DE1273077B - Magnetron beam switching tubes - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

HOIj

German class: 21g-13/27

Number: 1273 077

File number: P 12 73 077.7-33 (B 62764)

Filing date: June 2, 1961

Opening day: July 18, 1968

The invention relates to a magnetron beam switching tube with a transverse electrical Field and a longitudinal magnetic field, further with an electrode arrangement, the one longitudinally extending and an electron beam 5 delivering cathode and also a number of the Comprises electrode groups surrounding the cathode, each electrode group consisting of a target electrode for receiving the electron beam and for providing an output signal generated therewith, further a control electrode located between the cathode and the target electrode for forming and holding of the electron beam on the target electrode and finally a switching electrode that is in the distance of the target and control electrode is arranged and the position of the electron beam of a Target electrode to an adjacent target electrode by changing the electric field in the Proximity of the switching electrode advances.

A problem arises with such beam switching tubes when the target electrodes are abnormal high currents are to be drawn. Since the target electrodes show pentode-like operating characteristics, which are generally desirable must be in the potential of a target electrode for stable operation be kept within a narrow range of positive potentials. When the potential of a target electrode is below If this potential range is decreased, the target electrode is unstable and a defective one occurs Advancing an electron beam from this target electrode to the next. This instability results from the fact that a target electrode is incapable of falling below a certain potential threshold is to collect all the electrons of the electron beam flowing towards them. The excess electrons spread, flow to adjacent electrodes and eventually cause a defective one Advance. Methods are known to overcome this problem, but require them Process relatively complicated and expensive circuitry measures.

Another very important problem with the use of the beam switching tubes described above results from the physical, in particular the potential connection of the target and Switching electrodes in each electrode group. Because the target and switch electrodes are electrically adjacent to each other and the electric field of one electrode influences the other, the potential acts at a target electrode at every moment on the operation of the switching electrodes. Consequently the switching properties of the tube are determined by the magnetron beam switching tube

Applicant:

Burroughs Corporation, Detroit, Mich. (V. St. A.)

Representative:

Dipl.-Ing. H. Kosel, patent attorney,

3353 Bad Gandersheim, Braunschweiger Str. 22

Named as inventor:

Roger W. Wolfe, South Plainfield, N.J.

(V. St. A.)

Claimed priority:

V. St. v. America June 21, 1960 (37 607) -

The potential of the target electrodes is influenced, which also has an adverse effect on the switching properties of the tube as will be described in detail later.

The invention is based on the object through a special configuration of the electrode groups the magnetron beam switching tube to solve the problems described and the switching properties of the To improve beam switch tube.

This is achieved in that in each electrode group for electrical shielding of the target electrode a shielding electrode is provided opposite the switching electrode that the shielding electrode at a distance from the target electrode and outside the electron flow path from the cathode to the target electrode and that furthermore the shielding electrode is at a positive potential with respect to the cathode lies.

It is thereby achieved that the switching properties of the tube are practically independent of the potential the target electrodes are. The described risk of incorrect switching due to the mutual influence of switching and target electrodes is eliminated. The stability of the switching operation is significantly increased. Any additional complex circuit arrangements to stabilize the tube operation are completely unnecessary if the target electrode potential is low. It has also been shown that the inventive Arrangement of shielding electrodes

809 570/426

Switching operation of the tube at a higher operating frequency of the space between neighboring target electrons significantly compared to the known tubes and extends from target electrode to target electrode improves. The effects achieved by the invention the second leg in the radial direction on the and advantages in comparison with the known tubes switching electrode of the electrode group, are in the following description with reference to 5 According to a further embodiment of the inventor Drawing explained in more detail. Each shielding electrode has an output Es an electron beam interrupter is already clamped. This clamp can be used for this known, which also extend longitudinally and become, when the electron beam is switched on an electron beam delivering cathode and target to generate an output signal, having electrodes. In this known tube, io is used to further improve the tube operation however, the position of the electron beam on each shield electrode with the control electrode one individual switching stages electrically connected by a separate magnet-adjacent group of electrodes, controlled table field, which is parallel to the respective It can also each shielding electrode with a desired electron beam is aligned. This input terminal for the application of switching pulses known tube therefore has switching electrodes in the sense 15 to be provided.

