DE2130706A1 - Device for generating a plasma - Google Patents

Description

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G. Vtaluiusen

aa '^ 213070R

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Widenmayeratra 46 TeL 29512S

Teletype Corporation, Skokie (Illinois, USA)

Device for generating a plasma

The invention relates to a device for generating a plasma, with one with a gas or gas mixture filled chamber and at least two electrodes arranged on opposite walls of the chamber Generating a glow discharge by applying an appropriate alternating voltage to these electrodes.

Display devices in which characters are made visible by means of plasma or glow discharges and which devices have storage properties are known. One such storage and display device is on pages 541-547 of the Proceedings of the Fall Joint Computer Conference, 1966. It includes three Glass panes arranged one on top of the other and connected to one another. The middle pane of glass has a number Openings to form small gas-filled chambers through the two outer dielectric glass panes are limited. Electrical conductors are arranged on the outside of the outer panes of glass, the conductors being the one outer pane of glass run perpendicular to the conductors of the other outer pane of glass and the Crossing points of this ladder in the middle of the mentioned

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Openings are located. When an alternating voltage is applied to two crossing conductors, a special one builds up pronounced electric field at the crossing point, the field lines from one conductor through one outer glass pane run through the gas and through the other outer glass pane to the other conductor. By this relatively strong electric field is ionized the gas in this opening and a glow discharge is in this Position visible.

It is known further, a chamber defined by only two sheets of glass, the edges of which are tightly connected to each other, ψ, which is not divided by a middle sheet of glass to use. Such a device is described on pages 133-136 of the journal "Electronics", March 1969 issue.

As a result of the dielectric properties of the glass panes and the tendency of the ionized gas to opposite the polarity of the immediately adjacent electrode While charges accumulate on the inner surface of the two outer panes of glass, a glow discharge occurs only briefly every half cycle of an alternating voltage applied to the conductors running perpendicular to one another. At the next Half-cycle of the applied alternating voltage, the glow discharge is initiated at a voltage that is lower than that voltage which would be necessary to initiate ignition if the above-mentioned charges were on the inner surfaces the glass panes would not be present. The glow discharge begins when the sum of the instantaneous value of the applied The voltage and the voltage of the charges on the inner surfaces of the glass panes are equal to the ignition voltage of the gas taking into account the fact that the voltage drop across the capacitors formed by the dielectric glass panes must be taken into account. This charging phenomenon is responsible for the storage properties inherent in this arrangement because at of each glow discharge point the previous state is "remembered" for a short time, i.e. it becomes

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briefly recorded whether a glow discharge took place or not and the polarity of the applied voltage that initiated the last glow discharge.

It is the object of the invention to create a device which allows the glow discharge through external To shift influences controlled from one place to another place within the device.

The device according to the invention is thereby characterized in that the chamber is larger than that by a only glow discharge occupies space and that the width as a function of the length of at least one of the Electrodes or the chamber for generating the glow discharge on one of the size of those applied to the electrodes AC voltage dependent point is changeable.

The shape of the gas-filled chamber or at least one of the electrodes is chosen so that by applying a sufficient voltage ionizes the gas between the overlap area of the electrodes and that sections of the inner surfaces of the glass panes are charged, which sections have a certain shape, so that through the Applying voltages of different magnitudes a shift of the glow discharge is achieved.

A preferred embodiment can be designed so that the glow discharge from a pair of electrodes can be moved to a different pair of electrodes. This can be done by advancing the phase of that Electrode pair applied alternating voltage can be achieved, to which electrode pair transfer the glow discharge shall be.

Exemplary embodiments of the invention are described in more detail below with reference to the drawings, in which drawings the same or similar parts are provided with the same reference numerals. Show it:

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Fig. 1 shows a tapered or conically shaped slider on a dielectric wall of a gas-filled Chamber,

Fig. 2 is a section taken along line 2-2 of Fig. 1 showing the "cross-section of two glass walls which together form a gas-filled chamber with end pieces, shows, with conductors being arranged on the outside of the glass walls,

FIG. 3 shows the gas-filled chamber according to FIG. 1, with one conductor, however, being individual, widespread surface parts having,

4 shows a chamber with uniformly formed conductors, but the cross section of the gas chamber allr gradually getting smaller

5 shows a conductor with individual, separate surface parts which are all of the same size and which one conically shaped gas chambers are assigned,

6 different individual conductors which are arranged on a wall of a chamber,

7 shows a section along the line 7-7 of FIG. 6,

8 shows an ignition electrode and various conically shaped electrodes for step-by-step displacement the glow discharges from one electrode to the other,

9 shows a conductor arrangement which is able to "perform the function of a shift register,

10 shows part of a pattern of a conductor arrangement for shifting a signal back and forth, which Ladder arrangement represents a shift register in which the data can be shifted in two directions,

11 shows the shift register according to FIG. 10, which is designed in a folded-over form for special purposes,

12 shows the shift register according to FIG. 10 with a coding device and means for transmitting a Glow discharge from one shift register to another and

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13 shows the use of the shift registers according to FIGS. 11 and 12 for coding letters to be displayed, for transferring the same to a display device and for moving these letters along this display device.

1 and 2 is a gas-filled container, which is arranged essentially by two mutually parallel Glass walls 20 and 22 is limited, shown. Between these glass walls 20 and 22 is a glass seal 24 with the Glass walls 20 and 22 connected, arranged so that a gas-filled chamber 26 with a constant over its entire length Cross-section is formed. On the outer surfaces of the glass walls 20 and 22 there is a conductor 28 and 30 respectively connected to these. The width of the conductor 30 gradually decreases towards its free end, while the width of the Conductor 28 is the same over its entire length. Enclosed in chamber 26 is a mixture of inert gases, which Mixture preferably contains about $ 2.5 nitrogen and the remainder neon. The conductors 28 and 30 can come in two thick, stiff ones electrically insulating supports 27 and 29 may be included, which supports and conductors with the outside of the · glass walls 20 and 22 are connected.

