US2764711A

US2764711A - Multiple position beam tube

Info

Publication number: US2764711A
Application number: US370137A
Authority: US
Inventors: Kuchinsky Saul
Original assignee: Burroughs Corp
Current assignee: Unisys Corp
Priority date: 1953-07-24
Filing date: 1953-07-24
Publication date: 1956-09-25
Anticipated expiration: 1973-09-25
Also published as: FR1109274A; DE1128570B

Description

Sept. 25, 1956 s. KUCHINSKY MULTIPLE POSITION BEAM TUBE 4 Sheets-Sheet 1 Filed July 24, 1953 INVENTOR SAUL KUCHINSKY BY g AGENT Sept. 25, 1956 s. KUCHINSKY 2,

MULTIPLE POSITION BEAM TUBE Filed July 24, 1953 56 FIG.5I A

4 Sheets-Sheet 2 36 FIG? FIG. l0

l 'rfl l [WEI l lnn l ,3 0 0 26A 52 6 o o 0 E 56 o o o 0 3 INVENTOR SAUL KUCHINSKY AGENT Sept. 25, 1956 s. KUCHINSKY MULTIPLE POSITION BEAM TUBE 4 Sheets-Sheet 3 Filed July 24, 1953 IINVENTOR SAUL KUCHINSKY AGENT Sept. 25, 1956 s. KUCHINSKY 2,

MULTIPLE POSITION BEAM TUBE Filed July 24, 1953 4 Sheets-Sheet 4 FIG. l8

INVENTOR g/{WL KUCHINSKY AGENT 2,764,711 MULTIPLE PosmoN'BEAM'Tum:

Saul Kuchinsky,.Philadelphia, Pa-., assignor to Burroughs Corporation, Detroit, Mich.,.a corporalionntMichigan Application July '24, 1953, Seriail'No. 370,137

ssciaims. c1..-3 1s--21 This is a continuation-impartot-thepresentapplicantis United States Patent copending application Serial No. 291,531, filed June 3,

1952, entitled Multiple Position Electron Beam Device.

This inventionrelates to electron discharge devices and particularly to multiple position beamtubesin which the electron beam is subjected to the influence of a combined magnetic and electrostatic-field.

Such tubes are known in the prior art, but have had a restricted field of use for reasons which ,will be-explained below. Structurally, a typical multiple position tube of the prior art-type comprises, within an hermetically'sealed envelope, a centrally disposed thermionic icathode' around which is disposed a-coaxial array-of generally V shaped elements known as spades, the sides of the V extending in a radial direction. The apex of-each spade faces in the direction of the cathode. Antagnetic field whose lines of .force are substantiallyparallel to'the cathode is provided by an external magnet. Understatic conditions each of the spades is maintained at a positiveipotential, the potential being applied toeach spade through an individual resistance or :resistahcewapacitance :spade loading network. Under static conditions, with all? theispades at a positive potential and the magnetic field applied,-the tube is cut off. Thatis, the attraction of the-electrostatic field, which has substantially circular'equip'otential lines .(as seen along a.pla'ne perpendicular to the-cathode) due to the physical layout ofthespadesand:because all the spades are at substantially the same potential, and

which tends to attract electrons towards 'the :spades,lis overcome by the magnetic field which causes thezcleetrons to follow curvedtpaths around the cathodein accordance with well known physicaltlaws.

However, if the potential appliedrto one-of-the spades is reduced to, for example, the cathode potential, the rather symmetrical electric field mentioned. above. is distorted in the area between the cathodeand the spadeh'aving the lowered. potential. Such distortionof-the electrostaticfield modifiesthe effect of the magnetic field to the extentthat electrons are attracted to the spade-.havingthe lowered potential. Further, after .thespadecircuit voltage is returned to normal, the electron flow through the spade load resistor, previously mentioned, reducesth'e spade potential to an extent sufiicient to. hold theelectron beam on that spade.

Such a device can be used-as a switching tub-e butlis subject to limitations which limit its usefulness- For instance, the spade impedance (even 3 capacities of the order of a few micro-microfarads) must be held to avalue which in itself limits the application of thetube to/many devices. Also, the use-of a spade as an-outputelectrode is inherently ineflicient because the maximum spade current is a small percentage of the total cathode current under normal operatingconditions. 'Furtherpifthe electron stream is modulated, the spade is unsatisfactory as an output electrode. 1

An alternative form of multiple posit-ion beam tube which is known in the prior art is'similar -to thenone described aboverexcept that the: output :of- .thetube ic-taken 2,764,711 Patented Sept. 25;, 1956 from target electrodes which are disposed between the spade electrodes, there being one target between each pair of spades. Each target is maintained at a positive potential. Therefore, part of the electron beam is attracted by the electrostatic field of thetargets adjacent to the spade having the lowered potential. The direction of rotation of the magnetic field determines the target to which the electrons will be attracted, sincethere are two targets, one on each side of the spade, to which electrons could-be attracted.

The use of targets as output electrodes which are separate from the spade loading circuits has the advantage that the tube may becoupled to devices having input impedances other than the spade impedance. However, because the target electrodes are almost as close to the cathode .as'the controlling portion of the spades are, the electrostaticfieldof the targets exert a considerable influence .over the positioning of the electron stream or beam. Thus, variations in target potential, due to the position of the target between the spades, tends to spread the beam. Spreadingor shifting of the beam tends to cause instability of beam holding, for, if any electrons impinge on an adjacent spade, the voltage drop in the load network of that spade and the tendency of the-magnetic field to rotate the :beam will cause the beam to switch positions. -In this tube, --as in the-one described above, modulation of the electron beam would adversely afiect beam holdingstability. Further, the position of t the .targets with respect to adjacent spades provides capacity coupling .between inputspades and output-targets, thus providing cross talk in addition to limiting th upper frequency of operation of the tube.

In addition, because space exists betweenithe target andthe-spade on each side of the target, electrons not'collectedeither by the spade ortarget-will passthroughthis space-and,.under the infiuenceof the magnetic\field,'may be deflected to ether electrodes of the tube, providing undesired cross talk between outputtchannels.

Because of the limited amountof output of;pr-ior art multiple beamtubes, some applications of thetube have required thatthe tube output pass through-additional amplifieror buffer stages, or both, before driving a utilization device.

The operational limitations .of prior art .tubes have restricted-their use to relatively fewapplications. The improved tube of the present invention-is designedttopro- I vide superior operating characteristicsmuse in applications' Where the prior art tubes have proved unsatisfactory and can be used to advantage in .code conversion systems, switching and'multiplexing applications for either modulated or unmodulated signals, counting and-computing devices, and similar-applications requiring high speed beam switching and especially in suchapplications whereexternal circuitry mustabe simplified or equipment must be compact.

A principalobject of the present invention is tov provide an improved multiple position beam tube.

:A second object ofthe present invention; is lIO'iPl'OVldG an improved multiple position beam tube having'useful multiple outputs.

Another object ofthe present invention is-to. provide a multiple position-beam tube in which variations-inoutput load impedance exert little or no effect on the stability of tube. operation.

A further object of the present invention'is toprovide amultiple. position beam tube in which cross talk is minimized.

Still-another object of the invention is .to'provide a. multiple position beam tube having-increased power outputcapabilities.

Yet another .objectof' thepresent'inventicn is to pro vide an improved coding tube,

A still further object of the present invention is to provided a multiple position beam tube including, within an hermetically sealed envelope: an elongated thermionic cathode; an array of elongated trough-shaped spade electrodes each having a pair of radially extending sides joined at the inner edges thereof and disposed in side-byside relation one to another and spaced from and substantially in axial alignment with said cathode, the open parts or side of each of said spades extending generally away from said cathode; at least one apertured or slotted anode disposed adjacent to the open sides of said spades, said apertures or slots being located substantially in line with the space between adjacent spades; and at least one target electrode, said target electrode being disposed adjacent to said anode and on the side opposite said spades, and aligned so that electrons passing through said slots or apertures of said anode will impinge on said target.

Insertion of the slotted or apertured anode between the spades and targets provides an electrostatic shield therebetween, thus isolating the target field, which is subject to change due to output variations, from the area adjacent to the spades. This improves the operating stability of the tube, since the beam holding and directing functions may be practically completely controlled by the spade field independently of the target field.

