Secondary emission field effect charge storage system

Claim 2

A secondary emission field effect charge storage system comprising: a body of P-type semiconductor material, a pair of bodies of N-type semiconductor material respectively forming PN junctions with opposite sides of said P-type body in a first dimension thereby forming an NPN transistor, said P and N-type bodies forming a P-channel field effect transistor in a second dimension generally perpendicular to said first dimension, one of said N-type bodies having an outer surface having secondary emissive properties; means for collecting secondary electrons emitted from said surface in response to electron bombardment thereof whereby said surface has a posiTive charge stored thereon; and switching means for respectively selectively making first, second and third electrical connections of the other of said pair of N-type bodies and opposite ends of the P-channel of said P-channel transistor to predetermined potentials.

Claim 3

The system of claim 1 further comprising a third body of N-type semiconductor material forming a PN junction with said P-type body in said second dimension for preventing flow of current in said P-channel in a direction opposite said first-named current flow, said switching means selectively connecting said other and third N-type bodies and a part of said P-type body on the side of said pair of N-type bodies remote from said third N-type body to said potentials.

Claim 4

The system of claim 1 further comprising a direct current source for providing said potentials, said source having positive and negative potential points, a first intermediate potential point, and a second intermediate potential point more negative than said first intermediate potential point, and a load resistor connected to said first intermediate potential point; said switching means in said first connection thereof coupling parts of said P-channel respectively on opposite sides of said pair of N-type bodies to said negative potential point, and said other N-type body to said positive potential point; said switching means in said second connection thereof coupling one of said P-channel parts to said load resistor, said other N-type body to said second intermediate potential point, and the other of said P-channel parts to said negative potential point; said switching means in said third connection thereof coupling both of said P-channel parts to said load resistor and said other N-type body to said second intermediate potential point.

Claim 5

The system of claim 3 further comprising a diode coupled in series with said other P-channel part for preventing current flow in said P-channel in a direction opposite that of said first-named current flow.

Claim 6

The system of claim 1 wherein said P-type body has first and second generally parallel opposite sides spaced-apart in said first dimension and first and second generally parallel opposite edges spaced-apart in said second dimension, said edges respectively forming the opposite ends of said P-channel, said first and second N-type bodies respectively forming PN junctions with said first and second sides, and further comprising first and second means for respectively making electrical contact with said first and second edges, and means for coupling said contact means to said switching means, said potentials being applied in said first connection to bias both said NPN transistor and said P-channel transistor to cutoff thereby to permit said charge storage, said potentials being applied in said second connection to bias said NPN transistor to cutoff and said P-channel transistor to below cutoff thereby to permit current flow in said P-channel as modulated by said charge to provide a readout signal, said potentials being applied in said third connection to bias said P-channel transistor to cutoff thereby to neutralize the charge on said surface.

Claim 7

The system of claim 1 wherein said P-type body is elongated in a third dimension mutually generally perpendicular to said first and second dimensions, and further comprising at least a second pair of bodies of N-type semiconductor material spaced from said first-named pair in said third dimension and respectively forming PN junctions with said opposite sides of said P-type body in said first dimensions thereby forming a second NPN transistor, said P-type body and said second pair of N-type bodies forming a second P-channel field effect transistor in said second dimension, the corresponding one of said second pair of N-type bodies having an outer surface having secondary emissive properties, said secondary electron collecting means also collecting secondary electrons emitted from said surface of said second pair of N-type bodies, said switching means also selectively making said first, second and third connections of the other of said second pair of N-type bodies and the P-channel of said second P-channel transistor to said predetermined potentials thereby respectively to provide charging of said surface of said one of said second pair of N-type bodies, a readout signal from said second P-channel, and neutralization of the charge on said last-named surface.

Claim 8

The system of claim 1 wherein said first-named body has spaced opposite edges generally parallel with said first dimensions and forming the opposite ends of said P-channel, and further comprising a second body of P-type semiconductor material, said second P-type body having a first dimension generally parallel with the first dimension of said first P-type body and a second dimension forming an extension of the second dimension of said first P-type body, a second pair of bodies of N-type semiconductor material respectively forming PN junctions with opposite sides of said second P-type body in its said first dimension thereby forming a second NPN transistor, said second P-type body and said second pair of N-type bodies forming a second P-channel field effect transistor in the second dimension of said second P-type body, said second P-type body also having spaced opposite edges generally parallel with its first dimension and forming the opposite ends of said second P channel, first edges of said first and second P-type bodies being in juxtaposed relation, the corresponding one of said second pair of N-type bodies having an outer surface having secondary emissive properties, said secondary electron collecting means also collecting secondary electrons emitted from said surface of said second pair of N-type bodies, said switching means also selectively making said first, second and third connections of the other of said second pair of N-type bodies and the P-channel of said second P-channel transistor to said predetermined potentials thereby respectively to provide charging of said surface of said one of said second pair of N-type bodies, a readout signal from said second P-channel, and neutralization of the charge on said last-named surface.

Claim 9

The system of claim 7 wherein the other one of both of said pairs of N-type bodies are connected together and to said switching means, said first edges of said first and second P-type bodies being connected together and to said switching means.

