EP2306492A1 - High pressure discharge lamp with capacitive ignition aid - Google Patents

Abstract

The lamp (1) has a discharge vessel (2) accommodated in an outer bulb (3) and formed from silica glass or ceramic. An electrode system is fastened to an end of the vessel, and a frame holds the vessel in the bulb. Capacitive starting aids (11) are fastened on seals of the end of the vessel, and include winding parts (12) connected with each other via wires. The starting aids are formed as symmetrical or asymmetrical windings on the seals, and comprise two tongues that are interconnected via a web. The vessel includes a metal halide fill that is free of sodium.

Description

Technical area

The invention relates to a high-pressure discharge lamp according to the preamble of claim 1. Such lamps are in particular high-pressure discharge lamps for general lighting or for photo-optical purposes.

State of the art

From the US 6,198,223 and the US 6,268,698 is a high-pressure discharge lamp with discharge vessel is known in which a starting aid is designed as a winding around one end of the discharge vessel.

Presentation of the invention

The object of the present invention is to provide a high-pressure discharge lamp whose ignition is ensured by simple inexpensive means.

This applies in particular to metal halide lamps, wherein the material of the discharge vessel may be ceramic or quartz glass.

This object is achieved by the characterizing features of claim 1.

Particularly advantageous embodiments can be found in the dependent claims.

The invention relates to high-pressure discharge lamps with a discharge vessel made of quartz glass or ceramic, with or without outer bulb. Especially affected are discharge lamps for general lighting, which usually have an evacuated or gas-filled outer bulb and are designed for life of 6000h or more.

Such high-pressure discharge lamps are started by means of special ignitors. The ignition characteristics of these ignitors are defined by appropriate standards. The conditions in the discharge vessel (volume, electrode gap, filling gas, filling pressure, quantity of mercury, quantity and type of metal halides) must be coordinated so that the lamp safely ignites at the specified ignition conditions.

The disclosure of the invention describes a solution which ensures reliable ignition for high-pressure discharge lamps.

As the service life increases, the voltage required to ignite high pressure discharge lamps increases. This can result in old lamps not starting on conventional ignitors. However, the ignitability must be guaranteed over the entire lifetime, which is ensured by the arrangement according to the invention, without significant additional costs.

1. a) Dem Brennerfüllgas wird ein radioaktives Gas wie beispielsweise Kr85 beigemischt. Die Radioaktivität bewirkt eine Ionisierung des Füllgases, welche die Durchschlagsspannung herabsetzt und so die Zündfähigkeit sicherstellt. Jedoch wird der Gebrauch von Radioaktivität gesetzestechnisch zunehmend eingeschränkt.
2. b) Im Außenkolben wird ein sog. UV-Enhancer eingebaut. Dieser besteht aus einer miniaturisierten Entladungsröhre, die beim Anlegen der Zündspannung UV-Strahlung emittiert. Diese UV-Strahlung bewirkt ebenfalls eine Ionisierung des Brennerfüllgases und stellt so die Zündfähigkeit sicher, siehe EP-A 922296 .
3. c) Vom Bügeldraht wird ein Draht um die Kapillare mit der gegenpoligen Elektrode gewickelt. Beim Anlegen der Zündspannung entsteht so im Bereich dieser Elektrode eine dielektrisch behinderte Entladung, welche das Brennerfüllgas ionisiert und die Zündspannung herabsetzt, siehe z.B. EP-A 967631 .
4. d) Das elektrische Potential der einen Elektrode wird mit Hilfe elektrisch leitender Bauteile außerhalb des Entladungsgefäß in die Nähe der Gegenelektrode gebracht. Dazu wird in der Regel ein Draht, Clip oder ähnliches um die Einschmelzung, Quetschung oder die Kapillare in der Nähe der Elektrode gewickelt und elektrisch leitend mit der Stromzuführung der Gegenelektrode verbunden. Beim Anlegen der Zündspannung entsteht so im Bereich der umbauten Elektrode eine dielektrisch behinderte Entladung, welche das Brennerfüllgas ionisiert und die Zündspannung herabsetzt, siehe beispielsweise EP-A 967631 .
5. e) Für bestimmt Anwendungen wird ein Zündgerät mit deutlich höherem Zündpuls eingesetzt, z.B. Autolampe im Vergleich zur Allgemeinbeleuchtung

So far, there have been various approaches to this.

