EP0984480B1 - Process for the fabrication of a display tube - Google Patents

Description

The present invention relates to a method for manufacturing a display tube for display purposes, especially for the Light display technology and the illumination of advertising technology To form.

The illumination of shaped fonts for the purpose of illuminated advertising or light design presentation takes place after the prior art essentially with deformed high-voltage fluorescent tubes. This technology was developed in the 20s developed in Germany and has remained almost unchanged since then remained.

The arrangement of high-voltage fluorescent tubes for such Applications are usually carried out in series connection on a stray field transformer, which is the ignition and burning voltage for ignition and stable operation. The commonly used, maximum Open circuit voltage is 8,000 volts, according to the new European CENELEC standard now 10,000 volts. The installation of the components is complex because of the safety regulations for high-voltage systems, prescribed in VDE 0128 (or European successor regulation). The lines require an appropriate degree of isolation and relative compliance complicated laying regulations.

The luminous efficacy of high-voltage fluorescent tubes is very low, it is between 6 and 15 lm / W. To adequate and effective illumination results, especially with arrangement behind translucent materials practice Multiple parallel arrangements of high-voltage fluorescent tubes common. This leads to high costs for material components and wage benefits.

The lifespan of such lighting systems lies in practice at 10,000 to 15,000 burning hours. As a result of the last Years of increasingly technological shortenings due to cost pressure, is the quality and thus the economic Operating time rather declining.

FIG. 1a shows an example of the use of a high-voltage tube according to the prior art to represent a block letter L. The high-voltage tube 10, which for this purpose is arranged in a translucent form 12 to be illuminated, is connected to the secondary side of a high-voltage transformer 11. While the voltage U ₁ on the primary side of the transformer 11 corresponds to the mains voltage, the voltage U ₂ on the secondary side is calculated from the cathode case (approx. 300 V per tube) plus the burning voltage requirement of approx. 400 V per meter of pipe length.

Figure 1b shows the use as an alternative prior art of standard fluorescent lamps for illuminating illuminated signs Displays as a replacement for high-voltage fluorescent tubes. Low voltage standard fluorescent lamps are in elongated, d. H. straight, circular, U-shaped or compact shape available. Figure 1b shows the use of two low voltage standard fluorescent lamps 14 and 16 for illumination a translucent shape 18 to form a block letter L display. If the translucent shape 18 is dispensed with there would be an aesthetic problem because of the desired shape can only be represented in a very simplified manner and also the connection and bracket technology would be disruptively visible.

However, if the letter L should be in a more characteristic, more aesthetically pleasing shape, such as in Figure-1c shown, illuminated, is as follows to proceed: Behind a Form 20, which was mostly darkened Has areas 22 and only in area 24 of the L is translucent, is a low-voltage standard fluorescent lamp 26 arranged. Because only the area 24 can be made translucent a viewer can only recognize light in the shape of the region 24. Leave by coloring the translucent area 24 achieve the desired color effects. Form 20 cannot be made airtight because of air circulation necessary to dissipate the heat generated by the lamp 26 is. However, through these air supply openings penetrate - from Light attracted - insects that are hot when touched Die lamp or 20 spots on the inside of the mold leave. Dust can also penetrate through the openings. Overall, this leads to a spotty, unsightly display. For the formation of a lettering, several such Forms 20 are strung together, resulting in an aesthetic leads to an unappealing impression. In particular, hereby no lettering, as explained with regard to FIG. 15 will be generated. In this respect, this is often the case The procedure used is also not a sufficient substitute for the high voltage lighting tube.

FR 2393414 discloses a method for producing a display tube known, in which a part of the classically performed Production method for fluorescent lamps applied becomes. Especially in such a classic manufacturing process for fluorescent curved lamps becomes an elongated one Lamp body used and in a suitable heat zone brought in to heat it there until it is sufficient Temperature to be bent. Then be the opposite end pieces of said lamp body connected in order to be able to bend it so that the lamp body has a assumes a curved shape. Then the lamp body is emptied and closed again after being ionized Gas was filled. Finally, electrical connectors are attached.

