WO2012084439A1 - Low-pressure gas discharge lamp body, low-pressure gas discharge lamp, and method for producing a low-pressure gas discharge lamp body - Google Patents

Abstract

A low-pressure gas discharge lamp body (900) is described in various embodiments. The low-pressure gas discharge lamp body (900) can comprise a first tube segment (300) and a second tube segment (300), wherein the inner faces of the tube segments (300) are coated with a protective layer for the tube segment (302), wherein at least one tube segment end (306) of the first tube segment (300) and a tube segment end (306) of the second tube segment (300) are melted together at the end faces, wherein an end region (310) of the tube segment end (306) of the first tube segment (300) and an end region (310) of the tube segment end (306) of the second tube segment (300), which is melted to the tube segment end (306) of the first tube segment (300), are free of the protective layer for the tube segment (302).

Description

description

Low-pressure gas-discharge lamp body, low-pressure gas discharge lamp, and method for producing a

Low-pressure gas discharge lamp body

The invention relates to a low-pressure gas discharge lamp body, a low-pressure gas discharge lamp, and a

Method for producing a low-pressure gas discharge lamp body.

Desirable is often a low-pressure gas discharge lamp in flat geometry or in any spatial geometry that fills the largest possible area. In doing so, the manufacture of the low pressure gas discharge lamp should be as simple as possible and allow an inner coating for UV conversion (i.e., with a phosphor) and protection of the glass (usually Alon-C) of the low pressure gas discharge lamp. The coating should remain intact during the manufacturing process if possible.

Conventional flat lamps or lamps of any spatial geometry, which are formed as a low-pressure gas discharge lamp, can not be manufactured with an intact coating to protect the glass of Alon-C.

In various embodiments, a low pressure gas discharge lamp body is provided. The low pressure gas discharge lamp body may include a first one

Pipe segment and a second pipe segment; the

Inner surface of the pipe segments is coated with a pipe segment protective layer; where at least one

Pipe segment end of the first pipe segment with a

Pipe segment end of the second pipe segment frontally

fused together; an end portion of the

Pipe segment end of the first pipe segment and an end portion of the pipe segment end of the second pipe segment, which with the tube segment end of the first tube segment is fused, is free of the tube segment protective layer.

Furthermore, a method for producing a

Low-pressure gas discharge lamp body, the method may include: coating the inner surface of a first pipe segment with a pipe segment protective layer; one

Removing the pipe segment protective layer in an end region of the pipe segment end of the first pipe segment; a coating of the inner surface of a second tube segment with a

 Pipe segment protective layer; removing the pipe segment protection layer in an end region of the pipe segment end of the second pipe segment; and a front-side fusion of the pipe segment end of the first pipe segment, in whose

End region, the pipe segment protective layer has been removed, with the pipe segment end of the second pipe segment, in the end region of the pipe segment protective layer has been removed.

Thus, in the production of the low-pressure gas discharge lamp body, several are initially apparent

physically separated pipe segments with a

Tube segment protective layer and optionally additionally coated with a phosphor layer, in other words beschlämmt, and then in the ends of the pipe segments to be fused together, end portions of the pipe segment protective layer and optionally the

Luminescent layer freed and then these become

"Cleaned" pipe segment ends frontally (for example, over its entire cross-section) attached to each other and fused the front side fused together

Pipe segments form a low-pressure gas discharge lamp body with a common continuous discharge space formed by the fused pipe segments in the low-pressure gas discharge lamp to be formed.

By the frontal application and merging of

Pipe segment ends in particular over the entire cross section the tube segment ends can be avoided, a narrowing of the discharge space at the point of fusion substantially. Thus, an improvement in the electrical properties of the low-pressure gas discharge lamp to be formed can be ensured since there is essentially no bottleneck of the

 Discharge space is formed at the merger. As a result, good ignition properties of the gas discharge can be ensured. An occurring during operation

Firing voltage can, for example, compared to a

Low-pressure gas discharge lamp with a reduced diameter of the discharge space to be reduced at the point of fusion.

