EP0735568B1 - Low pressure mercury vapour discharge lamp - Google Patents

Description

The invention relates to a low-pressure mercury discharge lamp the preamble of claim 1. The mercury is either introduced into the lamp in liquid or solid form, in particular as amalgam. The amalgam lamps can be of different designs to have. For example, it can involve conventional fluorescent lamps act as a rod-shaped discharge vessel, or also compact fluorescent lamps with bent tubes, e.g. B. U-shaped or H-shaped, or spherical, electrodeless, low-pressure discharge lamps.

Such compact fluorescent lamps are for example from EP-A 373 567 known. The amalgam is introduced into the pump tube, the discharge-side opening is slightly narrowed. Alternatively, the pump tube themselves have a narrowing, see e.g. EP-A 161 725.

A spherical electrodeless low-pressure discharge lamp is for example known from EP-B 119 666. The main amalgam is in one introduced like a hollow. A variant of this lamp is in "News from the technology" No. 1/86 described, the main amalgam is in a closed pump stem, the top of which is one has slight asymmetrical narrowing. This is said to be avoided that the amalgam gets into the flask and the phosphor layer or damage other parts, or not the corresponding working temperature reached.

However, it is problematic that the amalgam get into the discharge vessel can if the opening as in the previously described prior art is relatively wide, so that safe pumping and filling is guaranteed. On the other hand previously the opening of the pump tube was narrowed to a capillary, to safely prevent the amalgam from escaping (see DD-DWP 70 661). With today's modern high-performance production lines pumping and filling would be too time-consuming. Such capillaries would have a diameter of the order of 0.5 mm have.

From Patent Abstracts of Japan, Vol. 10, No. 69, relates to JP-A-60.218757 it is known that the amalgam in the pump tube is fitted into it Nickel sleeve and a narrowing in the middle of the pump tube to hold.

From the Patent Abstracts of Japan, Vol. 12, No. 184, relates to JP-A-62.287546, it is known to use two pump tubes, one of which for filling is used while the other contains an amalgam, the discharge side a massive bar-like lock is upstream.

It is an object of the invention to provide a generic lamp enables quick and safe pumping and filling, but with the other hand it is ensured that no amalgam can escape into the discharge space can.

This object is achieved by the characterizing features of claim 1 solved. Particularly preferred embodiments can be found in the subclaims.

The present invention adopts the basic technologies of EP-A 581 160 and EP-A 228 005, the contents of which are hereby expressly stated is referenced. The latter describes a storage element for dosing and introducing mercury as liquid metal or liquid or solid amalgam, the storage element being formed by a porous pressed body, especially of iron. The former describes a fixed one Amalgam body or amalgam former body with a ferromagnetic Component.

It has now been shown that these basic technologies with a suitable modification provide an ideal basis for a compromise between the to both extremes, which were mentioned above as prior art to reach.

A quick pumping and filling with safe retention of the Mercury is used in a low-pressure mercury discharge lamp a pump tube attached to the discharge vessel, the outer end of which is melted and the inner discharge end is open, thereby achieved that the mercury (Hg) metallic or as amalgam (im hereinafter generally referred to as Hg body) in the pump tube is. The discharge-side opening of the pump tube is narrowed. Together with the Hg body, a solid is introduced into the pump tube so that it the opening of the pump tube as a plug for the mercury body partially closes. An arrangement in which the Solids have a different cross-section than the pump opening in every orientation owns. In this way, the effective opening for the Mercury diffusion between pump tube and discharge vessel is very large held without, however, the solid body or the mercury body in the discharge vessel can penetrate. At the same time, the special shape of the Narrowing of mercury diffusion between the pump tube and the discharge space.

The solid body can preferably be made of ferromagnetic material (especially iron) so that it turns on during the pumping and filling process can be held anywhere in the pump nozzle by means of a magnet can. This has proven to be even more economical than that Proven use of a ferromagnetic amalgam (former) body, which, however, is not excluded.

The solid body can be spherical, ellipsoidal or irregular be designed, the pump opening being a different one Shape, in particular an asymmetrical shape.

In a preferred embodiment, the solid forms at least approximately a circular cylinder (e.g. rounded exactly or in tablet form or slightly elliptically distorted) with assigned diameter and assigned height. Good results can be achieved if the diameter of the solid between 50 and 90%, in particular 60 and 80%, of Corresponds to the inner diameter of the pump tube, so that there is enough space between Solid and pump tube wall remains. In particular, it should the height of the solid be smaller than its diameter, in particular it should correspond to about 50 to 80% of the diameter of the solid. This According to experience, dimension is particularly favorable for a smooth Function of the filling process with regard to a randomly changing Orientation of the solid in the pump tube. Tilting or damage is minimized. The solid can flow freely in the pump tube rotate.