From DE 31 12 878 a low pressure lamp is known is introduced into a mold for shaping. With that you can Create standard shapes.

In a method for manufacturing known from DE 22 12 536 of lamps is based on the conventional melting of the Stalks to the lamp, evacuating the lamp bulb through a suction tube in the handle and the attachment of contact pins dispenses with the stems after processing the interior of the lamp.

DE 34 39 874 in turn relates to the manufacture of fluorescent lamps in standard forms.

DE 27 24 528 also describes a fluorescent lamp which manufactured using a complex bending device becomes.

DE-PS 892 505 also describes a fluorescent lamp which is produced by machine bending.

From EP 203 194 a fluorescent lamp is known which consists of standardized U types is composed, with the result only W types and WW types are manufactured.

DD 267 349 describes a method for rinsing and filling a low pressure gas discharge lamp, the gases during pumping on one side into the glass, on the other Side out of the glass.

From DE 30 03 700 and the corresponding US 4,303,290 is a method of evacuating a fluorescent tube or lamp known.

DE 34 39 326 relates to a pump-out device for pistons electric lamps, in particular circular fluorescent lamps. It describes the use of a bending machine for machine Production of standard lamps.

DD 133 381 relates to a method for producing a Discharge vessel for high pressure lamps.

DD 52 494 describes a method for merging Pump tubes, especially for fluorescent lamps.

Finally, from DE 32 12 276 is a U-shaped fluorescent lamp known, with an ignition aid near the electrodes is applied.

The present invention is therefore based on the object propose a method of manufacturing a display tube, the display tube for illuminated advertising produced thereafter or lighting design presentation is suitable much better ratio of luminous flux and spent electrical power than in the prior art, and straightforward in terms of installation effort is.

This problem is solved by a method with the features of claim 1.

Pure neon, for so-called Red discharge systems that can only glow red, or a mixture of neon argon nitrogen in combination with Mercury, for so-called blue discharge systems, all of them Luminous colors allow for consideration.

A display tube made by this process, which by no means Lighting purposes, only display purposes also has a number of important advantages.

In exemplary embodiments, display tubes could have a ratio from luminous flux to electrical power from 30 to 70 lm / W (luminous efficacy) can be realized. So that's the energy balance many times better than with high-voltage fluorescent tubes according to the state of the art.

A display tube manufactured in this way is only with low voltage operated, which is why the maximum voltage occurring is in the range of the mains voltage. This results in much lower requirements for the assembly effort, the Security requirements and with regard to the use of materials. While in the prior art according to the high-voltage fluorescent tubes a neon specialist with approval for installation the responsible local energy supply company (High voltage!) Was necessary, according to the present invention any electrician connect such a tube, in particular can according to the inventive method manufactured display tubes according to the low-voltage installation regulations be installed and are therefore safety-related unproblematic. All of this essentially results lower assembly costs.

A display tube produced by the method according to the invention can also be done by using a light sensor or illuminance meter in conjunction with a multi-stage Ballast and the coil heating of the electrodes to the ambient brightness in a suitable, below Adjust the interface shown.

While the high voltage indicator tubes from the prior art Technology at low ambient temperatures is a bad thing Provide illumination quality, d. H. the picture is blotchy and inhomogeneous, arise in the cold operation according to the invention Processed display tube by the higher one Operating current much more favorable conditions. Such high operating currents that are responsible for the high luminous efficacy of the the display tube produced by the method according to the invention is the cause are from the state of the art not achieve known high-voltage tubes. High voltage tubes for advertising purposes, as known in the prior art are operated with approx. 15 to 100 mA. So-called. slimline, for which very large transformers are needed, and therefore for use in light display technology unsuitable, are operated with operating currents up to 300 mA. In contrast, the operating current in one preferred embodiment of the according to the invention Process manufactured display tube 170 to 600 mA.

Continuous heating of the electrode coil makes it flicker-free Switching on with a defined switch-on time achieved, whereby this embodiment of the display tube for building Representations with high switching frequencies, e.g. for digital or analogue operating value displays (counter display, clocks, Score displays for sports stadiums, etc.) are used can.