If the on the conical conductor 30 and the evenly When the voltage applied to the shaped conductor 28 is increased, the dielectric property of the glass walls 20 and 22 is effected and the gas enclosed in the chamber 26 has an alternating current dividing effect, since a stress difference arises between the inner surfaces of the glass walls 20 and 22, which the applied voltage counteracts. When this voltage difference reaches the ignition voltage of the gas, it will Gas ionized and plasma-like, so that a glow discharge takes place.

The maximum field strength of the electric field between the two conductors 28 and 30 at any point along it occurs in the middle of its width. the

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maximum field strength occurs in the center of the widest part of the conical conductor 30, because this is due to the Edge effect of the field, which the glass walls and the gas located between the two conductors 28 and 30 enforced, favored. The glow discharge therefore begins between the two conductors 28 and 30 in the middle of the widest part of the conical conductor 30. To the extent that the voltage applied to the conductor across the for Achieving a "glow discharge necessary minimum value increases, the discharge area spreads more and more towards the tapered end of the conical conductor 30. because

"between conductors 28 and 30 and the gas or gas mixture there is no galvanic coupling, but only a capacitive coupling acting through the glass walls, the glow discharges only last half a period of the alternating current impressed in the conductors 28 and 30.

If the conductor 30 has discrete parts with ever larger areas, which are connected to one another by webs are, as shown in Fig. 3, the individual glow discharges increase with increasing Start tensioning in the middle of the largest sub-area. The position of each of the glow discharges is therefore dependent on its size the applied voltage can be determined in advance.

It was further found that when both conductors 28 and 30 are constant over their entire length Have width and the cross section of the gas-filled chamber 26 tapers, see FIG. 4, that then the ionization and the glow discharge begins at the widest point of the chamber 26 first.

If the conductor 30 according to FIG. 5 is designed like a comb and of the same size, at regular intervals has arranged comb teeth which overlap a conical gas chamber 26, the glow discharges occur first in the widest part of the chamber 26. So the same phenomenon occurs as with one

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Gas chamber with a uniform cross-section over which a conductor with discrete and uneven surface areas is arranged, as shown in FIG.

It has been found that when a glow discharge takes place, it is on the inner surface of the glass walls 20 and 22 electrical charges are stored, this storage area being larger than the corresponding one Surface part of the conductor, this is because the charges are accumulated beyond the edges of the conductor. When on the same glass wall a second conductor is placed very close to the first conductor, so the storage area reach up to this conductor or even overlap it.

It should be remembered that the electrical charge accumulated on the inner surface of the glass wall for the memory effect of the arrangement is responsible. These capacitive charges cause that after the initial Ionization of the gas, i.e. after ignition, a reduced alternating voltage between the opposing ones Ladders are sufficient to maintain the ionization of the gas.

If another voltage is subsequently applied to a second adjacent conductor is applied, ionization or a glow discharge will occur on the second conductor, even if the additional voltage applied to the adjacent conductor is less than the voltage, which would be necessary to generate a glow discharge if no electrical charge was stored on the glass wall were. Therefore, the stored information is indicated by a glow discharge, and the stored charge is displayed the inner surface of the glass wall can be transferred from the first conductor to the second adjacent conductor.

This charge transfer is shown in FIGS. Two flat glass walls 31 and 32 delimit one Chamber 34 filled with neon. Four conductor electrodes 35, 36, 37 and 38 are arranged on the outside of the glass wall 32.

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These conductor electrodes 35, 36, 37 and 38 are arranged relatively close to one another but isolated from one another. One common conductor electrode 40 is dei on the outside Glass wall 31 attached.

The output voltage "of a generator 41 is applied to the conductor electrodes 36 and 40. This alternating voltage is sufficiently large to each time a momentary glow discharge to be generated at each half-wave of this alternating voltage, on the inner surface of the glass walls 31 and 32 in the area of the conductor electrodes 40 and 36, respectively, a space charge cloud 42 'is formed. The quantity applied to this conductor electrode the alternating voltage, which is sufficient to generate a glow discharge, is of the size of the conductor electrodes, of the type of the gas in the chamber 34 and the gas pressure, the properties, the thickness and the spacing of the glass walls 31 and 32, as well as the proportion of any ultraviolet radiation that may be present. The size of this alternating voltage can for example 1000 volts from peak value to peak value. The frequency of this alternating voltage is preferably 40-300 kHz, but lower or higher frequencies can also be used.

Since the charges stored on the glass walls 31 and 32 are caused by the two opposing clouds of space 42 are formed, the conditions are similar to "in the case of a charged plate capacitor.

After a glow discharge has been initiated between the conductor electrodes 36 and 40, the output voltage of the generator 41 can be reduced to a value which ensures that the glow discharge is maintained. The reduced voltage can be between 20-300 volts less, this reduction being from the above depends on the parameters mentioned.

The two space charge clouds 42 on the inner surfaces of the glass walls 31 and 32 extend over the

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Edges of the conductor electrode 36 so that these space charge clouds a part of the closely adjacent conductor electrodes 35 and 37 overlap.

If, according to FIGS. 6 and 7, an alternating voltage of a suitable size, e.g. 700 volts from the peak value Peak value, are subsequently applied to the conductor electrodes 35 and 38 by means of a further generator 44 after the alternating voltage applied to the conductor electrode 36 has suddenly been reduced to less than 700 volts peak value to peak value, a glow discharge occurs occur between the conductor electrodes 35 and 40. The applied to the conductor electrode 35 by the generator 44 However, AC voltage is only large enough to cause a glow discharge if there is between the conductor electrodes

35 and 40 is at least partially a space charge cloud, a previous glow discharge. The polarity of the Charge and the instantaneous value of the applied alternating voltage must be added together to maintain the Glow discharge result in the voltage necessary for a corresponding glow discharge to occur. Because the applied If the voltage is an alternating voltage, the total voltage is always shortly after the alternating voltage is applied large enough to initiate the glow discharge. By overlapping the space charge cloud 42 in the area of Conductor electrode 35 suffices an alternating voltage which is smaller than the ignition voltage without the presence of a space charge cloud, to achieve a glow discharge between the conductor electrodes 3 5 and 40.

