EP2171741B1 - Production method for discharge lamps - Google Patents

Abstract

The present invention relates to a method for producing a discharge lamp using a two-stage filling process.

Description

Technical area

The present invention relates to a method of manufacturing a discharge lamp.

State of the art

Discharge lamps have a closed and a discharge gas-containing discharge vessel. Accordingly, a method for producing discharge lamps comprises introducing the discharge gas and closing the discharge vessel.

It is known to insert and close discharge vessel parts in a vacuum oven under a discharge gas atmosphere. Prior to forming the discharge gas atmosphere, the vacuum furnace enclosing the discharge vessel parts is evacuated to remove unwanted gases from the furnace and adsorbates from the discharge vessel parts.

It is also known to first pump out discharge vessels with a pumping tube and then to fill them with a discharge gas. After filling pump pipes are usually closed by melting; if necessary, protruding parts are removed.

The DE 101 47 727 A1 shows a continuous furnace for joining discharge vessel parts and filling the joined discharge vessels. The discharge vessel parts are introduced into an atmosphere with the discharge gas, added in this atmosphere and thereby also closed.

The DE 102 25 612 A1 shows a chamber for joining and closing of discharge vessel parts. The chamber comprising the discharge vessel parts is flooded with the discharge gas under moderate overpressure, so that the discharge vessel parts are surrounded by the discharge gas.

Presentation of the invention

The object of the invention is to provide a method advantageous for filling and closing a discharge vessel for producing a discharge lamp.

The invention relates to a method for producing a discharge lamp comprising the steps of: adding and filling an open discharge vessel of the discharge lamp with a first gas in an environment of the first gas, characterized by the subsequent step: adding a second gas to the first gas in the joined discharge vessel by a separate from the outer environment of the discharge vessel feed volume.

Preferred embodiments are the subject of the dependent claims and are also explained in more detail below.

The invention is based on the consideration that the pumping and filling of a discharge vessel via a pump tube is associated with a high outlay: For the pumping a certain amount of time is required to achieve the desired purity, a considerable pumping capacity must be used, corresponding systems are complex and therefore expensive. Especially with large discharge vessels, such as those for flat radiator with a large diagonal, it is difficult to ensure the desired purity due to the large inner surface of the discharge vessel (adhere to the adsorbate). In addition, some discharge lamps break during pumping.

The invention is further motivated by the idea that the joining, ie connecting, of discharge vessel parts and the filling of discharge vessels with a gas can be carried out simultaneously.

Finally, the invention is based on the finding that with discharge vessels, which are accordingly filled and closed in a discharge gas atmosphere, for example when joining discharge lamp parts under a neon / xenon atmosphere in a continuous furnace, typically a part of the discharge gas escapes into the environment and thus lost goes. Once this is economically disadvantageous, as some of the gases typically used for discharge gases, such as xenon, add significantly to the cost of the manufacturing process. In addition, the discharge gas may have components in which an escape into the environment for other reasons should be avoided, such as chemically very reactive, environmentally harmful and / or toxic gases. A collection and return of the gas that is not introduced into the discharge vessels requires an additional amount of equipment, which can be considerable.

As noted, the discharge gas typically includes several components, such as helium, neon, argon and xenon. The idea of the invention is now that ultimately for the Discharge gas desired components to a first gas and a second gas and first to fill an open discharge vessel in an environment of the first gas. Finally, the discharge gas is completed by the targeted introduction of the second gas into the discharge vessel after the discharge vessel is joined and at least partially closed.

For the second filling step, a feed volume is used that is separated from the environment of the discharge vessel, ie not alone forms the environment. Here, an exchange of the interior of the discharge vessel with the complete environment of the discharge vessel is not used, but limits the second gas to a certain volume and thus used selectively. By environment is meant here so the outer environment of the discharge vessel, not the discharge space therein. In consideration, which will be discussed in more detail, both the feeding through a line for the second gas and a connection of the line with a corresponding filling of the discharge vessel and the placement of a filled with the second gas separate volume in the discharge vessel for later mixing the two gases by opening this volume after the complete closure of the discharge vessel. In the first case, the feed volume is outside the discharge vessel, but only a small part of its environment and separated from the rest of the environment. In the second case it lies in the discharge vessel and is already separated thereby and by a further limitation of the external environment. In both cases, it is about the second gas targeted and not too large amounts or under Avoid spreading into the environment.

