EP1536453A2 - Discharge lamp with at least one external electrode and method for fabricating the same - Google Patents

Abstract

A discharge lamp comprises discharge vessel and electrode(s) similar to a conductor track. The electrode(s) is adhesively bonded to the outer side of the discharge vessel. The electrode(s) similar to a conductor track is integral part of laminate (5). The laminate is adhesively bonded to the outer side of the discharge vessel by using adhesive layer. The laminate comprises carrier film made of electric insulating material. An independent claim is included for production of discharge lamp comprising providing discharge vessel, providing flexible laminate made of carrier film and electrode similar to conductor track, and adhesively bonding the laminate to an outer side of the discharge vessel.

Description

Technical area

The invention is based on a discharge lamp, in which on the outside the discharge vessel at least one electrode, hereinafter also shortening called outer electrode, is arranged.

Such discharge lamps fall under the more general term "dielectric Barrier discharge lamps (DBD lamps) ", where here the wall the discharge vessel for the respective on the outside of the discharge vessel arranged electrode acts as a dielectric barrier. The shape of the Discharge vessel plays in this context at most a subordinate Role. Known are, inter alia, tubular lamp types, the For example, in office automation (OA) for copiers, fax machines and Scanners are used, as well as flat lamp types, which, inter alia, in the general lighting, for film lights as well as backlighting for Liquid crystal screens (LCD) are used.

State of the art

From US-A 5 994 849 a flat lamp with external electrodes is known. The discharge vessel consists of a flat bottom plate and a trough-shaped Front panel with a flat central area, both panels in the surrounding edge region are gas-tightly closed with each other. On the Outside of the bottom plate are strip-shaped electrodes made of aluminum glued. This is especially true for large area flat lamps with numerous strip-shaped electrodes, for example a typical 42 "flat lamp Piece, not practical. Another option is to use screen printing technology Electrode tracks of conductive silver paste on the outside of the bottom plate aufzudrucken, as it is similar with flat lamps with on the inside the discharge vessel wall applied electrodes is made (See, e.g., U.S. Patent No. 6,034,470). This technique has over the previous one the advantage that even filigree electrode tracks well applied can be. The disadvantage, however, is the relatively high cost, especially after application of the initially pasty electrode tracks additionally on Drying and subsequent baking step are required, wherein also the burning usually leads to embrittlement of the glass existing discharge vessel leads. Also, with both techniques taken an additional measure to cover the electrode tracks be to protect against contact and protection from further external To ensure influences. Otherwise, over time, unwanted Changes to the electrode tracks with resulting Operational disturbances up to early failures of these lamps occur.

Presentation of the invention

The object of the present invention is to provide a discharge lamp provide at least one outer electrode, which is easier to manufacture is. Another aspect is the improved reliability of the discharge lamp.

This object is achieved by a discharge lamp with a discharge vessel and at least one conductor track type electrode mounted on the Outside of the discharge vessel is glued, characterized that the at least one conductor track-like electrode - in the following simplicity also referred to as the electrode track - integral part one by means of an adhesive layer on the outside of the discharge vessel glued laminate with a carrier film of an electrical insulating material is.

Particularly advantageous embodiments can be found in the dependent claims.

In addition, protection is claimed on a method for producing this lamp.

The advantage of the solution according to the invention is that the laminate prefabricate and then completely on an outside of the discharge vessel stick on. Thus, the method is also good for a automated mass production. In addition, the production of the lamp thereby cheaper. This solution is particularly advantageous for discharge lamps with several strip-shaped electrodes, e.g. at the in of the aforementioned US 5,994,849 disclosed flat lamp, because then All electrodes with the laminate in a single step the discharge vessel are glued on. The adhesive can be separated directly before sticking the laminate on a designated area of the discharge vessel or on the laminate itself. But to simplify the lamp manufacturing, it can also be advantageous be when the laminate is already provided with an adhesive layer. to better storage and handling during production is the adhesive layer preferably protected with a cover, the first immediately is removed before sticking the laminate. So that the adhesive layer when removing the cover does not accidentally dissolves from the laminate, points the adhesive layer preferably comprises a stabilizing agent, for example embedded in the adhesive layer fibers. Alternatively, it is suitable as an adhesive layer also a thin, serving as a stabilizing agent film, the two sides coated with adhesive. When choosing the type and thickness of the adhesive It should be noted that the adhesive layer covers all cavities between fills the electrode tracks, so that when sticking as possible no air pockets arise. If larger air pockets form, At this point, part of the electrode tracks rises from the outside of the discharge vessel, which in the worst case to the discharge this point is missing. This in turn can improve the luminance homogeneity of the Affect lamp in unacceptable extent and is therefore undesirable. As suitable, for example, an adhesive has proven, as in the Tape tesa 4980 from Tesa AG is used. Good results were achieved with adhesive layers, the respective thickness in the range between about 40 to 200 microns, preferably between about 60 to 100 microns. It has surprisingly been found that no undesirable large Voltage drops across the electrodes occur.