In this way, the storage effect can be in the form of a space charge cloud below the conductor electrode

36 can be transferred to the conductor electrode 35 without generating a space charge cloud below the conductor electrode 38. Since the space charge cloud 42 only overlaps a part of the conductor electrode 35 and does not extend to the conductor electrode 36 extends only between the conductor electrodes

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35 and 40 and not between the conductor electrodes 37 and and a glow discharge is not generated between the conductor electrodes 38 and 40, although the conductor electrode 38 is also is connected to the further generator 44. Such a device can be used for data transmission will.

In order to detect the presence of a glow discharge between the conductor electrodes 3 5 and 40, the from Generator 44 supplied current monitors or the conductor electrode 35 from at least translucent, conductive Material are made, in the latter case with

a photocell 46 the glow discharge can be monitored. Next can with a test leader, not shown, the Charge can be scanned on the inner surface of the glass wall.

The transfer of the memory effect from the conductor electrode 36 to the conductor electrode 35 has been carried out simultaneous lowering of the alternating voltage applied to the conductor electrode 36 and by allowing the reached to the conductor electrode 3 5 applied alternating voltage. There are several ways this alternating voltage in the to control the manner indicated above, so that the glow discharge is transferred from one conductor electrode to the other. So that no transmission takes place, it is necessary that

"the instantaneous value of the voltage on the receiver conductor electrode 35 reaches a value sufficient to generate a glow discharge before it is sent to the transmitting conductor electrode 36 applied voltage reaches this value.

If between the receiver lead electrode 3 5 and a glow discharge occurs first on the common electrode 40, this receiver lead electrode 3 becomes 5 remove the stored charge from the transmission conductor electrode 36, and thus prevent it from occurring between this and the Conductor electrode 40 a glow discharge occurs, even if immediately after that the transmission conductor electrode

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applied voltage is equal to or slightly greater than the voltage applied to the receiver conductor electrode 35. The transfer of the memory effect can also be achieved by changing the phase between the conductor electrodes and 36 applied AC voltages are achieved.

Phase differences between the two applied AC voltages can be achieved by using the The frequency of one AC voltage is constant and the frequency of the other AC voltage is reduced over time or enlarged. Or even if the phase of one alternating voltage is advanced and the phase of the other AC voltage is shifted back. The only condition in each case is that the instantaneous value of the receiving conductor electrode 35 applied alternating voltage reaches its necessary value earlier than the instantaneous value of the transmitting conductor electrode 36 applied alternating voltage. In a similar way, the transference effect can be achieved by corresponding Adjusting the magnitude of the AC voltages can be achieved as described above. One of these alternating voltages can be kept at a constant value and the other voltage can be reduced or increased. Or it can also be the an alternating voltage can be lowered and the other alternating voltage can be increased at the same time.

To the transmission of a glow discharge from To improve one conductor electrode to another, the combination of the phase difference and the change is preferable the magnitude of the voltages applied to these conductor electrodes. The one to the receiver lead electrode

35 applied AC voltage is increased and its phase shifted back, while that of the transmitting conductor electrode

36 applied alternating voltage is reduced and its phase is advanced to ensure a proper shift of the To obtain glow discharge from the conductor electrode 36 to the conductor electrode 35.

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The conductor electrode 40 shown in FIGS. 6 and 7 works with both the conductor electrode 36 as well as with the conductor electrode 3 5 together. Therefore one output terminal of each of the two generators 41 and 44 is included the common Leitei & ektrode 4Q connected.

With reference to FIGS. 1-5, it was stated above that without taking into account that on the inside of the glass walls 22 stored charge, the field strength of the electric field between two each other opposite ladders in the middle of the widest part of the conductor 30 is largest. Hence the Glow discharge preferentially occur at this point.

8 shows an embodiment similar to that shown in FIGS. 6 and 7, the conductor electrodes of which have a special shape for generating a storage signal for transferring the storage effect or the glow discharge from one conductor electrode to the other and back again. The conductor electrode 36 acting as an ignition electrode is arranged on the glass wall 32. If such a store signal to be generated, so a sufficiently high alternating voltage between the circuit electrode 36 and shown in Fig. 7 common wiring electrode 40 is applied to a glow discharge without prior storage of charges on the inner surfaces of the glass W walls between these two To initiate conductor electrodes. As a result of this glow discharge, charges are stored on the insides of the inner surfaces of the glass walls 31 and 32, which run parallel to one another, in the intersection area of the two conductor electrodes 36 and 40. The space charge clouds 42 generated by these charges are shown in phantom in the figure.

As already explained earlier, these space charge clouds 42 extend over the edges of the conductor electrode 36 and overlap parts of a directly

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adjacent electrode 50. After ignition, the alternating voltage applied to the conductor electrode 36, which acts as an ignition electrode, and the common conductor electrode 40 can be reduced if an alternating voltage is applied to the electrode 50 that is insufficient to cause a glow discharge without the cooperation of the space charge cloud 42 achieve, no glow discharge will occur at the widest point of this electrode 50. However, W _e nn part of this space charge cloud 42 extends over parts of the electrode 50, it is through this space charge cloud between the electrode 50 and the common electrode 40 is inserted an additional voltage. When the correct polarity and size of the alternating voltage applied to the electrode 50 and the common conductor electrode 40 occurs, a glow discharge is initiated in the area in which the space charge cloud 42 overlaps the electrode 50. As already mentioned, a glow discharge occurs preferably at the widest part of an electrode, because the field strength in the center of this widest part of the electrode is greater than in the narrow part of the electrode. Therefore, the glow discharge migrates towards the wider end of the electrode 50 for each subsequent period of the AC voltage applied to the electrode 50. It has been found that 5-50 periods were required for this migration, this migration time being dependent on many factors such as the size of the electrode 50, the degree of their taper and the size of the applied alternating voltage is dependent.