1. a) The radioactive gas is mixed with a radioactive gas such as Kr85. The radioactivity causes an ionization of the filling gas, which reduces the breakdown voltage and thus ensures the ignitability. However, the use of radioactivity is increasingly limited by law.
2. b) A so-called UV enhancer is installed in the outer bulb. This consists of a miniaturized discharge tube, which emits UV radiation when the ignition voltage is applied. This UV radiation also causes ionization of the Brennerfüllgases and thus ensures the ignitability, see EP-A 922296 ,
3. c) From the hanger wire, a wire is wound around the capillary with the opposite pole electrode. When the ignition voltage is applied, a dielectrically impeded discharge arises in the region of this electrode, which ionizes the burner fill gas and reduces the ignition voltage, see, for example, US Pat EP-A 967631 ,
4. d) The electrical potential of the one electrode is brought by means of electrically conductive components outside the discharge vessel in the vicinity of the counter electrode. For this purpose, a wire, clip or the like is usually wound around the melt, pinch or capillary in the vicinity of the electrode and electrically conductively connected to the power supply of the counter electrode. When the ignition voltage is applied, a dielectrically impeded discharge arises in the vicinity of the electrodes, which ionizes the burner fill gas and reduces the ignition voltage, see, for example EP-A 967631 ,
5. e) For certain applications an ignitor with a much higher ignition pulse is used, eg car lamp compared to general lighting

The current arrangement takes up the principle of dielectrically impeded discharge, but simplifies it decisively.

Both electrodes are capacitively coupled together outside the discharge vessel. For this purpose, electrically conductive components behind the one and the other electrode form and / or non-positively externally attached to the discharge vessel or melting, pinch or capillary and electrically conductively connected from one to the other electrode side. It is essential that no direct electrical contact is made to either of the two electrodes or power supply lines.

It is advantageous if the components in the area behind the electrodes cover a large area and rest as closely as possible on the discharge vessel, capillary or meltdown. The connection from one end of the discharge vessel to the other is preferably made with the smallest possible component, e.g. a thin wire, made to avoid shading the light emission.

Technical embodiments are e.g. a wire made of nickel, niobium, molybdenum, tungsten or similar heat-resistant, electrically conductive material, which is wound behind the one electrode around the discharge vessel. The wire is stretched over the discharge vessel to the other electrode and there also wound around the electrode around the discharge vessel or capillary or melting. The windings can be symmetrical or asymmetrical. Preferred is an asymmetric winding.

Instead of a wire winding, a sleeve made of foil or sheet can be placed around the two ends of the discharge vessel or the capillary and welded. The slides on both sides are made by means of a wire or connected to a thin foil strip. Preference is given to a film, in particular a molybdenum foil as used for the melting, since it has a high flexibility and temperature resistance.

In a third variant, instead of a sleeve, a clip is inserted, which is pushed over the meltdown or capillary. The clip can be designed as a spring element, so that a non-positive connection is possible. It is advantageous to form a groove, flattening or other specific retaining aid on the capillary or sealing, into which the clip is fitted in a form-fitting manner.

There are according to the invention no more radioactive admixtures needed.

An ignition of aged lamps is ensured as well as the ignition of just switched off lamps (hot re-ignition). When using a starting aid, which is electrically connected to one of the two electrodes or power supply, it can come in the hot re-ignition to a several-minute discharge between the electrode and ignition aid. The discharge vessel is practically short-circuited in this case. This effect is avoided by a non-contacted ignition aid, since the dielectrically impeded discharge occurs at both electrodes and thus leads to a breakdown between the electrodes.

