US2770417A - Electronic distributor for counting and similar purposes - Google Patents

Description

1956 P. F. M. GLOESS ET AL. ZWOAN ELECTRONIC DISTRIBUTOR FOR COUNTING AND SIMILAR PURPOSES Filed June 9, 1949 5 Sheets-Sheet l INVENWMQ PAUL FRANCOIS FARE GLOESS AND JEAN ARTHUR MLRIE LOUIS GALIAVARD NOV, 13, 1956 p, F. M. GLOESS ET AL BJZQAN ELECTRONIC DISTRIBUTOR FOR COUNTING AND SIMILAR PURPOSES Filed June 9, 1949 s Sheets-Sheet 2 47. U INVENIORS. PAUL FRANCOIS MARIE GLOESS AND JEAN ARTHUR LOUIS GALLAVARDJN I In. 13 1956 P. F. M. GLOESS ET AL 577M ELECTRONIC DISTRIBUTOR FOR COUNTING AND SIMILAR PURPOSES Filed June 9, 1949 s Sheets-Sheet 5 PAUL FRANCOIS MARIE GLOESJ IKQ JEAN ARTHUR MARIE LOUIS QALLAVARDIN I ATTORNEY United States Patent ELECTRONIC DISTRIBUTOR FOR COUNTING AND SIJVHLAR PURPOSES Paul Francois Marie Gloess and Jean Arthur Marie Louis Gallavardin, Paris, France Application June 9, 1949, Serial No. 98,146 Claims priority, application France July 7,1948: Claims. (Cl. 2.35--6-1) This. invention relates to'the distributionin space of electrical pulses arriving successively and more particularly to the counting of pulses succeeding at a high speed.

Up to the present time, the pulses were counted by means of apparatus comprising vacuum or gas filledrelaytubes, and more particularly by; means of multivibrators. These apparatus are rather complicated and need a high number of tubes with numerous connexions; moreover, they generally count in a binary relation, and need supplementary devices to translate the recordedtot-al into a more usual counting system, such as a. decimal one. These additional devices and their connexions complicate still more the realization and introduce moreover substantially delays reducing the counting speed.

It is well known at present to use commutating' or distributing devices in the form of a cathode ray tube comprising a certain number of targets disposed generally in a circular relation, swept successively by an. electronic beam the movement of which is controlled by a rotating deflecting field. The pulses to be distributed can be either applied to the beam, such as by its modulation, and collected on the targets, or they inversely may be applied directly to the targets and then distributed by the beam, introducing them in the anode supply circuit. In these devices, the deflecting field turns at a constant. speed independent of the moment at which the pulses are ar riving, and they cannot therefore be used for counting purposes especially when the pulses are arriving irregularly, which is generally the case. On the other hand, in order to simplify the construction and the wiring, it would be of a high interest to use such a tube for counting purposes, but it would then be necessary to secure first that the change of the beam position from one target to another be controlled by the incoming pulses themselves, Whatever their arrival moment may be, and then that the beam remain in any new position, between the succeeding pulses or at the end of the counting period. Moreover, it would be necessary that the device give at any instant an indication of the total number of pulses recorded by it.

This invention has for its principal object a pulse counting apparatus, using a. cathode ray tube of a simplified design, of a reduced volume and working in a reliable manner.

The invention has also for its object a new type of cathode ray tube distributor, in which the movement of the electronic beam is controlled by the pulses to be distributed on the different targets, more particularly for counting them.

The invention has also for its object a cathode ray distributor in which the movement of the beam is controlled step by step by the incoming pulses, and in which the beam keeps its position as long as it is not acted by a new pulse.

The invention has also for its object a cathode ray device which indicates at any instant the number of pulses recorded by it, and more particularly a cathode ray tube the luminescent screen of which is combined with a scale marking the counting results.

The inventionhas. also for its object a cathode ray tube distributor whichcounts as well in the addition as in the subtraction senses and which more particularly can secure a differential counting effect responsive to the sign of the applied pulses.

Still another object of this invention a counting system comprisingseveral cathode ray tube distributors connected in series in a decimal or other relation.

Other objects oi the invention will hereinafter appear.

According to the general idea of the invention, the cathode ray tube is given several targets arranged in a particular manner, and one makes use either directly of the negative charge due to the electron impact or of the positive charge taken by the targets owing to their secondary emission, for building up a deflection field which makes the beam glide on the target until it gets an equilibrium position and comes there to a standstill. The equilibrium of this servo-regulation is reached when the charge of the target, with which is associated a. suitable leakage circuit, becomes stationary.

in order to build up. these deflection fields designated in the present specification as regulating fields, the tube is provided with a certain number of deflecting means, preferably in the form of electrostatically acting plates, each of them deflecting the beam in a particular direction and connected individually to its corresponding target.

To secure the commutation, e. the passage or" the beam from one target to the other under the action of the incoming pulses, the apparatus is equipped with an additional means designated as a commutating element, which receives the incoming pulse and impresses onthe beam a sudden supplementary deflection, so that it leaves the equilibrium position on one target and gets to another one where it comes to a standstill owing to the above mentioned servo-regulation effect and so on.