By joining after the first filling step, the discharge vessel is preferably but not necessarily completely sealed gas-tight. Thus, after closing, a comparatively small hole could remain in the discharge vessel wall, through which the second gas is introduced. It can also be opened again. Alternatively, the discharge vessel can be closed and already contain the separate volume with the second gas.

Overall, with the invention thus a filling step with the second gas in the complete environment of the discharge vessel, such as in a continuous furnace avoided.

It is correspondingly advantageous to strike the comparatively favorable or chemically unobjectionable components of the discharge gas to the first gas - the other components to the second gas.

Since a loss or spread of the second gas can be kept small or even ruled out, possibly even a costly recovery of components of the second gas can be dispensed with.

Thus, the invention enables a targeted introduction of certain discharge gas components with the second gas. The second gas and the first gas should thus differ according to the invention, in particular, the components with which a filling in one or from a complete environment of the discharge vessel is favorable, all or at least substantially associated with the first gas and correspondingly other components in which a targeted introduction of particular advantage, especially the second gas are assigned. This can also be quantified on the basis of the partial pressure of the discharge gas components: It is preferred if the second gas has a component whose partial pressure in the discharge gas is at least 70% due to the second gas, more preferably at least 90% or even 98% , In other words, the discharge gas should contain at least one component which essentially or virtually exclusively originates from the filling step with the second gas.

The preferably comparatively large opening of the discharge vessel before joining allows rapid filling of the discharge vessel with the first gas or even rinsing with this, in particular with still separated discharge vessel parts. By such flushing of the discharge vessel with the first gas, this can be cleaned and also other impurities can be kept away - even in the form of undesirable gases. An elaborate evacuation of a chamber, as in the vacuum furnace, can be dispensed with here.

If discharge vessels are completely closed in a gas atmosphere, the partial pressures of the components of this gas in the discharge vessel are dependent on the temperature of the gas during closing. If for certain components of the discharge gas conditional manufacturing tolerances are avoided, these components can be added to the second gas.

It is preferred to use a continuous furnace for the first filling step and to use the first gas in a continuous furnace also for cleaning the discharge vessel and also for keeping away impurities. For this purpose, a flow of the first gas and the discharge vessel is established in the continuous furnace. Depending on the distribution of the discharge gas components to the first and second gas, no recovery of the first gas may have to be carried out, even with high conversions.

Further, continuous furnaces do not need to be constantly heated from a cooled state, such as on batch furnaces, which is time and energy consuming; especially for large ovens for large lamps.

The discharge gas may contain components which make it difficult or even prevent analysis of the discharge gas by means of spectroscopy. Discharge gas components which are not to be analyzed with can be introduced into the discharge vessel with the second gas. In one embodiment, therefore, after the at least partial closing of the discharge vessel and before the introduction of the second gas, a spectral analysis of the first gas is carried out in the discharge vessel. For example, in this context, one could introduce the xenon via the second gas in a xenon / neon mixture. Like other light noble gases, neon has a much higher excitation energy than xenon, so that impurities can be detected by spectroscopy of the discharge radiation. Due to the relatively low excitation energy, xenon would usually interfere with this. Such a spectroscopic examination can be carried out, for example, by means of auxiliary electrodes, for example simple metal strips, outside the furnace and after the first filling step by ignition of a local discharge. The auxiliary electrodes can then be removed again so that they do not disturb the further manufacturing process and are not present on the finished lamp.

In one possible embodiment, the second gas is introduced into the discharge vessel via a filler neck. The filler neck, for example, can already be applied to a discharge vessel part prior to closing the discharge vessel and preferably still be closed before and also after this step. Alternatively, however, it is also possible for a stub to be placed on a hole of the discharge vessel remaining after closing, and the second gas can be introduced through it. Subsequently, this nozzle can be merged with about the discharge vessel. The filler neck can then be opened before the second filling step, such as broken.

In another particular embodiment of the invention, in the first filling step and the joining, an ampoule with the second gas is enclosed in the discharge vessel and subsequently opened. In this way, it is possible to precisely control the amount of the second gas introduced into the discharge vessel.

The ampoule can be broken up, for example, by means of a laser or other electromagnetic waves. When open, the second gas mixes with the first gas to form the discharge gas.

It is preferred to receive the ampoule at the edge of the discharge vessel. If the ampoule is outside the light field, it does not disturb the light emitted by the discharge lamp. Furthermore, it is possible, in particular at the edge of the discharge lamp, to receive the ampoule in such a way that it does not spatially restrict the discharge. Preferably in the same area or adjacent to the receptacle for the ampoule uncoated discharge vessel window, in particular openings in the phosphor layer in order to carry out the mentioned diagnostics, available.