By means of the pipe segment protection layer, it is possible in various embodiments, for example, the

To reduce mercury (Hg) concentration in the low-pressure gas discharge lamp and thereby, for example, the European Union environmental directives too

fulfill . Removing the pipe segment protective layer from the

 Pipe segment ends are provided, for example, because bonding of the material of the pipe segment, for example glass, with the material of the pipe segment protective layer can lead to poor, unstable fusions. This comes, for example, that in the presence of a

Pipe segment protective layer, the material of the pipe segment, such as glass, bulges when heated to the outside, so that when composing coated areas with each other

be contacted. If no pipe segment protective layer is present, the pipe segment, for example the glass, bulges inwards when heated (even if a glass segment)

Phosphor coating on the pipe segment is present), so that certainly the two pipe segment ends, for example, glass with glass, are fused together, resulting in good gas-tight connections. Cause for the

different curvature are different melting points of the pipe segment protective layer or the Phosphor coating in relation to the melting point of the glass. Thus, in particular, the melting point of

commonly used pipe segment protective layers larger than that of the glass.

Removing the pipe segment protective layer from the

Pipe segment ends can be done in different ways, for example by wiping. This is preferred

Wipe out as long as the pipe segment protection layer is still wet.

In various embodiments, the

Phosphor layer have one or more phosphors. A luminescent substance is a luminescent chemical

A compound that emits visible light when irradiated with other types of radiation (e.g., UV).

To the two pipe segment ends safe and gas-tight

For example, glass with glass can be melted together with one another

 Phosphor layer are removed before fitting of the pipe segment ends. In particular, the

 Luminescent layer as far as the pipe segment protective layer are removed, for example, less far, as it generally affects the bonding behavior less.

In this way, a very simple and inexpensive method is provided and thus a very low-cost low-pressure gas discharge lamp body, whereby it is ensured that no breakages occur in the inner coating and thus the inner coating with the

Pipe segment protective layer and optionally in addition to the phosphor layer remains intact. In particular, at joints between different pipe segments substantially no or only areas of low expansion remain, which are not coated with a pipe segment protective layer. Since the pipe segment protective layer remains substantially intact, which may be configured, for example

Diffusion of mercury contained in the low-pressure gas discharge lamp body into the pipe segment material, the filling of the low-pressure gas discharge lamp body and thus the tube segments with a mercury gas, the mercury consumption is reduced during operation of the low-pressure gas discharge lamp. In various embodiments, the pipe segment protective layer may comprise or consist of alumina, for example Alon-C. Alon-C can in various embodiments, a crystalline, very finely disperse

Gamma-alumina (gamma-Al 2 O 3) may be understood, for example, with an average grain diameter of about 10 nm. Alternatively, mixed layers of gamma-Al 2 O 3 and alpha-Al 2 O 3 may also be provided for the pipe segment protective layer. In other embodiments, the pipe segment protective layer may include or may consist of yttrium acetate that is converted to yttria when heated.

In various embodiments may / may the first

Pipe segment and / or the second pipe segment glass,

For example, silicate glass, in particular soda lime glass, or quartz glass, have or consist of.

In various embodiments, it may be contemplated that a pipe segment or both pipe segments to be joined together prior to fusing (and before or after coating the interior of the pipe segment or pipe segments with the pipe segment protective layer and

optionally with the phosphor layer). In various embodiments may or may

Tube segment or the pipe segments are bent after the brazing with the pipe segment protective layer and optionally with the phosphor layer and then to the

Pipe segment ends are fused together frontally. Thus, it is advantageously possible in this embodiment, initially unbent (in other words straight), but with the tube segment protective layer and possibly with the phosphor layer already beschlämmte tube segments (within certain limits) to bend such that no strong impairment of the coating with the phosphor and the protective layer material is caused. Serially produced coated straight pipe segments can thus be subsequently bent according to this embodiment and then one of the bent pipe segments with another curved (or unbent) pipe segment means

Fusion are connected to each other frontally. One advantage of this embodiment can be seen, inter alia, that the coating of straight pipe segments is the easiest and most uniform possible.

In various embodiments, the first pipe segment and / or the second pipe segment can / can thus be arranged after the

Coating but to be bent before merging.

In further embodiments, the first pipe segment and / or the second pipe segment may / may be bent before coating and thus before the end-side fusing. This allows any damage to the pipe segment protective layer and any possibly provided

Safely avoid phosphor layer. This is particularly advantageous for larger bending radii.

According to a development, the end of the

Pipe segment end of the first pipe segment and / or the

End region of the tube segment end of the second tube segment extend from the edge of the respective tube segment end to a maximum of 10 mm, for example a maximum of 5 mm, for example a maximum of 3 mm, for example a maximum of 1 mm, into the tube segment. Here, for example, between different

Pipe segment ends are distinguished. So can in the case the connection of a pipe segment end with a second

Pipe segment end or with an electrode holding a glass plate, the end portion of the pipe segment end extend in about 1 mm in the pipe segment. In the case of so-called rack melting of an electrode holding one

Electrode rack, in particular by means of so-called

Crushing technique, for example, 10 mm for the

Extension of the end portion of the pipe segment end may be provided.