This commutating element will be preferably given the form of an additional electrode inside the tube, producing a supplementary commutating field, superposed on the regulating field. This commutating deflection may also be secured through an action of the incoming pulse on the beam speed, such as by using this pulse to cliange suddenlybyall suitable and welliknown means, the anode voltagefixing the beam acceleration.

The targets will be given a band form, and theywill be by preference, arranged as well as the regulating electrodes, in a circular relationship around the tube axis, the regulation fields being thus distributed in different radial planes extending through this axis. On the other hand, the targets will be mutually distributed so as to meet successively in the same radial plane, at least two of them;

The commutation field will then be preferably secured by means of two cylindrical electrodes concentrically disposed respectively tothe tube axis and producing a radial field distributed uniformly round this axis.

According to one embodiment of this invention, the end portion of a target, corresponding to an equilibrium position of thebe'am and the end portion, corresponding to an instable position, of the next target are put in the radial plane of the regulation electrode connected to the first. target.

' Accordingxto another embodiment intended for differential counting, the target-bands are overlapping each other, the radial plane of a deflecting plate cutting the central portionof target connected to it.

' Means for stabilization of potential will be associated with each target and its regulation deflector, by preference in the form of leakage resistances of a suitablevalue, connected to the anode supply circuit of the tube. If secondary emissionproperty is used, this connection will be made through a suitable bias voltage source.

The starting or zero position of the beam will be secured by means of an axially disposed target, connected to one of the distributing targets or making part of it. For connecting in series several tubes in order to use their scales in a determined, such as decimal, numerical relation, it would be only necessary to connect the last target of one of them with the commutating element of the following tube. In order to secure with such system the differential counting, additional linking targets will be introduced, as it will be described later.

According to still another embodiment, the electronic beam will be given a relatively large section and a slow acceleration, and the means regulating its position will be adjusted in such a manner as to let in the equilibrium state, a portion of the beam impinge on the luminescent screen and give there rise to a spot marking the counting result which could be read on a scale associated with the front end of the tube.

By connecting the targets through the tube walls, to suitable exterior circuits, it would be possible to use it as a step by step distributor of any nature, which can be designed namely to illuminate successively glow-discharge indicator lamps, or which can act as a calling selector triggering suitable relays for telephone or similar purposes; by using in the like manner only one of the whole set of targets, it would be possible to demultiply the frequency of the incoming signals.

For a better understanding of the invention reference may be had to the accompanying drawings forming a part of this invention, wherein:

Figure 1 is a perspective schematic view of the cathode ray tube distributor and of its associated operating cir cuits, according to this invention;

Figure 2 is a more detailed schematic view of the target arrangement in this tube;

Figure 3 is a wiring diagram of a counting system comprising two series connected tubes;

Figure 4 is a schematic plan view of the target arrangement of an embodiment of this invention for difier ential counting;

Figure 5 is a more detailed schematic view of the said embodiment showing the starting target arrangement;

Figure 6 is a schematic plan view of a modification of the target arrangement of Figure 4, designed for the series setting as represented on Figure 3;

Figure 7 is a detailed perspective view of a complete counter tube realized according to Figures 1 and 2, the envelope of the tube being represented in a longitudinal cross-section; and,

Figure 8 shows an electrical diagram of operating characteristics of such a tube with practical data given by way of example.

Referring more particularly to the drawing wherein similar reference characters designate corresponding parts throughout, there is shown, in Figure 1, a vacuum tight envelope 1, containing an electron gun 2, an anode 19 producing a beam 3, and directing it along a reference axis which coincides with the tube axis, a deflecting set 4 comprising a plurality of plates producing the electrostatical regulation field, an additional deflecting system comprising two cylindrical coaxial electrodes 5 and 5' producing the commutating field and a set of targets such as 6 and 10, put against the luminescent screen 7, or situated near and opposite it, inside of the tube. The first deflecting system comprises several plates such as 8 and 9, the number of which is equal to the number of targets. To simplify the drawing, there were shown only two plates connected to the targets 6 and 10 by means of conductors 11 and 12.

The targets are distributed in a regular way around the tube axis which coincides with the gun axis and they are given a band shape and a symmetrical disposition as shown more clearly in Figure 2; these bands extend towards the periphery of the tube in the direction which is opposite to that of the beam movement, and in such a manner that the exterior end of each of them, such as 13 of the band 6, is situated on the radius 14 crossing the interior end 15 of the preceding one. Besides, one of the targets, 6 of Figure 1, is connected electrically by means of a strip 16 to a central target 21 disposed on the axis of the tube.