the beam switching tube specified at the beginning does not appear. In a further embodiment of the invention, the

In this known tube there are individual shielding electrodes of each electrode group between the one Target electrodes referred to as shielding pieces indirectly with a point of fixed potential without additional electrodes arranged. This additional interconnection of impedance elements verbun electrodes however, are used when operating the well-known ao to be.

Tube for generating the necessary discount An embodiment of the invention and several

nuity of the electrostatic field, the _re for directing re application examples are provided in the drawing dardes electron beam on a particular Zielelek-. It shows

trode is necessary. Because of the completely different shape. 1 is a perspective view of a magnetic

operating mode of the known tube, in particular 35 tron beam switching tube,

due to the lack of the switching electrodes, FIG. 2 shows a plan view of the electrode arrangement

of the known tube, the problems described with the tube according to FIG. 1,

with regard to the stability of the tube operation not FIG. 3 is a schematic representation of the tube

appear. The known additional electrodes are nocturnal. 1 and a circuit in which this can be operated with the shielding tube 30 in terms of structure and effect, electrodes of the invention are not comparable. F i g. 4 shows a graph of the properties

To improve the switching properties of the tube, from one point of view, Tube is in a further embodiment of the invention in Fig. 5 is a graphical representation of the properties

Each electrode group has an electrode as a perma from a different point of view during operation nentmagnet formed, namely preferably 35 of the tube,

the target electrodes are designed as permanent magnets. 6 is a schematic representation of the tube

forms. _{according to Fig} . 1 and another circuit in which

According to a further embodiment of the invention, the tube can be used The shielding electrodes are used as well as FIG. 7 is a schematic representation of the tube

remaining electrodes of the electrode arrangement in FIG. _{40 according to FIG.} 1 and a further circuit arrangement arranged in the longitudinal direction of the tube parallel to one another _m the tube can be used, each control electrode has a U-shaped transverse Fig. 8 is a schematic representation of the tube

cut and is also each target electrode little- according to Fig. 1 and a further circuit arrangement least a part behind the open end of the JE fo _r the operation of the tube.

because the associated control electrode is arranged. These 45, as shown in FIGS. 1 and 2, are the basic ideas According to the invention, the arrangement and shaping of the electrodes are in a magnetron beam switching tube Realized particularly favorable operating properties of the tube with 10 with a tube piston 12, the one themselves. Expediently, there is an electrode arrangement 14 with a central, long electrode between each target electrode and the cathode has an unobstructed electron-stretched, indirectly heated, electron-emitting flow path. 50 the cathode 16 and ten groups of elongated

The effect of the shielding electrodes is contained in th electrodes, which are at a radial distance further embodiment of the invention are still thereby arranged by the cathode and the cathode further improved that the control and target electronics surround.

electrodes are essentially radially aligned with each other - each group of electrodes represents a switching stage,

Tet are that the AbscMrmelffekten of the cathode 55 is formed at which an electron beam and from the one are further away than the output signal corresponding to the control and Zielelek can be derived Troden and each essentially in the intermediate can. An electron beam can go from switching stage to space between a target electrode and an adjacent switching stage can be advanced under the influence barten switching electrode are arranged and that the crossed electric and magnetic fields in-shielding electrodes for electrons of the electrode within the electrode arrangement. The direction in electron current are accessible, but the normal ones that an electron beam tries to switch on, becomes The flow of this electron current to the target electrodes is determined by the alignment of these fields and not affect. can run clockwise or counterclockwise.

