JPH08335453A - High pressure discharge lamp, manufacture of discharge tube body for high pressure discharge lamp, and manufacture of hollow tube body - Google Patents

Abstract

PURPOSE: To suppress devitrification by providing a film having a layer of acid nitride of an element on the inner wall face of a hollow tube body made of quartz glass in which inert gas and metal or metal halide are filled. CONSTITUTION: Tungsten electrodes 2 in the vicinity of the tip of which tungsten wires 5 are wound around are oppositely arranged inside a quartz glass tube body 1. An inner wall film 6 formed on the quartz glass tube body 1 is composed of two layers, an aluminum nitride layer 7 and an oxynitrided aluminum layer 8. In addition to the oxynitrided aluminum layer used as the inner wall film 6, a selected element from among tantalum, niobium, vanadium, chromium, titanium, zirconium, and lanthanum rare earth elements. It is desirable that Si, Mg, or Y is contained n the oxynitrided aluminum layer 8 of the inner wall film 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a high-pressure discharge lamp used for, for example, general lighting, a projection display, etc., and a discharge tube body for the high-pressure discharge lamp.
The present invention relates to a method for manufacturing a hollow tubular body.

[0002]

2. Description of the Related Art Conventionally, in the case of a metal halide discharge lamp, quartz glass (its composition is 100% is used as a discharge tube body.
Be close SiO ₂ is) is often used for.

However, when the cumulative time of lighting the lamp increases, the phenomenon that the optical transmittance decreases as a result of the quartz glass reacting with the high pressure vapor of the lamp enclosure is inevitable.
Also, the thermal conductivity of quartz glass is extremely low (about 0.9
W / mK), and the point that it is an obstacle to making the temperature distribution of the discharge tube uniform, and the like were the drawbacks of this quartz glass material.
Further, due to the non-uniform temperature distribution, thermal convection inside is promoted, resulting in a problem that the bending of the discharge arc becomes large.

Therefore, in order to solve these problems, measures have been proposed to provide a single-layer or multi-layer (multi-layer) protective film such as an aluminum oxide film or a tantalum oxide film on the inner surface of a quartz glass discharge tube. (For example, US Pat. No. 5,270,615.
Specification).

As another countermeasure, a ceramic discharge tube (Al ₂ O ₃ , AlN, YAG, spinel, etc.) is used to prevent devitrification due to high corrosion resistance and discharge due to high thermal conductivity. Attempts have been made to obtain effects such as uniform temperature distribution of the tubular body and improvement of heat load characteristics (for example, Japanese Patent Publication No. 5-87938).

[0006]

However, in the discharge tube body provided with the above-mentioned conventional measures to provide the protective film,
It has a drawback that the corrosion resistance of the oxide film at high temperature is not high enough for practical use.

That is, at a high temperature of about 1000 ° C. when the lamp is lit, a reaction between the rare earth halide, which is the lamp-encapsulating material, and the oxide film is observed. Was still insufficient.

Further, since the oxide film is used as the protective film, there is an insufficient point that the effect of soaking the discharge tube body cannot be obtained.

On the other hand, in the above-mentioned conventional ceramic discharge tube, there is a problem that the corrosion at the sealing portion of the ceramic tube and the end surface cannot be ignored, and the linear light transmittance due to the grain boundary reflection of the ceramic sintered body There is a problem in that the characteristics deviate from the ideal point light source due to the decrease, and the practical use of the ceramic discharge tube has been hindered.

Further, the discharge tube made of ceramics has a high cost as compared with the tube made of quartz glass, and further, a complicated manufacturing process is required.

By the way, the coefficient of linear expansion of quartz glass is characteristically small (0.54 ppm / ° C.), and aluminum oxide (7-8 ppm / ° C.) having a large coefficient of linear expansion is directly formed on it as a corrosion resistant film. However, the inner surface film is cracked or peeled off due to the dynamic mechanical stress generated by repeating high heat (about 1000 ° C. at the maximum) during lamp operation and room temperature when the lamp is off. There was also a problem that a durable structure was not realized. The above-mentioned US Pat. No. 5,270,615 attempts to solve the above problems by using an oxide film having a linear expansion coefficient of 1 to 4 ppm / ° C. as a base, but this is also still insufficient.

In consideration of the above-mentioned conventional problems, an object of the present invention is to provide a high pressure discharge lamp which can further suppress devitrification and has a longer life, and a discharge tube body for the high pressure discharge lamp. Is to provide a method for manufacturing the same.

Another object of the present invention is to provide a new method for manufacturing a hollow tube which can be used in, for example, a high pressure discharge lamp.

[0014]

According to the present invention of claim 1, an inner wall surface of a hollow tube made of quartz glass in which an inert gas and one or more kinds of metals or one or more kinds of metal halides are enclosed. With at least one layer of oxynitride of one or more elements
A high pressure discharge lamp comprising a film having more than one layer.

According to the present invention of claim 2, the one or more elements are aluminum, tantalum, niobium, vanadium, chromium,
It is a high pressure discharge lamp selected from titanium, zirconium, hafnium, yttrium, scandium, magnesium, silicon, and lanthanum rare earth elements.

The present invention of claim 3 is a high pressure discharge lamp, wherein the film includes at least a layer of aluminum oxynitride.

According to a fourth aspect of the present invention, there is provided a high pressure discharge lamp in which the layer of aluminum oxynitride contains Si, Mg or Y.