The solid forms, as it were, a stopper that merely serves as the pump opening incompletely sealed. To ensure this, solids need to be and pump opening have a different shape. In a Embodiment may open the pump tube with a circular solid (Ball or circular cylinder) should not be circular, but should define a largest longitudinal and transverse dimension, with the longitudinal dimension is larger than the transverse dimension.

Accordingly, in principle it is also possible in reverse, a non-circular one Solid body (ellipsoid, cube or cuboid) with a circular Combine opening.

As a reference for the geometric dimensions to be selected serve in the case of a circular cylindrical solid that either the largest transverse dimension larger, in particular 0.1 to 0.4 mm larger than the height of the solid is or that the largest longitudinal dimension is larger than the diameter of the solid. Advantageous if only one is observed of these conditions is that the narrowing of the opening extends beyond a certain Height (typically 1 to 2 mm) extends. Because of the different Even in this case, the solid can never have the shape of the opening Close the opening completely. Ideally, both conditions are met at the same time.

The largest transverse dimension of the opening is particularly advantageously smaller than the diameter of the solid.

In the case of a circular solid, the opening can preferably be an elliptical or have a crescent-like cross-section. It can also be similar to one "8" or crescent-shaped. It can be any asymmetrical Have shape. In principle, it does not matter whether the opening is attached centrally or decentrally with respect to the pump tube, however a decentralized, especially close to the edge, cheaper opening because it leaves more design options for the opening and makes it easier allows the narrowing to be greater in both the longitudinal and transverse directions than the height and diameter of the solid. The reason is that because of the close wall of the pump tube, the opening and the solid do not get the best possible coverage.

In the case of an elliptical narrowing, at least one dimension (transverse or Longitudinal dimension) larger (by approx. 0.1 to 0.3 mm) than the height or the Diameter of the solid. The optimal range is one Axis ratio of the narrowing between 1.1 and 2.0, the (shorter) Cross dimension should be greater than 1.0 mm so as not to impede diffusion.

In another embodiment, the circular opening of the pump tube leave. However, the effective cross section is narrowed by the fact that a piece of wire or similar spanned the opening transversely and thus as a barrier works.

Another option is to use a glass foam plug, which is introduced into the circular cylindrical opening of the pump tube. In a first embodiment, the foam is at least partially open-pored, to allow diffusion of mercury into the discharge vessel. In a second embodiment, the foam can also be a contain a high proportion of closed pores, but the opening does not is completely closed by the glass foam plug, but one The remaining opening for the diffusion of mercury remains. Finally are Mixed forms of both embodiments are also possible.

In a first particularly preferred embodiment, the solid not only as a plug, but also as a sponge for the mercury body Act. In this case, as is known per se, the solid forms a porous one Matrix as a basic body, which contains liquid mercury or contains liquid amalgam. In addition to that, one for the formation of the Amalgam's cheaper amalgam partner in liquid or solid form behind be introduced into the solid.

In a second particularly preferred embodiment, amalgam can also be used, which is solid at room temperature. In this case the solid is filled into the pump tube first and only then Amalgam, so that the latter with respect to the discharge-side pump opening lies behind the solid. In this case, the nature of the solid plays no role, but still its geometric dimensions.

Figur 1

eine schematisierte Darstellung eines Entladungsgefäßes

Figur 2

eine vergrößerte Darstellung der Quetschdichtung mit dem Pumpstengel

Figur 3

eine Draufsicht auf die Pumpöffnung mit schematisierter Darstellung des Festkörpers in drei Varianten

Figur 4

eine vergrößerte Darstellung der Quetschdichtung mit dem Pumpstengel bei einer zweiten Ausführungsform

Figur 5

eine Draufsicht auf die Pumpöffnung des zweiten Ausführungsbeispiels

Figur 6

eine vergrößerte Darstellung der Quetschdichtung mit dem Pumpstengel bei einer dritten Ausführungsform

Figur 7

zwei weitere Ausführungsformen der Pumpöffnung

Figur 8

eine weitere Ausführungsform der verengten Pumpöffnung

Figur 9

zwei weitere Ausführungsformen der Pumpöffnung

The invention is explained in more detail below with the aid of several exemplary embodiments. It shows

Figure 1

a schematic representation of a discharge vessel

Figure 2

an enlarged view of the pinch seal with the pump stem

Figure 3

a plan view of the pump opening with a schematic representation of the solid in three variants