If a sufficiently high alternating voltage is applied to the electrode 50, a glow discharge occurs, which extends over the entire surface of the electrode 50. If, on the other hand, a smaller alternating voltage is applied, a glow discharge occurs only in the region of the widest part of the electrode 50, the resultant being Space charge cloud 52 at the widest part of electrode 50 also overlaps the narrow part of the electrode 50, and thereby a discharge in the narrow area of this electrode

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prevented if a sufficiently high AC voltage is not applied.

Even if it is not essential, it is preferred ensured that the glow discharge between the conductor electrode 36 acting as an ignition electrode and the common conductor electrode 40 is maintained. For this purpose, the electrode 50 is applied AC voltage is normally kept in such a way that a complete displacement of the glow discharge from the conductor electrode 36 to the electrode 50 is prevented. However, if P is a shift in glow discharge from described below If desired, the voltage applied to electrode 50 can be controlled so that a complete shift of the glow discharge from the conductor electrode 36 to the electrode 50 takes place.

The glow discharge at the electrode 50 generates the space charge cloud 52 on the inner surfaces adjacent to it of the glass walls 31 and 32. Sufficient alternating voltage is applied to the electrode 50 to generate a Generate sufficiently large space charge cloud, which is the narrow part of a further electrode 54, which is also is conical in shape, overlaps. If then a | AC signal of sufficient size to the other Electrode 54, accompanied by a reduction in the alternating voltage applied to the electrode 50, is applied, so a glow discharge will occur in that part of the further electrode 54 which is overlapped by the space charge cloud 52. The occurrence of a glow discharge at the narrow end of the electrode 54 becomes the wide end area the electrode 50 removed charge, whereby the charge of the space charge cloud 52 formed by the electrode 50 is reduced will. The glow discharge in the adjacent part of the further electrode 54 takes that of the electrode 50 charge stored on the adjacent surface of the glass wall.

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In the manner described above with reference to the electrode 50, the glow discharge travels in FIG another electrode 54 with each period of the alternating current signal applied thereto to the widest part of this further electrode, further indicated by dash-dotted lines on the inside of the glass walls 31 and 32 Space charge clouds 62 arise.

This further space charge cloud 62 overlaps another, conically shaped electrode 64. When an alternating current signal is applied to this electrode 64 and at the same time the AC signal applied to the electrode 54 is reduced occurs in that overlapped by the space charge cloud 62 Part of the electrode 64 a glow discharge. This removes so much charge from the space charge cloud 62 that the The glow discharge between the electrode 54 and the common conductor electrode 40 is extinguished, even if it is still one A smaller alternating current signal is applied to the electrode 54. Under these circumstances, the space charge cloud 62 becomes fast dismantled and disappears. The alternating voltage applied to the electrode 64 causes the glow discharge from the narrow Part of the electrode 64 migrates to the broad part of this electrode and that a space charge cloud 66 is generated.

A binary bit of information relating to the electrode 50, which is input to the conductor electrode 36, can therefore be used be transmitted. By changing the amplitude of the alternating voltages applied to the further electrodes 54 and 64 this bit can be shifted from left to right in the arrangement shown in FIG. This information bit can therefore be in the form of a traveling glow discharge be moved from one electrode to the other electrode and back if necessary.

FIG. 9 shows an arrangement of a number of shift registers operatively connected to one another, in part shows which shift registers are arranged on the same glass wall 32. For entering a bit of a binary

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Information, a sufficiently high alternating voltage is applied to the conductor electrode 36, which acts as an ignition electrode, and the common conductor electrode 40, which is not shown in FIG. 9, is applied. The ones mentioned between these The glow discharge produced by conductor electrodes 36 and 40 is then transferred to the conductor electrode which acts as an intermediate electrode 50 and subsequently transferred to the conductor electrode 54 having a plurality of segments 54-1, 54-2, 54-3, etc. The glow discharge can then from segment 54-1 to the first segment 64-1 of the conductor electrode 64, the other segments 64-2, 64-3 etc. has to be transmitted. The signal or the binary

) Bit can be in the form of a glow discharge from segment 54-1 to segment 64-1 and back to conductor electrode 54 but to its second segment 54-2 and from there to the second segment 64-2 of the conductor electrode 64 are transferred. The individual segments of the two conductor electrodes 54 and 64 form together a shift register.

A number of perpendicular to the conductor electrode 64 arranged conductor electrodes 67, 68, 69 and 70 are electrically connected to the conductor electrode 64 and therefore have the same AC voltage signal that is sent to the conductor electrode 64 is created. A number of independent lead electrodes 72, 74, 76 and 78 extend substantially

k parallel to the conductor electrodes 67, 68, 69 ukM 70. One each the last mentioned conductor electrodes and one of the independent conductor electrodes together form a shift register, namely the conductor electrodes 72 and 67, 74 and 68, 76 and 69 and 78 and 70.

If a glow discharge is present at segment 64-1 of conductor electrode 64, this can be the first Segment 72-1 of the independent conductor electrode 72 are transferred. From Fig. 8 it can be seen that the Space charge cloud 66 overlaps the narrow part of the conically shaped segment 72-1 of the independent conductor electrode 72.

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The ignition of a glow discharge at segment 72-1 of the independent conductor electrode 72 removes the space charge cloud at segment 64-1 charge, which extinguishes its glow discharge.

The binary bit represented by the glow discharge is then held by segment 72-1, where the Glow discharge migrates to the wider part of the segment because of the alternating voltage applied to conductor electrode 72 is maintained. At the same time, another additional binary bit is generated by the one acting as an ignition electrode Transferring the conductor electrode 36 to the conductor electrode 50 which acts as an intermediate electrode. If that extra bit is transferred from segment 54-1 to segment 64-1, the first bit entered goes from segment 72-1 to the segment 67-1. The additional bit can then from segment 54-2 and possibly after further segments of the conductor electrodes 54 and 64 formed shift register are transferred.