The electrode arrangement shown in the drawing is particularly important for the effect of the shielding electrodes appropriate design and arrangement 65 voltage is for a movement of the electron beam in is achieved in that the shielding electrode is suitably clockwise. For a movement towards it Each electrode group has an L-shaped cross-section clockwise, the arrangement can be reversed has, one leg of which is in the outer loading. A switching step that works in every moment

5 6

ahead of an electron beam is referred to as the leading / trailing arm of the adjacent control electrode switch-off stage and its electrodes are directed as leading and lies directly on this arm.
electrodes. Each electrode group also has one in the electron beam, is shown as an L-shaped follow-up switch stage and its electrodes as follow-up electrodes. 5 shield electrode 30, which is intended to shield the target electrode 26 from. In addition, the designations "conductive" and the associated switching electrode 28 are intended to shield. The shielding electrode 30 is arranged between each target individual electrode in each electrode group electrode 26 and its switching electrode 28, turns. It therefore serves to electrically isolate the two

Each electrode group has four electrodes on one another called electrodes. Which is made up of

in place of three electrodes as in earlier, this design continues to provide advantages

commercially available magnetron beam interrupters are described below. The shield electrode is such

were applied. Thereby an additional is shaped and arranged that it does not have its effect

Flexibility and a wider scope for disrupting the electron flow path between the

Magnetron beam switching tubes achieved so that these 15 exerts cathode and a target electrode.

Tubes are now able to operate modes through- The L-shaped shielding electrode 30 has a

feed, the so far not in a satisfactory manner first, generally radial arm 32 to the one

could be executed. Has leading 34 and a trailing 36. The radial

As the F i g. 1 and 2 show, each electrode arm 32 is substantially connected to the trailing arm 22

group in the tube 10 on a control electrode 18, 20 of the adjacent lead control electrode 18 aligned

which is essentially both in structure and in tet. The leading end 34 of the radial arm 32 is tight

the mode of operation of the control electrode in hitherto depends on the switching electrode 28, which is between the radial

applied magnetron beam interrupters, arm and the trailing arm of the leading control electrode

z. B. the tube of the type 6700. Each control electrode lies. The shielding electrode 30 also has a

serves to pull an electron beam on its 25 transverse arm 38, which has the radial extent or the

to form and hold the target electrode. The limit of each electrode group is determined. The transverse

Control electrodes are generally U-shaped arm 38 is perpendicular to the trailing end 36 of the

formed and have a base part 20 of the radial arm 32 and protrudes very close to the

Cathode is closest and from which two arms approach target electrode 26 to which it belongs. The transverse

22 and 24 essentially radially and in the direction 30 arm 38 thus closes the gap between

going away from the cathode. The control electrodes from adjacent target electrodes 26.

are generally elongated and par- A suitable circuit arrangement for operation

allele to the cathode aligned on a circle, the tube 10 is shown in FIG. 3 shown. The tube is

the center of which is the cathode 16. schematically in linear form with only five cathode

The control electrodes are shown on the cathode of all 35 groups or beam switching stages. In the

Electrodes closest. Adjacent control electrical circuit arrangement is the cathode 14 to earth

they form a space between them through which one is connected. Each control electrode 18 is