According to another development can / can the first

Pipe segment and / or the second pipe segment may be formed according to an arbitrary shape, for example in a form that is (sufficiently) evenly with the

Protective layer or optionally in addition to the

 Limiting the phosphor layer, in other words coating, so that the light generation in the operation of the low-pressure gas discharge lamp with such a low-pressure gas discharge lamp body is high enough quality. Thus, for example, the first pipe segment and / or the second pipe segment may be formed in one of the following shapes: round, curved, U-shaped, angular,

polygonal, spiral. In principle, any number of initially separate and already beschlämmten pipe segments can be provided in various embodiments in the manner described above and by fusing corresponding ends of pipe segments of any different shape, a low-pressure gas discharge lamp of any shape and

Luminous characteristic can be provided.

In various embodiments, a low pressure gas discharge lamp is provided with a low pressure gas discharge lamp body as described above. The low-pressure gas discharge lamp may, in one embodiment, further comprise an electrode system for providing an operating voltage for the low-pressure gas discharge lamp. The low-pressure gas-discharge lamp body may be filled with a material which is adapted to emit ultraviolet radiation, for example

Mercury.

Embodiments of the invention are illustrated in the figures and are explained in more detail below.

Show it

1 shows a pipe segment according to an embodiment;

2 shows a pipe segment according to an embodiment; 3 shows a pipe segment according to an embodiment; 4 shows a pipe segment according to an embodiment; 5 shows a pipe segment according to an embodiment; 6 shows a pipe segment according to an embodiment;

FIG. 7 shows a pipe segment according to an exemplary embodiment;

8 shows a pipe segment according to an embodiment; FIG. 9 shows a low-pressure gas discharge lamp body according to an exemplary embodiment;

Figure 10 shows three U-shaped pipe segments according to a

Embodiment; and 11 shows a low-pressure gas discharge lamp body according to an exemplary embodiment, formed from the three U-shaped tube segments from FIG. 10.

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof and in which is by way of illustration specific

From embodiments are shown in which the invention can be practiced. In this regard will

Directional terminology such as "top", "bottom", "front", "back", "front", "rear", etc. used with reference to the orientation of the described figure (s). There

Components of embodiments in a number

different orientations can be positioned, the directional terminology is illustrative and is in no way limiting. It is understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. It should be understood that the features of the various exemplary embodiments described herein may be combined with each other unless specifically stated otherwise. The following detailed description is therefore not to be construed in a limiting sense, and the

Scope of the present invention is defined by the appended claims.

In the context of this description, the terms

"connected", "connected" and "coupled" used to describe both a direct and indirect connection, a direct or indirect connection and a direct or indirect coupling. In the figures, identical or similar elements are provided with identical reference numerals, as appropriate.

Fig.l shows a pipe segment 100 according to a

Embodiment. In various embodiments, the tube segment 100, and also the tube segments discussed below, is made of glass, such as quartz glass, although other suitable materials can be readily used. The tube segment 100 is a hollow body and forms the base, in other words a basic structural element, for a low-pressure gas discharge lamp body to be formed

Low pressure gas discharge lamp.

The tube segment 100 has one at its first

Pipe segment end 102 unbent course on, and at its second pipe segment end 104 a curved course.

Alternatively, a pipe segment in different

Embodiments at both pipe segment ends have a straight and thus unbent course or both

Pipe segment ends have a curved course (not shown in Fig.l). One possible implementation of a low pressure gas discharge lamp is the fluorescent lamp.

2 shows a pipe segment 200 according to a

Embodiment.

The pipe segment 200 has a straight and thus an initially unbent course. The tube segment 200 has three tube segment regions 202, 204, 206, wherein the

Pipe segment 200 at the transitions 208, 210 between the

Pipe segment regions 202, 204, 206 is bent so that the curved pipe segment 300 shown in Figure 3 is formed.

The tube segment 200 may be formed from a single prefabricated glass body or from a plurality of

separate prefabricated glass bodies, the front side (in this case, still uncoated) fused together are, for example, at the transitions 208, 210 and together form the tube segment 200.