Each target-plate arrangement is connected through a particular resistance to the negative pole of a common biasing voltage supply 18, which, as it will be explained later, is necessary to secure the operation of a tube using a secondary emission effect. There have been shown only a resistance 17 associated to the plate 8 and a resistance 17' connected to the plate 9. The positive pole of the said source 18 is connected to the anode 19 of the tube, which is grounded as usual. One of these deflector-target sets, 8-6 on Figure 1, is connected to the terminal 20 used for a series system as will be described later in connection with the Figure 3. The gun 2 comprises, as usual in a cathode ray tube, an emitting cathode and a controlling cylinder. A source of the anode voltage E is connected between the filament and the ground. One of the hollow cylinders 5 is connected to the terminal I1 to which are applied the incoming pulses. The other cylinder 5', in order to fix its potential, is connected to the anode, to which is also connected a concentrical conducting layer 24, deposited on the inside of the tube wall. Any suitable conducting means F is used to fix the potential of the screen and to connect it by means of a conductor g to the anode.

This apparatus operates in a following manner: nor mally, the electron beam follows the tube axis and hits the central target 21 forming a part of the target 6. As, owing to the biasing battery 18, the potential of this target is negative in respect to that of the anode, it emits secondary electrons, acquiring so a certain positive charge which is transmitted, through the connector 11, to the plate 8. The latter pulls up the beam and the impact spot of it will then glide radially upwards along the length of the strip 16. The beam takes an equilibrium position shown at 23 in Figure 1, and remains there on the target 6. This equilibrium position is fixed by the potential developed across the resistance 17 by the secondary emission current. The conditions and experimental data of these operation phenomenas are represented in a more clear and detailed manner in Figure 8, the description of which will be given later. The said current is collected by the conducting layer 24 deposited on the wall near the target arrangement. In some cases, this electrode may be omitted, and the anode 19 will then be given the function of a secondary emission collector.

According to one feature of the invention, the magnitude of the secondary emission is adjusted so that in its equilibrium position, the beam hits partially the target and that another part of the beam section impinges on the screen 7 giving there rise to a luminous spot indicating the beam position. This can be done by adjusting the beam speed, or the leakage resistances, or by choosing an appropriate secondary emission rate or other suitable regulations.

Thus, the starting conditions are characterized by the following particularities: the beam pencil takes a fixed position and remains there; a luminous spot 25 marks this position; a positive potential in respect to the common feeding potential of the targets, appears on the terminal 20 connected to the plate 8 and the target 6.

The commutating operation due to the incoming pulses, will be better understood by means of Figure 2, representing the target and plate arrangement, viewed through the tube end wall and in which, to simplify the drawing, the central target 21 and its radial strip 16 are omitted.

First, it is supposed that the arriving pulses are short and have substantially constant durations and amplitudes, and that moreover they are positive. These conditions may be easily fulfilled by any suitable well known levelling and duration controlling amplifier and similar device used normally in electroniccounters of the known types.

At rest, the beam passes through the hollow central commutating, cylinder 5', and as soon as the apparatus begins to work, the beam leaves this position and crosses the annular spacing between the cylinders.55". A positive pulse applied to the terminal I1, will build up a radial field between these cylinders directed towards the exterior one, and this additional field will increase momentan'ly substantially the radial deflection of the beam which will leave the spot 23 and get the next target 26 hit in 27. In this new position, of a very short transitory character due to the reduced length of the pulse, the beam produces a secondary emission from the exterior end of this target and the deflection plate 28 connected to it through conductor 29, will get a positive potential. The regulation field is then commutated, and passes through the radial plane of the plate 28. The latter will attract on its turn the beam towards the exterior of the tube, and at the same time will submit it to a movement of lateral translation. As the attraction eifect of the plate 8 which is losing its positive charge, decreases rapidly, the beam will glide, under the combining effect of all these superposed forces, along the target 26. and will occupy finally a new equilibrium position 30 similar to the position 23 on the preceding target. As before, only a part of the beam section will hit the target surface, the remainder of it will reach the screen and let appear therein a luminous spot 31 marking its new position corresponding to the first pulse.

When a new pulse is applied to the exterior commutating deflector 5, the same operating phenomena will take place again and the beam will reach the following target 32 and rest there until the arrival of a third pulse, producing so on the screen a spot marking the recording of the second pulse and so on for successively all targets.

When the beam hits any one of the targets, a positive potential appears on the deflecting plate connected thereto. This potential change may be used in a different way, for example to trigger control relays of a calculating machine. In the case of the counter as illustrated in the present invention, this eifect is used to control a second tube connected in series to the first, as represented in the Figure 3, where the terminal 20 connected to the plate 8target 6 set, controls the commutating system of a second tube 40 made according to the invention. Each tube has ten targets and counts therefore ten pulses, the result being read in the scale 34, impressed on a ring band 34 surrounding the screen; the result marking figures may be of course impressed directly on the tube bottom or projected on the latter. The mark corresponds to the equilibrium position 23 on the target 6, as shown in Figure 2. The mark 1 corresponds to the target 26, and finally the mark 9 to the tenth target preceding the target 6.

The incoming signalsare applied to the outer deflecting cylinder through a series condenser 36,.a resistance 37 links this cylinder to the anode. By giving to thecircuit 36-37 a feeble time constant, it becomes possible to transform even large pulses into short ones necessary to operate the counting tube.