1. a) Lampen ohne metallische Teile im Außenkolben
2. b) Lampen mit einem Entladungsgefäß aus Quarzglas und einer Natriumhaltigen Füllung

The invention is particularly advantageous in one or even more clearly in the combination of the following lamp types:

1. a) Lamps without metallic parts in the outer bulb
2. b) lamps with a discharge vessel made of quartz glass and a sodium-containing filling

In the case b), it may come to the discharge of sodium from the discharge vessel when live parts lead outside of the discharge vessel. Since the starting aid according to the invention is insulated from the two electrodes, no electrical charge can flow out of the components of the starting aid. Thus, the mechanism that leads to sodium leakage from the burner, effectively prevented. On the other hand, a directly contacted ignition aid causes a more or less pronounced sodium discharge during the lamp burning period, as has often been observed.

In the case of burners made of quartz glass, the formation of the ignition aid as a clip or foil behind the electrode additionally offers the possibility of dispensing with the normally customary reflector. For this purpose, the ignition aid covers the area behind the electrodes, which is otherwise covered by the reflector. The metallic surface of the ignition aid reflects the radiation in the area behind the electrode and provides additional heating of this area. For this purpose, it may be favorable to carry out the surface of the ignition aid directed toward the discharge vessel in a frosted manner (for example sandblasted or ground).

Brief description of the drawings

Fig. 1

eine Hochdruckentladungslampe mit Zündhilfe, ers- tes Ausführungsbeispiel;

Fig. 2

eine Hochdruckentladungslampe mit Zündhilfe, zwei- tes Ausführungsbeispiel;

Fig. 3

eine Hochdruckentladungslampe mit Zündhilfe, drit- tes Ausführungsbeispiel;

Fig. 4

eine Hochdruckentladungslampe mit Zündhilfe, vier- tes Ausführungsbeispiel;

Fig. 5

eine Hochdruckentladungslampe mit Zündhilfe, fünf- tes Ausführungsbeispiel;

Fig. 6

ein Detail aus Figur 5;

Fig. 7

eine Hochdruckentladungslampe mit Zündhilfe, sechstes Ausführungsbeispiel;

Fig. 8

ein Detail aus Figur 7;

Fig. 9

das Detail aus Figur 7 um 90° gedreht;

Fig. 10

ein weiteres Ausführungsbeispiel einer Hoch- druckentladungslampe;

Fig. 11-12

Details aus Figur 10;

Fig. 13

ein weiteres Ausführungsbeispiel einer Hoch- druckentladungslampe;

Fig. 14

ein Detail aus Figur 13.

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

Fig. 1

a high-pressure discharge lamp with starting aid, first exemplary embodiment;

Fig. 2

a high-pressure discharge lamp with starting aid, second exemplary embodiment;

Fig. 3

a high-pressure discharge lamp with starting aid, third exemplary embodiment;

Fig. 4

a high-pressure discharge lamp with ignition aid, fourth exemplary embodiment;

Fig. 5

a high-pressure discharge lamp with ignition aid, fifth embodiment;

Fig. 6

a detail from FIG. 5 ;

Fig. 7

a high pressure discharge lamp with ignition aid, sixth embodiment;

Fig. 8

a detail from FIG. 7 ;

Fig. 9

the detail FIG. 7 turned by 90 degrees;

Fig. 10

Another embodiment of a high-pressure discharge lamp;

Fig. 11-12

Details from FIG. 10 ;

Fig. 13

Another embodiment of a high-pressure discharge lamp;

Fig. 14

a detail from FIG. 13 ,

Preferred embodiment of the invention

FIG. 1 schematically shows the basic structure of a high-pressure discharge lamp 1 with ignition aid. It has a discharge vessel 2 made of ceramic, possibly also made of quartz glass, which is housed in an outer bulb 3. The outer leads 4 of the discharge vessel, which contact electrodes inside, are connected to two frame wires 5 and 6. A short frame wire 5 leads to a first foil 7 in a pinch 8 of the outer bulb. A long frame wire 6, often called stirrup wire, leads to a second film 7 in the pinch 8. The discharge vessel 2 has at its ends in each case a capillary 10, as known per se, and a filling of an ionizable gas, usually argon or Xenon, mercury and metal halides, also known per se. Two electrodes are located in the interior of the discharge vessel, as also known per se, and not shown here.