It should be noted that the pipe segments in

various embodiments may have an arbitrary shape per se. However, the pipe segments should be shaped so that the respective pipe segment still sufficiently uniform (in other words, with a sufficient

uniform layer thickness) can be coated with a tube segment protective layer which will be explained in more detail below and, if appropriate, additionally with a phosphor layer, in other words, it can be sufficiently well-embedded. In various embodiments, the

Pipe segments may be formed, for example, according to one of the following shapes: round, curved, U-shaped, angular,

polygonal, and spiral.

4 to 8 show various other possible

Basic forms for a respective pipe segment according to

various embodiments, it should be noted that in alternative embodiments, the

Pipe segments may also have a different basic shape.

FIG. 5 shows an angle-shaped tube segment 500, wherein the tube segment 500 has an internal angle 502 α of approximately 90 °. However, the internal angle 502 α can be changed so that, for example, an internal angle 602 α of less than 90 °, for example in an angular range between approximately 45 ° to less than 90 °, for example in an angular range between approximately 60 ° to approximately 80 °, for example in FIG an angle range between about 65 ° to about 75 °, be provided. Such a pipe segment with an internal angle 602 α of less than 90 ° is shown in FIG. In an alternative embodiment, a tube segment 700 may also be formed spirally, as shown in Figure 7. Fig.8 shows another alternative Embodiment, wherein the pipe segment 800 is U-shaped, in other words, is formed as a U-bend.

Referring again to Fig. 3, a potting is performed for each frame segment provided for the low-pressure gas-discharge lamp body to be formed. It should be noted that in various embodiments basically any number of arbitrary

differently shaped pipe segments (for example, one or more forms, as shown in Figures 3 to Fig. 8)

are shown) can be combined with each other, and as will be explained in more detail below, each with

at least one pipe segment end can be fused with a pipe segment end of another pipe segment, wherein the two respective pipe segment ends are attached to one another via their respective complete cross sections.

In the following, using the tube segment 300 of FIG. 3, the processes provided before fusion with one or more other tube segments to form the low-pressure gas-discharge lamp body will be described

described in each case for each to be formed

Low-pressure gas discharge lamp body provided

Pipe segment are performed.

First, inner surface of the pipe segment 300 is potted. This means that the inner surface of the tube segment 300 is coated with a tube segment protective layer 302 and, if desired, a phosphor layer 304 on the

Pipe Segment Protection Layer 302. The Pipe Segment Protection Layer 302 may be a layer of one or more materials, which may be configured, for example

Diffusion of located in the low-pressure gas discharge lamp body located in the mercury mercury tube segment material to prevent. In various embodiments, the pipe segment protection layer 302 may be an Alon C layer 302. The layer thickness of the tube segment protective layer 302 depends on the design (such as internal volume, length, material) of the respective pipe segment 300 and should be chosen such that the pipe segment protective layer 302 formed without cracks or interruptions and the coating can be ensured sufficiently uniform over the inner surface of the pipe segment 300, so that for example, the mercury is not in the material of the tube segment,

For example, glass, diffused into it. Furthermore, the phosphor layer 304 may basically comprise any suitable phosphor, depending on the

desired luminous characteristic of the to be formed

 Low-pressure gas discharge lamp. For example, the

 Phosphor layer 304 for emitting radiation in a wavelength range of 300 nm to 400 nm one or more 2+

 Eu-doped phosphors have. In blue or

Cyan area would be e.g. the aluminates BAM

 (BaMgA110O17: Eu2 +), BAM: Mn [(Bal-x Srx) MgA110O17: Eu, Mn] and strontium aluminate: Eu (Sr4A114025: Eu2 +). In other

Exemplary embodiments, the phosphor layer 304

of course, depending on the desired wavelength range of the light to be emitted by the low-pressure gas discharge lamp during operation have other phosphors. The

Layer thickness of the phosphor layer 304 depends on the

Design (such as internal volume, length,

 Material) of the respective tube segment 300 and from the phosphor used and should be chosen such that the phosphor layer 304 without cracks or

Interruptions can be formed and the coating can be ensured sufficiently uniformly over the inner surface of the tube segment 300, so that the desired

Luminous characteristic can be ensured.