The anode serves also to minimize cross talk, for most of the electrons which do not impinge on the spade or target associated with the particular beam position are absorbed by the positively charged anode and do not, under the influence of the magnetic field, become attracted to adjacent positively charged target electrodes.

Power output capabilities of tubes made in accordance with the present invention'are increased over that of prior art tubes in two ways. First, because the targets ,are located beyond rather than between the spades, as in prior art tubes, larger area targets may be utilized, with the result that more of the electrons from the beam impinge thereon. Secondly, because the target field exerts very little influence on tube operating stability, larger output voltage variations may be utilized without adversely afiecting tube operation.

An improved coding tube is provided, in accordance with the present invention, by providing apertures or slots in the anode at the various beam positions in accordance with a predetermined coding arrangement. A plurality of targets are disposed with respect to the anode in such a manner that a coded output for each beam position is obtained. Such a tube can, for example, be used to provide decimal to binary conversion in a simple manner and with a minimum of external circuitry associated with the tube.

Tubes made in accordance with the present invention are especially useful as counting or switching tubes if, for example, the anode is slotted at each beam position and separate targets, one opposite each slot, are utilized to achieve a separate output for each beam position. A decade counter tube, a specialized counting tube in which.

in multiplexing or other switching applications, for example, where modulation of the electron beam takes place.

Further, because multiple position beam tubes made in accordance with the present invention have few critical spacings and are comprised of parts which may be easily and economically fabricated, the tubes may be easily assembled and economically produced.

Referring to the accompanying drawings,

Fig. 1 is an isometric view, partly broken away, of a multiple position beam tube, including a magnet supplying a magnetic field therefor, constructed in accordance with the present invention and which is adaptable for use as a code converter tube;

Fig. 2 is a top plan view of the electrode assembly of the tube of Fig. 1 with the top spacing and supporting member thereof omitted;

Fig. 3 is an isometric view, partly broken away, of a mount assembly constructed in accordance with the present invention and adapted for use in a decade counter tube;

Fig. 4 is a schematic view of the tube shown in Fig". 1 and 2 as incorporated into a binary counting circuit;

Fig. 5 is a side elevation view and Fig. 6 is a plan view of the cathode of the tube illustrated in Fig. 1;

Fig. 7 is a side elevation view and Fig. 8 is a plan view of a spade electrode element of the tube shown in Fig. i;

Fig. 9 is a top plan view and Fig. 10 is a side elevation View of a collector ring of the tube shown in Fig. 1;

Fig. 11 is a developed view of the anode electrode employed in the tube of Fig. 1 and showing the binary coded arrangement of the apertures therein;

Fig. 12 is a perspective view, partly broken away, of a tube mount assembly embodying the present invention and illustrating a multiple-position beam tube having ten individual output electrodes;

Fig. 13 is a sectional view of a tube employing the mount assembly of Fig. 12;

Fig. 14 is an exploded view of the mount assembly of Fig. 12, also showing the tube base with contact pins therein;

Fig. 15 is a perspective view of a modification of the anode 32' shown in Fig. 14;

Fig. 16 is a partial sectional view of a tube employing a modification of the tube mount shown in Fig. 12;

Fig. 17 is a partial sectional view of a tube employing another modification of the tube mount of Fig. 12; and

Fig. 18 is an isometric view, partly broken away, of a multiple position beam tube in accordance with the present invention and in which the spades and anodes are arranged in substantially a straight line.

Referring now to Figs. 1 and 2, a multiple position beam tube 20 comprises, within an envelope 22, a contrally disposed thermionic cathode which is illustrated as an indirectly heated cylindrical oxide coated cathode 24. A coaxial and concentric array of elongated trough-shaped spade electrodes 26 is radially disposed with respect to the cathode 24, these spade electrodes also being referred to herein as beam forming or positioning electrodes. Each spade 26, having the general form of a V or U. has its apex facing the cathode 24 while the two sides 30-30 thereof extend outwardly away from the cathode. Surrounding the array of spades 26 on the side opposite v said cathode is a sleeve type anode 32 which is provided an output signal is derived in only one of ten possible f with a plurality of apertures or slots 34. The apertures or slots 34 are aligned with the spaces between adjacent spades. A plurality of ringlike targets or collector electrodes collectively identified by reference character 36 are disposed substantially concentrically about the longitudinal axis of the cathode 24 in axially spaced apart relationship. Each target is aligned with certain ones of the apertures or slots 34 in the anode. The individual target or collector electrodes 36a, 36b, 36c and 36d, there being four such targets in this illustrated embodiment of the invention, are secured to and supported by .75

a plurality ofinsulating support members 38 disposed Parallel: topflie cathode 2A., andl preferably-anterior of:- the target flQCtrOd$F as ShQWllti; Top; and; bottom mica insulating spacers 40.2 and; 425 respectively; maintains the, cathode 24, spades-.26,- and anodew32, in proper: spaced relationship'one to, another.; 5

Le ds for the. ath dehea erdn tz hqwn), cathode 24, each of;the spades; 26,,anode;=32,-. and eachqot :thetargetor: collector electrodes 36,-are, brought nout through-the,- tube base-4.43m the basepins :46. The; magnetic;;field;.for:thca tube-sis providedn y he-magnetAS whichmay be cylindrical in shape and encircle the tubezin the manner shown iILElg-C, 1; Thje; magnet provides aimagneticgfield'; whose: lines-(of: force in the; tube. are; substantially: parallel with .r the longitudinal'axis of; the cathudei24e Inordentoprovide uniform dispersion of the flux lines within thetube, hezvarious;electrodes; leads andasupports; are preferably made; ofi materialsywhich areynon-magnetic;

Asgshown-tin Figs; 5, and;,6',lth'e cathode-24;comprisestcoret Stbhavingxlocatingtbeadst52 adjacent to: each end: i11 order 1' to: axially, locate' the; electron. emissive oxidecoated 1 portion 541 betweenthe .IIllCflxSPflCtiISLAQl and 42;

The spade; electrodes 26 5 each-t comprise, as: shown: in. Figs: 7 and 8', an; elongated trough-shaped; conductive memberrroughly havingya V.-shaped-':transversecross section; Artonguejois'provided on-xeach endtof'the spade 26;for:locating,and, when bent,-.lockingrthe.z spade in position between: the mica spacers w40zandv42:

Figs: 9.*and- 10 represent'plan-andiside elevationrviews, respectively, of one of,the'ring-likevtargets 0r-collecton electrodes {36.

Fig: 11' shows: the; cylindricalanode as it: would appear it ."itrwerezunfolded and-flattened onto: ac-plane :SlJIi-r face; ThezaperturesfiA-in the anode 32ishown in Fig. 11i aregarranged: to' provide; an output, in;binaryform, cor.- responding'toxtheznumerals zero to nine, inclusive, as:W-i1l 35 beaeXplained later. Thus, withthetbinary codingarrange ment-on-;the anode, a.simple-convenient tube arrangement is provided for converting from a2 decimal to at binary number system.-

The tube=20 operatesgenerally,asvfollows, Referring 40 to Fig. 1, under static conditionszall'. the spades r26 are at substantially the samepotential. The anode 32' is positively charged, and the'magneticfield; of the magnet 48 permeates the tube 20in lines extendingsubstantially parallel to the longitudinal axis of the cathode 24. Under theabove conditions the magnetic field cuts ofl'the flow-of electrons which would normally, beattracted .to.the.p,osie tively charged spades 26 and anode 32bycausing the electrons to follow curvedpaths .aroundthecathode 24in. the space between the cathode and the spades.