According to the present invention of claim 5, when the film is a plurality of layers, the plurality of layers are formed by using a nitride layer and the same element as that used for forming the nitride. High-pressure discharge lamp including at least a layer of oxynitride.

According to a sixth aspect of the present invention, the hollow tube body is a discharge tube body, and a high-pressure discharge lamp is provided with an electrode protruding inside the discharge tube body.

According to the present invention of claim 7, the hollow tube body is a discharge tube body, an electrode is not provided inside the discharge tube body, and the microwave is supplied from the outside of the discharge tube body. Alternatively, it is a high-pressure discharge lamp that is excited to emit light by high frequency.

The present invention of claim 8 is a high-pressure discharge lamp in which the quartz glass is exposed on the inner wall surface of the end of the hollow tube.

According to a ninth aspect of the present invention, a pair of elements containing the same element as the element of the film to be formed on the inner wall surface of the hollow tubular body is provided through the openings provided at both ends of the predetermined hollow tubular body. The sputter electrodes are inserted, and the pair of sputter electrodes are fixed so that the tips of the pair of sputter electrodes facing each other are separated by a predetermined distance, and a DC voltage is applied between the fixed sputter electrodes. Alternatively, it is a method for producing a hollow tube body in which a glow discharge is generated by applying a high frequency voltage and the film is formed on all or part of the inner wall surface of the hollow tube body by a sputtering method.

According to a tenth aspect of the present invention, there is provided a pair of sputter electrodes, each of which is provided with a target having a target element containing the same element as the element of the film to be formed on the inner wall surface of the predetermined hollow tube body at the tip end thereof. The pair of sputter electrodes are fixed and fixed so that the tips of the pair of sputter electrodes facing each other are separated by a predetermined distance from the openings provided at both ends of the body. A hollow tube body in which a glow discharge is generated by applying a DC voltage or a high frequency voltage between the sputtering electrodes to form the film on all or part of the inner wall surface of the hollow tube body by a sputtering method. Is the way.

In the present invention of claim 11, the part of the inner wall surface of the hollow tubular body is the whole or a part of the inner wall surface of the hollow tubular body other than the inner wall surface near the opening. Is a method for manufacturing a hollow tubular body.

A twelfth aspect of the present invention is a method of manufacturing a hollow tube body in which a tip portion of the sputter electrode has a non-planar shape.

A thirteenth aspect of the present invention is a method for manufacturing a hollow tubular body in which the tip of the target has a non-planar shape.

The present invention according to claim 14 is a method of manufacturing a discharge tube for a high pressure discharge lamp, wherein a predetermined film is formed on the inner wall surface of a hollow tube made of quartz glass. A nitride layer of one or more elements is formed on the inner wall surface, and then the formed nitride layer is subjected to an oxidation treatment to oxynitride all or part of the nitride layer. It is a method of manufacturing a discharge tube body for a high-pressure discharge lamp, which is changed into a layer of material.

A fifteenth aspect of the present invention is a method for producing a discharge tube body for a high pressure discharge lamp, wherein a predetermined film is formed on the inner wall surface of a hollow tube body made of quartz glass. An oxide layer of one or more elements is formed on the inner wall surface, and then the formed oxide layer is subjected to nitriding treatment to oxynitride all or part of the oxide layer. It is a method of manufacturing a discharge tube body for a high-pressure discharge lamp, which is changed into a layer of material.

The present invention of claim 16 is a method of manufacturing a high pressure discharge lamp in which a predetermined film is formed on the inner wall surface of a hollow tube made of quartz glass, wherein the inner wall surface of the hollow tube is provided with a predetermined film. A high-pressure discharge lamp for forming a metal layer of, and then subjecting the formed metal layer to an oxynitriding treatment to change all or part of the metal layer into an oxynitride layer. It is a manufacturing method of a discharge tube body.

The present invention according to claim 17 provides an inert gas and 1
Transparent with a coefficient of linear expansion of substantially 0.8 to 2 ppm / ° C formed on the inner wall surface of a hollow tube made of quartz glass in which at least one metal or at least one metal halide is enclosed. A first layer of the dielectric film, a second layer of the transparent dielectric film having a coefficient of linear expansion formed on the first layer of substantially between 2 and 5 ppm / ° C., and a second layer of the second layer. A high pressure discharge lamp comprising a film having at least a third layer of a transparent dielectric film having a coefficient of linear expansion of substantially between 5 and 10 ppm / ° C formed thereon.

The present invention of claim 18 is a high-pressure discharge lamp in which the uppermost layer of the film is composed of a layer of oxynitride.

In the present invention, for example, in an operating environment of a high pressure discharge lamp, an oxynitride film having a higher corrosion resistance than the conventional one is provided on the inner surface of the discharge tube. It is possible to provide a high-pressure discharge lamp that can be suppressed and has a longer life.

Further, according to the manufacturing method of the present invention, for example, the film is made uniform by sputtering and the film adhesion is strengthened, so that peeling of the film is less likely to occur than in the conventional case.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a high pressure discharge lamp of the present invention,
Embodiments of a method for manufacturing a discharge tube for a high pressure discharge lamp and a method for manufacturing a hollow tube will be described.

FIG. 1 is a schematic cross-sectional view of a high pressure discharge lamp according to an embodiment of the present invention.
The configuration of the present embodiment will be described.

A plurality of layers formed by laminating on the surface of the inner wall surface of the hollow tubular body are collectively called a film. That is, the film here usually has a plurality of layers. Therefore, instead of simply calling a film, it may be called a multilayer film.
However, when only one layer is formed, the film means the layer having only one layer. Therefore, this is also called a single-layer film from the concept of the above-mentioned multilayer film.

