JPH11162411A - High pressure discharge lamp and lighting equipment - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To reduce the occurrence of airtight leakage due to corrosion of a translucent ceramic discharge vessel, damage to electrodes, reduction in luminous flux due to blackening, and abnormal rise in temperature. An inner surface portion surrounding a discharge space of a discharge vessel made of a translucent ceramic includes at least a bulge portion and an end portion having an inner diameter smaller than the bulge portion communicating with both ends of the bulge portion. The power supply conductor 3 composed of the sealing portion 3a and the halide-resistant portion 3b is formed so as not to have the spinel type structure, and forms a slight gap 7 in the end portion of the transparent ceramic discharge vessel. It is introduced and hermetically sealed by a ceramic sealing compound seal 6, and an electrode 4 is provided at the tip of the power supply conductor.
The translucent ceramic discharge vessel is provided with a getter means 5 for removing impurity gases, and is filled with a metal halide and a rare gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-pressure discharge lamp having a translucent ceramic discharge vessel and a lighting device using the same.

[0002]

2. Description of the Related Art A high-pressure discharge lamp provided with a discharge vessel made of a translucent ceramic such as translucent alumina has excellent heat resistance and corrosion resistance as compared with quartz glass, and therefore has excellent life characteristics. Further, it is expected that the devitrification phenomenon due to the reaction with a luminescent metal such as dysprosium Dy and sodium Na is small, and therefore, it is possible to suppress the reduction of the luminous flux due to this.

By the way, in a light-transmitting alumina ceramic most commonly used as a light-transmitting ceramic, several hundred ppm of MgO is used as an additive in order to control the crystal grain size. The added MgO is discharged out of the crystal grains in the course of alumina grain growth, and forms a so-called spinel which is a compound with alumina at the grain boundaries. When spinel is present at the crystal grain boundary, light is scattered and light transmittance is reduced. In order to prevent a decrease in light transmittance, reducing the spinel is disclosed in Japanese Patent Publication No. Sho 59-6.
No. 831. However, this technology
It is assumed that a spinel phase exists.

[0004]

According to the study of the present inventor, in a metal halide lamp using a translucent ceramic discharge vessel, in a conventional configuration, a reaction between a sealed metal halide and the discharge vessel is caused. It has been found that there is a problem that the corrosion of the translucent ceramic discharge vessel is remarkably easy to proceed.

According to the inventor's consideration, the above problem is due to the following reasons. That is, in the translucent ceramic containing MgO as an additive, spinel is formed only when MgO is mixed with Al ₂ O _{3 at} a ratio of 1: 1. Does not form spinel. That is, when the translucent ceramic has a spinel-type structure, it is considered that crystals containing an additive that does not form the spinel-type structure coexist. And
The spinel structure has high stability and does not adsorb impurity gases such as hydrogen and oxygen.

On the other hand, crystals containing an additive but not forming a spinel are considered to be unstable and adsorb hydrogen and oxygen.

Further, the present inventor has found that when a conventional high-pressure discharge lamp using a translucent ceramic discharge vessel having a spinel structure is turned on, an impure gas mixed in a pellet of an enclosure at a relatively early stage. Hydrogen and oxygen disappeared.

[0008] By the way, since the crystals which could not become spinel are formed from the extra materials discharged, as described above, the unstable mixed state of various phases deviated from the stoichiometric composition. In the state,
This is considered to be due to adsorption of hydrogen and oxygen in the translucent ceramic discharge vessel.

In summary, it can be said that a ceramic having a spinel structure has a getter function.

However, it is considered that, by continuing the lighting, the crystal which could not become a spinel containing water by adsorbing hydrogen and oxygen this time reacts violently with the metal halide.

Therefore, the present inventor prepared a translucent alumina ceramic discharge vessel containing no spinel, produced a prototype metal halide lamp using the discharge vessel, and tried to light it.

As a result, although almost no corrosion was observed in this lamp, the tungsten electrode was strongly attacked by residual moisture, particularly oxygen, and the blackening of the lamp was conspicuous. For this reason, there is a problem that airtight leakage or the like due to a decrease in the luminous flux or an abnormal rise in the temperature is likely to occur.

According to the present invention, the light-transmitting ceramic discharge vessel hardly reacts with the metal halide, and the metal parts such as the electrodes are less damaged by the removal of the impurity gas. It is an object of the present invention to provide a high-pressure discharge lamp with less inconvenience such as leakage and airtight leakage, and a lighting device using the same.