If, however, the'potential of one of thespades, such as, that indicated atv 26a,tis; lowered to near' the cathode potential, for example, the electrostatic field betweenthe' spade 26a andthe cathode 24-is altered to the extent that themagneticfield is :nolonger ableto-cutofitheflow. of electrons to theareaadjacentspade 26:1,; Once; electrons flow; to the; spade: 26athezvoltage; drop; across: the. spade. impedance is sufiicientto hold the; beaminthat position even though external meansfor, lowering the spade potential be removed, Since onlyasmall proportion of the electronsuinzthe beam is needed for reducing the spade potential:to near cathodepotential: (thespade impedance is'high), most ofi'the electrousofthe beam or, streamare attracted-to the'anode electrode 32iand to the targets 36. Theeside of the spade-26ato whichtheelectronswill-go dependsupon the: direction of'rotation giventhem by-the magnetic; field; As shown in :Fig. 2 by-way 'of' example, the electron-beam- 112; istinfiuenced by, the polarity of; the magneticfield to rotate, ina: counterclockwise; direction.- Assu ning that. the electron beam 112 isimpingingon the edge-of the; spade-26a,- most of the beam; current (that in CXCCSSzOf' the amount'neededztmkeep the potential of the spadeaatgnear to cathodetpotential): willagocto the anode 32311d"l10:0116 or'more of the target electrodes '36 ifz'anode- 32 hast-apertures or slots;34lbetweencspades.-26z1tand26b, 75.

h eposi icn: 0f: the. electron; beam 1 may; be changed'con venientlyabywayof example;,by applyingtatnegative pulse to;the anode 32; thus momentarily/lowering-the:potential of thejanode. Lowering the-anode potential'hastthe-eifect of spreadingjtheelectron beam, betweensspades- 26a and the next adjacent spade 26b in the present-case, causingajsmalltamountof electrons todmpinge on spade 26b; The impinging of-electronsof: spade 26b causes -the p0ten-- tial. of thatxspade to drop, altering the electrostatic-field in the area adjacent to spadezb and, because of the tendency of the magnetic fieldito rotate the beamin the ounterclockwise direction, causes-the electron beamto switch fromspade26t to spade-26b. Once: the electron beam:112 has.-left spade 26a the potentialiofthat spade rises to its usual positive: value. It should'be noted that ifithenegative pulseapplied to the-anode '32iis of too great" adoration, the beam may advancemorethanone-spade or beam position.

Fig. 4showsaschematioview of a: decimal-tobinary converter. tube ofthe type shown inFigs. 1 and 2 and a circuit suitable for: use in operation of the tube, The spades26 are arranged concentrically around the cathode 24. Theanode 32, which has aperturesor slots-34 asshown. in Fig. 11; for example, surrounds the arrayot" spadesl'oz. The circle 58'adjacent-to theanode 32-reprcsents. the targetstiio asseen inplan. Four leads, 60a, 60b, 60c, and'60d; shown: connected to the circle 58 rep--- resent: the leads to.the targets 36a, 36b, 36cand 36d" respectively shown in Figs. 1 and 11. Each of thespad'es: 263186011131641 to aconductor 62 through a separate resistance-capacitance network, as, for example, resistor 64 and-* capacitor -66; The resistors and capacitorsin each of the: spade networks: are ofsimilar values. Forexample, resis-' tor 64 may have avalue of 200,000 ohms and capacitor 66- mayhave'a: value of 30 micro-microfarads-t The operation of the device of Fig; 4- is as follows: stepping pulses are, applied to the terminal 68 and are coupled to the control grid 70 0f the tube 72 through thecondenser 74' and the I resistor 7 6 connected in series between-the grid 70 and-the terminal 68; The output of" the tube-72, taken from theanode 78 and developed across the anode load resistor 80,- is applied-to the grid or control} electrode 820f the-tube S t through capacitor-86. The tube 84, together with inductances SS and 90, which are closely coupled, comprises a blocking oscillator" which: delivers an output pulse through a coupled inductance 92f and shunt resistor 94to'the anode 32; Ano-de'78 of the tube 72 is connected to asource of-positive potential (250" volts, for example) indicated by the battery 96 through itsload resistor80.- The anode'98of the tube 84' is'oon:

nectedto the potential sourceor battery 96 through the inductance 90. The

cathodes

100 and 102 Otthetubes '72 and 84; respectively, are maintained at ground 'p oten tial. The cathode 24 of tube 20 isconnected to ground" through'the fixed current limiting resistor 104 and the variable resistor 106. The-grid resistor -108;of-tube 72%.

has a high value, 470,000 ohms, for example, andjs con nected between the battery 96 and the junction betweenthe condenser74 and the resistor 76, The control grid; 82-ofthe tube 34 is biased negativelyby the potential of" the battery 110 applied through the resistor 1 12 and the inductance 88.

Each time a negative pulse is appliedtothe terminal 68 the electron beam of the tube 20 is caused'to advance one position. When power is applied to the tube 20,211 negative potential, relative to the positive potential, supplied by battery 96, applied to spade 260 through the lead 114 cause that spade to assume the potential of the negative pulse. The negative potential may be pro vided, for example, by grounding the spade 260 through the resistor 118' by operating the switch 120'which nor mally connects the spade 26c to the battery 96. If the negative-pulse approaches oris below the potential 'of the cathode 24,- anelectron beamwill flow to the spade 260- because of the change in the e1ectrostatic=field between that spade and the cathode 24'as mentioned above.

Once the electron beam impinges on the spade 260 it locks in through its spade impedance 116. The path of the beam moves in a clockwise or counter-clockwise direction, depending on the polarity of the magnetic field, and only a small portion of the beam continues to impinge on the spade 26c to maintain the locking effect. The remainder of the electron beam, for example, impinges on that portion of the anode 32 between spade 26c and spade 26d. The negative input pulse can be removed and the electron beam will continue to impinge upon the said portion of the anode 32 and the spade 26c since the current flowing through the resistance 116 maintains the spade 260 at close to the potential of the cathode 24. Thus, upon initial operation of the tube, the electron beam can be caused to always flow to the same position. In effect, a negative potential applied to the lead 114, such as by opening switch 113, indexes the electron beam or stream on the zero position of the tube, which position is defined as existing when the beam is locked on the spade 26c.

Pulses which are to be counted are applied to the input terminal 68. The input pulse, as applied to the circuit illustrated in Fig. 4, must be a negative pulse, and is applied to the control grid 7b of the tube 72' through the capacitor 74 and resistor 76. When the grid 70 of the tube 72 is caused to become negative the current flow through the tube 72 decreases and the potential on the anode 78 thereof rises positively. The increase of anode potential of the tube 72 results in a positive increase in the potential of the control grid 82 of the tube 84, since the anode 78 of the tube 72 is capacity coupled to the grid 82 of the tube 84. Since the tube 84 and the associated inductances 88 and 9t) constitute a blocking oscillator, as mentioned previously, the negative pulse generated at the anode 98 of the tube 84 due to the positive potential impressed on the control grid 82 thereof will be of a definite duration determined by the constants of the circuit. In the particular circuit illustrated theduration of the pulse generated at the anode of the tube 84 will be of the order of 0.8 microsecond. This pulse, inductively coupled through the inductances 9d and 92 to the anode 32 of the tube 20, decreases the potential of the anode 32 to approximately cathode potential, or even below cathode potential. As mentioned previously, the lowering of the anode potential to near the potential of the cathode 24 has the effect of broadening or switching the electron beam. When the beam is switched a few electrons impinge on the next adjacent spade (26d in Fig. 4), causing a voltage drop across the spade impedance. Once the potential on the spade 26d starts to decrease, more electrons are attracted to the spade due to further switching of the beam, and the spade, due to the increased electron fiow thereto, is reduced to near or even below the potential of the cathode 24 because of the voltage drop across the spade impedance. Thus, with the electrostatic 1 field being favorable adjacent to spade 26d, the magnetic field causes the beam to advance to the leading edge of spade 262, that is, the beam will impinge on spade 26c,

but the major part of the beam will impinge on that portion of the target which lies between spades 26d and 26e. In a similar manner the beam may be advanced from spade to spade each time a pulse is applied to the terminal 68. In the illustrated embodiment of the invention, there are ten beam positions, as may be seen in Fig. 2 and Fig. 4. These beam positions as used in the coding tube of Figs. 1, 2 and 4, correspond to the numerals to 9 inclusive. The beam, following its advance to the 9 position will advance to the zero or index position where it was positioned when the tube was indexed by applying a pulse to the lead 114. The tube may, of course, be rc-indexed V at any time without advancing in a discrete step by step manner, by applying a pulse to the lead 114. In some casesit may be also desirable to cut off the electron beam.