On the other hand, the numbering of each layer forming the film is, for example, the layer formed on the surface of the inner wall surface of the quartz glass tube 1 of the high pressure discharge lamp as the first layer, and the layer formed on the surface of the first layer. The formed layer is referred to as a second layer. That is, the layers are numbered such that the numbers of the layers increase as the distance from the inner wall surface of the hollow tube increases.

In FIG. 1, reference numeral 1 denotes a quartz glass tube, inside of which a tungsten electrode 2 having a tungsten wire 5 wound around the tip thereof is arranged to face each other.

Reference numeral 3 is a molybdenum foil, and 4 is a molybdenum electrode. An inner wall film 6 is formed on the quartz glass tube 1. The inner wall film 6 is composed of two layers, an aluminum nitride layer 7 and an aluminum oxynitride layer 8, as described below.

That is, FIG. 2 is an enlarged schematic cross-sectional view taken along the line AB in FIG. In the present embodiment, the quartz glass tube body 1
A layer 7 of aluminum nitride was formed thereon to a thickness of 600 angstroms, and an aluminum oxynitride film 8 was formed to a thickness of 1200 angstroms.

Next, a method of manufacturing a discharge tube body for a high pressure discharge lamp according to an embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic view of a sputtering apparatus used in the method for manufacturing a discharge tube body for a high pressure discharge lamp according to an embodiment of the present invention.

As shown in FIG. 2, the tungsten electrode 2 is formed to form a film (hereinafter also referred to as a two-layer film) composed of two layers of an aluminum nitride layer 7 and an aluminum oxynitride layer 8. It is carried out in the manufacturing stage before being sealed in the quartz glass tube body 1.

Therefore, at the time of forming this two-layer film, the side tube 16 used for enclosing the metal and the metal halide still exists. This is because the side pipe 16 is necessary in the subsequent manufacturing process.

On the other hand, in the case of the present embodiment, the conventional method is that the sputter electrode 10 is made of a material containing the same element as the element of the film to be formed on the inner wall surface of the quartz glass tube 1. This is a major difference from the configuration. That is, the sputter electrode 10 has both the function of an electrode for sputtering and the function of a target, which are conventionally provided as separate elements.

Aluminum nitride layer 7 and aluminum oxynitride layer 8
Both elements are aluminum. Therefore, the sputter electrode 1
In both cases of forming the aluminum nitride layer 7 and the aluminum oxynitride layer 8, metal aluminum (purity 99.999%), which is the same element as each of the layers, was used. .

The sputter electrode 10 was inserted through the openings 301 at both ends of the quartz glass tube, and the vacuum seal was realized by the O-ring seal 17.

In this way, the pair of sputter electrodes 10 inserted so that their tip portions face each other were fixed so that the inter-sputter electrode distance Wsp was about 12 mm. The diameter t0 of the sputter electrode was set to 4.4 mm.

A high frequency power source 13 was connected to the pair of sputter electrodes 10 via a matching unit 14.

A heat radiating plate 12 made of an aluminum block has an effect of suppressing an increase in target temperature during sputtering. In the case of the present embodiment, since the sputter electrode 10 also serves as the sputtering target as described above, there is an effect of suppressing an increase in the temperature of the sputter electrode 10.

In the gas introduction section 15, an inert gas Ar,
Reactive gases O ₂ and N ₂ and inner wall plasma cleaning gas CF ₄ are connected by pipes so that they can be supplied.

The magnet 11 is arranged so that the electric field and the magnetic field are parallel to each other and contributes to the increase in the sputtering rate, but it is not always necessary.

The side pipe 16 is connected to an exhaust system having a turbo molecular pump as a main exhaust pump. As the high frequency power source 13, a model having a frequency of 500 kHz and a maximum power of 250 W was used.

The high-pressure discharge lamp having the above-mentioned film composed of the two layers of the aluminum nitride layer and the aluminum oxynitride layer will be described in more detail, and one embodiment of the manufacturing method thereof will be described. Further details will be described.

As shown in FIG. 3, from the openings 301 at both ends of the quartz glass discharge tube, aluminum metal (purity 99.
999%) sputter electrode 10 is inserted and 5 × 10 ⁻⁴
Evacuate to high vacuum up to Pa.

Next, Ar gas of 3.1 sccm and nitrogen gas of 1.4 sccm were passed, and a high frequency of 20 W was applied by the high frequency power supply 13.

Next, an Ar gas of 3.1 sccm, a nitrogen gas of 0.9 sccm, and an oxygen gas of 0.5 sccm were made to flow, and a high frequency of 20 W was applied.

The thickness of each layer is 600 for aluminum nitride layer 7.
The sputtering discharge time was set so that the layer 8 of angstrom and aluminum oxynitride had a thickness of 1200 angstrom.

Next, the tungsten electrode 2 (see FIG. 1) was attached to the quartz glass discharge tube body 1 so that the distance between the electrodes was 5.5 mm, and mercury, dysprosium iodide, neodymium iodide, and cesium iodide were attached. A high pressure discharge lamp was completed by enclosing and Ar gas.

Here, the time until the screen illuminance of the high pressure discharge lamp becomes 1/2 of the initial value is defined as the life of the high pressure discharge lamp. In that case, it was confirmed that the life of the high-pressure discharge lamp configured as described above was extended by 30% or more as compared with the life of the high-pressure discharge lamp without the inner wall film.