In principle, the first gas could be included in a recovery. However, the two-stage process according to this invention makes it possible to carry out the filling process for such gases as a second step, so that the first gas can be discarded more simply and advantageously.

The invention is directed in particular to the production of so-called flat radiators, in which the discharge vessel is flat and relatively large in size compared to the thickness. Usually, the large sides of the flat radiator are formed by two substantially plane-parallel plates. The plates can be structured and must, despite the name "flat radiator", not be flat in the strict sense of the word.

Furthermore, the invention is directed in particular to the production of dielectrically impeded discharge lamps. Here, the power to sustain the discharge via dielectrically separated from the discharge gas electrodes is capacitively coupled into the discharge gas.

Brief description of the drawings

In the following, the invention will be explained in more detail with reference to exemplary embodiments. Disclosed individual features may also be essential to the invention in combinations other than those shown.

Fig. 1

zeigt einen Durchlaufofen zur Durchführung des erfindungsgemäßen Verfahrens.

Fig. 2

zeigt den Durchlaufofen aus Figur 1 mit Ergänzungen.

Fig. 3

zeigt ein Entladungsgefäß, das einen Teil des erfindungsgemäßen Herstellungsverfahrens durchlaufen hat.

Fig. 4

zeigt eine schematische Darstellung zu einer al- ternativen Möglichkeit zur Figur 3.

The figures show:

Fig. 1

shows a continuous furnace for carrying out the method according to the invention.

Fig. 2

shows the continuous furnace FIG. 1 with additions.

Fig. 3

shows a discharge vessel, which has passed through a part of the manufacturing process according to the invention.

Fig. 4

shows a schematic representation of an alternative way to FIG. 3 ,

Preferred embodiment of the invention

FIG. 1 shows a continuous furnace 1 for joining discharge vessel parts 2 to discharge vessels 3. The discharge vessel parts 2 are introduced in the drawing from right to left on a conveyor belt 4 through an opening 5 of the continuous furnace 1 in this and the joined discharge vessels 3 through an opening 6 from the oven 1 transported out.

The discharge vessel parts 2 correspond to cover (top) and bottom (bottom) of the finished discharge vessel 3. The discharge vessels 3 are for dielectrically impeded flat radiators certainly. The external electrodes or their contacting are attached in a manner known per se in the following method steps (not shown).

The discharge vessel parts 2 pass through prior to introduction into the furnace 1 already known cleaning and processing steps (not shown); For example, the inner sides of the discharge vessel parts are coated in advance with a phosphor and in some cases a reflector layer.

The continuous furnace 1 has heating elements 7 for heating the furnace interior. Gas supply 8 are provided with further heating elements 9. The interior of the oven is heated by the heating elements 7 and by a gas introduced via the gas feeds 8 and heated by the heating elements 9 first gas.

For joining the first still spaced discharge vessel parts 2 are placed between these SF6 glass pieces as spacers. Due to the high temperature in the continuous furnace 1 soften this and the upper discharge vessel part 2 lowers to the lower discharge vessel part 2 from. The edges of the discharge vessel parts 2 are provided with a glass solder, which is melted in the continuous furnace 1 and over which the discharge vessel parts 2 are joined together in a gastight manner.

Before the actual filling, the discharge vessel parts or the assembled discharge vessels must be cleaned and rinsed in a manner known per se in order to remove residual moisture and any residual constituents of organic materials such as solvents or binder constituents.

The inside of the oven is flooded via the gas feeds 8 with the first gas, a helium / neon mixture. In this case, the helium / neon mixture is introduced with sufficient pressure to ensure a constant flow through the furnace interior and the openings 5 and 6 of the continuous furnace. Between the first still spaced discharge vessel parts 2 is located, besides the SF6 glass pieces, within the continuous furnace exclusively introduced by the gas feeds 8 first gas. As the SF6 glass pieces soften, the first gas is trapped on the lower discharge vessel portion 2 as the upper discharge vessel portion 2 is lowered.

FIG. 2 shows the continuous furnace FIG. 1 supplemented by Gasabsaugleitungen 10 and a pump 11. Here, the first gas flows mainly into the Gasabsaugleitungen 10. The exhausted noble gases are then recovered in a conventional manner (not shown).

A manufacturing method using a continuous furnace with a plurality of furnace chambers in which various operations are performed, is in DE 101 47 727 A1 shown in more detail. To improve understanding, reference is made to this.