Because of the use of low voltage there is also the maintenance effort significantly lower than with the display tubes the state of the art, while the lifespan at least the same if not higher.

The procedure requires an additional one for smooth operation Ionization aid, which is in the form of ignition aids such as ignition strips, Glow starter, capacitor circuits can be formed can. When operating the tube with electronic instead of one Inductive or capacitive ballast will do this function adopted by the ballast, since here the ratio of Discharge column resistance to required ignition energy is cheaper.

To dim the display tube can be used in conjunction with the ballast a dimming device can be provided, in the case of a inductive ballast, for example with a choke multiple taps or a series connection of several chokes with taps in between or one for a corresponding one Functional electronic ballast. The heating transformer used for heating the spiral electrodes can also be provided in the ballast his.

In a particularly advantageous manner, the display tube can be used Light sensor (luminance meter with switching function) connected his. In cooperation with the dimming device can for example, the light output can be increased at dusk and then gradually switched back in the dark become. When dimming, note that the lowering of the indicator tube voltage reduces the filament current becomes. If the voltage falls below a predetermined level this may require permanent heating of the filaments, thus the reduced energy flow through the heating current is compensated. Otherwise, there would be a risk of destruction the display tube or at least the impossibility of the Reignite.

Depending on the choice of the phosphor or the mixture of illuminants, leave different colors are realized.

The ignition and lamp voltage of the different manufactured Tube lengths of the display tube resulting from the design and intended use are determined by the choice of the appropriate Ballast adapted to the need.

The display tube produced by the method according to the invention can be operated in different ways: With continuous operation the display tubes are the spiral electrodes up to Ignition preheated, then the heating is switched off. This Operating mode is preferably used when there is no high one Switching frequency is required, e.g. in an advertising facility, which turned on in the evening and turned off in the morning becomes.

With a high switching frequency with a defined switch-on time or in effect circuits with intended continuous changes in operating values, such as. by means of phase control, continuous heating must be used, i.e. the Spirals are permanently on after the entire system has been commissioned on the heating voltage and are triggered by the respective switching pulse of the pulse generator, e.g. in the form of an electronic watch module, ignited.

For use with a method according to the invention manufactured display tube is in particular a ballast advantageous, whose outer shape is designed such that it can be built into the display tube. This is made possible in a system consisting of display tube and ballast of the low voltages used, which is why the ballasts can be kept smaller than in the prior art. Further advantageous developments of the invention are in the Subclaims defined.

Figur 1

Lichtwerbeanzeigen beleuchtet mit einer Hochspannungs-Leuchtstofflampe bzw. Niederspannungs-Leuchtstofflampen nach dem Stand der Technik;

Figur 2

eine Lichtwerbeanzeige beleuchtet mit einer nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhre;

Figur 3

eine Detaildarstellung einer nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhre;

Figur 4a

eine Beschaltung der nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhre für Vorheizung bei Gegenschaltung;

Figur 4b

eine Beschaltung der nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhre für Vorheizung bei Zuschaltung;

Figur 5

eine Beschaltung einer nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhre für Dauerheizung;

Figur 6

eine Beschaltung zweier nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhren für Dauerheizung;

Figur 7

eine Beschaltung für Dauerheizung von fünf nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhren;

Figur 8

den Einsatz dreier nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhren in einem elektronischen Farbmischer bei Dauerheizung;

Figur 9

eine Beschaltung einer nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhre für Dauerheizung mit Spannungsüberhöhung;

Figur 10

eine Beschaltung einer nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhre für Dauerheizung mit Spannungsüberhöhung für elektronische Steuerung;

Figur 11

eine nach dem erfindungsgemäßen Verfahren hergestellte Anzeigeröhre in einer Ausbildung als Segment einer 7-segmentigen Anzeige;

Figur 12

eine 7-Segment-Anzeige unter Verwendung von sieben nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhren;

Figur 13

vier Vorheiztransformatoren für unterschiedliche Einsatzzwecke;

Figur 14

ein Vorschaltgerät, das ein stufiges Dimmen ermöglicht;

Figur 15

schematisch die Verwendung des Anschlußsystems bei der Darstellung eines Buchstabens "S";

Figur 16

Ausführungsformen eines Adapters, den das Anschlußsystem umfaßt, und Beispiele der Verwendung unterschiedlicher Adapterausführungsformen; und

Figur 17

ein Beispiel unter Verwendung mehrerer nach dem erfindungsgemäßen Verfahren hergestellten Anzeigeröhren.