The explanation of the operation of the device and circuit illustrated in. Fig. 4 has thus far. been concerned With one type of movement and control of the electron beam within thetube. Referring now to Figs. 1 and 11, it may be seen that the anode 32 is provided with a series of apertures which are arranged, generally speaking, in nine 5 columns and four levels. The columns of apertures are aligned with respect to the positions of the beam to pro vide an output to one or more of the targets 36 when the electron beamis-in any of the 1 to 9 positions. There are no apertures aligned with the zero position, since no output is to be taken from the target electodes 36 when the beam is in that position. The output of the tube is taken from four target rings 36a, b, c, and d which are arranged in levels around the anode 32 as shown in Fig. l and indicated along the right side of the anode in Fig. 11. t i i It can be seen that when the electron beam of the tube 20 is in the zero or indexing position, no electrons impinge on any of the four target rings. That is, since there are no slots or apertures 34 in the anode 32 in linewith the zero beam position of the tube, no electrons pass on to the targets 36." However, the anode 32has at least one aperture or slot 34 in each of the beam positions corresponding to the numbers 1 to 9, and consequently when the electron beam is in the position corresponding to one of these numbers, electrons will impinge on one or more of the targets 36a, b, c, and d and provide an output which is, as will be explained in detail later, indicative of the binary code equivalent of the decimal number input to the tube.

By way of background information, in thebinary code a number is expressed in terms" of exponents of the numeral 2. That is, the number 7 in binary code would be 2 +2 +2 expressed in terms of exponents of the numeral 2, or 4+2+1 expressed in the usual decimal notatation. Such a system of number representation is well adapted to use in computers, for example, and the general use where electron tubes are employed in number representation as is Well known in the art.

The following table illustrates how the four targets 36a, [2, c, d are utilized to provide a binary coded output from decimal input to the tube:

Binary Code Representation and Arithmetical Equivalent Output on Target ecimal Input Referring now to Fig. 1, it is seen that the apertures 34 in the anode 32 are so positioned with respect to the targets 36a, b, c, d that the electron stream passes through the anode 32 to impinge on a different combination of the targets 36a, b, c, d at different beam positions. Fig. 11 shows more clearly the arrangement of the apertures 34 which provide a binary coded output when the input to thetube causes the beam to lock in at one of the ten beam positions. The anode 32 as shown in Fig. 11, is unfolded onto a flat surface. .The beam positions with respect to the anode 32 are indicated adjacent to the anode as are the target ring positions. The arrangement of the apertures 34 with respect to the beam positions and to the target rings 36a, b, c, d may thus be seen to correspond to the binary coding arrangement shown in the table above and the output of the tube, as taken from the target rings 36a, b, c, d is thus indicative of the binary coded equivalent of the decimal input to the tube. It should be realized that tubes made in accordance with the present invention are adaptable to other output coding arrangements. The target rings 36 are shown in Figs. 1 and 11 as...being ;substantially perpendicular; tothe columns.'of.. apertures.. on. slots. 34,. ,but this arrangement. is not- .necessarily so.

Thesspades26 have been..heretofore:described ashav ing a..trough-shap ed transverse cross. section; V.-shaped cross:section,.etc., butit shouldbe'recog nized thatsolid on tubularzspades, .or. spades having. other configurations.

Likethe: coding. tube previously, described,.the tube.

shown.in.Figs..12,...l3, and.14 has an elongated thermionic cathode. 24.which is: centrally disposed within a. hermetically sealed envelope.22,and.is surrounded; by. a.

substantially, cylindrical array of-elongated .trougheshaped spades. Asleeve type cylindrical anode.32. of larger diameter. thanthe spade; array. is disposed coaxially. and concentrically withrespect thereto.v Theanode has elona gated siots 34, equal in number to the number of beam. positions-.of..the tube, disposedsubstantially inparallel alignment with.- the. cathode. 2A.. and; so...located..withrespect .to. the space. between. adjoining. pairs of. spades that a substantial part of-the. electron beamlockedin on any, spade. will; pass. through. oneof. the, slots. 3.4L In. the embodiment-shown in.F.ig., 13. theslots are disposed directly inlinewiththe spacebetweeneach pair ofjadjoim ing spadesh However, in.vie.w. of. the. facttha-t v the elec: tron. beamusually approaches the. slots in.. a slightly curved. path, it. is. possible to. pass. a. larger. percentage. of .thebeam. through the. slots. if. the. latter. are ofiset. cir-. cumfrentially slightly. with. respect. to, the. spaces be: tween the spades. In. such; case. the..direction.in which the. slots. are offset should: be opposite. to. the direction of rotationoithe electron beam...

Inorder. to prov-idea separate. output from every. beam. position, individual. target electrodes 36f are. disposed, op, posite each slot.34-fin.the.anode 32 and the; side. of; the.

anode, which: is opposite. to. they spades 216;. Whilethe.

targets 36 are aligned. Withthe. space between. theadja centv spades. asv are,v the. slots 3.4. in thev anode 32,. the. targets 3'6. like. the slots 34. may be circumferentially displaced. slightly, withirespect. to. the spades. and in. the: same directiomasthe. slots.34'-are displacedin orderto permit a. larger portion of they electron.beam. toimping e, thereon. Fig 16 shows. the ottset anode: slotsand target.

arrangement.

Leads (not shown) tothe individual spades, individual targets, anode, andJcathode.arebroughtpout througltthe;

stem 124 (which may. beglass). tothebase pins..46... The:

switching.tiinerequiredtomove the beamfrommne post-- tion to another may be mademoreuniformif-thespade. resistors. 64 are located within. the. tube. envelope. One

such arrangement of thespade. resistors-64is shown. in

Figs. 12 and.13';.in.which.each.of. theresistors. 64..-is..dis.-

posed' between thesides oi. the. spadelfi. to..which.,the.

individual. resistor. is connected. Because. the resistors 64are connectedjdirectly to the. spades. in. thisrarranger ment, lead capacitancesare. minimized/and have much:

less etfect on. the: switching. timebetween. individual .heam. positions thanv iflleads. were provided. to'resistors. which.

were l'ocated'outside the; tube.

Other advantages. accrue to theuseiof'. resistorswhich are located inside the tube. envelope. Albthe resistors;

operate at thesame femperatureand are .unaflfectedtby,

changesvin. humidity. Because the. resistors-operatedn atv vacuum, they mayhave a: larger wattage. rating, per. unit.

Physical size without burning. out and. consequently, re

sult in-eai-saving:in,space.--Wi1ich is an .importan-t,adyantag; where: equipment is..- to. be miniaturized. However; I the; increase in switching-speed, andthe uniformity-of. wave: shape. achievedthrough the. use of the internalspade. impedance elements 6.4; is. more than sufficient reason-to justify, their-use. In addition to'theadvantageousi increase in. switching. speed made.- possible by the use of: internal. spade resisfors,. theswitching. time. from; one. beam-position to another; is-.made.moreunif0rm.; Such: uniformity becomes impprtant whenit isconsidered-that in many applications a discrete pulse. width -is.;-requir.ed.: to. switchthe .position' of. the beam.v Variations in spade. impedances would result in. changes. inthe. pulse 1 widths: required toswitch thebeanrfrom position. toposition; Thus; thespulse.widthrrequired. to switchthe .beam to, an. average beam. position might,.for,.example, .be too. short. to. switch. the beam to. another: position or.long=.enough. toadvanee the: beam .twopositions: if only a-very sl'lortiv pulse width. is. required,v for switching; from .one& position. to another.

Further, a reduction in the number. ofleads which must. pass-through the. tube envelope. mayyhe. achievedif the switching of the beam-isto beaccomplished by means.- other th-anipulsing the sp ade;electrodes. If'the-spades. arenot-used: to. switchthe electron bearnzfrom one p.osi-- tionz lIQt3I10thf, individual spade leadsare-unnecessary. and the internally mounted spade resistors arelconnected. to-a 'commondeadwhichmay bezconnectedto the source of.spadeoperatingpotential..