An ignition aid 11 in the form of a film is placed in each case as a sleeve around the two capillaries of the discharge vessel and connected together via a primer 15, this may be a coating or a sintered material, as taken in itself known.

FIG. 2 shows as ignition aid 11 a symmetrical wire winding with 2-3 windings per side. The two winding parts 12 and 13 on the two bruises or melts of the discharge vessel 2 made of quartz glass are via a wire 16 or other conductor, the extends over the bulbous middle part of the discharge vessel, connected to each other.

FIG. 3 shows a similar system in which the wire windings are designed asymmetrically. In this case, there are approximately two to three windings 21 on a pinch 20, and approximately eight to ten windings 22 on the second pinch 20. These two winding parts 21 and 22 are again connected via a primer or wire 23. The ratio of the number of turns of the winding should preferably be 2: 1 to 4: 1.

FIG. 4 shows a discharge vessel 2 made of quartz glass, in which at the ends of the bulbous discharge vessel foil strips 25 are wound as dome around the ends of the discharge vessel and connected to wire 26. This exemplary embodiment makes sense precisely when a reflector at the ends is to be used anyway in the case of quartz glass discharge vessels. Because the films have additional reflective properties.

FIG. 5 shows a discharge vessel 2 made of quartz glass, in which the ignition aid is a clip 30 at both seals, seals or bruises, which is pushed laterally over the melt 32 shown here. FIG. 6 shows a cross section at the location of the clip 30. The two clips are connected to a wire 31. This embodiment is equally well suited for discharge vessels made of quartz or ceramic. The cross section of the FIG. 6 shows a seal (round cross section) with flattening 33, so that a particularly good fit of the clip 30 is made possible. In principle, however, the melting can also do without flattening and the clip is a C-shaped bent circle of spring steel. In principle, an asymmetric embodiment can be realized in that the width of the clips or a film is chosen differently on the two seals. Alternatively or additionally, the length of the clips or foils can be chosen differently. The design rule is preferably analogous to FIG. 3 explained.

FIGS. 7 to 9 shows a clip variant at discharge vessel 36 made of quartz glass with pinch 37. These are two clips 35 made of spring steel, which are pushed onto the pinch 37 and are connected to each other via a wire 38. The spring plate clip 35 has a central hole 39 whose contour is adapted to the double T-shape of the pinch. Two tongues 40 are each supported centrally on the broad sides of the pinch and act in a fixed manner in cooperation with two barbs 41 acting on the narrow sides of the pinch.

FIG. 10 and the detail FIGS. 11 and 12 show a high-pressure discharge lamp with a discharge vessel made of quartz glass, which is closed on two sides with a pinch. Again, two clips 35 are pushed onto the bruises and connected to each other via a wire 38. A pronounced asymmetry of the induced electric field strength is achieved in that an approximately rectangular plate 45, 46 of thin sheet metal is placed on the two broad sides of each pinch. The plate 45, 46 is respectively clamped by the clip 35 in the direction of the pinch, or it may also be made integral with the clip. In this case, on a first side, the plate 45 a possible small area on. The width of the plate 45 is approximately adapted to the width of the pinch 37. The axial length of the plate 45 is relatively short, but it should preferably be at least 2 mm. The area of the platelets 46 on the second pinch 37 should be chosen to be significantly larger, preferably at least three times as large. The platelet can last in particular until the end of the bruise.

In particular, it should be 4 to 6 times larger than on the first page. In this way, a suitably high field strength is induced by the smaller plate when igniting the lamp when igniting. In particular, each plate 45, 46 should be as close as possible to the discharge volume of the discharge vessel. This is ensured by the fact that a small portion 47 of the plate reaches from the pinch to at least the exit point of the electrode shaft. The plate 45, 46 may even be angled outwardly at its short end in the region of the small part 47, so that it is guided along the discharge volume over a certain distance d.