In addition, a case where the inner wall film is composed of only an aluminum oxide layer (single layer film), and a two-layer film (multilayer film) in which the aluminum nitride layer is the first layer and the aluminum oxide layer is the second layer The results of verifying the cases of (1) and (2) are as follows. That is, in both of these cases, the life was extended by 30% or less as compared with the discharge lamp in which the inner wall film was not formed, and in some cases, the life was shortened in some cases. From these results, it can be seen that the oxynitride layer acts extremely effectively for extending the life.

Next, the high pressure discharge lamp was lit for 1000 hours, after which the linear transmittance of the tube wall of the high pressure discharge lamp was measured.

As a result, the average linear transmittance measured at 10 points in the circumferential direction of the tube wall was 53% in the case of an oxide single layer film and 49% in the case of a nitride single layer film. In the case of a single layer film of oxynitride, it was 77%.

In this case, the measurement light source is a He-Ne laser (wavelength 6328 angstrom).

As described above, the oxynitride layer (film) stably exhibits a much longer life effect than the oxide layer (film) and the nitride layer (film). It was

Further, due to the high thermal conductivity which is a characteristic of the aluminum nitride layer (film), the temperature distribution of the quartz glass tube 1 becomes more uniform, and the arc bending when the lamp is horizontally lit is
Diminished. In the case of the present embodiment, the temperature of the tube wall of the quartz glass tube 1 at the time of horizontal lighting is 811 at the upper center.
There is almost no difference in temperature at ℃ and 809 ℃ at the bottom center.

On the other hand, when no film was formed on the inner wall surface of the quartz glass tube, the temperature was 818 ° C. in the upper center and 786 ° C. in the lower center, and the temperature difference between them was as large as 32 ° C. The lamp power is 250 W in each case. For this reason, the nitride layer is effective for realizing the uniform temperature of the tube wall of the hollow tube. Since oxynitride also has high thermal conductivity close to that of nitride, the oxynitride layer (membrane) is excellent also for realizing uniform temperature of the wall of the hollow tubular body. It can be seen that the effect is excellent.

In the above embodiment, high-purity (99.999%) metallic aluminum was used as the sputtering electrode 10. However, an aluminum alloy in which Si, Y, Mg, or the like is added to this aluminum is used as the sputtering electrode. You may use as.

As another embodiment, a high-pressure discharge lamp was produced in which the inner wall surface of a quartz glass tube was coated with a layer of oxynitride by a sputter electrode formed of an aluminum alloy containing 2 wt% of Si. With this structure, the life is extended by 5% as compared with the case of the sputtering electrode 10 of the high-purity aluminum alloy.

In addition to the substances mentioned above, the substance to be sealed in the high pressure discharge lamp may be various rare earth iodides or metal iodides. Further, it is understood that the present invention can be applied to a high pressure sodium discharge lamp.

The reason why the present invention can be made effective is that a layer of highly corrosion-resistant aluminum oxynitride is used as the uppermost layer of the film formed on the inner wall surface of the hollow tubular body, and that of the first layer. The use of an aluminum nitride layer as the base film contributes to the improvement of the film quality of the uppermost aluminum oxynitride layer.

When the film is formed as described above, it is not necessary to replace the sputter electrode that also serves as the sputter target each time when forming various layers, and the gas introduction unit 15 (see FIG. 3) can be used. There is an extremely great advantage that the above-mentioned two-layer film can be obtained only by changing the setting of the gas to be introduced into the quartz glass tube body 1.

Although the aluminum oxynitride layer is the uppermost layer in the above-mentioned embodiment, in practice, various other than aluminum can be considered.

For example, tantalum, niobium, vanadium,
Even if a film is formed by forming one or more layers of oxynitride of an element selected from chromium, titanium, zirconium, hafnium, yttrium, scandium, magnesium, silicon, and lanthanum rare earth elements. Good. Needless to say, this film may include layers other than the layer of the oxynitride portion.

The film may be composed of a single-layer film, a two-layer film, a three-layer film, and a multilayer film of four or more layers, or a so-called functionally graded film in which the composition is continuously modulated from the underlayer to the upper layer. But it's okay.

In the case of a single-layer film, needless to say, a thin film formed by using an oxynitride such as the aluminum oxynitride layer 8 may be directly formed on the inner wall surface of the quartz glass tube 1.

Further, the thickness shown in the above embodiment is
The thickness of the aluminum oxynitride layer may be selected from the range of 200 to 5000 angstroms.

The present invention utilizes the fact that the oxynitride layer is superior as the inner wall film as compared with the oxidized layer and the nitride layer.

The nitride layer of the above element has a higher melting point than the oxide layer (for example, the melting point of aluminum nitride is 2800).
However, aluminum oxide is 2054 ° C.), which is preferable in consideration of use in a high temperature environment.

Further, the coefficient of thermal expansion of the nitride layer is lower (for example, aluminum nitride is 4.5 ppm / ° C., whereas aluminum oxide is 7 to 8 ppm / ° C.), and low thermal expansion quartz glass (0 0.54 ppm / ° C.) It is more advantageous than an oxide layer for forming a film on a tube.

On the other hand, the disadvantages of the nitride layer are its lack of oxidation resistance and its high vapor pressure due to sublimation. By using the oxynitride layer, a film of an excellent high temperature corrosion resistant material having both advantages can be realized.

In the above embodiment, the metal sputter electrode 1 is used.
Although 0 was used to form a film by reactive sputtering, it is apparent that the same effect can be obtained by sputtering using a sputtering electrode containing oxynitride, oxide, or nitride.