A quantized or stepped outpubtrom the. tube of Figs. 12, 13,, or. 14 may beobtainedifthe anode 32." shown in. Fig. 15 is. substituted for. the. slotted anode shownin those. figures. The; slot.leng th=is-.variedi to control the: amount. of. output current available at the target of. each beam,p.osition, Thequantized. or'stepped. output c0uld, of. course, .be. achievedby varying-other. dimensions of :the. slots 34'.

Another.;variation otthev tube: shown iii-.Eig. 12, is shown in Fig. 3. In that structure the anode32iv is slotted at. only one beamposition, providinga decadecounter tube. having an output in only one of thetenbeam positions. The spaderesistorsM shown.in,Eig. 3 are similar. to those .inliig. 1 2. i

The; anode. 32 as; shown inrvarious formsain, each of. the embodiments. of. the. present invention,= acts asxan. electrostatic. sl'n'eld between. the targets and. spades, thus.v allowingthe. target, output to varyto a greater. extent than wasformerly possible without the target field extending inwardly: to. suchaanextentt that; it causes the beam to switch. The positioning fi the targets, beyondthe spades,

rather than between; themalsoreduces the, effect. of, the. target. field. on. beam switching 'stability. Further, this. arrangementv isolates the; target from. adjoining spades. both capacity wise. and. physically. Reduction in-spade-tospade capacitance (through the target) results in improved beam'switchingcharacteristics which. result in the. unmodulated, outputr wave. more nearly resembling a.- square wave. Thephysical isolation. of spades. and targets, permits targetshaving larger: areas to housed; thus permitting langenpower: output, Fringe electronsnean the. edge of the.electron.beamimpinge. onthe anode 32' and:v thus arenot free'to. escape to adjoining electrodesand causecrosstalk. Theanode 32 and targets 36.n1ay advantageously be composedof. materialswhich are'poor. secondary. electron emittersor. the electrodes-may be pro: vided with a.coating which reduces, thesecondary emis sion capabilities of. the..material..

Fig..l7. shows an. electrode configuration which is. similar to, that. shown in.Fig.. 13, but has suppressor electrodes126 disposed. between adjacent. targets. These sup.- pressor. electrodes,v whichare illustratedas elongated rods, arenormally maintained) at or near. to cathode: potential and tendv to. repel. stray: electrons: which do not impinge. on theintended. targetorany other electrons which might, under. the. influence of. the. magnetiofield or. the positive.

11 field, on adjacent targets, tend to impinge on adjacent targets and cause cross talk. The suppressors 126 may be connected to the cathode inside the tube or they may be provided With a common lead through the tube envelope in order that they may be biased in any desired manner.

Fig. 18 shows a straight line version of the coding tube illustrated in Fig. 1. In this tube the spades 26'. individual coded anodes 32' and target or collector electrodes 36 are disposed in substantially a linear manner. The coding of the anodes 32" and the arrangement of the targets 36" with respect to the coding apertures 34 may be similar to those shown in connection with Fig. l. The general functioning of the tube is similar to that of the concentric type coding tube shown in Fig. 1 in that a crossed electric and magnetic field are utilized to form and switch the electron beam from one position to another. The cathode 24 lies adjacent to a sheet-like rail electrode 123 which is bent and folded back (at 130) towards the spade 26 which is most remote from the cathode 24. The rail 128 is electrically connected to the above mentioned remote spade and functions as an equipotential boundary for the electron beam. The generally L shaped electrode 32" is maintained at a potential such that electrons emitted from the cathode 24' are, under the combined influence of the magnetic and electrostatic fields, caused to travel along a generally trochoidal path.

Electron beam switching from one beam position to another is accomplished in a manner similar to that used to switch the beam in the tube in Fig. l. Leads, not shown, connect the various electrodes to the base pins 46.

While specific embodiments of the present invention have been described, it will be apparent that this invention is by no means limited to the exact forms illustrated or the use indicated, but that many variations may be made in the particular structure used and the purpose for which it is employed without departing from the scope of the invention as set forth in the appended claims.

What I claim is:

l. A multiple position beam tube comprising, within a hermetically sealed envelope, an elongated thermionic cathode, an array of elongated trough-shaped spade elec trodes disposed in side-by-side relation one to another and spaced from said cathode, the sides of each of said spades extending generally away from said cathode, at least one anode disposed adjacent to the open sides of said spades and remote from said cathode relative thereto, said anode having at least one aperture, said aperture being located substantially in line with the space between a pair of adjacent spades, and at least one target elec trode, said target electrode being disposed adjacent to said anode and on the side of said anode which is opposite said spades and aligned with one of said apertures so that electrons passing through the aperture will impinge on the target.

2. A magnetic field tube having positioned in the order named; an electron emissive cathode, a plurality of spades, a shielding electrode remote from said cathode relative to said spades and having an aperture, and a collector electrode, said collector electrode being displaced behind the aperture of said shielding electrode with respect to the cathode to intercept electron beam current passing through the aperture; and means for establishing a mag netic field permeating the area occupied by said elements and having field lines thereof extending substantially perpendicular to the alignment of the elements.

3. An electron discharge device comprising, in combination, an electron emissive cathode element, a plurality of spaced apart electron beam directing spade elements positioned substantially equidistant from the cathode and in insulatingly spaced relationship to one another, a plurality of electron beam collecting elements positioned in spaced relation to said spade elements, said beam collecting elements being more remotely disposed from said cathode than are said spade elements and aligned with the spaces between said spade elements to intercept an electron beam emitted by the cathode element and directed through any of said spaces, means for permeating the area occupied by said elements with a magnetic field having field lines extending substantially perpendicular to a common line extending across said spaces and joining the several spade elements, and beam switching anode means positioned intermediate said spade elements and said beam collecting elements.

4. In an electron discharge device having crossed magnetic and electrical fields, a rod-shaped electron emissive cathode disposed substantially in axial alignment with the lines of force of magnetic field within said device, a sleeveshaped anode positioned about said cathode with its axis substantially coincident with that of the cathode, a plurality of beam directing spade electrodes symmetrically disposed in spaced apart relation interiorly of the sleeve anode and adjacent to, but spaced from the inner surface thereof, said anode being provided with a plurality of apertures in column arrangement, said columns being aligned substantially between adjacent pairs of said beam directing electrodes, and a plurality of collector electrodes disposed in spaced apart relation exteriorly of the sleeve anode and adjacent to, but spaced from the outer surface thereof, said collector electrodes having portions thereof overlying said apertured columns of the anode.

5. Electron discharge apparatus comprising, in combination, a rod-shaped electron emissive cathode, a sleeveshaped anode positioned about said cathode with its longitudinal axis substantially coincident with that of the cathode, a plurality of beam directing electrodes disposed in circularly spaced apart relation interiorly of the sleeve anode and adjacent to, but spaced from the inner surface thereof, said anode being provided with a plurality "ing electrodes, a plurality of collector electrodes disposed in spaced apart relation exteriorly of the sleeve anode and adjacent to, but spaced from the outer surface thereof, each of said collector electrodes overlying one or more of said apertured columns so as to intercept at least one of said radial planes, magnetic means operable to permeate thedischarge space of the apparatus with a substantially uniform magnetic fieldhaving field lines extending substantially parallel to the axis of the cathode, means for impressing on the anode and on each of the beam directing electrodes a potential which is positive with respect to the cathode, and means for modifying the impressed positive potential to form a discrete electron beam which is directed along one of said radial planes and extends from the cathode through the space between an adjacent pair of said beam directing electrodes to said sleeve anode, a substantial portion of the electron beam thus formed being passed through the aperturecl column on the radial plane of the beam for impingement upon a collector electrode overlying the apertured column.