Electron beam can flow. suitable resistance 40 with a common

Each electrode group also has a target line 42 connected to the control electrodes, or output electrode 26 for receiving the electrode 40 which is appropriately transmitted through line 44 to an electron beam from which an output signal negative DC voltage source V _{s is} approximately conducted . In the embodiment of the invention 250 V is connected. A suitable zero setting according to FIG. 1 and 2, the target electrode also serves the circuit for setting an electron beam to generate the required longitudinally directed to the "O" switching stage after extinguishing the tube is magnetic field within the tube bulb. 45 provided. This circuit can simply be designed as a permanent magnet and consist of a switch 45, which is preferably in the form of a rod between. The "0" control electrode and earth can also be switched on. Other suitable means of generating a longitudinally each rod-shaped target electrode 26 can be used over a directed magnetic field. Suitable load resistor 46 for the target electrodes with the target electrodes are connected parallel to the cathode directly 50 a busbar 48, which are connected to a getet and lie on a circle, the center of which is a suitable positive direct voltage source F ₇ - from either the center of the cathode. The rods of about 300 V is connected. Each target electrode is target electrodes are further from the cathode further provided with a terminal 50, which is arranged with as the control electrodes 18 and in such a way, a suitable consumer, e.g. B. an indication that they receive the electron beam flowing from the cathode, a printing device or the like. In the embodiment can be. The shield electrodes 30 are shown in FIG. 1, each target electrode 26 is largely connected to one another and via the line 51 to the collecting part between the arms of the associated control rail 42 for the control electrodes, where the electrode is arranged, but closer to its guide arm. through them the positive potential of the busbar. The target electrode is thus maintained radially with its control 60 42. The switching electrodes 28 are aligned to form two electrodes and are preferably connected in such a way that the electrodes are arranged in such a way that they receive the electron beam without even-numbered switching steps in a group and those too close to a rod-shaped switching electrode 28 to electrodes on the odd-numbered ones Switching steps are in, which is provided in each electrode group. the other group. Each group of switching elec-

The switching electrodes 28 run parallel to the electrode 65 with one of the output terminals of a geCathode and lie on a circle, the middle of which is connected to suitable flip-flops 56. At the entrance point represents the center of the cathode. Each of the flip-flops is a source 58 of appropriate switch gate electrode is connected essentially radially to the impulse. The switching electrodes are on

7 8

any way in a low positive voltage. B. about 25 V. This bias electrodes 30 has solved a problem that users can be applied through the hip-hop circuit. of beam switching tubes in the past frequently during operation of the circuit arrangement according to FIG. 3 bothered. In many applications it has been customary for each input pulse from the source 58 to the 5, each target electrode of a beam switching tube flip-flop 56 to generate an output pulse which is applied to one of the groups of switching electrodes with one of the cathodes of a gas-filled cold cathode and then- To connect display device, e.g. B. with a through the electron beam in the tube 10 around a display tube of the type 6844 A. Such a tube switching stage advances. When an electron beam has a characteristic gas ionization time that it flows to a switching stage, most electri- cal cathode glowing are accompanied; This time in the tronen in the beam through the target electrode can be under the order of 2 to 5 microseconds, most operating conditions collected, and a normal during this period of time the display tube is painful, stable tube operation is the result. This represents an extraordinarily high impedance. As a result, the situation prevails when the potential of each target exists - the target electrode tends to be kept at a sufficiently high value to drop to the cathode potential. If there were none, so that it is able to essentially present the shielding electrodes, then this would collect the entire current of the electron beam. The potential drop leads to an excessive stray current and this type of stable operation leads to faulty switching. As in shield electrodes 30, however, no special function. 4, however, the shielding electrode absorbs under circumstances where the target electrode 20 trode 30 during this short period of time in which it is brought to a very low potential, e.g. B. the target electrode has fallen off, the excessive at cathode potential, the target electrode is not stray current and prevents incorrect switching able to collect all electrons accessible to it- as a result of instability. When finally the display means. This represents an unstable state and the tube ignites, if the target electrode potential rises in the known tubes, a faulty value would have a value at which the target electrode can collect the electrons. This results in a new gear step. However, the shielding electrode operating characteristics of the tube according to the invention trode 30, which is associated with the receiving electron beam, are equally advantageous in the operation of all the target electrodes, capable of any non-linear connection units, ζ. B. from gas any electrons that cannot be collected by the target electrode 30 charge tubes, relays and pulse transmitters, in turn to collect, so that the stability is maintained with the improved properties of the target electrode. As a result, troding as described above can improve the potential of the target electrode to substantially closely related switching properties. Practice and any potential can be reduced without theory showing that the location of a target electrode interferes with the stable operation of the tube with respect to its associated switching electrode and would. corresponding electrical potentials of these elec- The importance of the shielding electrode 30 is in troden the effectiveness of the function of the Schaltelek-Fig. 4 illustrates. In Fig. 4, the curve I ₇ shows trode influence for a beam switching operation. When changing the target electrode current in dependence on previously known beam switching tubes, it was determined from the potential of the target electrode and curve 40 shows that the amplitude of the switching electrode I ₅ Q changes the shielding electrode current from the flip-hop for switching a beam depending on the potential the target electrode. In the given switching pulse, generally independently known magnetron-beam switching tubes, this depends on the potential of the target electrode to which a stability of the tube in a substantial amount of electron beam flows at any moment, the threshold of the target electrode voltage. At 45 This means that if the target electrode voltage is increased (voltage undershoot voltage has a greater amplitude of the switching below the knee of the target electrode characteristic curve I ₇ ) , impulse tends to be required in order to have a good switching effect, the tube to instability, since not the entire one is closed - to obtain. This is essentially because current current collected by a target electrode can become a denser and more compact electron beam and part of the current to other 50 is assigned to a high target electrode potential. Scatters tubular elements. Conversely, if the target level is reduced, if it is not controlled, a defective electrode potential, the electron beam will be less. F i g. 4 shows a lower amplitude of the switching pulse for a, as according to the invention, this leakage current is required in the 55 switching process.