Further, the oxynitride layer may be formed by a thermal CVD method, a plasma CVD method, a vacuum vapor deposition method, an ion plating method, etc. other than the above-mentioned sputtering method.

Further, first, a layer of nitride is formed, and thereafter,
Oxidation treatment such as thermal oxidation or plasma oxidation may be applied to form the oxynitride layer, or conversely, an oxide layer is first formed and then thermal nitridation or plasma nitridation is performed. A nitriding treatment may be performed to obtain a layer of oxynitride.

The contents shown in FIGS. 4 (a) to 4 (c) are an example of a manufacturing process for forming a nitride layer and then subjecting it to an oxidation treatment to form an oxynitride layer. That is, in the figure, the above-mentioned oxidation treatment is performed on the nitride layer 81 formed first.
(See FIGS. 4 (a) and 4 (b)), and the surface portion as a part of the nitride layer 81 is covered with the oxynitride layer 8
An example in the case of changing to 2 (see FIG. 4C) is shown. In addition, as another example, it is of course possible that the entire nitride layer 81 initially formed is changed to the oxynitride layer 82. Reference numeral 80 in FIG. 4B schematically shows oxygen ions used for the oxidation treatment.

After forming the metal layer, a heat treatment or plasma treatment may be performed to obtain an oxynitride layer.

When sputtering is performed with the apparatus shown in FIG. 3, the sputtered film grows only on the inner wall surface of the quartz glass tube 1 facing the space between the pair of sputter electrodes 10. To do. Then, almost no film grows on the portions corresponding to the roots of the tungsten electrodes 2 (see FIG. 1) to be inserted in a later step, that is, on the inner wall surface near the opening 301. However, it could be confirmed by the experiment.

By positively utilizing such a phenomenon and adjusting the distance between the tip portions of the sputter electrode 10, as shown in FIG.
In 1, the quartz glass can be exposed, that is, exposed. The configuration shown in FIG. 5 is different in the configuration of the root portion 51 of the tungsten electrode 2 as compared with the case of the lamp schematic diagram of FIG. 1 showing a state in which a protective film is attached to the entire inner wall surface.

In the case of the structure shown in FIG. 5, the devitrification phenomenon caused by the reaction between the enclosed material in the quartz glass tube body 1 and the quartz glass is caused by the intentional formation of the portion without the protective film as described above. It progresses selectively, and the devitrification phenomenon becomes slower in the protective film region.

Even if the root portion of the tungsten electrode 2 is devitrified, it has a small effect on practical use. Therefore, according to such a manufacturing method of the present invention, the devitrification of the main region through which most of the lamp luminous flux passes. Is effectively suppressed, and as a result, the life of the lamp can be extended.

Further, although the uniformity of the film thickness is important for the optical thin film, as shown in FIG. 3, when compared with the case where the surface of the tip of the sputter electrode 10 is a flat surface, the inner wall is different when the surface is a non-planar shape. The uniformity of the film thickness can be improved. FIG. 6 shows a case where the tip of the target has a convex shape as an example of a non-planar shape.

Further, by optimizing the sputter conditions such as the tip shape of the pair of sputter electrodes 10 and the distance between the tips, and the gas flow rate according to the shape of the discharge tube, the layer thickness or the film thickness can be changed. Distribution uniformity of ± 10%
Can be done within.

The tip of the sputter electrode should be projected to the center of the discharge tube formed in a spherical or spheroidal shape, and if there is no projection length, the film thickness distribution deteriorates.

In the above embodiment, the so-called electrode type HID lamp having the tungsten electrode 2 has been described, but the present invention is not limited to this, and for example, as shown in FIG. 7, an electrode protruding inside the discharge tube body is used. The present invention can be applied to a high-pressure discharge lamp which is not provided and is excited and emitted by microwave or high frequency from the outside. Even in that case, the same effect as described above can be obtained. In FIG. 7, numeral 32 is for exciting the high pressure discharge lamp to emit light,
A high-frequency power source is provided externally, 31 is a matching unit, and 30 is a turn coil arranged so as to surround the outer circumference of the quartz glass tube body 1.

Next, a linear expansion coefficient of 0.8 to 2 ppm / ° C. was used as the first layer on the inner surface of the tube wall of the quartz glass hollow body.
A transparent dielectric layer having a linear expansion coefficient of between 2 and 5 ppm / ° C. as a second layer,
An example of a structure including a three-layer film composed of a transparent dielectric layer having a linear expansion coefficient of 5 to 10 ppm / ° C. as a layer will be described (see FIG. 8). FIG. 8 is a schematic cross-sectional view of a quartz glass tube and a film formed on the inner wall surface thereof for showing the structure of a three-layer film in another embodiment of the present invention. Note that FIG. 8 is a schematic cross-sectional schematic view of a portion shown by a section line AB in FIG. 1.

As shown in FIG. 3, a sputter electrode 10 made of tantalum metal (purity 99.99%) is inserted into a discharge tube made of quartz glass and evacuated to a high vacuum of 5 × 10 ⁻⁴ Pa.

Next, an Ar gas of 2.4 sccm and an oxygen gas of 1 sccm were made to flow, and a high frequency of 15 W was applied.

Next, the sputter electrode made of tantalum metal is replaced with a sputter electrode made of aluminum (purity: 99.999%), and the vacuum electrode is evacuated to a high vacuum up to 5 × 10 ⁻⁴ Pa.