6. Electron discharge apparatus comprising, in combination, a rod-like electron emissive cathode, shielding electrode means concentrically surrounding said cathode, a circular row of spaced apart electron beam positioning electrodes positioned interiorly of said shielding electrode means and adjacent to but spaced from the inner surface thereof, each of said beam positioning electrodes being generally U-shaped in cross section and disposed with the base of the U nearest to the cathode, said shielding electrode means providing a plurality of apertures positioned in line with the spaces between adjacent pairs of the beam positioning electrodes, a plurality of spaced apart collector electrodes positioned outside of said shielding electrode means adjacent to but spaced from the outer surface thereof so as to overlie said apertures,

magnetic means arranged for providing a magnetic field permeating the electron dischargespace with field lines extending substantially parallel to the cathode,meansfor impressing a-positive potential with'respect to the cathode on said shielding electrode means and on ,the separate beam positioning electrodes, means for modifying such impressed potential to form a discrete electron beam extending from said cathode through said apertured shieldingelectrode means for impingement on at least one of said collector-electrodes, and output leads separately connected to the collector electrodes, each of the collector electrodes and its respective output lead'being electrically isolated from said shielding electrode means except when said electron beamimpinges thereon.

7. Electron discharge apparatus comprising a rodshaped electron emissive cathode, a sleeve-shaped anode arranged concentrically around said cathode, said anode having a plurality of-rows of apertures extending substantially parallel to the axis of'the cathode and spaced circularly around the anode, a plurality of ring-shaped collector electrodes encircling said anode in radially spaced relation thereto and in axially spaced relation to one another and in such a manner that the collector electrodes overlie the-rows of apertures, a plurality of beam forming and positioning electrodes positionedbetween said cathode and said anode, .means to permeate the space encompassed by said collector electrodes with a ;substantially uniform magnetic field, said magnetic field having the flux lines thereof extending substantially parallel to the axis of the cathode, and D. C.-means to impress relative differences in electrical potential on said cathode, said anode and said beam forming and positioning electrodes to cause an electron beam to beformed and directed through any selected one of said rows of apertures for impingement on the collector electrodes overlying the same.

8.'Electron discharge apparatusdn accordance with claim 7, wherein means is provided for delivering electricalpulses to said apertured anode forbeam switching purposes.

9. A multiple position beam tube comprising, within a hermetically sealed-envelope, an-elongated thermionic cathode, an array of beam directing spades, said array of'spades comprising a plurality of similar elongated electrodes symmetrically disposed with 'respect'to said cathode and each presenting a curved surface thereto, an anode exteriorly of said array of spades, said anode having apertures, each of said apertures in said anode being aligned with the space between a pair of adjacent spades, a plurality of target electrodes exteriorly of the anode, said target electrodes being aligned with said apertures in the anode, and suppressor-electrodes respectively positioned adjacent said target electrodes.

10. A multiple position beamrtube in accordance'with claim'9, wherein said suppressor electrodes are conductively connected to said cathode.

11. A multipleposition'beam tube comprising within a substantially evacuated envelope, an elongated cylindrical cathode disposed centrally thereof, said cathode having an electron emissive portion, a plurality of substantially identical spade electrodes, said spade electrodes being substantially coextensive in length with said emissive portion of said cathode and being arranged to form a circular array centered on said cathode in which said spades are equidistantly and insulatingly spaced one from another, a hollow cylindrical anode, said anode being disposed exteriorly of said array of spades and surrounding the same, said anode having a plurality of substantially identical slots spaced equidistantly around the circumference thereof, each slot being aligned with the space between a pair of'adjacent spades and corresponding in length to substantially that of the electron emissive portion of said cathode, a plurality of conductive planar target electrodes equal in number to the number of slots in said anode and shaped similarly to said slots and each being at least as large in area as said slots, said target i4 electrodes being disposed exteriorly of saidanode and adjacenttoand aligned with each of said slots whereby electrons passing from said cathode between a pair of spades and through the anode 'slotaligningwith the space between the pair of spades will impinge on the target electrode. aligning with the slot.

12. A multipleposition beam tube comprising within asubstantially evacuated envelope, an elongated cylindrical cathode disposed .centrally .thereof, saidcathode having an electron emissive portion, .a plurality of substantially identical spade electrodes, said spade electrodes. being substantially coextensive in length with said emissive portion of said cathode and being arranged to form a circular array in' which said spades are equidistantly and insulatingly spaced one from another and in which each spade presents a curvedvsurface towards said cathode, a hollow cylindrical anode, said .anode being disposed exteriorly of said array'of' spades and surrounding the same, said anode having a vplurality of substantially identical slots spaced equidistantly aroundthe circumference thereof, each slot being aligned .With the space between a pair of adjacent spades and corresponding inlength to substantially that of the electron emissive portion of said cathode, a plurality of conductive planar target electrodes equal in number to the number vof slots in said 'anode and shaped similarly to said slots and each being at'least as large in area as said slots, said target electrodes being disposed exteriorly of said anode and adjacent to and aligned with each of said slots whereby electrons passing from said cathode between a pair of spades and through the anode slot aligning with the space between the pair of spades will'impinge ion the target elect-rode aligning with the slot, and'an elongated electron suppressor electrode positioned in side-by-side "relation to each of said target electrodes.

-l3. A multiple position beam tube comprising Within a substantially evacuated envelope, an elongated cylindrical cathode disposed centrally thereof, said cathode having an electron emissive portion, a plurality of substantially identical spade electrodes, said spade electrodes being substantially coextensive in length with said emissive portion of said cathode, and being arranged to form a circular-array in which said spades are equidistantly and insulatingly spaced one from another and in which each spade presents a curved surface towards said cathode, a hollow cylindrical anode, said anode being disposed exteriorly of said array of spades and surrounding the same, said anode having a plurality of substantially identical slots spaced equidistantly around the'circumference thereof, each slot being aligned with the space between a pair of.adjacent spades and corresponding in length to substantially that of the electron emissive portion of said cathode, a plurality of conductive planar target electrodes equal in number to the number of slots in said'anode and shaped similarly to said slots and each being at least as large in area as said slots, said targets being disposed exteriorly of said anode and adjacent to and aligned with each of said slots whereby electrons passing fromsaid cathode between a pair of spades and through the anode slot aligning with the space between the pair of spades'will impinge on the target electrode aligning with the slots, and a plurality of elongated electrodes, one of said elongated electrodes being disposed in side-by-side relation to each of said targets and insulated therefrom, each of said elongated electrodes being electrically conductively connected to said cathode within said evacuated envelope.

'14. A multiple position beam tube comprising within an evacuated envelope, an elongated cylindrical cathode disposed centrally thereof, said cathode having an electron emissive portion, a plurality of substantially identical spade electrodes, said spade electrodes being coextensive in length with said emissive portion of said cathode and being arranged to form a cylindrical array centered on said cathode in which said spades are equidistantly and insulatingly spaced one from another and in which each spade presents a curved surface towards said 'cathode,'a

hollow cylindrical anode, said anode being disposed exteriorly of said array of spades and surrounding the same,

said anode having a plurality of apertures spaced around the circumference thereof arranged in a coded manner,

each aperture being aligned'with thespace between a pair of adjacent spades, a plurality of conductiveringdike target electrodes, said target electrodes having a larger diameter than and being disposed in stacked relation one being substantially coextensive in length with said emissive portion of said cathode'and being arranged to form a circular array in which said spades are equidistantly and insulatingly spaced one from another, a sleeve-like anode,

said anode being disposed exteriorly of said array of spades and surrounding the same, said anode having'a plurality of slots spaced equidistantly around the circumference thereofleach slot being alignedwith the spacew between a pair of adjacent spades, the length of said slots varying in predetermined stepped manner, a plurality of conductive target electrodes equal in number to the norm.

ber of slots in said anode and disposed exteriorly of the anode with a different one of said target electrodes adjacent to and aligning with each' of said slots whereby electrons passing from said cathode through the space be tween a pair of spades and through the anode slot aligning therewith'will' impinge on one of said target electrodes. 16. A multiple position beam tube comprising'within a substantially evacuated envelope, an elongated cylindrical cathode disposed centrally thereof, said cathode having an electron emissive portion, a pluralityof substantially identical spade electrodes, said spade electrodes being substantially coextensive in length with said emissive portion of said cathode and being arranged to form a circular array in which said spades are equidistantly and insulatingly spaced one from another, a sleeve-like anode, said anode being disposed extcriorly of said array of spades and surrounding the same, said anode having a plurality of slots spaced equidistantly around the circumference thereof, each slot being aligned with the space between a pair of adjacent spades, the areas of said slots differing from one another in accordance with a predetermined pattern, a plurality of conductive target electrodes, said target electrodes being equal in number to the number of slots in said anode and shaped similarly to said slots and each being at least as large in area as said slots, a different one of said target electrodes being disposed adjacent to and aligned with each of said slots exteriorly of said anode whereby electrons passing from said cathode through the space between a pair of spades and through the anode slot associated therewith will impinge on said target electrode.