Exemplary embodiments of the invention are described in more detail below with reference to the attached drawings. They represent:

Figure 1

Illuminated advertisements illuminated with a high-voltage fluorescent lamp or low-voltage fluorescent lamps according to the prior art;

Figure 2

a illuminated advertising display illuminated with a display tube produced by the method according to the invention;

Figure 3

a detailed view of a display tube produced by the method according to the invention;

Figure 4a

a circuit of the display tube produced by the method according to the invention for preheating with counter-connection;

Figure 4b

a circuit of the display tube produced by the method according to the invention for preheating when switched on;

Figure 5

a circuit of a display tube produced by the method according to the invention for permanent heating;

Figure 6

a connection of two indicator tubes for continuous heating produced by the method according to the invention;

Figure 7

a circuit for permanent heating of five display tubes produced by the method according to the invention;

Figure 8

the use of three display tubes produced by the method according to the invention in an electronic color mixer with continuous heating;

Figure 9

a circuit of a display tube produced by the method according to the invention for permanent heating with excessive voltage;

Figure 10

a circuit of a display tube produced by the method according to the invention for permanent heating with excessive voltage for electronic control;

Figure 11

a display tube manufactured according to the method of the invention in the form of a segment of a 7-segment display;

Figure 12

a 7-segment display using seven display tubes produced by the method according to the invention;

Figure 13

four preheating transformers for different purposes;

Figure 14

a ballast that enables step dimming;

Figure 15

schematically the use of the connection system in the representation of a letter "S";

Figure 16

Embodiments of an adapter comprising the connection system and examples of the use of different adapter designs; and

Figure 17

an example using several display tubes produced by the method according to the invention.

Figure 2 shows a display tube 30, which is a desired Form, here a curved L, and after the invention Process was made. Dashed is a translucent optional form 32 shown. Furthermore are the lamp ends 34 drawn in, the enlarged view are shown in Figure 3.

In the method of manufacturing a display tube for display purposes, for example for use in illuminated advertising systems, as illumination light source as well as for shaped, linear ones architectural lighting designs, is in a first Step a glass tube covered with a fluorescent material manually bent into any shape. For this, the glass tube 30 at the points to be bent up to a temperature heated, so that they are then from a glassblower in the desired shape can be bent. In a next step are spiral electrodes at each end of the now deformed glass tube 36, see Figure 3, melted, at least a spiral electrode is provided with a pump nozzle 38. By external energy supply, for example by a high-frequency device or a heating oven, the glass tube is heated, on the one hand, components of the blank which interfere with oxidation to effect and on the other hand the formation of the spiral electrodes bring about. This is the conversion process the activation paste applied to the metal electrodes into a tungsten oxide, which is responsible for the charge carrier emission is needed. Furthermore, purge gases are in the Glass tube introduced and together with the resulting gases in a pumping device via the at least one pump nozzle 38 removed from the glass tube. This sequence of steps of heating and rinsing is repeated until the unwanted chemical components are below a certain limit. Then the tube is up to a certain negative pressure pumped empty via the pump nozzle 38, with the required Gas or gas mixture and, if necessary, under Addition of mercury filled, melted from the pump nozzle 38 and then burned in.

The bakeout temperature is approximately in the middle of the glass tube between 350 and 550 ° C, preferably 400 ° C, and at the Electrodes in a range of 1,000 to 1,200 ° C, preferably 1,100 ° C.

While at a high voltage tube this temperature goes through Current load of the cup electrodes there by a connected bombers would be achieved in the display tube produced by the method according to the invention used spiral electrodes are not suitable for this. The sensitive Would be filaments if you wanted the bakeout temperature according to the prior art according to the high voltage tube achieve by electrode glow, burn out.