Next, Ar gas was flowed at 2.4 sccm and nitrogen gas was flowed at 1 sccm, and a high frequency of 15 W was applied.

Next, with the sputtering electrode as it is, Ar gas of 2.4 sccm, oxygen gas of 0.3 sccm and nitrogen gas of 0.7 sccm were caused to flow, and a high frequency of 15 W was applied.

The layer thickness is 5 for the tantalum oxide layer 101.
00 Angstrom, 500 layers of aluminum nitride 102
Angstrom, 1000 layers of aluminum oxynitride 1000
The sputter discharge time was set to be angstrom (see FIG. 8).

Next, the tungsten electrode 2 was attached to the discharge tube body 1 so that the distance between the electrodes was 5.5 mm, and mercury, dysprosium iodide, neodymium iodide, cesium iodide and Ar gas were sealed and the discharge was performed. Completed the lamp.

The life of the high-pressure discharge lamp of this embodiment is
Compared to the life of a conventional discharge lamp without an inner wall film, 30
It was confirmed that the life was extended to 100%.

Further, due to the high thermal conductivity of the aluminum nitride film,
The temperature distribution of the quartz glass tube was made uniform, and the arc bending when the lamp was lit horizontally was reduced.

Other than the above, the rare earth iodide and the metal iodide can be used as the encapsulating substance.

It is also understood that the present invention can be applied to a high pressure sodium discharge lamp.

The following are possible causes for the effectiveness of the present invention.

That is, the coefficient of thermal expansion of each layer constituting the film is
By selecting and stacking the materials of each layer so that the value becomes larger from the lower layer to the upper layer, it has a stable structure in a large temperature range, and the uppermost layer is made of aluminum oxynitride with high corrosion resistance. Adopting a layer, and an aluminum nitride layer with high thermal conductivity (150 W / mK) as an intermediate layer
Is adopted so that the discharge tube body is soaked.

Therefore, various constitutions of the three-layer film other than the above-mentioned embodiment can be considered.

That is, as shown in (Table 1), the coefficient of linear expansion is 0.8 to 2 ppm just above the inner wall surface of the quartz glass tube.
A transparent dielectric having a linear expansion coefficient of 2 to 5 ppm / ° C. is formed as a second layer on the first layer, and a second layer having a linear expansion coefficient of 2 to 5 ppm / ° C. is formed on the first layer. By providing a three-layer film formed by forming a transparent dielectric material having a linear expansion coefficient of 5 to 10 ppm / ° C. as the third layer on the layer, the length of the high pressure discharge lamp can be increased similarly to the above. The life can be extended. In addition, the left column of (Table 1) shows the material of each layer described in the above-mentioned embodiment, and the central column shows
The allowable range of the linear expansion coefficient of the material of each layer is shown, and the right column shows usable materials in place of the materials listed in the left column.

[0110]

[Table 1]

In Table 1, for example, HfO ₂ + T
iO ₂ means a composite oxide of Hf and Ti, and cordierite is 2MgO + 2Al ₂ O ₃ + SiO ₂ , β-
Supodeyumen the _{Li 2 O + Al 2 O 3} + 4SiO 2, sialon Si-Al-O-N, mullite 3Al ₂ O ₃ +
It is 2SiO ₂ .

The value of the coefficient of linear expansion varies depending on the direction of the crystal axis in a single crystal having an asymmetric crystal structure, but here, the value of the coefficient of linear expansion that is average in practical use is considered. .

For example, with aluminum nitride (AlN), 4.15 ppm / ° C. in the a-axis direction and 5.27 ppm in the c-axis direction.
/ C, but in the case of a polycrystal, an average value of 4.5 to
It may be regarded as exhibiting a value in the range of 4.8 ppm / ° C. Therefore, aluminum nitride (AlN) is classified as a material having a coefficient of linear expansion of 2 to 5 in (Table 1).

Further, aluminum, tantalum, niobium, vanadium, chromium, titanium, zirconium, hafnium, yttrium, scandium, magnesium, silicon,
Alternatively, the value of the linear expansion coefficient of various oxynitrides formed using an element such as a lanthanum rare earth element varies depending on the type of material and the composition ratio of oxygen and nitrogen. Can be used for

For example, in the case of silicon oxynitride (SiON),
SiO₂If the composition is close to, the linear expansion coefficient corresponding to the first layer
Number (0.8 to 2 ppm / ° C.), Si₃N_FourClose to
In the case of composition, the linear expansion coefficient (2-5ppm) corresponding to the second layer
/ ° C.). Therefore, in (Table 1), it is used for the second layer.
SiON, which is classified as a usable material, is Si ₃
N_FourIt has a composition close to.

For example, if spinel MgAl ₂ O ₄ is used instead of aluminum oxynitride in (Table 1), higher corrosion resistance can be obtained when an alkali metal (Na, Li, etc.) is used as the encapsulating material. .

Although a three-layer film structure is used in the above-mentioned embodiment, it is possible to further increase the number of layers in practice. In FIG. 9, 6
An example of a film composed of layers is shown. This figure shows A- in FIG.
It is a schematic cross-sectional schematic diagram of the part shown by the B cutting line.

As shown in FIG. 9, as the first layer 91, HfO ₂ + T having a linear expansion coefficient smaller than that of tantalum oxide is used.
iO ₂ layer, tantalum oxide layer as second layer 92, third layer
The layer 93 is a layer of Al ₂ O ₃ + Nb ₂ O _{5 having} a smaller linear expansion coefficient than aluminum nitride, the fourth layer 94 is an aluminum nitride layer, the fifth layer 95 is an aluminum oxide layer, and the uppermost sixth layer. As 96, a layer of MgAl ₂ O ₄ was laminated to form a film. By increasing the number of layers in this way, a lamp with higher durability was obtained.