Claim 10

The system of claim 6 wherein said first P-type body has spaced opposite edges generally parallel with said third dimension and forming the opposite ends of said first and second P-channels, and further comprising a second body of P-type semiconductor material, said second P-type body having a first dimension generally parallel with the first dimension of said first P-type body and a second dimension forming an extension of the second dimension of said first P-type body, said second P-type body being elongated in a third dimension generally parallel with the third dimension of said first P-type body, at least third and fourth pairs of bodies of N-type semiconductor material respectively forming two pairs of PN junctions with opposite sides of said second P-type body in its first dimension and being spaced-apart in its third dimension thereby forming third and fourth NPN transistors, said second P-type body and said third and fourth pairs of N-type bodies respectively forming third and fourth P-channel field effect transistors in the second dimension of said second P-type body, said second P-type body also having spaced opposite edges generally parallel with its third dimension and forming the opposite ends of said third and fourth P-channels, first edges of said first and second P-type bodies being in juxtaposed relation, said third and fourth pairs of N-type bodies being respectively spaced from said first and second pairs of N-type bodies in said second dimensions thereby forming a mosaic, the corresponding one of each of said third and fourth pairs of N-type bodies having an outer surface having secondary emissive properties, said secondary electron collecting means also collecting secondary electrons emitted from said surfaces of third and fourth pairs of N-type bodies, said switching means also selectively making said first, second and third connections of the other one of each of said third and fourth pairs of N-type bodies and the P-channels of said third and fourth P-channel transistors to said predetermined potentials thereby respectively to provide charging of said surface of said one of said third and fourth pairs of N-type bodies, readout signals from each of said third and fourth P-channels, and neutralization of said charges on said last-named surfaces.

Claim 11

The system of claim 9 wherein the other one of both of said first and third pairs of N-type bodies are connected together and to said switching means, the other one of both of said second and fourth pairs of N-type bodies being connected together and to said switching means, said first edges of said first and second P-type bodies being connected together and to said switching means.

Claim 12

The system of claim 9 wherein said switching means includes a diode matrix, and further comprising means for energizing said matrix to provide said second connections in a predetermined sequence.

Claim 13

The system of claim 9 wherein each of said NPN and P-channel transistors forms an element, the elements in each of said P-type bodies forming a line, and means coupled to said switching means for sequentially actuating the same to provide said second connections for the elements of each line in succession thereby to provide said readout signals from said elements in line and frame raster fashion.

Claim 14

The system of claim 12 wherein said switching means includes first and second diode matrices, and further comprising first circuit means for connecting the other one of both of said first and third pairs of N-type bodies to said first matrix, second circuit means for connecting the other one of both of said second and fourth N-type bodies to said first matrix, said first matrix providing sequential switching of successive columns of the other ones of said pairs of N-type bodies to said second condition thereby providing line scanning, third circuit means for connecting the second edge of said first N-type body to said second matrix, fourth circuit means for connecting said first edges of said first and second P-type bodies to said second matrix, and fifth circuit means for connecting said second edge of said second P-type to said second matrix, said second matrix providing sequential switching of successive lines of said P-channels to said second condition thereby providing frame scanning.

Claim 15

The system of claim 13 wherein said actuating means comprises a first binary pulse counting register having at least first and second stages respectively coupled to said first and second circuit means, clock pulse generating means coupled to said first register for supplying pulses thereto, a second binary pulse counting register having at least three stages respectively coupled to said third, fourth and fifth circuit means, and means for coupling said first register to said second register for supplying a pulse thereto in response to each said line scan.

Claim 16

The system of claim 13 further comprising means for actuating both of said matrices to provide said third connection.

Claim 17

The system of claim 9 further comprising photocathode means for converting an optical image to an electron image, said photocathode means being spaced from said mosaic with said surfaces of said one of said pairs of N-type bodies facing said photocathode means, said collecting means being intermediate said surfaces and said photocathode means, and means for directing said electron image from said photocathode means toward saiD surfaces for impingement thereon.

Claim 18

A combined NPN and P-channel field effect transistor device comprising: a body of P-type semiconductor material having a wide dimension and a narrow dimension, a pair of bodies of N-type semiconductor material respectively forming PN junctions with opposite sides of said P-type body in said narrow dimension thereby forming an NPN transistor, a further N-type body spaced from said pair of bodies and extending transversely through said P-type body between said opposite sides, said P and N-type bodies forming a P-channel field effect transistor in said wide dimension generally perpendicular to said narrow dimension, and means for selectively applying predetermined potentials to opposite ends of said P-channel and to said N-type bodies whereby said device may be biased to function selectively as an NPN transistor and a P-channel field effect transistor.

Claim 19

A combined NPN and P-channel field effect transistor device comprising: a body of P-type semiconductor material having a wide dimension and a narrow dimension, a pair of bodies of N-type semiconductor material respectively forming PN junctions with opposite sides of said P-type body in said narrow dimension thereby forming an NPN transistor, a further N-type body spaced from said pair of bodies and extending transversely through said P-type body between said opposite sides, said P and N-type bodies forming a P-channel field effect transistor in said wide dimension generally perpendicular to said narrow dimension, and means for selectively applying predetermined potentials to opposite ends of said P-channel and to said N-type bodies whereby said device may be biased to function selectively as an NPN transistor and a P-channel field effect transistor.

Claim 20

The device of claim 17 wherein said means for applying a potential to one of said N-type bodies comprises an outer surface of said one N-type body having secondary electron emissive properties capable of storing a positive charge thereon in response to electron bombardment thereof.

Claim 21

The device of claim 17 wherein said further N-type body forms a PN junction with one end of said P-channel for preventing reverse current flow therein.

Claim 22

The device of claim 18 including means adjacent said outer surface for collecting secondary electrons emitted therefrom.

Claim 23

The device of claim 20 including switching means for selectively applying said potentials to obtain an output signal in accordance with said charge.