Tube 10 is collected by the shield electrode 30 On the other hand, in the tube according to the invention, when the target electrode voltage falls below each switching electrode 28 mainly through the knee of its characteristic. It is precisely this effect that influences the potential of the shielding electrode 30. It is the shielding electrode that controls the operation of the tube. Switching electrodes are accordingly essentially independent of the effect of the target electrode potential, according to the invention. This makes target electrode voltage. One aspect of the invention so far is shown in FIG. 5, drifted below the knee of the target electrode characteristic in which curves A and B relate switching voltage and target line to a limited extent by means of a comparison electrode voltage with various positive evidence of very complicated circuit arrangements. By adding the shield electrode 65 e.g. B. at bias voltages of approximately 25 or 15 V. However, operation is possible without such a complicated process. impulses a switching process of the electron beam

cause the target electrode voltage to vary over a relatively wide range can.

It is also known that the potential of the target electrode generally has its electrical effect exerts on the switching electrode and, as a result, has an influence on the switching operation. This is special obviously at higher operating frequencies of the tube. In normal operation of a beam switch tube when an electron beam is advanced and flows to a target electrode, the potential becomes target electrode is reduced to a lower value. If later a switching impulse is sent to the associated Switching electrode is given to advance the beam to the next switching stage, the Switching effect supported by this relatively low potential on the target electrode. But when the operating speed of the tube is increased, the resistance-capacitance time constant prevents of the target electrode circuit, the target electrode potential drops to this advantageous low level Potential if the target electrode receives an electron beam before the next switching pulse is applied will. The faster the tube operation, the higher the target electrode potential remains. There As a result, the target electrode is at an unfavorably high potential when the switching action should occur, the switching operation becomes more difficult and a stronger switching pulse is required.

However, since in the tube according to the invention for each switching electrode always mainly the potential the shielding electrode 30 is decisive, the switching electrode remains essentially unaffected by the potential of the target electrode. The tube 10 is therefore characterized by improved operation at high Frequencies marked.

In addition to the usual modes of operation in which the tube 10 can be used, the shield electrodes 30 can be applied in many different ways. According to FIG. 6, at the it is assumed that all the necessary connections according to Fig. 3 are provided, e.g. a source 60 for negative switching pulses is conductively connected to the shielding electrodes 30. The switching pulse source is set up in such a way that it has a negative pulse on the one electron beam receiving target electrode is assigned to the shielding electrode at the same time in which a switching pulse is placed on the associated switching electrode in order to advance the electron beam to the next switching stage. The negative pulse applied to a shield electrode in this way supports a state the instability, as it has been described, and thus promotes the switching operation.