It may later be desired that a further additional bit of the binary information be transferred to one of the perpendicular conductor electrodes connected to conductor electrodes 54 and 64, e.g., to independent conductor electrode 76 transfer. For this purpose it is necessary to have an alternating current signal at the right time and of a certain size across the independent lead electrode 76. The right time is when the bit is on the segment 64-3 of the conductor electrode 64 has arrived. If these requirements are met, this additional bit will be transferred to segment 76-1 of independent conductor electrode 76. In a similar way, glow discharges, which correspond to one bit are transferred to the first segments of the independent conductor electrodes 72, 74, 76 or 78 and shifted from these first segments in the shift registers, as shown with reference to FIG the shift register formed by the conductor electrodes 54 and 64 has been described.

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To the arrangement according to FIG. 9 as a data shift register To use it, the data must be sampled at prescribed points and at specific times to determine if a glow discharge is occurring on any particular segment of one of the conductor electrodes or not. This can be done, for example, by that one monitors the glow discharge with an appropriately arranged photocell, as did with 6 and 7 is described above. Instead of the photocell, one with a Bit checker 79 connected scanning electrode 77 are used, which are attached to the outside of the glass wall 32

^ is arranged. When there is a glow discharge at that of the scanning electrode 77 adjacent segment 72-3 occurs, the associated space charge cloud becomes the scanning electrode 77 overlap. With the help of a generator in the bit checker 79, the glow discharge, on the above can be transferred from the segment 72-3 to the scanning electrode 77 as described above. By monitoring the bit checker 79 outputted to the scanning electrode 77 current can then be determined whether a corresponding bit of the Segment 72-3 has been transferred to the scanning electrode 77 or not. Once established, the bit may if if this is necessary, go back to segment 72-3.

) will wear.

Another way to determine whether or not a bit got to segment 72-3 is in that the overlap area of the space charge cloud generated by this segment 72-3 with the scanning electrode 77 with a field effect transistor.

Further above, in connection with FIGS. 6, 7, 8 and 9, it is stated that the common conductor electrode ._ .. 40 is arranged on the outside of the glass wall 31, and that all AC signals that are applied to the conductor electrodes arranged on the glass wall 32,

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AC voltages in relation to the common conductor electrode 40 are. It should be noted that the glow discharges in any conductor electrode or a segment of a conductor electrode are only possible) because a corresponding alternating current signal between the relevant conductor electrode or applied to the relevant segment of the conductor electrodes and the common Leiteiö-ektrode 40 shown in FIG is. This alternating voltage is of such a size that, together with the stored charge, it increases the gas able to ionize. However, this size is insufficient to ionize the gas without the presence of a to effect a corresponding charge.

If one looks at the two mutually adjacent conductor electrodes 54 and 64 in FIG. 9, one finds that that a glow discharge remains at segment 54-1 of the conductor electrode 54 and not to segment 64-1 of the conductor electrode 64 is transmitted, as the alternating voltage applied to the conductor electrode 54 is greater than that of the Conductor electrode 64 applied alternating voltage. When the alternating voltage applied to the conductor electrode 64 is greater is than the alternating voltage applied to the conductor electrode 54, the voltage of the gas between the increases Glass walls is exposed to below the conductor electrode 64 faster than below the conductor electrode 54. Therefore has the glow discharge tends to spread more rapidly under the conductor electrode 64 than under the conductor electrode 54 relocate. Indeed, the occurrence of the glow discharge under segment 64-1 becomes all or sufficient Amount of charge detached from the charge previously stored under segment 54-1, so that the glow discharge goes out under segment 54-1. By a corresponding change in the applied to the conductor electrodes 54 and 64, respectively AC voltages will therefore shift the glow discharge from one conductor electrode to the other conductor electrode causes.

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The relocation of the glow discharges is less due to the absolute size of the conductor electrodes the glass wall 32 applied alternating voltages, but essentially the ratio between the mass Conductor electrodes 64 and 54 applied alternating voltages. The only condition of the absolute size of this AC voltages is that the higher of the two AC voltages must have a peak value that is sufficient to initiate a glow discharge in the presence of a space charge cloud and the higher of these two AC voltages must not have a peak value that would be sufficient to produce a glow discharge even without the

W to generate the essence of a space charge cloud. It has been found that a relatively wide range, between 20 and 300 volts, of voltage values for the AC signals is acceptable. These values depend on the nature, the pressure and other properties of the gas located between the two glass walls, the properties, the thickness and the distance between these glass walls and the shape and dimensions of the conductor electrodes and their distances.

Because the conductor electrodes 64, 67, 68, 69 and 70 are all electrically connected to each other, it is possible to apply all these conductor electrodes to the same constant alternating voltage and to transmit the glow discharges the alternating voltage signals applied to the conductor electrodes 54, 72, 74, 76 and 78 in relation to the constant alternating voltage to increase or decrease. Therefore, the alternating voltage applied to the lead electrode 64 is not necessary to change. Every time the alternating voltage applied to the conductor electrode 54 is opposite to the the AC voltage applied to the conductor electrode 64 is significantly reduced, glow discharges are generated at the wide Parts of the segments of the conductor electrode 54 occur on the narrow parts of the immediately adjacent segments of the conductor electrode 64 transferred. In a similar way

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when the AC voltage applied to the conductor electrode 54 is significantly increased compared to the alternating voltage applied to the conductor electrode 64, which may be Segments of the conductor electrode 64 occurring glow discharges on the segments of the conductor electrode adjacent to their broad parts 54 transferred.

Correspondingly, there are also glow discharges from segments of the conductor electrode 64 to those adjacent to them first segments of the independent and perpendicular to the conductor electrode 64 conductor electrodes 72, 74, 76 or 78 transmitted when the alternating voltages applied to this compared to the alternating voltage applied to the conductor electrode 64 can be increased significantly. By shifting the glow discharges from the conductor electrode 64 to the first Segments of the independent conductor electrodes so much charge is withdrawn from the segment of the conductor electrode that this Glow discharges go out. The AC voltages applied to the independent conductor electrodes 72, 74, 76 and 78 can be controlled individually, as already mentioned above, or these independent conductor electrodes can be electrically connected to one another connected, and thus controlled together.