17. A multiple position beam tube comprising within an evacuated envelope, an elongated cylindrical cathode disposed centrally thereof, said cathode having an electron emissive portion, a plurality of substantially identical spade electrodes, said spade electrodes being coextensive in length with said emissive portion of said cathode and being arranged to form a cylindrical array in which said spades are equidistantly and insulatingly spaced one from another and in which each spade presents a curved surface towards said cathode, a hollow cylindrical anode, said anode being disposed exteriorly of said array of spades and surrounding the same, said anode having a plurality of substantially identical slots spaced equidistantly around the circumference thereof, each slot being aligned with the space between a pair of adjacent spades,

- l6 and corresponding in length to the electron emissive portion of said cathode, a'plurality of conductive planar target electrodes, said target electrodes being equal in number to the number of slots in said anode and shaped similarly to said slots and each being at leastas large in area as said slots, a diiferent one of said target electrodes being disposed adjacent to and aligned with each of said slots exteriorly of said anode whereby electrons passing from said cathode through the space between a pair of spades and through the anode slotassociated therewith will impinge on said target electrode, said spade electrodes, anode, and target electrodes being composed of conductive substantially non-magnetic materials which have poor secondary electron emission capabilities.

18. An electron discharge device comprising a hermetically sealedenvelope, a cathode secured within said envvelope, an anode secured within said envelope, a plurality of spade electrodes positioned within said envelope, be-

tween said cathode and said anode, said spade electrodes tor electrodes positioned behind said anode with respect 1 I to .said cathode, said collector electrodes being adapted to receive electron beams respectively, traversing said apertures aligned therewith, a first means to accelerate, an electron beam from said cathode toward said anode, a second means to vary the potential of said anode, and a third means to create a magnetic field substantially parallel with each of said columns of apertures.

19. Electron discharge apparatus comprisinga hermetically sealed envelope, a rod shaped cathode in said envelcpe, a; sleeve shaped anode in said envelope and positioned concentrically around said cathode, a plurality of between said cathode and said anode in a manner coniii) ' centric with said anode and said cathode, said anode having a plurality of columns of coded apertures and each of said columns being substantially parallel with the axis of said rod shaped cathode, each aperture in each column being intersected by one of a given number of imaginary planes substantially perpendicular to the axis of said rod shaped cathode, a plurality of ring-like collector electrodes in said envelope and positioned concentrically around said anode, each of said collector electrodes being further positionedso as to intercept any straight line drawn perpendicularly from said cathode through any aperture associated with a given one of said imaginary planes, one collector electrode being associated with an individual one of said imaginary planes, a first means to maintain said electrodes positive with respect to said cathode, a second means to apply to said anode a potential which is positive with respect to said cathode, a third means to apply negative pulses upon said anode, and a fourth means to create a magnetic field permeating the envelope and having flux lines thereof extending substantially parallel with the axis of said rod shaped cathode.

20. Electron discharge apparatus in accordance with claim 19 in which said anode and said plurality of spade electrodes are of non-magnetic material.

21. Electron discharges device in accordance with claim 19 in which each of said spade electrodes comprises an.

anode arranged concentrically around said row of spade electrodes, a plurality of ring-shaped collector electrodes in said envelope and arranged concentrically around said anode, said plurality of collector electrodes being axially spaced from one another so as to each be opposite a different portion of the surface of said anode, said anode having a plurality of rows of apertures and each row of apertures being arranged in a coded manner, each of said rows of apertures further being substantially parallel with the axis of said anode and opposite a different space between adjacent pairs of said spade electrodes, and electrode means for displacing said electron beam from one of said rows of apertures to another of said rows of apertures, said plurality of collector electrodes being adapted to intercept and detect the electron beam current flowing through the apertures of any one of said given rows of apertures.

23. Electron discharge apparatus comprising a rodshaped cathode adapted to emit an electron stream, cylindrically shaped anode means arranged concentrically around said cathode, a plurality of collector rings positioned concentrically around said anode means and spaced axially apalt so that each of said collector rings is adja-- cent to a dilferent portion of said anode means, means to permeate the area between said cathode and said anode means with a substantially uniform magnetic field having flux lines thereof extending substantially parallel with the axis of said rod-shaped cathode, said anode means having a plurality of columns of apertures circularly spaced thereabout and each arranged in a coded manner, electrode means positioned between said cathode and said anode means and operable to cause a portion of said electron stream to selectively and individually impinge upon said columns'of apertures, said collector rings being positioned so as to detect the coded arrangement of the apertures in said columns of apertures by individually intercepting portions of the electron stream passing through said apertures.

24. Electron discharge means for producing and displacing an electron beam to cause selective impingement thereof for controllable periods on a plurality of target electrodes comprising within a hermetically sealed envelope an elongated cathode, a cylindrical array of circumferentially spaced beam forming and directing electrodes coaxial therewith, target electrodes in a second coaxial cylindrical array remote from said cathode relative to said first array, each target electrode having a portion thereof in radial alignment with a space between adjacent ones of said beam forming electrodes, means for producing a unidirectional magnetic field parallel to the axis of said cathode for action conjointly with an electrostatic field between said cathode and said electrodes to control the formation and the path of an electron beam therebetween, and electrode means intermediate at least one beam forming and directing electrode and an adjacent target electrode constructed and arranged to produce, when suitably excited, a modification of the electrostatic field in which said beam is formed and directed for causing the switching of the beam from one target electrode to another. 1

25. Electron discharge means as defined in claim 24 wherein said electrode means comprises circumferentially alternating conductive portions and apertures devoid of conductors, at least a portion of each of said apertures being in radial alignment with a space between adjacent beam forming electrodes and with a portion of a target electrode.

26. Electron discharge means for producing and directing an electron beam to cause selective impingement thereof for controllable periods on a plurality of target electrodes comprising an elongated cathode, beam forming electrodes equidistant from the cathode in spaced cylindrical array and each having a radially extending portion, target electrodes in spaced cylindrical array coaxial with said cathode and remote therefrom relative l8 to said first array of beam forming electrodes, each of said target electrodes having a portion thereof intercepted by radial lines from said caliiode extending through the space between adjacent ones of said beam forming electrodes and further having another portion thereof in substantial radial alignment with said radial portion of one of the adjacent beam forming electrodes, means for producing a unidirectional magnetic field parallel to the axis of said cathode to control the formation and path of a beam of electrons originating at the cathode for action conjointly with an electrostatic field between the cathode and said other electrodes, and further electrode means positioned within the space between the radially aligned portions of the beam forming electrodes and the adjacent target electrode for creating, when suitably excited, an electrostatic field for beam switching purposes.

27. Electron discharge means for producing and directing an electron beam to cause selective impingement thereof for controllable periods on a plurality of target electrodes comprising an elongated cathode, beam forming electrodes equidistant from the cathode in spaced array and each having a radially extending portion, target electrodes in spaced cylindrical array coaxial with said cathode and remote therefrom relative to said first array of beam forming electrodes, each of said target electrodes having a portion thereof intercepted by lines from said cathode extending through a space between adjacent ones of said beam forming electrodes and another portion thereof in substantial radial alignment with said radial portion of one of said beam forming electrodes, means for producing a unidirectional magnetic field parallel to the axis of said cathode to control the formation and path of a beam of electrons originatingat the cathode conjointly with an electrostatic field between the cathode and said other electrodes, and further electrode means positioned within the space between the radially aligned portions of the beam forming electrodes and the adjacent target electrode for modifying the electrostatic field in said space for switching the beam from one target electrode to another target electrode.

28. Electron discharge means as defined in claim 26 wherein circuit means are provided for supplying an electric impulse of short duration to said further electrode means for the excitation thereof to switch the beam from one target electrode to another.