Therefore the required heat input must be external, e.g. under Use a baking oven. This is next to the Pumping station placed so that both the pump stem and the heat protected electrical supply through the wall of the Oven is carried out. The tube blanks are in the oven introduced in a suitable manner, melted onto the pump stem and connected the electrodes to the electrical lead. Then the oven is heated to a temperature of approx. 350 - 550 ° C ramped up, the entire display tube as possible is brought to this temperature evenly, over Pumping station and pump stem performed the well-known pumping process and the electrodes by a current input of approx. 500 formed up to 1000 mA. Due to this brief current flow using the electrode coils for a period of 1 to 2 minutes a power supply unit located outside the oven temperatures of 1000 to 1200 ° C are generated at the electrodes. Then the tubes are cooled, rinsed, emptied, gas filled, annealed, melted and then baked.

In a further step, an ignition strip can be used as an ionization aid applied to the display tube. Suitable for that is for example a metal foil strip that one Receives ground connection. Other ways of applying a fuse are known to the person skilled in the art.

To the spiral electrodes for the operation of the display tube Avoiding the harmful cold start at emission temperature to bring, a heating transformer is used, the heating voltage the electrode coil is fed. The heating voltage, which is required to make the electrode coil ready for ignition To bring about is the resistance of the wire helix dependent. This varies depending on the manufacturer's design and the heating voltage must be adjusted accordingly become. The heating voltage is in any case within the limits 5 V and 9 V. Especially in connection with the described Ionization aid thus becomes a gentle ignition process of the display tube ensured. Please note at the dimensioning that the sum of indicator tubes and heating current flows.

Experiments have a favorable influence on the continuous heating the lifespan of those produced by the process according to the invention Display tubes result, probably because of the even filament heating has no pronounced focal spot the helix is created, thus preventing punctiform wear becomes.

Figure 4a and 4b show circuit variants that are used when the display tube is working in cold mode should and the indicator tube start by sufficient filament preheating must be secured. The transformer dimensioning has to be done in such a way that the coil is under voltage in the network still reaches the necessary emission temperature in the event of overvoltage however, evaporation of the emitter is avoided. In the variant of the preheating shown in FIG. 4a, in which the secondary windings 40, 42 of the heating transformer in reverse connection are operated when the tube is not ignited Heating transformer and on the display tube the mains voltage, minus twice the heating voltage. At the ballast 48 falls with the low no-load load little voltage.

In the preheating variant shown in Figure 4b, in which Corresponding components marked with the corresponding reference numerals the secondary windings are switched on operated, which is why about heating transformer and display tube the sum of the mains voltage plus twice the heating voltage issue.

The heating coils of the The two coils up to the emission temperature on. The applied ignition strip 50 reduces the longitudinal resistance of the indicator tube so that the tube ignites without additional start impulse.

Of course, the method according to the invention manufactured display tube as a replacement for the described Ignition strips also with other ignition aids, e.g. a capacitor cascade (for quick switching sequences) or a glow starter (with low switching frequency) are operated.

The preheating circuit breaks after ignition Voltage on the transformer to the indicator tube voltage together and the heating transformer is practically switched off. If the network is inclined to undervoltage, this is shown in Figure 4b shown circuit variant with connection, with frequent Surges with the variant shown in Figure 4a Preference to switch the heating windings to the 220 volt winding is preferable.

The ignition strip 50 must be in a defined ratio to Mains voltage are brought. Either it receives protective conductor potential or it is connected to a resistor of 1 MΩ Conductor connected.

Figure 5 shows a circuit variant with continuous heating Helices.

Figure 6 shows a circuit variant for permanent heating for operation of two produced by the process according to the invention Display tubes. It comprises two ballasts 50, 52, two indicator tubes 54, 56, two ignition strips 58, 60, one Primary side of the heating transformer 62, a winding 64 for the return for both tubes and one winding per tube 66 or 68 for supplying the indicator tube current.

FIG. 7 shows an extended circuit variant for permanent heating, designed for the operation of five display tubes is.