In Fig. 10, a further embodiment is shown partially in plan view, in which several Conductor electrodes are arranged on both glass walls. Those shown with thin lines and hatched areas Conductor electrodes 80 and 82 are on one glass wall and those with thick lines and non-hatched areas Conductor electrodes 84, 86 and 88 shown are arranged on the other glass wall. The one on the individual conductor electrodes The alternating voltage applied to one glass wall is on individual conductor electrodes and not on the other glass wall related to a common conductor electrode.

The mode of operation of the arrangement according to FIG. 10 is described below using an example by

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^{FIG. 1} assumes that a high AC voltage is applied to the conductor electrode 80 and that a low AC voltage is applied to the conductor electrode 82. It is further assumed that a high alternating voltage is applied to the conductor electrodes 84 and 86, which run perpendicular to the conductor electrodes 80 and 82, and a low alternating voltage is applied to the conductor electrode 88 at the same time. In addition, it is assumed that a glow discharge is present in the overlapping area of the conductor electrodes 80 and 84. The high alternating voltages that are applied to these conductor electrodes 80 and 84 must be shifted by around 180 ° to one another, so that

ψ the peak values add up and result in a high peak value.

Because the AC voltage applied to the conductor electrode 82 is smaller than that to the conductor electrode 80 applied alternating voltage, the effective alternating voltage between the conductor electrodes 82 and 84 is less than the alternating voltage effective between the conductor electrodes 80 and 84. Likewise is between the conductor electrodes 80 and 88 a smaller alternating voltage effective than between the conductor electrodes 80 and 84. Therefore, the glow discharge takes place in the overlapping area of the conductor electrodes 80 and 84 instead.

| When the applied to the conductor electrode 80

AC voltage is reduced and the voltage applied to the conductor electrode 82 is increased, the glow discharge migrates from the overlapping area of the two conductor electrodes 80 and 84 to the overlapping area of the two conductor electrodes 82 and 84 when the AC voltage applied to the lead electrodes 84 and 86 is the higher value and the the AC voltage applied to the conductor electrode 88 is maintained at the lower value.

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If subsequently the alternating voltage applied to the conductor electrode 88 increases and that to the conductor electrodes 84 and 86 applied alternating voltage are reduced, and no change to the conductor electrode 82 applied high AC voltage and the low AC voltage applied to conductor electrode 80 occurs, so the glow discharge migrates from the overlapping area of the Conductor electrodes 82 and 84 for the overlapping area of conductor electrodes 82 and 88. From the above it can be seen that that a glow discharge by controlling the to the conductor electrodes of the two opposite glass walls applied alternating voltages from one stiffener to another Position can be relocated.

The shifting of the glow discharge in the overlapping area of the conductor electrodes 82 and 88 by increasing the the alternating voltage applied to the conductor electrode 80 with a simultaneous reduction in the voltage applied to the conductor electrode 82 applied AC voltage causes the glow discharge to the overlap area of the conductor electrodes 80 and 88 wanders. A subsequent reduction in the alternating voltage applied to the conductor electrode 88 is accompanied by a Increase in applied to lead electrodes 84 and 86 AC voltage causes the glow discharge to be shifted to the overlapping area of the conductor electrodes 80 and 86.

Although the same alternating voltage is applied to the conductor electrode 84 as to the conductor electrode 86, In the example described above, the glow discharge is not directly from the conductor electrode 88 to the conductor electrode 84 migrate because the conductor electrode 80 is closer to the overlap area of the conductor electrodes 84 and 88 and further from the overlap area of the conductor electrodes 86 and 88 is removed. In addition, the conductor electrode 88 is in the immediate vicinity of the conductor electrode 86 adjoining area de: conductor electrode 80. While conductor electrode 88 is in the area of conductor electrode 80

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is less close to the conductor electrode 84.

When the order of increasing and decreasing the alternating voltages applied to the various conductor electrodes are carried out in reverse order, see above this has the consequence that the glow discharge is shifted in the opposite direction. For example, suppose that a glow discharge takes place in the overlapping area of the conductor electrodes 80 and 88. The diminishing of the AC voltage applied to conductor electrode 88 and the simultaneous increase in the voltage applied to conductor electrode 82 applied AC voltage causes the AC voltage applied to the conductor electrodes 84, 86 and 88 to be kept constant.

ψ voltages that the glow discharge is shifted from the overlapping area of the conductor electrodes 80 and 88 to the overlapping area of the conductor electrodes 82 and 88.

In a similar manner, the is applied to the conductor electrodes 84 and 86 by subsequently enlarging AC voltage and by reducing the AC voltage applied to the conductor electrode 88, the glow discharge relocated to the overlap area of the conductor electrodes 82 and 84.

In Fig. 11 is a similar conductor electrode arrangement as shown in FIG. This arrangement is designed so that a glow discharge along a first Cantilever 89 of a shift register 90 and back via a second arm 91 of this shift register can, wherein, the second arm 91 is folded over the first arm 89. Four conductor electrodes 92, 93, 94 and 96 are parallel to each other on the outer surface of one of the two enclosing a gas-filled chamber Glass walls arranged. The same alternating voltage is applied to the conductor electrodes 92 and 94. The conductor electrodes 93 and 96 are supplied with an alternating voltage that differs from the aforementioned alternating voltage. if

10 9 8 5 3/1701 ^ ^{0 0RiG! N} AL

a high alternating voltage is applied to the conductor electrodes 92 and 94, a low alternating voltage is applied to the Conductor electrodes 93 and 96 on and vice versa. On the outside surface an ignition electrode 9B is arranged on the other glass wall. It is supplied with a sufficient alternating voltage in the With reference to the conductor electrode 92 or 93 supplied, so that regardless of the state in this area, a glow discharge in the overlapping area of the ignition electrode 98 and the conductor electrode 92 or 93 occurs. The function of this ignition electrode 98 is similar to that as an ignition electrode active conductor electrode 36 according to FIG. 8, therefore there is always a glow discharge for transferring to a first one Intermediate electrode 100 available.