As it was described before, the single terminal 2%} is connected to the target 6 on which the beam impinges when no pulses have been applied, or when after recording ten pulses, the beam has swept an entire circle. The outer cylinder 38 of the commutating element 39 belonging to the second tube 4t designated to count groups of ten similar to the units tube 33, is connected to this terminal 20 through a differentially acting time constant circuit comprising a condenser 41 and a resistance 42 connccted to the anode 43. The increase of potential of the terminal 20 at the moment when the beam hits the target 6 gives then rise to a short positive triggering pulse 44 controlling the movement of the second counter ill beam.

When, on the contrary, the beamfleaves the target 6,

"when it is commutated to the next one 26, the potential of the terminal 20 will decrease, and this will give rise on the terminal of the circuit 41-42 to a negative parasite pulse 45. But the latter does not introduce any disturbing effect, as it will displace the beam inwardly towards the tube axis without touching any other target. Furthermore, this inward movement will bring the entire sect-ion of the beam on the target surface, and therefore increase quantity of electrons hitting it. The corresponding sudden increase of the positive charge of the deflecting plate connected to this target, will try to reduce and to nullify this parasite displacement.

Several other similar tubes recording groups of hundreds, thou-sands, etc., can be connected in the similar manner, in order to increase the counting capacity of the apparatus.

The embodiment represented on the Figure 4 is intended for adding pulses of different natures and more particularly pulses of opposite signs. This dilferential counter is derived from the described one, by simply giv ing to the targets a particular form and disposition. They are as before in the band form of the same size and shape and arranged obliquely in a plane transverse to the tube axis; but in this modification, one band overlaps the preceding one by about a half of its length, in such a manner that a radius such as 46 crosses successively the end of the target 47 near the tube axis, the middle of the next target 48 and finally the farthest end of the target 49. Each target is connected, as before, to a particular regulating deflecting plate, i. e. the target 47 is connected to the plate Stl, the target 48 to the plate 51 and the target 49 to the plate 52, and so on. These plates are now arranged so as to deflect the beam in a radial plane which crosses the central part of the corresponding targets. For example, in its equilibrium position the beam will hit the target 48 at the point 53 in the radial plane of the plate 51. In order to simplify the drawing there has not been shown the starting target arrangement.

If the beam impinges at a given moment on the target 48, and if a control pulse to be recorded, of a suitable amplitude and length, deflects the beam radially outwards, as it was described in connection with the preceding figures, the beam will reach the next target 49 at the point 54, will then glide along it and finally get an equilibrium position at 55. But if the control pulse is of such a nature that it deflects the beam inwardly towards the axis, the beam will reach the preceding plate 47 at 56, and will then glide towards 57 under the deviating control of the plate 50. Therefore, in order to secure a differential distribution of pulses, the latter must, according to their sign, or their source of supply give rise to commutating deflections of opposite senses, and this will be secured in the following manner: if it is wanted to sum up algebraically a certain number of positive and negative pulses, it is only necessary to apply all them to the same input terminal of the tube such as the ll of the Figure 1, leading to the exterior cylindrical deflector 5. Then the positive pulses will deflect the beam outwardly and the negative inwardly thus letting the beam return to-the end of the preceding target.

If, on the contrary, it is wanted to realize a difference between two series of pulses, all of the same sign, but supplied for instance from different sources, then the pulses of one of the series will be applied as before to the terminal I1 of the Figure 1, and the pulses of the second one to the terminal is connected by a dashed line to the interior commutating cylinder 5' where they will give rise to an opposite radial deflection action.

It is clear that the positive and negative pulses or the pulses of the two series must present substantially the same amplitude which will be adjusted suitably according to the operating characteristics of the tube, in order that the radial deflection amplitudes be sufficient to drive the beam from one target to the other, but not strong enough to let it overshoot this target and reach thethird one. If these conditions are fulfilled, the distributor will act exactly as a counter marking the algebraic sum of the pulses, but not the sum of their amplitudes.

If it is supposed that the target 48 forms the origin of the counting, and that the spot 53 marks the zero, then, on the contrary to the counter of the Figure 1, in this differential embodiment, the starting auxiliary electrode 59 must be connected, by a conductor 60, to the following target 49, as it is represented on the Figure This elec trode 59 is arranged radially in the sense of the deviation imparted to the beam by the plate 52, connected to the target 49, but it ends slightly before the target 48 and is therefore insulated therefrom. As the equilibrium position of the beam is out of the electrode 59 edge, the beam after it has travelled along it, continues its radial movement and reaches the interior end 61 of the target 48. At this moment, the secondary emission from the latter produces a change of potential of the corresponding plate 51, whereas the deflecting charge of the plate 52 disappears owing to the stopping of the secondary emission of the target 49. The beam is then attracted laterally towards its starting position 53 on the target 48. If the starting electrode was connected to the origin target 48, the initially secondary emission would bring the beam in the contact with the intermediate target 47 and then it would be pushed the length of the latter until the middle point corresponding to the equilibrium position.