Figure 4

an enlarged view of the pinch seal with the pump stem in a second embodiment

Figure 5

a plan view of the pump opening of the second embodiment

Figure 6

an enlarged view of the pinch seal with the pump stem in a third embodiment

Figure 7

two further embodiments of the pump opening

Figure 8

a further embodiment of the narrowed pump opening

Figure 9

two further embodiments of the pump opening

Figure 1 shows a discharge vessel 1 for a compact fluorescent lamp, the Is bent into a U-shape. It has two ends 2a, 2b in which electrodes (not visible) are squeezed. One end 2a is in the middle with a pump tube 3 equipped, the discharge-side narrowed end 4 in the discharge vessel 1 protrudes while the distal circular end 5 is accessible from the outside. During the evacuation and filling with the help a pump connector 9 and a seal 9a are initially both pump ends 4, 5 open. A solid 6, which consists of iron, is through one Magnet 7 held in the middle of the pump nozzle 9. Behind it is a fluid one or solid amalgam (or liquid mercury) 8 into the pump tube brought in. After filling the discharge vessel with inert gas, the Magnet 7 removed so that the solid 6 and the amalgam 8 (or Hg) slide to the discharge end 4 of the pump tube. Then will the end of the pump tube remote from the discharge was shortened and melted.

FIG. 2 shows an enlarged illustration of the squeezing area 2a. The Discharge-side pump tube end 4 is narrowed, so that the solid 6 Opening blocked despite orientation oriented and that Amalgam 8 prevents it from escaping into the discharge space. That far from discharge Pump end 5 'has melted.

Figure 3a shows that the solid body 6 shown here transversely and the pump opening 4 are coordinated. The pump tube 3 has an inner diameter of about 2.5 mm and a wall thickness of 0.75 mm. The Pump opening 4 is arranged elliptically and centrally with respect to the pump tube 3. The largest longitudinal dimension is about 1.70 mm (corresponding to the Double the major semiaxis), the largest transverse dimension (accordingly double the small semiaxis) is about 1.4 mm. The solid is a circular cylinder with a diameter of 1.8 mm and a height of 1.2 mm. The Formation of the opening extends over a height h of approximately 1.6 mm (Fig. 2). Due to the different shape of the opening, the solid can Do not close the opening even if it is lying crosswise.

As Figure 3b and 3c shows, however, it is also possible to have other dimensions to choose. Fig. 3b shows the case mirrored to Fig. 3a, that the longitudinal dimension the opening is larger than the diameter of the solid. Figure 3c shows the theoretical (because of the unimpeded diffusion) best case that the largest longitudinal or transverse dimension of the opening are larger than the diameter or the height of the solid. Indeed this opening is very difficult to make. A plasma torch is advantageous for this used.

Such regular pump openings are produced by two opposite gas burners with different intensities are directed towards the originally circular opening of the pump tube. The melted glass contracts and forms a non-circular (here elliptical) opening.

In a second embodiment (FIGS. 4 and 5), the pump opening is 10 decentrally arranged and asymmetrically shaped. It is partial again blocked by the solid body 11, which here is a porous compact with a circular cylindrical Shape is. It contains liquid mercury in its matrix. Fig. 5 shows that the pump opening 10 has a crescent shape. Of the The inner diameter of the pump tube is 2.5 mm. The largest longitudinal dimension the opening is 2.5 mm, the largest transverse dimension is 1.5 mm. The compact has a diameter of 1.8 mm and a height of 1.2 mm.

Such irregular pump openings are produced by a gas or plasma torch that is one-sided on the area of the original circular opening is directed to that of the later crescent Opening is opposite.

In a third exemplary embodiment (FIG. 6) there is 15 behind the solid body a body 16 made of solid amalgam or solid amalgam partner. As is known per se, it consists of a bismuth / indium alloy in a ratio of approx. 2: 1 or a bismuth / lead / tin alloy. Other examples are alloys made of Bi-Pb or Bi-Pb-In or Bi-Pb-Ag. In addition, they each contain a few percent mercury. It with regard to the amalgams used, for example, on EP-A 373 567, EP-A 327 346, DE-OS 35 10 156, EP-A 157 440 and US-A 4 093 889 referenced.

FIG. 7a schematically shows the top view of a pump opening 20 with a crescent shape Shape, in Figure 7b, is an "8" like shape of the pump opening 21 shown. The crosspiece 22 of the "8" is made of process engineering Reasons not fully trained.

FIG. 8 shows the top view of a pump opening 25 with a circular shape, wherein a piece of wire 26 transversely narrows the opening 25.

Figure 9a shows the top view of a pump opening 30 with a circular Shape, with a glass foam plug 31 completely closes the opening 30. The foam consists of open pores. The thickness of the plug is, for example, on the order of about 2 to 10 mm.

Figure 9b shows the top view of a pump opening 30 with a circular Shape, with a glass foam plug 35 partially opening (30%) closes. The remaining opening 40 allows sufficient diffusion even if the glass foam is mostly closed Pores.

For the production of such a glass foam plug, for example Water glass used, which the water suddenly by heating is driven out. The escaping water vapor causes foaming of the glass, whereby pores are formed.