However, with the above configuration, the number of manufacturing steps increases,
Since the cost may increase, it is rational to determine the number of layers from the desired performance level.

In the above example, the metal sputtering electrode was used to form the film by reactive sputtering. However, the same effect can be obtained by using sputtering using an oxide or nitride sputtering electrode. It's clear.

The film forming method is preferably a sputtering method,
The effect can be expected even if it is created by another thermal CVD method, plasma CVD method, vacuum deposition method, ion plating method, or the like.

The method of manufacturing the hollow tube of the present invention has been described in the above embodiment by taking the method of manufacturing the high pressure discharge lamp and the discharge tube for the high pressure discharge lamp as an example. However, the present invention is not limited to this. For example, it is also applicable to a method for manufacturing a hollow tube for a fluorescent lamp, etc., in short, as long as a film can be formed on all or part of the inner wall surface of the hollow tube by a sputtering method, The shape, size, type, application, etc. of the hollow tubular body do not matter.

Further, in the case where the film of the present invention has a plurality of layers, as an example in which the nitride layer and the oxynitride layer constituting the plurality of layers are formed, in the above-mentioned embodiment, the oxynitride layer is formed. Although the case where the layer is the uppermost layer has been described (see FIG. 2 and FIG. 4C), the present invention is not limited to this, and, for example, in the opposite case, the nitride layer may be the uppermost layer. In this case, as a method of manufacturing a discharge tube body for a high pressure discharge lamp in which a film is formed on the inner wall surface of a hollow tube body made of quartz glass, it may be manufactured by the following steps. That is, a layer of an oxide of one or more elements is formed on the inner wall surface of the hollow tube, and then the formed oxide layer is subjected to a nitriding treatment to form the oxide layer. All or part of is converted into an oxynitride layer. Furthermore, as another example, for example, as a method of manufacturing a discharge tube for a high-pressure discharge lamp in which a film is formed on the inner wall surface of a hollow tube made of quartz glass, the following steps are performed. Good.

That is, specifically, a layer of a predetermined metal is formed on the inner wall surface of the hollow tubular body, and then the formed metal layer is subjected to oxynitriding treatment to obtain the metal. Is a manufacturing method in which all or part of the layer is changed to an oxynitride layer.

Further, in the above embodiment, the case where the pair of sputter electrodes 10 are made of a material containing the same element as the element of the film to be formed on the inner wall surface of the quartz glass tube 1 will be described. However, not limited to this, for example, FIG.
As shown in FIG. 5, a pair of sputter electrodes 101 may be used in which a tip 102 is provided with a target 102 containing the same element as the element of the film to be formed on the inner wall surface of the hollow tubular body. In this case, the material of the sputter electrode 101 does not need to contain the same element as described above. As described above, the present invention can suppress the devitrification phenomenon during the lamp lighting of the quartz glass tube,
A high-pressure discharge lamp with a long life can be realized.

Further, in the present invention, since the ceramic discharge tube is not used, the linear transmittance of light is high, good optical characteristics close to that of a point light source can be obtained, and the tube can be molded three-dimensionally easily. It has many advantages such as low cost.

Further, according to the present invention, the temperature distribution of the discharge tube is made uniform by utilizing the aluminum nitride film having a high thermal conductivity.
It also has the effect of reducing heat convection and reducing arc bending.

[0128]

As is apparent from the above description, the present invention has the advantages that devitrification can be further suppressed and the life can be further extended, as compared with the prior art.

Further, the present invention has an advantage that it can provide a new method of manufacturing a hollow tube which can be used in, for example, a high pressure discharge lamp.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a high pressure discharge lamp according to an embodiment of the present invention.

FIG. 2 is an enlarged schematic cross-sectional view taken along the line AB in FIG.

FIG. 3 is a schematic diagram of a sputtering apparatus used in a method for manufacturing a discharge tube body for a high pressure discharge lamp according to an embodiment of the present invention.

FIG. 4A is a schematic view showing a step of forming a nitride layer on the inner wall surface of a quartz glass tube. FIG. 4B is a schematic view showing a step of subjecting the nitride layer formed in the step shown in FIG. 4A to an oxidation treatment. (C): It is a schematic diagram which shows the process of changing the surface part of a nitride layer into an oxynitride layer by oxidation treatment.

FIG. 5 is a schematic cross-sectional view of a high-pressure discharge lamp configured so that quartz glass is exposed at the root of a tungsten electrode as another embodiment of the present invention.

FIG. 6 is a schematic diagram showing the shapes of the sputter electrode and the tip of the sputter electrode used in the method for manufacturing a discharge tube for a high pressure discharge lamp according to an embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of an electrodeless discharge lamp.

FIG. 8 is a schematic cross-sectional view of a quartz glass tube and a film formed on an inner wall surface thereof to show a structure of a three-layer film according to another embodiment of the present invention.

FIG. 9 is a schematic cross-sectional view of a quartz glass tube and a film formed on the inner wall surface thereof to show the structure of a six-layer film in another embodiment of the present invention.

FIG. 10 is a schematic diagram showing the shape of a sputtering electrode of a sputtering apparatus used in a method for manufacturing a discharge tube body for a high pressure discharge lamp according to another embodiment of the present invention, and a target portion provided at the tip thereof. is there.