If the first intermediate electrode 100 has a high AC voltage is applied, a glow discharge is generated from the overlapping area of the ignition electrode 98 and the intermediate electrode 100 transferred along the conductor electrode 92 to the first intermediate electrode 100. When the to the conductor electrode 9 2 applied alternating voltage is subsequently reduced and that applied to the conductor electrode 93 If the voltage is increased, a glow discharge occurs shifted from the first intermediate electrode 100 in the area in which the conductor electrode 93 the first Intermediate electrode 100 overlaps. When the alternating voltages applied to the intermediate electrode 100 and the conductor electrode 93 are high, a glow discharge will always take place in the area where they overlap.

A second intermediate electrode 102 is adjacent to the first intermediate electrode 100 and along the conductor electrode 93 arranged. The second intermediate electrode 102 is normally supplied with a very low alternating voltage, so that usually no glow discharge from the first intermediate electrode 100 in the region of the conductor electrode 93 is transferred to the second intermediate electrode 102. if

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however, it is desired that a glow discharge along the Shift register 90 is shifted, then the alternating voltage applied to the second intermediate electrode 102 is: i the AC voltage applied to the conductor electrode 93 is also increased. This increased alternating voltage is sufficient, to cause a glow discharge from the first intermediate electrode 100 to the second intermediate electrode 102 migrates while the conductor electrode 93 to a hoho AC voltage and the conductor electrode 92 to a lower one AC voltage are applied.

The second intermediate electrode 102 then remains connected to a high alternating voltage, while the on

ψ the conductor electrode 9 3 is reduced and the voltage applied to the conductor electrode 9 2 is increased in order to cause the glow discharge to pass from the overlap area of the second intermediate electrode 102 and the conductor electrode 93 to the overlap area of the second intermediate electrode 102 and the conductor electrode 92. Subsequent alternation of the alternating voltages applied to the conductor electrodes 9 2 and 9 3 and to the ignition electrode 9B arranged on the same glass wall, as well as intermediate electrodes 100 and 102, causes the glow discharge to be shifted along the first arm 89 of the shift register 90 in the same way as this Referring to Fig. 10 is described above.

| 'If the glow discharge exceeds the overlap area

a conductor electrode 110 and the conductor electrode 93 reached, the alternating voltage applied to the conductor electrode 110 is reduced and that to further conductor electrodes 112 and 114 applied alternating voltage increased * This has the consequence that the glow discharge in the overlapping area of conductor electrodes 9 3 and 114 advances. When the voltage applied to the conductor electrodes 93 and 96 is reduced and When the voltage applied to the conductor electrodes 92 and 94 is increased, this glow discharge becomes along the conductor electrode 114 from its adjacent to the conductor electrode 93

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Move the area to its area adjacent to the conductor electrode 94. During this process, the AC voltage applied to the conductor electrode 114 is kept at a constant high level. The alternating voltage applied to the conductor electrodes 14 and 114 is then reduced and the alternating voltage applied to the conductor electrode 110 is increased, while the voltage applied to the conductor electrode 94 is maintained unchanged. As a result, the glow discharge i η shifts to the overlapping area of the conductor electrodes 9 4 and 110.

The subsequent alternation of the alternating voltages applied to the various conductor electrodes causes the glow discharge migrates to the left along the second arm 91 of the shift register until it reaches the overlapping area a transmission electrode 120 and the conductor electrode 9 6 achieved. From there the glow discharge along the transmission electrode 120 to a further conductor electrode 122 of an adjacent shift register reach. The further conductor electrode 122 corresponds to the conductor electrode 92 of the shift register 90. Das This adjacent shift register does not require an ignition electrode 98 and no intermediate electrodes 100 or 102.

It should be emphasized that several such folded shift registers are arranged one after the other can and that the glow discharges selectively in the final shift register via the ignition electrode, the intermediate electrodes 100 and 102 or via other shift registers and along a serpentine path through several Shift register can be moved through. The shift registers can be a display device or an electronic one Create storage with large storage capacity.

In Fig. 12 is a further embodiment of the shift register according to FIG. 10, in which the information bits are selectively sent to different Places are entered along this shift register 130 and then into a shift register arranged perpendicular to it

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transmitted v / ground. An ignition electrode 132 with a plurality of surface sections 13 5 is arranged on one of the glass walls. An elongated ignition electrode 134 is arranged on the other glass wall. The surface sections 13 5 are according to a certain pattern in the vicinity of the shift register 130 arranged. By applying a high alternating voltage to the two ignition electrodes 132 and 134, at all surface sections 13 5 are initiated a glow discharge. After their ignition, the applied alternating voltage is then applied reduced to the normal operating voltage.

The to a conductor electrode 136 of the sliding

| AC voltage applied to registers 130 is then increased

and the one running parallel to the shift register 130 AC voltage applied to conductor electrode 136 is reduced, while at the same time a high AC voltage is applied to a number of conductor electrodes 140 which are perpendicular to the Conductor electrodes 13.6 and 138 run, is applied. At this time, the is applied to the ignition electrodes 132 and 134 AC voltage is greatly reduced, so that occurring along the surface sections 13 5 of the ignition electrode 132 Glow discharges in the overlapping areas of the conductor electrodes 136 and 140 violate. However, only glow discharges are transferred into those areas of the shift register v / earth, which is in the neighborhood of the

"Surface sections 13 5 of the ignition electrode 132 are located. Um To make an alphanumeric display visible, it is necessary that the surface sections 13 5 of the ignition electrode 132 are arranged to form a number or letter which is displayed shall be.

The glow discharges occurring in the shift register 130 can be shifted along this shift register as described above with reference to FIG. 10. When a glow discharge ends with 142 has reached the designated point, it can be perpendicular to a

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21 O "'ir r-

to shift register 130 arranged shift register are transferred if at this point in time this Location 142 adjacent area 146 of the health register 144 is exposed to a high alternating voltage. The glow discharge displaced in this way can then travel along the shift register 144 can be shifted further, as already explained in the manner described with reference to FIG became.