29. Electron discharge means for producing and di resting an electron beam to cause selective impingement thereof for controllable periods on a plurality of target electrodes comprising an elongated cathode, beam forming electrodes equidistant from the cathode in spaced array, target electrodes equidistanct from the cathode in spaced array and remote therefrom relative to said beam forming electrodes, each target electrode having a portion thereof intercepting straight lines from said cathode extending through the space between adjacent ones of said beam forming electrodes, means for producing a unidirectional magnetic field parallel to the axis of said cathode for cooperation with an electrostatic field'between the cathode and said other electrodes for controlling the formation and the path of a beam of electrons originating at said cathode, beam switching electrode means in the space intermediate each of said beam forming electrodes and the adjacent target electrode, an evacuated envelope enclosing all said electrodes, a base therefor, and contact pins mounted on said base providing external connections to said several electrodes and said beam switching electrode means, the latter being electrically isolated within said envelope from said other electrodes.

30. Electron discharge means for producing and displacing an electron beam to cause selective impingement thereof for controllable periods on a plurality of target electrodes comprising Within a hermetically sealed envelope an elongated cathode, beam forming and directing electrodes in circumferentially spaced apart cylindrical array and coaxial with the cathode, target electrodes in a second coaxial cylindrical array remote from. said cathode relative to said first array, means for producing a unidirectional magnetic field parallel: to the. axis: of said. cathode for action conjointly With an electrostatic field between said cathode and said electrodes, other electrode means intermediate at least one beam forming and, directing electrode and an adjacent target electrode for beam switching purposes, contact means passing through said envelope for making external connection to said: seva eral electrodes, and circuit means connecting a contact, of said last means with one of said several electrodes, said circuit means including a resistor ITlOlll'ltCdl within. said envelope.

31. Electron discharge means on producing: and, dis: placing an electron beam to cause selective impingement: thereof for controllable periods on, a, plurality of target electrodes comprising within a hermetically; sealed: envelope an elongated cathode, spade electrodes incircum: ferentially spaced apart cylindricalarray andicoaxialcwith the cathode, target electrodes in a, secondcoaxial, cylin:

drical, array'remote from said cathoderelatiye tmsaidg first array, means for producing a unidirectionalimagnetic field parallel to the axis of said cathode in crossed; relation, to an electrostatic field between said: cathode, and said, electrodes, other electrode means intermediate at leastone spade electrode and an adjacent target electrode for, beam switching purposes, contact means passing through said; envelope for making external connectionto said several electrodes, and circuit means connecting a, contact of said last means with one of said spade electrodes, Said. circuit means including a resistor; mounted within said envelope.

32. Electronidischarge means for producing and displacingan electron beam to cause selective impingement thereof for controllable periods on a plurality of target electrodes comprising Within a hermetically sealed envelope an elongated cathode, spade electrodes in circumfercntiallyspaced apart cylindrical array and coaxial with contact meanspassing through said envelopetor making; externahconnectionto said several electrodes, and circuit m ana nnw s a o ta of a a m ans th r ne of said; spade electrodcs, saidcircuit means includinga resistor mountedwithinsaid, envelope within the area ner ll bo nd d y e p e le t e Q hL i o iest dt whereby ai e s ielded: r m. he:

electron beam,

33. Electron discharge apparatus comprising, a; hermetically sealed envelope, a rod shaped cathode insaid', enVeIope a sleeveshaped anodein said envelope and; positioned concentricallyaround said cathode, a plurality" of; spade electrodes uniformly spaced apartand POSl q ad stw snsaidrs de i anode i a nns r. concentric with said anode andsaid cathode, said anode having plurality of columns; of coded apertures and each oi said columns being substantially, parallel with;

the axis of I saidirod shaped cathodes, each aperture in eachcolurnn being intersected lay-one of a: given number;

of imaginary planes substantially perpendicular to the axis of said rodxshaped cathode, a pluralityuof:ring lilge,

collector electrodes in said envelope and positionedcom. centrically aroundthe outside of said anode, eaclrof said collector electrodes being further positioned so as: to,

intercept any straight line drawn perpendicularly fromsaid cathode through any aperture associated; with a given one of said imaginary planes, one C01leCtOD61QtTQdQ being associated with an individual one of said imaginary planes, a first meansto maintain said electrodes positive with respect to said cathode, a second means: to apply a positive potential with respect to said cathode upon said anode, a third means to apply negative pulses upon said anode, and a fourth means to create a magnetic field permeating the envelope and having the field lines thereof extending substantially parallel with the axis of said rod shaped cathode.

34. Electron discharge apparatus comprising within a hermetically sealed envelope, an elongated thermionic cathode, a plurality of uniformly spaced apart spade electrodes concentrically disposed with respect to said cathode, a sleeve shaped anode arranged concentrically around said spade electrodes, a plurality of ring-shaped collector electrodes arranged concentrically around the outside of said anode, said plurality of collector electrodes being axially spaced from one another so as to each be opposite a different portion of the surface of said anode, said anode having-aplurality of rows of apertures and each row of apertures being arranged in a coded manner, each of said rows of apertures further being substantially parallel with the longitudinal axis of said anodeand opposite the space between adjacent pairs of said spade electrodes, and electron-deflecting means for causing stepping of an electron beam current from one pocketbetween spade electrodes to another, said plurality of collector electrodes being adapted to intercept in a detectable manner the electron beam current flowing through the apertures of any one of saidgiven rows of apertures.

35; In, an; electron discharge device having crossed magnetic and electrical fields, a rod shaped cathode in the magnetic field and arranged with its axis substantially paralleling the lines of force of the magnetic field, a sleeve shapedanode positioned about said cathode with its axissubstantially coincident with that of the cathode, a plurality of beam control electrodes disposed in circularly spaced apart relation inside the sleeve anode and adjacentrto but spaced from the inner surface thereof. said anode being provided with a plurality of apertured columns, each of said columns extending substantially parallel to the axiszof thc cathode and on radial planes paralleling; and intersecting the axis of the cathode and extending substantially between adjacent pairs of said controlelectrodes, andwaplurality, of collector electrodes disposedin spaced apart relation on the outside of the, sleeve anode and adjacent to but spaced from the outer surface-thereof, each of said collector electrodes being arranged to intercept, at least one of said radial planes to receivean electron beam ;directedthrough the apertured column coextensive with the plane.

36. In electron dischargeapparatus for forming and directing an electronbeam'in which the electrons thereot follow trochoidalpaths responsive to the joint action of crossed electrostatic-and magnetic fields to cause selective impingement of the, beamon a plurality of collector electrodes, thecombination ofa hermetically sealed ens velope, a source, of electrons therewithin adapted to emit a beam of electrons, a, first electrode structure spaced from said electron source and constituted by a, plurality ofbearn formingand controlling spade electrodesspaccd from each other to define passageways therebetween into which the, electronbeam may be directed, and locked, a

second electrode structure spaced from said firstelectrode structure and disposed, on the-side thereof remote from said electron, source constituted by a plurality of1coll ector electrodes arranged with respect to the electrodes of said first structureso that each collector electrode has an area overlying the passageway between two adjacent spade electrodes and, disposed to receive an electron beam directed through saidpassagew-ay, and a beam switching,

structure situated intermediate said spade electrode structure and said, collector electrode structure and spaced from each constructed and arranged to permit electron flow to the beam receiving areas of the collector electrodes and including distinct conductive portions thereof respectively associated with juxtaposed spade and collector electrodes serving to effect, when suitably excited, the switching of beam from one passageway to another.

37. The combination defined in claim 36 wherein said beam switching structure is constructed and arranged to provide openings therein intermediate adjacent ones of said conductive portions thereof, said openings being respectively aligned with said beam receiving areas of the collector electrodes to permit passage of electrons of the beam to said areas.

22 38. The combination defined in claim 36 wherein said conductive portions of the beam switching structure are electrically interconnected for common excitation thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,591,997 Backmark Apr, 8, 1952 2,616,061 Char-ton Oct. 28, 1952 2,616,062 Charton a Oct. 28, 1952 2,620,454 Skellett Dec. 2, 1952