After completion of the impregnation and drying of the

Pipe segment protective layer 302 and phosphor layer 304 are end-to-end at one or more pipe segment ends 306, 308 that terminate with a pipe segment end of another pipe segment to be merged, in one or both

End portions 310, 312, the tube segment protective layer 302 and the phosphor layer 304 removed. For example, the respective end region 310, 312 in the tube segment interior

cleaned, generally cleaned by the pipe segment protection layer 302 and the phosphor layer 304. The edges of the tube segment ends 306, 308 may be chamfered if required by the shape of the low pressure gas discharge lamp body to be formed.

In various embodiments, each "cleaned" end portion 310, 312 of a pipe segment end 306, 308 may extend from the end edge of the respective one

Pipe segment end 306, 308 to a maximum of 10 mm, preferably a maximum of 5 mm, preferably a maximum of 3 mm, preferably a maximum of 1 mm, extend into the pipe segment 300 inside. It should be noted that in the case that only one pipe segment end 306, 308 of the two pipe segment ends 306, 308 with a

Pipe segment end of another pipe segment to be merged and the other pipe segment end 306, 308th

For example, to be provided with an electrode and to serve as the final gas-tight closure of the low-pressure gas discharge lamp body, the extent of the end portions 310,312 can be selected differently. It is provided in various embodiments, including the end portion 310, 312 of not intended for fusing with a pipe segment end of another pipe segment

Tube segment end 306, 308 of the tube segment protective layer 302 and the phosphor layer 304 to clean.

For forming one shown in FIG. 9, for example

Low-pressure gas-discharge lamp body 900, two are finished with the tube segment protective layer 302 and the phosphor layer 304 (in this case, pre-bent)

Pipe segments 300 as shown in Fig. 3 at their

respective first pipe segment end 306 over the complete cross section of the pipe segment diameter attached to each other and fused together at a fusing point 910. In this embodiment, the end portion 310 of the respective first tube segment end 306 is purged of the tube segment protective layer 302 and the phosphor layer 304, where the fusing point 910 is formed. Of the

 End portion 312 of the respective second tube segment end 308 is also purged of the tube segment protection layer 302 and the phosphor layer 304, since the two second tube segment ends 308 are provided for receiving an electrode system, for example one each

 Electrode having two power supply lines, for example, two power supply lines 902, 904 in one of the two second pipe segment ends 308 and two power supply lines 906, 908 in the other second pipe segment end 308. Furthermore, the two second pipe segment ends 308 after filling the

Low Pressure Gas Discharge Lamp Body 900 With One

suitable filling gas closed gas-tight. The fill gas may include, for example, mercury and argon, or other suitable gas components, as desired.

The thus formed low-pressure gas discharge lamp body 900 has a polygonal shape, which forms a common continuous discharge space in the low-pressure gas discharge lamp to be formed. Thus, a polygonal lamp can be formed as a flat lamp with a ring shape, wherein the tube segment protective layer 302 and also optionally the phosphor layer 304 in all

Pipe segments 300 of the low-pressure gas discharge lamp body 900 remains intact. The tube segment protective layer 302 and also optionally the phosphor layer 304 in the low-pressure gas discharge lamp body 900 are only in one place, the fusion point 910, in other words the

Approach point of the two pipe segments 300 damaged or

slightly interrupted, namely by the two

"Cleaned" end portions 310 of the first pipe segment ends 306th In the described embodiments, a

Improvement of the maintenance and the achievable luminous flux can be achieved for example for lamps in ring geometry compared to conventional lamps. Furthermore, reduced mercury consumption can be achieved because the tube segment protection layer 302 remains intact, as above

has been described. Also, the low-pressure gas discharge lamp body 900 can be manufactured in a simple and therefore very cost-effective manner.

Fig. 10 shows three pre-looped (in this case U-shaped pre-bent) tube segments 800, as shown in Fig.8, wherein the tube segment ends are chamfered. The bevelled pipe segment ends are attached to a star at two fusing points 1102, 1104 (see FIG. 11) and fused together at these fusing points 1102, 1104 over the entire cross section of the pipe segments 800, so that a low-pressure gas discharge lamp body 1100 is formed which forms a common continuous discharge space in the low-pressure gas discharge lamp to be formed. In this

Embodiment are both end portions of

Pipe segment ends of all three pipe segments 800 (illustratively both at the Ansetzstellen representing the Verschmelzungsstellen, as well as at the Elektrodeneinschmelzseiten of the pipe segment protective layer 302 and the phosphor layer 304 cleaned.