Preferably, the laminate is oriented so that the at least one conductor track-like Electrode between the relevant outside of the discharge vessel and the carrier film is arranged. This has the advantage that the carrier film except as a carrier at the same time as a protective film against external Actions and protection against contact acts.

Preferably, the laminate is flexible. This can be done by suitable Choice of material and thickness of the carrier film and the electrode web (s) laminated thereon achieve. For the carrier film have electrically insulating Plastics, in particular the materials polyethylene naphthalate (PEN) or Polyester (PET) but also polyimides (e.g., Kapton) have been found suitable. The thickness of the carrier film is a few microns to a few hundred Micrometer, preferably in the range between about 5 microns and 200 microns, more preferably between about 20 microns and 100 microns. The least a conductor-like electrode consists of an electrically conductive Material, in particular of metal, e.g. Copper or aluminum. Your thickness is preferably in the range between about 5 microns and 40 microns, more preferably between about 5 microns and 20 microns. The resulting flexibility of the Laminate makes it possible, preferably an integral feed line for the at least to provide an electrode. This means that the electrode tracks is continued in a continuous area of the laminate, wherein this extension is not glued to the discharge vessel, but freely movable remains and thus acts as a foil-like supply line. For the business the lamp is the free end of the foil-like supply line either directly or by means of a connector connected to the supply end with the Output connected to an electrical supply unit. Is advantageous in any case, that to the usual soldering a separate supply line the discharge vessel can be dispensed with.

The width of the electrode tracks is of the electrical requirements of Lamp dependent. For lamps known for one disclosed in US Pat. No. 5,604,410 Pulsed mode is provided, the width of the electrode tracks typically about 1 mm or slightly less or up to a few a few millimeters. The electrode webs can be screen-printed, for example from silver solder, be applied directly to the carrier film. alternative The electrode tracks can also be achieved by means of conventional etching methods from a copper foil laminated with the carrier foil. The copper foil can e.g. glued by means of an adhesive layer on the carrier film be. It is likewise conceivable to apply the carrier foil directly to a copper layer Mistake.

A first embodiment relates to so-called aperture lamps with external electrodes, which have a tubular discharge vessel. This lamp type has at least one, typically two strip-shaped outer electrodes on, parallel to the longitudinal axis of the tubular discharge vessel are oriented. According to the invention, at least one with a carrier film laminated electrode track parallel to the longitudinal axis of the tubular discharge vessel glued. In the case of two parallel electrode tracks, These are in a predetermined mutual distance with a carrier film laminated. This ensures that after gluing the laminate on the outside of the tubular discharge vessel, the two electrode tracks are arranged at the desired position. Besides, that is Laminate glued so that the aperture of the lamp, through which the light is emitted, remains free. This has compared to the conventional one Solution in which the typically glued electrodes subsequently a translucent plastic shrink tubing is applied the advantage that here no reduction of passing through the aperture Luminous flux through a shrink tubing occurs.

In a particularly preferred embodiment, the discharge lamp a flat discharge vessel - shortening in the following also as a flat lamp designated - with a plurality of conductor track-like electrodes (electrode tracks), the evenly distributed over the surface of the discharge vessel are. The electrode tracks are in at least two comb-like, interlocking Electrode groups arranged on a common carrier film. This laminate thus formed is usually on the back of the flat discharge vessel - i. the outside of the light emission direction opposite surface - glued. With the multiplicity at a large-area flat lamp required electrode paths come the beginning mentioned advantages of the invention naturally particularly bear. For this purpose, the electrode tracks including the collection tracks, with where the electrode tracks form comb-like electrode groups and possibly Leads to these electrode groups, for example, with in the electronics usual exposure and etching process from a copper coated carrier sheet exposed or alternatively from silver solder paste by means Screen printing technique applied directly to the carrier film. The must Electrode sheets may not necessarily be completely straight, but can also have a substructure, as in the following embodiment is shown. Anyway, then the laminate prepared in this way preferably provided on the electrode side with an adhesive layer and subsequently onto a surface, e.g. the back of the discharge vessel of the Flat lamp glued. In this case, in a relatively new type of DBD flat lamps, during operation, a large number of individual discharge structures form support protrusions formed in the front panel, particularly high demands on the positional accuracy of the electrode tracks because the individual discharge structures only at the by the special shape of the front panel predetermined locations should train. It has surprisingly been found that this with a prefabricated and then glued laminate with such high Accuracy can be realized that such flat lamps also with relative large diagonals, for example 23 "and more, for more Details on the design of these flat lamps is on the WO 03/017312, the disclosure of which by reference Reference is hereby included.

