with and between said address plate and accelerator grid, whereby the address plate is able to act on electrons within said cloud in a controlled way so as to cause the electrons acted upon to impinge on specific areas of the back face of said face plate in order to produce a desired image at the front face of the face plate.

Claim 12

A flat visual display device, comprising: (a) a flat face plate having a front face and opposite back face and electrically positive means on the latter which, as a result of impingement of elec­trons thereon, provides a visual image at said front face; (b) cathode means for providing a supply of free electrons in an area behind and spaced from said face plate; (c) address means including an apertured address plate disposed in spaced-apart, confronting relationship with the back face of said face plate between the latter and said area containing said supply of free electrons; (d) a backing electrode extending in a plane parallel with and behind said area; (e) a grid-shaped accelerator electrode extending in a plane parallel with and between said address grid and said backing electrode within said area; and (f) means for voltage biasing said address means and said backing and accelerator electrodes in a way which causes the three to act on the free electrons supplied by said cathode means within said area to establish a uniform space-charge cloud of free electrons within a planar band parallel with and between said address plate and accelerator grid, whereby the address plate is able to act on electrons within said cloud in a controlled way so as to cause the electrons acted upon to impinge on specific areas of the back face of said face plate in order to produce a desired image at the front face of the face plate.

Claim 13

A device according to Claim 10 wherein said cathode means includes a plurality of wire-like cathodes within a plane parallel with said face plate and in said area.

Claim 14

A device according to Claim 11 wherein said accel­erator electrode is disposed between said wire-like cathodes and said address plate.

Claim 15

A device according to Claim 10 wherein said address means includes a buffer electrode between said address plate and space-charge cloud.

Claim 16

A flat electron control device, comprising: (a) means defining an electron receiving plane; (b) an arrangement including cathode means for establishing a uniform space-charge cloud of free electrons within a planar band parallel with and rear­ward of said receiving plane; and (c) address means disposed in spaced-apart, confronting relationship with said receiving plane between the latter and said uniform space-charge cloud for acting on electrons within said cloud in a con­trolled way so as to cause the electrons acted upon to be directed into specific areas of said receiving plane.

Claim 17

A flat electron control device, comprising: (a) means defining an electron receiving plane; (b) an arrangement including cathode means for establishing a uniform space-charge cloud of free electrons within a planar band parallel with and rear­ward of said receiving plane; and (c) address means disposed in spaced-apart, confronting relationship with said receiving plane between the latter and said uniform space-charge cloud for acting on electrons within said cloud in a con­trolled way so as to cause the electrons acted upon to be directed into specific areas of said receiving plane.

Claim 22

In a device which requires the use of free elec­trons, an arrangement for supplying said free electrons, said arrangement comprising means including a cathode for establishing a uniform space-charge cloud of free electrons in the form of a planar band at a location remote from said cathode.

Claim 23

In a device which requires the use of free elec­trons, an arrangement for supplying said free electrons, said arrangement comprising means including a cathode for establishing a uniform space-charge cloud of free electrons in the form of a planar band at a location remote from said cathode.

Claim 24

In a flat electron control device including means defining an electron receiving plane, a supply of free electrons, and address means including an address plate having a plurality of spaced-apart apertures there­through, said address means being disposed in spaced-­apart confronting relationship with and behind said receiving plane and configured to act upon free electrons from said supply in a controlled way to cause the electrons acted upon to be directed through specific ones of the apertures and into specific areas of said receiving plane, the improvement comprising: (a) means for producing a source of free electrons at a location remote from said address plate; and (b) means acting on said source of free electrons for establishing space-charge clouds of free electrons which form virtual cathodes at predetermined locations immediately adjacent and behind said apertures in said address plate and which serve as said supply of free electrons to be acted upon by said address means, each of said space-charge clouds displaying a uniform density of free electrons which is greater than the density of free electrons filling the space between said clouds and remotely located source of free electrons, at least during the operation of said device when the supply of free electrons are not being acted upon by said address means.

Claim 25

In a flat electron control device including means defining an electron receiving plane, a supply of free electrons, and address means including an address plate having a plurality of spaced-apart apertures there­through, said address means being disposed in spaced-­apart confronting relationship with and behind said receiving plane and configured to act upon free electrons from said supply in a controlled way to cause the electrons acted upon to be directed through specific ones of the apertures and into specific areas of said receiving plane, the improvement comprising: (a) means for producing a source of free electrons at a location remote from said address plate; and (b) means acting on said source of free electrons for establishing space-charge clouds of free electrons which form virtual cathodes at predetermined locations immediately adjacent and behind said apertures in said address plate and which serve as said supply of free electrons to be acted upon by said address means, each of said space-charge clouds displaying a uniform density of free electrons which is greater than the density of free electrons filling the space between said clouds and remotely located source of free electrons, at least during the operation of said device when the supply of free electrons are not being acted upon by said address means.

Claim 26

The improvement according to Claim 18 wherein the space-charge cloud of free electrons behind any given one of said apertures has substantially the same uniform density of free electrons as the other clouds behind the other apertures.

Claim 27

The improvement according to Claim 19 wherein said means for establishing a space-charge cloud of free electrons behind each of said apertures includes means for establishing a continuous overall cloud defining a generally planar band parallel with said address plate whereby different sections of said overall cloud provide said first mention clouds immediately adjacent and behind respective ones of said apertures.