[0014]

According to a first aspect of the present invention, there is provided a high-pressure discharge lamp, wherein at least an inner surface portion surrounding the discharge space is provided with a bulge formed so as not to have a spinel structure, and at both ends of the bulge. A translucent ceramic discharge vessel having an end portion that is in communication and has an inner diameter smaller than the bulge;
A sealing portion and a halide-resistant portion having a base end connected to the distal end of the sealing portion, penetrate the inside of the end portion of the light-transmitting ceramic discharge vessel, and A power supply conductor forming a small gap therebetween; an electrode disposed in the bulge portion and connected to the power supply conductor; a ceramic sealing compound seal for sealing the end portion and the power supply conductor; and a metal halide. And a discharge medium sealed in the discharge space portion; and getter means for removing impurity gas in the discharge space.

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

"Translucent ceramic discharge vessel" means a discharge vessel made of a refractory material made of translucent airtight aluminum oxide and a polycrystalline metal oxide such as yttrium-aluminum-garnet (YAG). .

The term "translucent" means that the light emitted by the discharge is transmitted to such an extent that it can be transmitted through the discharge vessel to the outside, and may be either transparent or diffuse translucent.

The spinel structure is defined as R ₂ MO ₄ (M is M
g, Fe, Zn, and Mn, and R refers to Al, Fe, and the like. ), Which is often a compound of an additive for controlling the crystal grain size and a ceramic constituent material, but the purpose of the present invention does not matter.

The expression "at least the inner surface portion surrounding the discharge space does not have a spinel structure" includes the case where the spinel structure does not exist in the entire translucent ceramic discharge vessel or the entire bulging portion. This means that the spinel-type structure does not exist only in the inner surface portion of the bulging portion of the conductive ceramic discharge vessel, and the other portions include the case where the spinel-type structure exists. The inner surface portion refers to a depth of about 20 μm from the inner surface.

An example of a method for obtaining a configuration in which a spinel structure does not exist on the inner surface will be described. That is, the addition amount of MgO is reduced to about half of the conventional amount, and the temperature during sintering is reduced to 5%.
0 to 100 ° higher, about 1850 °. This allows
Since the spinel of the surface layer is sublimated, the spinel structure at the inner surface can be removed. The presence or absence of the spinel structure can be determined by quantitative analysis by chemical analysis or analysis by an electron microscope.

The "bulging portion" of the translucent discharge vessel has a relative meaning to the inner diameter of the end portion, and is for forming a discharge space. Therefore, in addition to the one having a clear step portion between the bulging portion and the end portion, a discharge vessel in which the both are connected by a continuous curve may be used.

By the way, in order to manufacture the translucent ceramic discharge vessel, the bulging portion and the end portion can be integrally formed from the beginning. As a method different from this, the bulging portion is formed by a pair of end plates each having a central hole for closing both ends of the cylindrical body and the cylindrical body, and the end portion is formed by inserting an elongated tube into the central hole of the end plate. It may be formed, sintered and integrated.

The “feeding conductor” functions to apply a voltage between the electrodes from a power supply via ballast means to start a high-pressure discharge lamp, to introduce a current, and to light the lamp. A member that is hermetically sealed and introduced into the translucent ceramic discharge vessel and connects to the electrode. In order to obtain good airtightness with the translucent ceramic discharge vessel, the power supply conductor is composed of a sealing portion and a halide-resistant portion following the sealing portion. It is fixed to the end portion of the discharge vessel through a ceramic sealing compound seal.

The term "sealing portion" means that the translucent ceramic discharge vessel is sealed between the end portion and the sealing portion or the ceramic sleeve is further sealed by the sealing of the ceramic sealing compound. Any material may be used as long as it is a material suitable for intervening sealing. For example, hafnium, vanadium, niobium, tantalum, or an alloy thereof may be used. The sealing portion may have any permeability to hydrogen and oxygen, but the material described above is the same as the hydrogen and oxygen permeable material as a result.
When a translucent alumina ceramic is used as the material of the translucent ceramic discharge vessel, niobium and / or tantalum have almost the same average thermal expansion coefficient as the translucent alumina ceramic. It is preferable to use tantalum. The difference is also small in the case of YAG.