Figure 8 shows one using three according to the invention Process manufactured display tubes electronic color mixer, the indicator tubes in continuous heating operate. This color mixer comprises a first one red indicator tube 70, a second blue indicator tube 72 as well a third green indicator tube 74. Each indicator tube has one Ballast 76, 78, 80 assigned. There is also control electronics 84 provided, which via a winding 86 with the Primary winding of the heating transformer 88 is connected.

In the circuit variant shown in FIG. 9, under Permanent heating a voltage surge can be achieved. A display tube 90, which is coupled to an ignition strip 100, stands over their spirals with the secondary pages 94 and 96 of Heating transformer in connection. There is also a ballast 98 provided, which is connected in series to a Winding 102 is located, with which the voltage increase is achieved becomes. The primary winding 92 of the heating transformer is applied Mains voltage on.

The modification shown in Figure 10 also has a electronic controller 104, for example the controller the on and off time for the execution of lighting effects can serve.

The variants shown in FIG. 9 and FIG. 10 offer solutions for display tubes based on their constructive data cannot be operated on the basis of the mains voltage. Through the series connection of the winding 102 with the primary winding 92 an excessive supply voltage can be achieved. For example, if the mains voltage is 220 volts the winding 102 are dimensioned so that 40 volts on it drop, with an excessive supply voltage of 260 Volts is available (with heating coils switched on) or 245 volts (with heating coils connected in opposite directions).

The great advantage of this circuit arrangement is that that while maintaining a technologically and lighting technology very favorable glass tube diameter tube lengths from to Display tubes produced according to the method realized that are over 1 m long and very good the requirement for illumination of small areas, but also for small cold-resistant lighting fixtures.

FIG. 11 shows one produced by the method according to the invention Display tube 100, which is shaped so that it in a 7-segment display 110 shown in FIG can be. Especially when operating in continuous heating extremely short turn-on times can be achieved, so that the 7-segment display 110 shown in FIG. 12, for example be used as a display point of a digital clock can.

FIG. 13 shows various embodiments for a preheating transformer. In Figure 13a, the winding 120 is at mains voltage connected while the windings 122 and 124 connected to one or the other side of the display tube become. The windings are in a dimensioning example 122 and 124 for a voltage of 6.8 volts and one Current of approximately 0.4 A each. Figure 13b shows a preheating transformer, which is used to operate two indicator tubes is designed. The winding 126 is at the mains voltage connected. The windings 128 and 130 provide the Power supply to the respective display tube ready while the Winding 132 as a common current return line of both tubes serves and is therefore designed for a current flow that is double is as high as that through windings 128 and 130. In Figure 13c, the winding 140 is connected to the network, while windings 142 and 144 with the indicator tube input and are connected to the indicator tube output. The winding 146 serves to generate an increased display tube voltage, such as it was described in connection with FIG. 9.

FIG. 13d shows a preheating transformer for operating a 7-segment display. The winding 150 is connected to the mains connection, while the windings 152, 154, 156, 158, 160, 162, 164 are connected to the respective display tube inputs and winding 166 is the common current feedback for all Display tubes. It is obvious that the winding 166 for seven times the current of the windings 152 to 164 must be designed.

Figure 14 shows a ballast that a step dimming of Display tube allows. For this there is a throttle 130 with two Taps 132 and 134 are provided. An output 136 is connected to the Display tube connected while three inputs 138, 140, 142 are provided, which correspond to three service areas, where the input 138 power range is the largest and the Power range of input 142 is the lowest. The switchover between the individual service areas can be electronic respectively. The ballast can also with a Illuminance meter for determining the ambient brightness can be connected, which includes, for example, a photocell and which are used to control the ballast can. For example, at dusk the input with the highest power can be selected while in full darkness the lowest power entrance preference can be given. The respective ballast can match the length of the display tube in terms of its output voltage be adjusted.

It is particularly advantageous to place the heating transformer in the Record ballast and design the ballast such that it is housed in the display tube liner can be. This leads to a further simplification of the Assembly. In this variant, it has proven to be particularly advantageous exposed if the at least one choke and the at least one heating transformer on a common one Core are arranged.