Brief description of the drawings

Fig. 1a

die Draufsicht einer Flachlampe,

Fig. 1 b

die Seitenansicht der Flachlampe aus Fig. 1a,

Fig. 2

die Seitenansicht des auf die Außenseite der Flachlampe aus Fig. 1a, 1 b aufgeklebten Laminats einschließlich Kleberschicht,

Fig. 3

eine Draufsicht des Laminats aus Fig. 2 mit Elektrodenbahnen.

In the following, the invention will be explained in more detail with reference to an embodiment. The figures show:

Fig. 1a

the top view of a flat lamp,

Fig. 1 b

the side view of the flat lamp of Fig. 1a,

Fig. 2

the side view of the laminated on the outside of the flat lamp of Figure 1a, 1 b laminate including adhesive layer,

Fig. 3

a plan view of the laminate of FIG. 2 with electrode tracks.

Preferred embodiment of the invention

FIGS. 1a, 1b schematically show a flat lamp 1 with a diagonal of 21.3 "and an aspect ratio of 4: 3 in plan view and side view, respectively. The discharge vessel of the flat lamp 1 is characterized by a front plate 2, a bottom plate 3 and a frame 4 arranged therebetween, wherein the frame 4, the two plates 2, 3 connects to each other gas-tight. Alternatively, it is also possible to dispense with a frame if ground and Front panel not both are completely flat, but at least in the edge area are shaped such that the frame in at least one of the two plates as it were integrated. For further details, see the already cited US Pat. No. 5,994,849 and WO 03/017312, the contents of which are incorporated herein by reference The disclosure content is hereby incorporated by reference is. Inside the discharge vessel are xenon and neon with a partial filling pressure of about 10 kPa or about 20 kPa. On the outside the bottom plate 3, a laminate 5 is glued, whose structure in Fig. 2 coarse is shown schematically. An unfixed extension 5 'of the laminate 5 serves as a flexible supply line. Further details can be found in the description to the figure 3.

For the explanation below, reference will now be made to the one just mentioned Fig. 2 taken. The outermost layer of the laminate 5 forms an approximately 50 μm thick carrier film made of PET (polyester), which also serves as a protective film for it lying about 15 microns thick electrode tracks 5b (for details see Fig. 3) made of copper. This is finally followed by an approx. 80 μm thick adhesive layer 6, with which the laminate 5 adhered to the outside of the bottom plate 3 is. As an adhesive for the adhesive layer 6 of the adhesive, as he used in the Tape tesa 4980 from Tesa AG is used.

Fig. 3 shows in plan view the copper layer side of the laminate 5. This consists in detail from 29 parallel to each other and at a mutual distance mutually arranged electrode tracks 7, for a first polarity are provided as well as 29 electrode tracks 8, for a second polarity are provided, wherein continuously an electrode web. 7 the first polarity with an electrode track 8 of the second polarity alternate. On opposite sides is the respective one end of each electrode track 7, 8 of a polarity to a collecting track 9, 10 summarized. In this way, the electrode tracks 7, 8 form with their associated Collection channels 9, 10 comb-like structures, the structures of both Polarities, as it were, intermesh. The individual, essentially straight electrode tracks 7, 8 have opposite wave-like substructure on, whereby in each case between two next adjacent electrode tracks 7, 8 a plurality of narrow points 11 are formed. At each of these Digits 11 is formed in the above-mentioned pulsed operation according to the US Pat. No. 5,604,410 already cited a single discharge (not shown). In a variant, not shown, the laminate is on the outside of the Bottom plate of a flat lamp glued, which -as already mentioned - has in the front plate molded numerous support projections, whereby predetermined positions for single discharges between the support projections are. In this variant, with correct positioning of the laminate the above-mentioned narrow points of the electrode tracks and the for the individual discharges predetermined positions exactly matched. The average distance of the electrode tracks is 4.5 mm, whose width is approx. 1.45 mm. In two variants, not shown, the electrode web width 2.05 mm or 0.85 mm. The collection tracks 9, 10 go in turn Feed lines 12, 13 over, which are parallel along an edge region of the Carrier foil 5a lead. All copper tracks 7-13 are conventional Etching process from a copper foil laminated with the carrier foil 5a emerged. Before sticking the laminate 5 on the outside of the bottom plate 3 of the discharge vessel, the laminate 5 along a line 14, which the supply lines 12, 13 of the electrode tracks 7, 8 and the Sammelbahn 9 separates, cut. As a result, the strip-shaped extension 5 'of the laminate 5 with the two supply tracks 12, 13 after the Sticking the remaining laminate 5 movable and then serves to connect the lamp to an electrical supply unit (not shown). In this way, finally, each of the two comb-like electrode groups connected to a pole of the supply device. For protection from external influences as well as touch are the two feed lines 12, 13 with the exception of their respective terminal end with an additional Insulating layer (not shown) covered.