[Explanation of symbols]

 1 Quartz glass tube 2 Tungsten electrode 3 Molybdenum foil 4 Molybdenum electrode 5 Wound tungsten wire 6 Inner wall film 7 Aluminum nitride layer 8 Aluminum oxynitride layer 10 Sputtering electrode 11 Magnet 12 Radiator 13 High frequency power supply 14 Matching device 15 Gas introduction part 16 side tube 17 O-ring seal 102 target 301 opening

Claims (18)

[Claims] 1. An oxynitride of one or more elements is provided on the inner wall surface of a hollow tube made of quartz glass in which an inert gas and one or more metals or one or more metal halides are enclosed. A high-pressure discharge lamp comprising a film having at least one layer. 2. The one or more elements are selected from aluminum, tantalum, niobium, vanadium, chromium, titanium, zirconium, hafnium, yttrium, scandium, magnesium, silicon, and lanthanum rare earth elements. The high-pressure discharge lamp according to claim 1, wherein 3. The high pressure discharge lamp according to claim 1, wherein the film includes at least a layer of aluminum oxynitride. 4. The high pressure discharge lamp according to claim 3, wherein the aluminum oxynitride layer contains Si, Mg or Y. 5. When the film is a plurality of layers, the plurality of layers are a nitride layer and an oxynitride layer formed by using the same element as that used for forming the nitride. The high pressure discharge lamp according to claim 1, further comprising: 6. The high pressure discharge lamp according to claim 1, wherein the hollow tube body is a discharge tube body, and a protruding electrode is provided inside the discharge tube body. 7. The hollow tube body is a discharge tube body, and no electrode is provided inside the discharge tube body, and excitation and light emission are performed by a microwave or a high frequency applied from the outside of the discharge tube body. The high-pressure discharge lamp according to claim 1, characterized in that. 8. The high pressure discharge lamp according to claim 1, wherein the quartz glass is exposed on the inner wall surface of the end portion of the hollow tube body. 9. A pair of sputter electrodes containing the same element as the element of the film to be formed on the inner wall surface of the hollow tube are inserted through openings provided at both ends of the predetermined hollow tube. , The pair of sputter electrodes are fixed so that the intervals between the tip portions of the pair of sputter electrodes facing each other are separated by a predetermined distance, and a DC voltage or a high frequency voltage is applied between the fixed sputter electrodes. Then, a glow discharge is generated and the film is formed on all or part of the inner wall surface of the hollow tube by a sputtering method. 10. A pair of sputter electrodes, each of which has a target containing the same element as the element of the film to be formed on the inner wall surface of a predetermined hollow tube at its tip, are provided at both ends of the hollow tube. The pair of sputter electrodes are fixed so that the tip portions of the pair of sputter electrodes facing each other are separated from each other by a predetermined distance, and a direct current is applied between the fixed sputter electrodes. Voltage or high-frequency voltage is applied to generate glow discharge, and the film is formed on all or part of the inner wall surface of the hollow tube by a sputtering method. . 11. A part of the inner wall surface of the hollow tubular body is the whole or a part of the inner wall surface of the hollow tubular body other than the inner wall surface in the vicinity of the opening. The method for producing a hollow tubular body according to claim 9 or 10. 12. The method for manufacturing a hollow tube according to claim 9, wherein the tip of the sputter electrode has a non-planar shape. 13. The method according to claim 10, wherein the tip of the target has a non-planar shape. 14. A method of manufacturing a discharge tube body for a high-pressure discharge lamp, wherein a predetermined film is formed on the inner wall surface of a hollow tube made of quartz glass, wherein the inner wall surface of the hollow tube body comprises one kind. A nitride layer of the above elements is formed, and then the formed nitride layer is subjected to an oxidation treatment to change all or part of the nitride layer into an oxynitride layer. A method of manufacturing a discharge tube body for a high-pressure discharge lamp, comprising: 15. A method of manufacturing a discharge tube body for a high-pressure discharge lamp, wherein a predetermined film is formed on the inner wall surface of a hollow tube made of quartz glass, wherein the inner wall surface of the hollow tube body comprises one kind. An oxide layer of the above elements is formed, and then the formed oxide layer is subjected to nitriding treatment to change all or part of the oxide layer into an oxynitride layer. A method of manufacturing a discharge tube body for a high-pressure discharge lamp, comprising: 16. A method of manufacturing a high pressure discharge lamp, wherein a predetermined film is formed on the inner wall surface of a hollow tube made of quartz glass, wherein a predetermined metal layer is formed on the inner wall surface of the hollow tube body. Then, the formed metal layer is subjected to an oxynitriding treatment to change all or part of the metal layer into an oxynitride layer, which is a discharge for a high pressure discharge lamp. Manufacturing method of tubular body. 17. The coefficient of linear expansion formed on the inner wall surface of a hollow tube made of quartz glass in which an inert gas and one or more kinds of metals or one or more kinds of metal halides are enclosed. A first layer of transparent dielectric material having a linear expansion coefficient of substantially between 8 and 2 ppm / ° C. and a first layer of transparent dielectric material having a linear expansion coefficient of substantially between 2 and 5 ppm / ° C. formed on the first layer. A film having at least two layers and a third layer of transparent dielectric material having a coefficient of linear expansion of substantially between 5 and 10 ppm / ° C. formed on the second layer. High pressure discharge lamp. 18. The high pressure discharge lamp according to claim 17, wherein the uppermost layer of the film is an oxynitride layer.