FIG. 3 shows one of the just described as assembled discharge vessels 3 from above. It includes gas-tight the He / Ne mix; Further, it contains two received at the outer edge ampoules 12, which are provided in the lateral smaller channels and round in section. The ampoules themselves and the inside of the discharge vessel 3, along which they are received, are not - like the rest of the inner surface of the discharge vessel 3 - coated with a phosphor or a reflector layer. Incidentally, shows FIG. 3 between the two ampule channels in cross-section larger channels that form the actual discharge volume and are already described elsewhere in the prior art.

Preferably, an IR laser is used to open the ampoules. For example, microwaves can also be used. In any case, by energy coupling into partial areas of the ampoules temperature gradients can be generated, which lead to breakage due to material stresses. For this purpose, the sections, such as ampoule tips, for example, metal coated.

The discharge vessel is 40 cm wide, 70 cm long and in the middle inside 0.3 cm high, in places, but also up to 0.55 cm high (clear inside height). The ampoules have 1 mm quartz walls, are 67 cm long and have an inside diameter of 3 mm. At a xenon pressure of 10 bar within the ampoules 12 (at room temperature), a xenon partial pressure of 0.1 bar within the discharge vessel 3 results when the ampoules are opened by laser irradiation and the xenon has been distributed in the discharge vessel 3 ( at room temperature).

Before opening the ampoules, the emission spectrum of the He / Ne mixture is examined. Impurities can be detected and the production of other defective discharge lamps can be avoided.

FIG. 4 outlines a further variant for the second filling step with a filler neck 13. This is introduced via a seal 14 in a filling volume 15 and closed at its arranged in this filling volume 15 end. The other end of the filler neck 13 opens into the left schematically drawn discharge vessel 16th

The filling volume 15 is connected via a first valve 17 to a gas outlet and via a second valve 18 with a gas inlet. It also has an indicated heating 19. The filling volume 15 is part of another device for filling, so not the continuous furnace, and surrounds the filler neck 13 in the manner outlined here. The exterior of the filler neck 13 and the interior of the filling volume 15 are cleaned by a rinsing step using the two valves 17, 18 and the gas inlet and outlet. Optionally, with the second valve closed and the first valve open, it can also be pumped out for cleaning purposes.

The filler neck 13 is opened by a not shown mechanical means (passage in the filling volume 15) or by IR laser or microwave irradiation on a metal coating at its end to introduce a second gas into the interior of the discharge vessel, which previously via the gas inlet was introduced into the filling volume 15. In this case, a gas pressure is set, which leads after opening of the filler neck 13 to the desired discharge gas mixture in the discharge vessel itself.

The filler neck 13 can be shortened and closed by melting and peeling off with a flame in so-called pump stems in the lamp technology generally known manner and closed when the second filling step is completed. It preferably consists of the same Glass material from which the cover glass of the discharge vessel also consists.

In the manner described, as an alternative to the above FIG. 3 described ampoule technology a second filling step can be performed. The first filling step of the two variants is the same.

Claims (9)

1. Method for producing a discharge lamp, having the steps:

   assembling an open discharge vessel (2, 3, 16) of the discharge lamp and filling it with a first gas in an environment (1) of the first gas,

   characterized by the subsequent step:

   adding a second gas to the first gas in the assembled discharge vessel (3), using a supply volume (12, 15) separate from the environment of the discharge vessel (3).
2. Method according to Claim 1, characterized in that the assembly and filling of the discharge vessel (2, 3, 16) with the first gas are carried out in a continuous furnace (1).
3. Method according to Claim 2, characterized in that the first gas flows around the discharge vessel (2, 3).
4. Method according to one of the preceding claims, characterized in that a spectral analysis of the first gas in the discharge vessel (3, 16) is carried out after closing the discharge vessel (3, 16) and before introducing the second gas.
5. Method according to one of the preceding claims, characterized in that the second gas is introduced into the discharge vessel (16) through a filling spout.
6. Method according to one of the preceding claims, characterized in that the discharge vessel (2, 3) is fully closed after filling with the first gas and contains an ampoule (12) of the second gas, the ampoule (12) subsequently being opened.
7. Method according to Claim 6, characterized in that the ampoule (12) is opened by electromagnetic waves.
8. Method according to Claim 6 or 7, characterized in that the ampoule (12) is held on the edge of the discharge vessel (2, 3).
9. Method according to one of the preceding claims, characterized in that the discharge lamp is a flat radiator.

Images