Although the invention above, the example of a flat lamp closer has been explained, extends the advantageous effect of the invention and the claimed protection, however, also on discharge lamps according to the invention with differently shaped discharge vessels, especially on tubular discharge lamps.

Claims (17)

Discharge lamp (1) with a discharge vessel and with at least one conductor track-like electrode (7, 8), which is glued on the outside of the discharge vessel, characterized in that the at least one conductor track-like electrode (7, 8) an integral part of a means of an adhesive layer (6 ) is on the outside of the discharge vessel glued laminate (5) with a carrier foil (5a) made of an electrical insulating material. A discharge lamp according to claim 1, wherein the laminate (5) is oriented is that the at least one conductor track-like electrode (7, 8) between the outside of the discharge vessel and the carrier film (5a) is. Discharge lamp according to claim 1 or 2, wherein the laminate (5) is flexible is. Discharge lamp according to one of the preceding claims, wherein the Laminate (5) an integral feed line (5 ') with at least one feed line (12, 13), which for the connection of the at least one Electrode (7, 8) provided with an electrical supply device is, wherein the integral feed line (5 ') not on the discharge vessel is glued on. Discharge lamp according to one of the preceding claims, wherein the Carrier film (5a) consists of PEN, PET or polyimides. Discharge lamp according to one of the preceding claims, wherein the Thickness of the carrier film (5a) a few microns to a few hundred microns is, preferably in the range between about 5 microns and 200 microns, more preferably between about 20 microns and 100 microns. Discharge lamp according to one of the preceding claims, wherein the at least one conductor track-like electrode (7, 8) of an electric conductive foil (5b), in particular of metal, preferably copper or aluminum. Discharge lamp according to claim 7, wherein the thickness of at least a conductor track-like electrode (7, 8) in the range between about 5 microns and 40 microns, more preferably between about 5 microns and 20 microns. Discharge lamp according to one of the preceding claims, wherein the Adhesive layer (6), with which the laminate (5) on the outside of the discharge vessel is glued, a thickness of about 40 to 200 microns, preferably from about 60 to 100 microns. Discharge lamp according to one of the preceding claims, wherein the Discharge vessel is tubular and the at least one conductor track-like Electrode parallel to the longitudinal axis of the tubular discharge vessel is arranged. Discharge lamp according to one of claims 1 to 9, wherein the discharge vessel is flat and a plurality of conductor-like electrodes (7, 8) are evenly distributed over a surface of the discharge vessel. Discharge lamp according to claim 11, wherein the electrodes in at least two comb-like interdigitated electrode groups (7, 9; 8, 10) are arranged. Discharge lamp according to one of the preceding claims wherein at least two next adjacent conductor track-like electrodes (7, 8) a Have structure through which a plurality of narrow points (11) between the two conductor track-like electrodes (7, 8) are formed. Discharge lamp according to claim 13, provided that claims 12 and 11 back related, the flat lamp has a front panel with numerous formed support projections and the laminate positioned so is that the narrow spots of the electrode tracks on the areas are matched between the support projections. Process for producing a discharge lamp according to one of the preceding claims, comprising the following process steps: o provision of a discharge vessel, providing a flexible laminate comprising a carrier foil and at least one conductor track-like electrode, o gluing the laminate on an outside of the discharge vessel. The method of claim 15, wherein the laminate additionally comprises at least one connected to the at least one conductor-like electrode Zuleitungsbahn is applied and wherein the at least a supply line having part of the laminate not with the discharge vessel is glued. The method of claim 16, wherein the at least one lead track is guided parallel to an edge region of the carrier film and thereafter the laminate is slit such that this edge area with the at least one supply track - after sticking of the remaining part of the laminate - a flexible strip-like feed line forms.

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