Claims (20)

1. Low-pressure mercury discharge lamp with a discharge vessel (1), a pumping tube (3) being attached to the discharge vessel (1), the outer end (5') of which pumping tube (3) is sealed by melting and the inner end (4) of which is open, mercury (Hg) being introduced, in metal form or as an amalgam, in the pumping tube (3), the opening (4a) of the pumping tube (3), on the discharge side, being constricted, and, together with the mercury, a solid body (6;11;15) being incorporated in the pumping tube, characterized in that the solid body (6; 11; 15) is incorporated in the pumping tube in such a way that it partly closes off the opening (4a) of the pumping tube (3) on the discharge side.
2. Low-pressure mercury discharge lamp according to Claim 1, characterized in that the solid body (6; 11; 15) has, in every orientation, a different cross-section from the opening (4a) of the pumping tube (3) on the discharge side.
3. Low-pressure mercury discharge lamp according to Claim 1, characterized in that the solid body (6; 11; 15) forms at least approximately a circular cylinder with assigned diameter and assigned height.
4. Low-pressure mercury discharge lamp according to Claim 3, characterized in that the diameter of the solid body (6; 11; 15) corresponds to between 50 and 90%, in particular 60 and 80%, of the internal diameter of the opening (4a) of the pumping tube (3) on the discharge side.
5. Low-pressure mercury discharge lamp according to Claim 3, characterized in that the height of the solid body (6; 11; 15) is smaller than its diameter, the height in particular corresponding to about 50-80% of the diameter of the solid body (6; 11; 15).
6. Low-pressure mercury discharge lamp according to Claim 3, characterized in that the opening (4a) of the pumping tube (3) on the discharge side defines a largest length dimension and transverse dimension, the length dimension being larger than the transverse dimension, in particular by a factor of 1.1 to 2.0.
7. Low-pressure mercury discharge lamp according to Claim 6, characterized in that the largest transverse dimension is larger, in particular larger by 0.1 to 0.4 mm, than the height of the solid body (6; 11; 15).
8. Low-pressure mercury discharge lamp according to Claim 6, characterized in that the largest length dimension is larger than the diameter of the solid body (6; 11; 15).
9. Low-pressure mercury discharge lamp according to Claim 6, characterized in that the largest transverse dimension is smaller than the diameter of the solid body (6; 11; 15).
10. Low-pressure mercury discharge lamp according to Claim 1, characterized in that the opening (4a) of the pumping tube (3) on the discharge side is of a similar shape to an ellipse, half-moon, crescent or "8".
11. Low-pressure mercury discharge lamp according to Claim 1, characterized in that the solid body (6; 11; 15) is ferromagnetic.
12. Low-pressure mercury discharge lamp according to Claim 1, characterized in that the solid body (6; 11; 15) has a porous matrix as its base.
13. Low-pressure mercury discharge lamp according to Claim 1, characterized in that the mercury or its amalgam is liquid and, in particular, is incorporated in the matrix.
14. Low-pressure mercury discharge lamp according to Claim 1, characterized in that the amalgam is solid at room temperature and, relative to the opening (4a) of the pumping tube (3) on the discharge side, is arranged behind the solid body (6; 11; 15).
15. Low-pressure mercury discharge lamp according to Claim 1, characterized in that the pumping tube (3) is arranged at one end (2a) of the discharge vessel (1).
16. Low-pressure mercury discharge lamp according to Claim 15, characterized in that the end (2a) is closed off by means of a pinch.
17. Low-pressure mercury discharge lamp according to Claim 1, characterized in that the opening (4a) of the pumping tube (3) on the discharge s.ide is constricted by means of a transverse wire piece (26).
18. Low-pressure mercury discharge lamp according to Claim 1, characterized in that the pumping tube (3) is closed off by means of a glass foam stopper (31; 35), the constricted opening (30) being formed by at least some of the pores of the glass foam stopper (31) being open and/or by a free residual opening (40) remaining.
19. Low-pressure mercury discharge lamp according to Claim 1, characterized in that the opening (10) of the pumping tube (3) is arranged off-centre.
20. Method for producing a fluorescent lamp, characterized in that a pumping tube (3) with a constricted opening (4a) is produced and is sealed into an opening of the discharge vessel (1), a solid body (6; 11; 15) and, optionally, a further body are subsequently introduced into the pumping socket (9), the discharge space is subsequently evacuated via the pumping socket (9) and the pumping tube (3) connected thereto, the solid body (6; 11; 15) being held in the pumping socket (9), and an inert gas at low pressure is subsequently introduced into the discharge vessel (1), the solid body (6; 11; 15) and, optionally, the further body are subsequently introduced into the pumping tube (3) and, finally, the pumping tube (3) is closed off.

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