When using an electronic ballast instead of the inductive ballast just described is instead a choke 130 electronically between different Power ranges switched. This also results the dimming ability of the process according to the invention manufactured display tube.

Figures 15 and 16 show a connection system comprising standardized plug connections with which the the display tubes assigned ballasts in a straightforward manner can be connected. The supply of the mains voltage carried so that they are tapped at every junction and a multiple supply line can be dispensed with can. With this connector system, it is also special advantageously possible, the arrangement of each Ballasts in the sometimes complicated in terms of design to fit shaped tube lamination, so that special accommodation options, e.g. in the form of specially arranged device housings, are not required. This leads to further cost savings and improvement of aesthetic effect of the overall arrangement.

Fig. 15 shows an example of a letter "S" with a developed Length of 6 m. The technology of the invention Manufacture of the display tubes leaves only a maximum length 1.5 m for a display tube. For example therefore 4 display tubes AZ1 to AZ4 used to populate the "S", 4 ballasts VG1 to VG4 are also used needed. For the sake of clarity, the connections of the Indicator tubes not shown on the ballasts. Only VG4 is connected to the mains connection. To the ballast VG4 closes this in a serial link Ballast VG3, in turn the ballast VG2 and finally the ballast VG1. The mains voltage is looped through all ballasts, which is why separate ballast connections to the mains voltage unnecessary.

The plug-in system for the ballasts, for example a choke and the heating transformer for inductive versions is shown in more detail in FIG. 16. 16a shows two examples of the basic link. A plug 150a, which on one side to a Line 158a is connected, the mains voltage and possibly Control signals leads, has connector pins on its other side for connection to a choke 154. The throttle 154 has connectors on its other side for connection to a Adapter 156 on. The other side of the adapter 156 faces also connecting pins for connection to the first side of a Heater transformer 152 on while on the other side of the heating transformer 152 in turn a connector 150 b to Continuation of the mains voltage and possibly the control signals a next ballast can be connected. 16a shows the connection using a 0 ° adapter is an example (left) and a 45 ° adapter (right).

16b shows various adapters 16 for use in the Connection system, which is characterized by different angles distinguished. Adapters with angles of 0 °, 30 °, 45 °, 60 °, and 90 ° for use. Any realization Angles and adapter lengths are of course possible.

It is obvious to a person skilled in the art that the principles of Plug-in systems for any kind of ballast, e.g. electronic or capacitive ballast can be used. In the case of electronic ballasts, for example to a first connector through which the mains voltage is looped in the actual ballast. it the angled adapter follows and the second follows Plug that establishes the connection to the next ballast.

Figure 17 shows a system of several of the according to the invention Processed display tubes, in which that with reference to FIGS. 15 and 16 described in more detail Connection system is used. This representation underlines that the assembly by a low voltage technician, d. H. a conventional electrician, while in the high-voltage fluorescent tubes of the prior art Technology a neon specialist is needed. This example also shows like the individual letters by individually shaped Indicator tubes are illuminated. The individual letters are operated in parallel as shown in FIG. 17, while the display tubes within each Letters can be operated in series.

Claims (3)

1. Method for manufacturing a display tube for display purposes, in particular for being employed in luminous advertising facilities, comprising the following steps:

   a. manual bending of a glass tube (30) washed with luminescent material to form a desired shape;

   b. melting helical electrodes (36) in at the ends of the bent glass tube (30) with a helical electrode (36) comprising a pump socket (38) and the temperatures in the centre of said glass tube ranging around 350 to 550°C and around 1000 to 1200 °C at said helical electrodes (36);

   c. alternate heating of said glass tube (30) through external energy supply for the oxidation of irritating components of said display tube and for supporting the activation of said helical electrodes and the rinsing of said glass tube with rinsing gases via said pump socket (38);

   d. filling said glass tube (30) with at least one gas or one gas compound;

   e. melting said pump socket (38) off said glass tube (30);

   f. firing said glass tube (30);
2. Method according to claim 1,
   characterized in that
   a further step of applying an ignition aid (50) is provided.
3. Method according to one of claims 1 or 2,
   characterized in that
   the external energy supply in step b. is effected via a high frequency device or a heater.

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