Claim 28

The improvement according to Claim 18 wherein said means for producing a source of free electrons includes a plurality of wire-like cathodes spaced rearwardly of said address plate and said space-charge clouds.

Claim 29

The improvement according to Claim 18 wherein said means acting on said source of free electrons for establishing a space-charge cloud of free electrons behind each of said apertures includes means for causing a portion of the electrons acted upon to oscillate back and forth between said predetermined locations behind and adjacent said apertures and locations spaced further behind said apertures.

Claim 30

In a flat electron control device including means defining an electron receiving plane, a supply of free electrons, and address means including an address plate having a plurality of spaced-apart apertures therethrough, said address means being disposed in spaced-apart confronting relationship with and behind said receiving plane and configured to act upon free electrons from said supply in a controlled way to cause the electrons acted upon to be directed through specific ones of the apertures and into specific areas of said receiving plane, the improvement comprising: (a) means for producing a source of free electrons at a location remote from said address plate; and (b) means acting on said source of free electrons for causing a portion of the electrons acted upon to oscillate back and forth between first locations immediately adjacent and behind said apertures whereby to form concentrated clouds of free electrons at said first locations which serve as said supply of free electrons acted upon by said address means and second locations further behind said apertures whereby to form concentrated clouds of free electrons at said second locations.

Claim 31

In a flat electron control device including means defining an electron receiving plane, a supply of free electrons, and address means including an address plate having a plurality of spaced-apart apertures therethrough, said address means being disposed in spaced-apart confronting relationship with and behind said receiving plane and configured to act upon free electrons from said supply in a controlled way to cause the electrons acted upon to be directed through specific ones of the apertures and into specific areas of said receiving plane, the improvement comprising: (a) means for producing a source of free electrons at a location remote from said address plate; and (b) means acting on said source of free electrons for causing a portion of the electrons acted upon to oscillate back and forth between first locations immediately adjacent and behind said apertures whereby to form concentrated clouds of free electrons at said first locations which serve as said supply of free electrons acted upon by said address means and second locations further behind said apertures whereby to form concentrated clouds of free electrons at said second locations.

Claim 32

In a method of operating a flat electron control device including means defining an electron receiving plane, a supply of free electrons, and address means including an address plate having a plurality of spaced-apart apertures therethrough, said address means being disposed in spaced-apart confronting relationship with and behind said receiving plane and configured to act upon free electrons from said supply in a controlled way to cause the electrons acted upon to be directed through specific ones of the apertures and into specific areas of said receiving plane, the improvement comprising the steps of: (a) producing a source of free electrons at a location remote from said address plate; and (b) acting on said source of free electrons for establishing space-charge clouds of free electrons which form virtual cathodes at predetermined locations immediately adjacent and behind said apertures in said address plate and serving as said supply of free electrons to be acted upon by said address means, each of said space-charge clouds displaying a uniform density of free electrons which is greater than the density of free electrons filling the space between said clouds and remotely located source of free electrons, at least during the operation of said device when the supply of free electrons are not being acted upon by said address means.

Claim 33

In a method of operating a flat electron control device including means defining an electron receiving plane, a supply of free electrons, and address means including an address plate having a plurality of spaced-apart apertures therethrough, said address means being disposed in spaced-apart confronting relationship with and behind said receiving plane and configured to act upon free electrons from said supply in a controlled way to cause the electrons acted upon to be directed through specific ones of the apertures and into specific areas of said receiving plane, the improvement comprising the steps of: (a) producing a source of free electrons at a location remote from said address plate; and (b) acting on said source of free electrons for establishing space-charge clouds of free electrons which form virtual cathodes at predetermined locations immediately adjacent and behind said apertures in said address plate and serving as said supply of free electrons to be acted upon by said address means, each of said space-charge clouds displaying a uniform density of free electrons which is greater than the density of free electrons filling the space between said clouds and remotely located source of free electrons, at least during the operation of said device when the supply of free electrons are not being acted upon by said address means.

Claim 34

In a method of operating a flat electron control device including means defining an electron receiving plane, a supply of free electrons, and address means including an address plate having a plurality of spaced-apart apertures therethrough, said address means being disposed in spaced-apart confronting relationship with and behind said receiving plane and configured to act upon free electrons from said supply in a controlled way to cause the electrons acted upon to be directed through specific ones of said receiving plane, the improvement comprising the steps of: (a) producing a source of free electrons at a location remote from said address plate; and (b) acting on said source of free electrons for causing a portion of the electrons acted upon to oscillate back and forth between first locations immediately adjacent and behind said apertures whereby to form concentrated clouds of free electrons at said first location serving as said supply of free electrons acted upon by said address means and second locations further behind said apertures whereby to form concentrated clouds of free electrons at said second locations.

Claim 35

In a method of operating a flat electron control device including means defining an electron receiving plane, a supply of free electrons, and address means including an address plate having a plurality of spaced-apart apertures therethrough, said address means being disposed in spaced-apart confronting relationship with and behind said receiving plane and configured to act upon free electrons from said supply in a controlled way to cause the electrons acted upon to be directed through specific ones of said receiving plane, the improvement comprising the steps of: (a) producing a source of free electrons at a location remote from said address plate; and (b) acting on said source of free electrons for causing a portion of the electrons acted upon to oscillate back and forth between first locations immediately adjacent and behind said apertures whereby to form concentrated clouds of free electrons at said first location serving as said supply of free electrons acted upon by said address means and second locations further behind said apertures whereby to form concentrated clouds of free electrons at said second locations.