In Fig. 13 is a coding and display device, the gerr: äss with several folded shift registers 11 works, shown schematically. This device includes a display panel 150. The shift register 144 area of FIG. 12 is perpendicular to a number Shift registers 133-A, 130-fi, 130-C, etc. arranged. One Numbers of ignition electrodes 132-A, 132-B, 132-C, etc. are similar arranged like the ignition electrode 132 according to FIG. The letters added to the reference symbols in FIG. 13 indicate which ignition electrode belongs to the relevant shift register.

The following is, for example, the function of the display device according to FIG. 13 for displaying the letter "A" described. For this purpose, a none AC voltage is applied to the ignition electrode 132-A. The at The glare discharges occurring in the surface sections of this ignition electrode 132-A are referenced with reference to FIG. described procedure Transferring shift register 130-A. These glow discharges transferred to the shift register 130-A are then shifted to the right with reference to FIG. 13 and into the shift register directed perpendicular thereto 144 entered, which then transmits the glow discharges to the display panel 150. The glow discharges are entered in the display field and saved there, as described above in connection with FIG. Of course, the entered

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Glow discharges very rapidly shifted to that place in which they then allow a reasonable display. As soon all glow discharges reached in the assigned location the shift is stopped, ε ^. that good visible display is guaranteed.

If the next Bu'jx bar to be displayed is a "B", then a high alternating voltage is applied to the ignition electrode 132-B. Then the Gli: ^r .: R. Discharges are transferred to the shift register 130-B and entered into the shift register 14 4. Lie Zlindelokr:.: -'- '^; 132-B extends further to the right in relation to FIG. 13 than the ignition electrode 132-A. Lies results in an adjustment of the running time, because the shift register 130-B is never coupled to the first input of the shift register 144. *. is. There are three elements of the shift register 144 between the coupling point of two adjacent l - :: ii ebere registers 130 rr.it and shift register 144. Therefore, the ignition electrode 132 extends for each subsequent alphanumeric character opposite the ignition electrode of the previous character, three elements of the associated shift register 130 further to the right. Each alpanuceriscr.e character should, if possible, have exactly the same number of shift cycles. in order from the time of ignition of the assigned ignition electrode to complete over-

"delivery to the same place of the display area, like the previous sign.

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Claims (15)

? 13/06 .) Performing the generation of a plasma, with a chamber filled with a gas or gas mixture and at least two on opposite walls of the chamber arranged electrodes for generating a glow discharge by applying a corresponding alternating voltage to them Electrodes, characterized in that the chamber (26) is larger than that occupied by a single glow discharge Pa urn is and that latitude as a function of longitude of at least one (30) of the electrodes or the chamber for generating the glow discharge at one of the size of the the electrodes applied V / alternating voltage dependent point is changeable. 2. Device according to claim 1, characterized in that the electrodes between the walls (20, 22) the chamber and each a carrier (27, 29) are arranged. 3. Apparatus according to claim 1, characterized in that the cross section of the chamber over its whole Length is the same and the width of at least one of the electrodes decreases with increasing length. 4. The device according to claim 1, characterized in that the width of the electrodes over their whole Lengths are the same and that the cross-section of the chamber decreases with increasing length. 5. The device according to claim 1, characterized in that the electrodes arranged on one of the walls a narrow and a broad part each on v / iron, the narrow part of one electrode being the broad part of the other Electrode is adjacent, so that a glow discharge from the narrow part to the wide part of one of these electrodes and can then be transferred to the narrow part of the adjacent electrode. 6. The device according to claim 1, characterized in that the electrodes are arranged so that they 1 U 9 8 5 3/1 ^{7 0 1 BAD ORIGINAL} 213U706 a shift register (54, 64; 130) which has two electrodes (64-1, 64,2 etc,; 54-1, 54-2 etc.) and transverse to it and with one of the electrodes (67, 68, 69, 70) connected to one of the electrodes running in parallel has that means (36, 50) for inputting a bit of information in the form of a glow discharge between two of the parallel electrodes (64-1, 64-2 etc .; 54-1, 54-2 etc.) and that means for The individual bits are transmitted to the transverse electrodes (67, 68, 69, 70), the • transverse electrodes have several surface sections connected by thin conductor pieces. " 7. Apparatus according to claim 6, characterized in that that the transverse electrodes (67, 68, 69, 70) to form further shift registers more electrodes (72, 74, 76, 78) running parallel to these electrodes are provided that these further shift registers are arranged so that the glow discharges each representing one bit from the first-mentioned shift register C54, 64) can be transferred to the further shift register and can be shifted along these. 8. The device according to claim 6, characterized in that the means for inputting an information bit an ignition electrode (36; 98; 132) for igniting a glow ) include charge. 9. The device according to claim 8, characterized in that the ignition electrodes are arranged so that they represent a pattern of an alphanumeric character. 10. A method for operating the device according to claim 1, characterized in that two opposite one another arranged electrodes an alternating voltage is applied, so that on the inside of the intervening Walls (32, 31) of the chamber (26) space charge clouds (42, 52, 62, 66) arise which extend over the edges of the ORIGINAL INSPECTED 10 9 8 5 3/1701 Electrodes to which the alternating voltage is applied extend and at least partially an adjacent electrode overlap. 11. The method according to claim 10, characterized in that the alternating voltage has a frequency of 40-300 kHz and that the voltage is at least approximately 700 V measured from peak to peak. 12. The method according to claim 10, characterized in that the displacements of the glow discharges of one electrode to another is achieved by shifting the phase of the applied alternating voltages. 13. The method according to claim 10, characterized in that the size of the applied alternating voltage is chosen so that the glow discharge is only shifted from one electrode to the other when the other electrode is overlapped by the space charge cloud. 14. The method according to claim 13, characterized in that the glow discharge represents an information bit. 15. The method according to claim 11, characterized in that the alternating voltage applied to the ignition electrode after ignition of the glow discharge is reduced to a value which is sufficient to maintain the glow discharge but is not so large as to initiate a glow discharge. 109853/1701 ORIGINAL INSPECTSÖ