In the case of a series system comprising several differential counting tubes as described, forming decades counter, it is not sufficient, as in the diagram of the Figure 3, to use the potential acquired by the origin target 48 to trigger the following tube. In this case it becomes necessary to make either advance or move backwards this commutator according to the polarity or the origin of the controlling pulse which may bring the beam on the origin target or let it leave it. That is if, for example, the first tube or units tube is commutated fro-m the position 9 to the position 0, the second tube marking the group of tens must advance from 0 to l, but if the first returns back, from 0 to 9, it must trigger back the tube of tens from the posit-ion 1 to the position 0.

The Figure 6 represents an embodiment of the invention permitting to control in an appropriate sense the second decade counter, and using for this purpose two auxiliary targets electrodes 62 and 63. When the counter is in the position 9 the beam spot occupies the position 57 on the target 47. If, at this state, the incoming pulse is to be counted in a positive sense, that is if the tube has to get the position 0 and must then let advance by an unity the following decade counter, this pulse produces a radial deflection of the beam directed outwards, from the position 57 to the position 64 in which it hits entirely the auxiliary electrode 62. The latter takes a transitory positive charge which can be transmitted in the form of a short pulse, to the commutating electrode of the following tube, to let it advance by one I unity.

At the end of the control pulse applied to the first counter tube, the beam deflection will decrease and the spot will then leave the electrode 62 and reach the target 48 and glide along it until it will get its equilibrium position 53.

If, on the contrary, the first tube is at the position 0 and the control pulse is to be counted in a negative sense, the second auxiliary electrode 63 will then be used. The spot being at 53, this control pulse will direct it radially inwardly towards the tube axis and it will therefore hit during a short time the target 63, which will acquire a fugitive positive charge. The latter will be transmitted to the suitable commutating electrode of the following tube, making it go back by one unity. At the end of the control pulse, the spot leaves the electrode 63 and meets the preceding target 47 at 56 and glides therefrom to its equilibrium position 57.

It can be observed that during its deflection caused by the control pulse, the beam crosses the next target before reaching the auxiliary electrode. But it is easy to adjust the operating characteristics of the tube in such a manner as to reduce greatly the time of this crossing and to render negligible the secondary emission and its effect. On the contrary, duringits back travel, the beam returns much more 'slowly to its normal equilibrium position and the deflecting potential created at the corresponding plate enters immediately into action and prevents the beam from overshooting the band target it had met.

To bring the counters according the invention to a zero position, at the end of a counting operation, it would be sufiicient to stop simply the beam of all commutator tubes, such as by applying a negative pulse of a suitable very short duration to their control cylinders. The targets under action at this moment, will lose their charges and the deflection fields would disappear. If then the tube beam is started again, it will impinge axially on the central starting electrode and after gliding automatically along the origin target, reach its zero position as described above.

The complete distributing and simultaneously counting tube represented on the Figure 7 comprises inside the tight envelope 1 of glass or other insulating material, a stem 81 surrounding by a metal collar 83 supporting, by means of a flat strips and 82, the electron gun 2 comprising an emitting filament and a surrounding con trol cylinder. Their lead-in conductors are embedded in the said stem. The anode 74 is fixed to an annular piece of mica 74 partly sectioned so as to show the inner electrodes. Four similar flat insulating supporting rings 70, 71, 72,.and 72, are mounted inside the tube and fixed thereto by means of clasps 78 represented only in combination with the ring 70. These rings are crossed by a series of metal rods 11, 12, arranged round the tube axis and forming with the rings a rigid fixture which can be assembled out of the tube and slipped into it. The pair of rings 7273 carries the regulating deflecting plates 89, fixed thereto by means of their flanged ends 8 respectively 9'. Each of them is connected through a conducting layer not designated on the ring to its corresponding rod. Each rod supports a particular leakage-potential fixing resistance 17-17', which end in an annular conducting deposit 79 forming a common point, lead out through a wire crossing the stem. The ring 71 carries the outer commutating cylindric electrode 5 by means of riveted straps 75, the inner tubing 5 being fixed in the same manner by means of straps 76. Two independent wires lead them to the stem. The band shaped metallic targets 6, 26, 10 (the others being omitted for the sake of clearness) are riveted to the side of the ring facing the screen '7 and are so arranged that all their active portions, that is those hit by the beam, protrude into the circular opening of the ring. During the commutating period the beam would strike the screen but as this period is very short, its trace would even not be noticeable. These target strips can also be fixed to the surface of the ring facing the gun, letting merely their interior tips penetrate into the ring opening, allowing thus the beam to strike the screen in its equilibrium position. Then during the commutating period the beam would charge somewhat the insulating ring surface, but this phenomena would not be practically noticeable, and moreover, the natural leakage effect of the ring and its surrounding medium, would secure the necessary equilibrium effect. Conducting deposits such as 77 on the screen side of the ring, connect each target to a particular rod 11, 12, leading to a corresponding deflecting plate. A circular conducting layer 24 on the inside wall of the tube formed by spraying a conducting substance such as graphite solution, is connected through the wire 8 to a lead in conductor in the tube stem 81, and moreover to the fluorescent screen of a conducting or semi-conducting type, through a conducting layer 3, such as are commonly employed in the cathode ray tube practice. The targets are made of a suitable material of a high secondary ernission power; nickel can be employed eventually coated with a barium or a strontium oxide or other alkali metal compound. The counting result marks are traced directly on the outside of the tube bottom.