The two end portions of the Elektrodeneinschmelzseiten the pipe segments 800 are provided with an electrode system (not shown in Figure 11) in a conventional manner and these pipe segment ends are after filling the

Low-pressure gas discharge lamp body 1100 closed gas-tight with a suitable filling gas. The fill gas may include, for example, mercury and argon, or other suitable gas components, as desired. Thus, a central base and a - depending on the number of rays of the formed by the low pressure gas discharge lamp body 1100 star - relatively high area filling possible.

In the star-shaped low-pressure gas-discharge lamp body 1100, the discharge length is compared to one

circular low-pressure gas discharge lamp body

enlarged.

For forming a low pressure gas discharge lamp from the

Low-pressure gas discharge lamp body can still be connected to the corresponding desired drive circuits (for example in the form of an electronic ballast) and, if desired, the electrode terminal end of the low-pressure gas discharge lamp body in a

Lamp base to be installed.

In various embodiments, thus becomes a

Low-pressure gas discharge lamp is provided, which forms a flat light source with a high

Illuminance.

Claims

claims 1. Low-pressure gas-discharge lamp body (900),  comprising:  A first tube segment (300);  • a second tube segment (300);  • wherein the inner surface of the pipe segments (300) with  a pipe segment protection layer (302) is coated;  Wherein at least one pipe segment end (306, 308) of the first pipe segment (300) is connected to a pipe segment end (306, 308) of the second pipe segment (300)  are fused together frontally; • wherein an end portion (310) of the pipe segment end  (306) of the first pipe segment (300) and a End portion (310) of the tube segment end (306) of the second tube segment (300) fused to the tube segment end (306) of the first tube segment (300) is free of the tube segment protection layer (302). 2. Low-pressure gas discharge lamp body (900) according to  Claim 1,  wherein the inner surface of the tube segments (300) is additionally coated with a phosphor layer (304). 3. Low-pressure gas discharge lamp body (900) according to  Claim 1 or 2,  wherein the pipe segment protection layer (302) is adapted to prevent diffusion in the low pressure Gas Discharge Lamp Body (900) located  To prevent mercury in the pipe segment material. 4. Low-pressure gas discharge lamp body (900) according to  Claim 3, wherein the pipe segment protective layer (302) comprises or consists of alumina, preferably AlonC. Low-pressure gas discharge lamp body (900) according to one of claims 1 to 4, wherein the first pipe segment (300) and / or the second pipe segment (300) comprises or consists of glass, in particular silicate glass or quartz glass. Low-pressure gas discharge lamp body (900) according to one of claims 1 to 5, wherein the end region (310) of the tube segment end (306) of the first tube segment (300) and / or the end region (310) of the tube segment end (306) of the second Tube segment (300) extends from the edge of the respective tube segment end to a maximum of 10 mm, preferably not more than 5 mm, preferably not more than 3 mm, preferably not more than 1 mm, into the tube segment (300). Low-pressure gas discharge lamp body (900) according to one of claims 1 to 6, wherein the first pipe segment (300) and / or the second pipe segment (300) is formed according to one of the following shapes: round, curved, U-shaped, angular, polygonal, and spiral. Low-pressure gas discharge lamp, with a low-pressure gas discharge lamp body (900) according to one of claims 1 to 7. A low-pressure gas discharge lamp according to claim 8, further comprising:  • an electrode system (902, 904, 906, 908) for  Providing an operating voltage for the  Low pressure gas discharge lamp;  • wherein the low-pressure gas discharge lamp body (900) is filled with a material which is set up for the emission of ultraviolet radiation, preferably mercury. A method of manufacturing a low pressure gas discharge lamp body (900), the method comprising:  Coating the inner surface of a first  Pipe segment (300) having a pipe segment protection layer (302);  Removing the pipe segment protection layer (302) in an end region (310) of the pipe segment end (306) of the first pipe segment (300);  Coating the inner surface of a second  Pipe segment (300) having a pipe segment protection layer (302);  Removing the pipe segment protection layer (302) in an end region (310) of the pipe segment end (306) of the second pipe segment (300); and  • end-side fusion of the pipe segment end  (306) of the first pipe segment (300), in whose  End portion of the pipe segment protective layer (302) has been removed, with the tube segment end (306) of the second tube segment (300), in the end region (310), the tube segment protective layer (302) has been removed. 11. The method according to claim 10,  wherein the inner surface of the tube segments (300) is additionally coated with a phosphor layer (304). 12. The method according to claim 10 or 11,  wherein the first pipe segment (300) and / or the second pipe segment (300) is bent after coating but before the end-side fusing / is.