On the second side with the second pinch 37, the plate 46 anchored there is approximately four times as long axially as on the first pinch. The tile is according to FIG. 11 pressed by a tab on the broad side of the clip to the pinch. The plate 45, 46 may be made of stainless steel, Mo, or Ni, or of another sheet, the temperatures up to about 600 ° C well tolerated.

FIG. 13 shows an embodiment of a cantilever high-pressure discharge lamp 50. For this purpose, a clip 51 is used, which is crimped on a narrow side 52 of the single pinch 37 of the discharge vessel 53. For the crushing 37 is preferably designed I-shaped or double-T-shaped. From the narrow side 52 of a base body 63 of the clip 51 extends a short distance (distance D1) on the broad side 54. Preferably, a metal strip 55 of the clip, which is parallel to the axis covers the area of the first, the clip adjacent power supply 57 or film from, wherein a first tongue 58 with a width B1 extends to the edge of the discharge volume. Arranged transversely to the strip is a thin web 60 which ends at a second tongue 59, which sits in the discharge volume in the region of the entry of the second electrode system 61. This second tongue 59 usually has the same or even a smaller width as the first tongue, or even a greater width B2 than the first tongue as shown here. It is essential that an asymmetry of the respectively induced on the associated electrode electric field is generated here. The decisive factor in the case of the first electrode, the surface of the metal strip 55 plus first tongue 58, which act together as the first functional part, and in the case of the second electrode, the second tongue 59 alone, which acts as a second functional part. Specifically, the base body of the clip is preferably realized only by two yokes 64, which connect the metal strips 55 on both sides of the pinch 37 together. The base body can also be designed differently.

1. 1. Hochdruckentladungslampe mit kapazitiver Zündhilfe, mit einem Entladungsgefäß, das in einem Außenkolben untergebracht ist, wobei das Entladungsgefäß mindestens ein Ende mit einer Abdichtung aufweist, in der ein Elektrodensystem befestigt ist, wobei ein Gestell das Entladungsgefäß in dem Außenkolben haltert, dadurch gekennzeichnet, dass eine Zündhilfe, die zwei funktionelle Teile aufweist, auf der Abdichtung befestigt ist,
2. 2. Hochdruckentladungslampe nach Anspruch 1, dadurch gekennzeichnet, dass das Entladungsgefäß zwei Enden besitzt, wobei jeweils eines der beiden Zündhilfsteile auf einer Abdichtung sitzt, und wobei die beiden Zündhilfsteile über eine elektrische Leitung, insbesondere einen Draht, miteinander verbunden sind.
3. 3. Hochdruckentladungslampe nach Anspruch 2, dadurch gekennzeichnet, dass die Zündhilfe eine symmetrische Wicklung auf beiden Abdichtungen ist, insbesondere ein bis vier Wicklungen.
4. 4. Hochdruckentladungslampe nach Anspruch 2, dadurch gekennzeichnet, dass die Zündhilfe eine asymmetrische Wicklung auf beiden Abdichtungen ist, insbesondere in einem Verhältnis von 2:1 bis 4:1 als Windungszahl aufgeteilt.
5. 5. Hochdruckentladungslampe nach Anspruch 2, dadurch gekennzeichnet, dass die Zündhilfe je ein Folienstreifen auf den Enden des Entladungsgefäßes ist.
6. 6. Hochdruckentladungslampe nach Anspruch 2, dadurch gekennzeichnet, dass die Zündhilfe ein Clip auf den Abdichtungen ist, insbesondere symmetrisch gestaltet oder asymmetrisch gestaltet, bevorzugt mit einer unterschiedlichen Breite des Clips.
7. 7. Hochdruckentladungslampe nach Anspruch 1, dadurch gekennzeichnet, dass die Zündhilfe ein Federblechteil ist.
8. 8. Hochdruckentladungslampe nach Anspruch 1, dadurch gekennzeichnet, dass das Entladungsgefäß einseitig abgedichtet ist, wobei die Abdichtung eine Quetschung ist, und wobei die Zündhilfe zwei Zungen aufweist, die über einen Steg miteinander verbunden sind, wobei insbesondere die beiden Zungen im Bereich der Quetschung angeordnet sind und insbesondere die funktionellen Teile asymmetrische Flächen aufweisen, nämlich ein erstes funktionelles Teil eine erste Zunge plus ein Basisteil, und ein zweites funktionelles Teil nur eine zweite Zunge.
9. 9. Hochdruckentladungslampe nach Anspruch 1, dadurch gekennzeichnet, dass das Entladungsgefäß aus Quarzglas ist und eine Metallhalogenidfüllung aufweist, die im wesentlichen frei von Na ist.