In the Figure 8 representing an equilibrium state of the tube operation, the different arrows show the conventional direction of the current flow which is opposite to the direction of the electron movement. The electron beam of 0.15 milliampere, chosen by way of example, is furnished by the anode supply E of 1000 volts. This voltage can be fixed relatively low, as neither sharp focusing eifect nor high brillancy of the spot are needed; on the other hand, a low accelerating voltage increases the sensibility of the beam deflection and protects. the screen against burning. After its deflection by the transverse field of the plate 8, the beam gets to the plane of the target 6 where it is divided into two parts: the one of 0.10 ma. intensity follows the same trajectory, impinges on the screen giving there rise to a luminous spot and returns to the plus pole of the anode battery through. the secondary emission eflect of the screen and the leakage path comprising the layer 24 as it is usually the case in the normal cathode ray tubes. The other fraction of the beam of 0.05 ma. intensity hits the target giving rise to a secondary emission current of 0.25 ma., by supposing a ratio of 5. This emission, owing to the battery 18 biasing the target negatively in respect to the anode, is collected by the layer 24 put to the anode, and returns to the positive pole of the anode supply through the latter. The total current leaving the layer 24 is therefore of 0.35 ma. The target receives a current of 0.05 ma. and supplies current of 0.25 ma. and their difference is compensated by a current of 0.2 ma. furnished by the biasing battery 18. This current develops on the leakage resistance 17 of 100,000 ohms, a potential difference of 20 volts appearing between the active plate 8 and the others, determining the deflection field directed towards the first one. As it was represented on the Figure 2, the beam position and section were so regulated that its spot overshot the outer rim of the target. Thus any operating conditions variation, such as an accidentally change of secondary emission, would be automatically compensated by a more or less deep penetration of the beam into the target section, and this floating characteristic of the beam spot would maintain it on the target surface during the commutating period and stabilize it in its equilibrium position. On the other hand, this self-regulation of the equilibrium condition is enhanced by the fact that the secondary emission is a function of the potential difference between the target and the collecting layer and that, in these conditions, the said potential, the deflecting field and the secondary current are interacting to secure the said self regulating etfect.

It must be well understood that this invention is not limited to the particular form and disposition of targets or deflecting electrodes as represented on the drawings and described above. The first can be given any other shape and mutual arrangement provided that a radial sudden push or pull will let the beam leave one target and reach the next one, and that, under the action of the operating field, the beam glides along the target until it reaches a new equilibrium position on it.

Instead of the embodiment shown on the Figure 7, the targets may be realized by depositing a layer of suitable material on the bottom of the tube supporting the screen and then the target-plate connectors may be made by means of exterior wires; the screen may also be supported by the mica ring carrying the target strips. The regulating resistances 17 may be made by coating the inner wall of the tube, or assembled out of the tube and provided with necessary lead-in wires. Instead of using a fluorescent screen for illuminating and reading the counting results, the targets may be provided with connectors crossing the tube walls and leading out their charges to signal indicators in the case of counting, or

relays or other suitable responsive devices in the case of using the tube simply as distributor. V

The commutating counting devices according to the-invention are very simple to build, operate reliably and moreover are very sensitive. They mark at any instant the total of the algebraic addition of received pulses according to their polarity, and also the difference between two series ofpulses. Moreover, they secure a high speed operation, i. e. they can record very short pulses and can therefore be controlled by pulses arriving at a high rate. If C is the total capacity of the target, of its deflecting plate and all connectors, if R is the resistance connecting the plate to the bias battery, such as 17 (Fig. 1), and r is the resistance of the secondary emission path, the rate of the counting speed is fixed by the timeconstants CR and Cr. By adjusting C to a 5 micromicrofarads, R to 100,000 ohms, and supposing that the secondary emission current which determines the resistance r is of about 0.25 milliarnpere, the said time constants will be of about 5/10 microsecond, thus allowing a counting speed of about 2 million pulses per second. This speed can be substantially increased by choosing a beam of a larger intensity and by reducing leakage resistance.

Besides, the cascade counter allows to add up a very' high number of pulses with onlya relatively few tubes.. As each of them can record until 10, it becomes possible to secure a counting power of 1.0 with only 7 tubes con-- nected in series.

To get the same. result, it would be necessary with the: hitherto known electronic counting systems such as using binary multivibrators, to use 5 of them for each decade recording, this increasing substantially the number of' tubes and of coupling, circuits, as like as the number of visual indicators associated herewith, whereas the tube of this invention fulfills simultaneously the counting and indicating functions. All leakage resistances 17 being situated inside the tube wall, the lengths of their circuits. can be reduced to minimum thus diminishing still more the time constants and increasing the counting speed.