In Fig. 7, each of the shield electrodes 30 is provided with an output terminal 62 which is used for this purpose can be to obtain an output signal when an electron beam from a switching stage to the next will be advanced. The output pulse generated in this way can, for. B. can be used to create a to drive the subsequent tube in a cascade counter or for any other suitable purpose.

In Fig. 8 is each shield electrode with the immediately adjacent trailing control electrode connected by a conductor 64 conductively. This conductive connection implies that during a Beam switching a negative pulse is given to the tracking control electrode. This an ^ Order gives the electron beam desirable properties and improves tube operation.

Claims (11)

Patent claims: 1. Magnetron beam switching tube with a transverse electric field and a longitudinal one magnetic field, further comprising an electrode arrangement having a longitudinally extending and a cathode providing an electron beam and also a number of the cathode surrounding electrode groups, each electrode group consisting of a target electrode to receive the electron beam and to deliver an output signal generated therewith, also a control electrode located between the cathode and the target electrode for formation and for holding the electron beam on the target electrode and finally a switching electrode consists, which is arranged at a distance from the target and control electrode and the position of the electron beam from a target electrode to an adjacent target electrode by changing of the electric field in the vicinity of the switching electrode continues, characterized in that that in each electrode group for the electrical shielding of the target electrode (26) from the switching electrode (28) a shield electrode (30) is provided that the shield electrode at a distance from the target electrode and outside of the electron flow path from the cathode (16) to the target electrode and in that further the shield electrode is on a positive potential with respect to the cathode. 2. Tube according to claim 1, characterized in that one in each electrode group Electrode is designed as a permanent magnet. 3. Tube according to claims 1 and 2, characterized in that the target electrodes (26) are designed as permanent magnets. 4. Tube according to claims 1 to 3, characterized in that the shielding electrodes (30) as well as the other electrodes of the electrode arrangement (14) in the longitudinal direction of the Tubes are arranged parallel to each other that each control electrode (18) U-shaped cross-section and that further each target electrode (26) is at least partially behind the open end the respectively associated control electrode (18) is arranged. 5. Tube according to claims 1 to 4, characterized in that between each target electrode (26) and the cathode (16) there is an unimpeded electron flow path. 6. Tube according to claims 1 to 5, characterized in that the control (18) and the target electrodes (26) are aligned essentially radially with one another that the shielding electrodes (30) are further away from the cathode (16) than the control and target electrodes and each essentially in the space between a target electrode and an adjacent one Switching electrode are arranged and that the shielding electrodes for electrons of the Electron stream are accessible, but the normal flow of this electron stream to the target - Do not affect the electrodes. 809 570/426 7. Tube according to claims 1 to 6, characterized in that the shielding electrode (30) each group of electrodes has an L-shaped cross section, one leg (38) of which in the outer area of the space between adjacent target electrodes (26) of target electrode extends to the target electrode and its second leg (32) in the radial direction on the Switching electrode (28) of the electrode group runs to. 8. Tube according to claims 1 to 7, characterized in that each shielding electrode (30) is provided with an output terminal (62). 9. Tube according to claims 1 to 8, characterized in that each shielding element electrode (30) electrically connected to the control electrode (18) of an adjacent electrode group is (64). 10. Tube according to claims 1 to 9, characterized in that each shielding electrode (30) is provided with an input terminal for the application of switching pulses. 11. Circuit with a tube according to claims 1 to 7, characterized in that that the shielding electrode (30) of each electrode group is fixed directly to a point Potential is connected without the interposition of impedance elements. Considered publications:
German patent specification No. 914 661. 1 sheet of drawings 809 570/426 7.68 © Bundesdruckerei Berlin