Essential features of the invention in the form of a numbered list are:

1. A high-pressure discharge lamp with capacitive starting aid, comprising a discharge vessel accommodated in an outer bulb, the discharge vessel having at least one end with a seal in which an electrode system is mounted, a frame supporting the discharge vessel in the outer bulb, characterized in that a starting aid having two functional parts to which the seal is attached,
2. 2. High-pressure discharge lamp according to claim 1, characterized in that the discharge vessel has two ends, wherein each one of the two Zündhilfsteile sits on a seal, and wherein the two Zündhilfsteile via an electrical line, in particular a wire, are interconnected.
3. 3. High-pressure discharge lamp according to claim 2, characterized in that the starting aid is a symmetrical winding on both seals, in particular one to four windings.
4. 4. High-pressure discharge lamp according to claim 2, characterized in that the starting aid is an asymmetric winding on both seals, in particular in a ratio of 2: 1 to 4: 1 divided as a number of turns.
5. 5. High-pressure discharge lamp according to claim 2, characterized in that the starting aid is ever a foil strip on the ends of the discharge vessel.
6. 6. High-pressure discharge lamp according to claim 2, characterized in that the ignition aid is a clip on the seals, in particular designed symmetrically or asymmetrically shaped, preferably with a different width of the clip.
7. 7. High-pressure discharge lamp according to claim 1, characterized in that the ignition aid is a spring plate part.
8. 8. High-pressure discharge lamp according to claim 1, characterized in that the discharge vessel is sealed on one side, wherein the seal is a pinch, and wherein the ignition aid has two tongues which are interconnected via a web, wherein in particular the two tongues arranged in the region of the pinch and in particular the functional parts have asymmetric surfaces, namely a first functional part a first tongue plus a base part, and a second functional part only a second tongue.
9. 9. High-pressure discharge lamp according to claim 1, characterized in that the discharge vessel is made of quartz glass and has a metal halide, which is substantially free of Na.

Claims (9)

High-pressure discharge lamp with capacitive starting aid, with a discharge vessel, which is accommodated in an outer bulb, wherein the discharge vessel has at least one end with a seal, in which an electrode system is fixed, wherein a frame supports the discharge vessel in the outer bulb, characterized in that a starting aid having two functional parts, is attached to the seal, High-pressure discharge lamp according to claim 1, characterized in that the discharge vessel has two ends, wherein each one of the two Zündhilfsteile sitting on a seal, and wherein the two Zündhilfsteile via an electrical line, in particular a wire, are interconnected. High-pressure discharge lamp according to claim 2, characterized in that the starting aid is a symmetrical winding on both seals, in particular one to four windings. High-pressure discharge lamp according to claim 2, characterized in that the starting aid is an asymmetric winding on both seals, in particular in a ratio of 2: 1 to 4: 1 divided as a number of turns. High-pressure discharge lamp according to claim 2, characterized in that the ignition aid is ever a foil strip on the ends of the discharge vessel. High-pressure discharge lamp according to claim 2, characterized in that the ignition aid is a clip on the seals, in particular designed symmetrically or asymmetrically shaped, preferably with a different width of the clip. High-pressure discharge lamp according to claim 1, characterized in that the ignition aid is a Federblechteil. High-pressure discharge lamp according to claim 1, characterized in that the discharge vessel is sealed on one side, wherein the seal is a pinch, and wherein the ignition aid has two tongues which are interconnected via a web. High-pressure discharge lamp according to claim 1, characterized in that the discharge vessel is made of quartz glass and has a metal halide, which is substantially free of Na.

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