What is claimed is:

1. In an electric step by step type pulse distributor, a cathode ray tube, means inside said tube for producing an electron beam and for directing said. beam along a predetermined reference axis, a plurality of targets located inside the tube and around said axis for receiving the beam, a plurality of deflecting means arranged around the said axis so as to deflect thebeam in different radial planes extending through said axis and said targets, means to connect separately and directly each target to the corresponding deflecting means located in the same radial plane, a supplementary starting target located in said ref erence axis, connected to one of said targets and independent means under control of the incoming pulses to be distributed for acting upon the beam so as to change the amplitude of its deflection imparted by the aforesaid deflecting means irrespective of the beam position.

2. In an electric step by step type pulse distributor, a cathode ray tube, means inside said tube for producing an electron beam and for directing said beam along a predetermined reference axis, plurality of electrostatically deflecting means inside said tube and arranged circularly with respect to said axis so as to form a plurality of differ ent radial deflecting planes passing through said axis, a plurality of band shaped beam receiving targets distributed around said axis and located obliquely with respect thereto, in such space relationship to said deflecting means, that a radial plane drawn through each of the latter cuts at least two targets, independent means to connect directly each one of said targets solely to the deflector situated in its plane, a supplementary, independent commutating deflector inside said tube, for producing a radial electric field distributed uniformly around said referance axis, means for applying to said deflector the incoming pulses, a supplementary starting target located in said reference axis, connected to one of said targets and means associated with the targets and controlled by the beam impact. 7

3. In an electric pulse counting apparatus, a cathode ray tube, a cathode and an anode inside for producing an electron beam and directing said beam along the tube axis, a plurality of deflecting plates inside said tube and arranged circularly in respect to said axis, a plurality of band shaped targets, of a material emitting a high ratio of secondary electrons distributed around said axis and located obliquely with respect thereto in such space relationship to said plates that a radial plane drawn through any one of the deflecting plates cuts at least two targets, independent means to connect separately and directly each one of said targets to the plate situated in its plane, a supplementary, hollow commutating electrostatical deflector inside, said tube between said targets and plates, for producing a radial field distributed uniformly around said axis, means to apply to said deflector the incoming pulses, a fluorescent screen associated with the targets, a supplementary starting target crossing said tube axis, connected to one of said targets a particular leakage resistance leading from each deflecting plate to a common connection point, and a continuous bias source having a negative pole connected to said point and positive pole to said anode.

4. In an electric pulse counting apparatus, a cathode ray tube, means inside said tube for producing an electric beam and for directing it along a predetermined reference axis, a plurality of electrostatically deflecting plates inside said tube arranged circularly with respect to said axis so as to form a plurality of different radial deflecting planes'passing through said axis, a plurality of band shaped targets for receiving the beam, located substantially in the same transverse plane and distributed regularly and obliquely with respect to said axis and in such a manner that the outer end of one target overlaps in a radial direction drawn from this axis, the inner end of the following target; independent means to connect separately and directly each of the aforesaid plates to the target the inner end of which is situated in the radial plane extending through said plate, a supplementary commutating deflector inside the tube between said plates and targets for producing a radial field distributed uniformly around said axis; means to apply the incoming pulses to said deflector, a fluorescent screen associated with the targets, a supplementary starting target located in said reference axis, connected to one of said targets, a supply circuit for energizing the tube, and a leakage resistance between each of said plates and said circuit.

5. In an electric pulse counting apparatus of the differential type, a cathode ray tube, means inside said tube for producing an electron beam and directing said beam along a predetermined reference axis, a plurality of deflecting plates inside said tube arranged circularly with respect to said axis so as to form a plurality of different radial deflecting planes passing through said axis, a plurality of targets for receiving the beam, of a curved elongated band form located in the same plane substantially perpendicularly to said axis, arranged symmetrically and extending obliquely with respect to said axis, overlapping each other and situated in such a space relationship to said deflecting plates that a radial plane passing through a plate cuts the outer end of one target, the middle part of the intermediate one and the inner end of a third target, independent means to connect separately and directly said plate to said intermediate target, a supplementary commutating deflector inside the tube between said plates and targets for producing a radial field distributed uniformly around said axis, means to apply to said deflector the incoming pulses, a fluorescent screen associated with the targets, a supplementary starting target located in said reference axis, connected to one of said targets a supply circuit for energizing the tube,

12 and a leakage resistance between each of said plates and said circuit.

6. Tube for counting purposes comprising an evacuated vessel and enclosed therein means for producing an electron beam and directing it along a tube axis, a plurality of deflecting plates arranged circularly in respect to said axis so as to form a plurality of different radial deflecting planes passing through said axis, a plurality of band shaped targets of high secondary emission for receiving the beam distributed around said axis and located substantially in the same transverse plane and distributed regularly and obliquely with respect to said axis and in such a manner that the outer end of one target overlaps in a radial direction drawn from this axis, the inner end of the following target, independent connectors for linkll'lg separately and directly each of said plates to the target, the inner end of which is situated in the radial plane extending through said plate, and which is located on the same side of the tube axis two hollow cylindrical coaxial electrodes spaced apart'and disposed concentrically with respect to said axis between said targets and plates, control lead-in conductors connected to said electrodes, a supplementary starting electrode located centrally in said target plane, a radially extending conducting path connecting said electrode to the zero position target; and a fluorescent screen associated with the targets.

7. Tube as claimed in 6, wherein the target, last struck by the beam, is led out by a particular conductor to an output terminal.

8. Tube as claimed in 6, wherein each deflecting plate is connected with a particular leakage resistance, said resistances terminating at a common connecting point.

9. Tube for counting purposes comprising an evacuated vessel and enclosed therein, means for producing an electron beam and directing said beam along a tube axis, a plurality of deflecting plates arranged circularly with respect to said axis so as to form a plurality of different radial deflecting planes passing through said axis; a plurality of targets of high secondary emission for receiving the beam of a curved elongated band form located in the same plane substantially perpendicular to said axis, arranged symmetrically and extending obliquely in respect to this axis, overlapping substantially each other and situated in such a space relationship to said plates that a radial plane passing through a plate cuts the outer end of one target, the middle part of the intermediate one and the inner end of the third target, independent connector for linking separately and directly said plate to said intermediate target, located on the same side of the tube axis, two hollow coaxial cylindrical electrodes spaced apart and disposed concentrically with respect to said axis between said targets and plates, a supplementary starting target located centrally in said target plane, a conducting path extending radially from said electrode towards the Zero position target and connected to the following target overlapping it, and a fluorescent screen associated with the target.

10. Tube as claimed in 9, comprising two additional targets situated, respectively, near the outer end of one of its targets and the inner end of the following target overlapped by the first one.

11. Electric pulse counting system comprising at least two series connected tubes as claimed in claim 7, a resultindicating scale associated with each of said tubes, an output terminal connected to one predetermined platetarget set of the first tube, an input terminal connected to the commutating cylindrical deflector of the second tube, and a coupling circuit having a predetermined time constant between said terminals.

12. In an electric pulse step by step distributor, a cathode ray tube, means inside said tube for producing a pencil-like electron beam, a plurality of targets for receiving said beam located inside said tube, a plurality of beam deflecting means, each determining a particular deflection plane, to each target corresponding a particular deflector, both being situated in the same deflection plane, an independent connector directly linking each target to its corresponding deflector, a supplementary starting target located in the trajectory of the undefleeted beam and linked to one of said targets, a supply circuit, an independent resistance to link separately each target deflector set to said supply circuit, and independent means controlled by the incoming pulses to be distributed, for acting upon said beam so as to commutate it from one target to another.

13. In an electric pulse counting apparatus, a cathode ray tube comprising inside thereof means for producing an electron beam a plurality of targets for receiving said beam, each determining an equilibrium position, a plurality of beam deflecting plates, each determining a particular deflection plane, an independent direct connection between each deflecting plate and the target located in its deflection plane, a supplementary starting target located in the trajectory of the undeflected beam and linked to one of said targets, an external supply circuit for energizing said tube, an independent resistance to link separately each target-deflector set to said supply circuit, an input circuit for receiving the incoming pulses to be counted, and a supplemental hollow deflectingcommutating system inside the tube, located between said targets and plates, controlled by said circuit and arranged so as to create a supplementary electrostatic field simultaneously in all said deflection planes.

l4. Tube for counting purposes comprising an evacuated vessel, and inside thereof means for producing an electron beam and directing said beam along the tube axis, a plurality of deflecting plates arranged circularly with respect to said axis, each determining a particular radial deflection plane, a beam receiving target of high secondary emission in each of said planes, an independent direct feedback connection between each of said deflectors and the target located in its plane on the same side of the tube axis, an independent potential stabilizing connection for each target-deflector set; a hollow beam commutating system for creating a supplementary electric field distributed around said axis, and a starting means actuated by the beam in its undeflected position and drawing the beam to the zero position target.

15. An electronic counter tube comprising an envelope, an electron gun in said envelope for generating an electron beam, a plurality of substantially coplanar anodes positioned in the path of said beam, a plurality of defleeting plates in said envelope equal to the number of anodes therein, means simultaneously interconnecting said anodes with their corresponding deflecting plates and the electron gun to cause said beam to have a stable position on whichever of said anodes the beam may be received on in the absence of additional beam deflection forces when said anodes are energized, said anodes being shaped to have more than one anode intersected by radial movement of said beam; a ring shaped control electrode passing around all positions of the beam, means for feeding energizing pulses to said ring and thereby effective to move said beam radially from one anode to the next in either direction.

References (Iited in the file of this patent UNITED STATES PATENTS 2,200,745 Heymann May 14, 1940 2,201,323 Shelby May 21, 1940 2,233,275 Wolff Feb. 25, 1941 2,365,476 Knoop et a]. Dec. 19, 1944 2,414,444 Busignies Jan. 21, 1947 2,447,233 Chatterjea et al Aug. 17, 1948 2,488,452 Overbeek Nov. 15, 1949 2,597,360 Moon May 20, 1952

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