The "halide-resistant part" is a part consisting of a substance present in the translucent ceramic discharge space vessel during the operation of the high-pressure discharge lamp and having little or no corrosive action due to halide and free halogen. Means that. For example, tungsten, molybdenum,
A metal selected from the group consisting of platinum, iridium, rhenium and rhodium or a portion composed of at least one kind of silicide, carbide or nitride of these metals; It may be coated with a material.

The "small gap" means that the thickness of the space formed between the power supply conductor and the inner surface of the end portion of the translucent ceramic discharge vessel is at least 5 μm or more, and the thickness of the end portion at the maximum. Approximately 200 μm in size less than 1/4 of inner diameter
The following vacancies mean: Therefore, the diameter of the halide-resistant portion of the power supply conductor penetrating the end portion is set to at least １ ／ of the inner diameter of the end portion.

[0027] The small gap may be formed by interposing a ceramic sleeve between the end portion and the power supply conductor. In this case, a slight gap is formed between the power supply conductor and the ceramic sleeve and between the ceramic sleeve and the inner surface of the end portion.

Further, when the halide-resistant portion of the power supply conductor is constituted by a rod and a coil wound around the rod,
A slight gap can also be formed between the outer peripheral surface of the coil and the inner surface of the end portion.

Further, a small gap is formed during operation of the high-pressure discharge lamp by surplus halide entering in a liquefied state to form a coldest part. The desired coldest part temperature can be achieved.

When a ceramic sleeve is used, it is acceptable that the sleeve is made of the same material or cermet as the above-mentioned materials that can constitute the translucent ceramic discharge vessel.

By using a ceramic sleeve,
It is easy to form a small gap.

Further, by providing the ceramic sleeve so as to surround the front end portion of the sealing portion of the power supply conductor, that is, in the vicinity of the boundary with the halide-resistant portion, good sealing can be achieved. Can be obtained.

The "getter means" is intended to remove hydrogen and oxygen remaining in the translucent ceramic discharge vessel mainly by the moisture mixed in the pellets of the filling, and is a lamp constituent member such as a power supply conductor. Can also function as getter means. However, getter means can be provided separately from the lamp components. In the latter case, it is effective to arrange the getter means at a halogen-resistant part located near the boundary between the halide-resistant part and the sealing part, that is, near the base end.

The reason why it is effective to define the getter means at the above position is as follows. That is, when the getter means is disposed near the base end of the halide-resistant portion, it is easy to maintain the getter means at a temperature of 400 to 750 ° C. which is effective for the getter function during operation of the high-pressure discharge lamp.
If the temperature is lower than 400 ° C., the effect of absorbing impurities is insufficient. If the temperature is higher than 750 ° C., the reaction with halogen becomes violent, and the light emitting metal is exchanged with a getter metal, for example, niobium. This tends to cause a decrease and a change in the emission color.

The means and the shape for supporting the getter means are not limited. However, when the getter means is formed into a thin wire and wound around the halide-resistant portion, or when a ceramic sleeve is provided around the power supply conductor, the getter is wound around the outside of the sleeve so that the support is provided. It will be easier.

The getter means may be covered with a ceramic sealing compound after absorbing hydrogen and oxygen in the translucent ceramic discharge vessel. That is, the sealing portion of the power supply conductor is sealed to the end portion of the translucent ceramic discharge vessel by the sealing of the ceramic sealing compound, and then the hydrogen and oxygen are released from the translucent ceramic discharge vessel. Heat to temperature. The hydrogen and oxygen released by this heating are absorbed by the getter means. Next, when the sealing portion of the ceramic sealing compound is heated again, the compound melts and flows over the getter means and extends to cover the getter means.

As the getter means, the same material as the sealing portion of the power supply conductor can be used.

Thus, in the present invention, since the spinel type structure does not exist in the inner surface portion of the transparent ceramic discharge vessel surrounding the discharge space, the transparent ceramic discharge vessel does not function as a getter. However, the spinel structure containing water by adsorbing hydrogen and oxygen does not react with the metal halide of the discharge medium and corrode.
Since the residual impurity gas in the translucent ceramic discharge vessel is removed by the getter means, it is possible to suppress the occurrence of blackening, an increase in starting voltage, and an airtight leak of the translucent ceramic discharge vessel due to an abnormal rise in temperature.

Accordingly, a high pressure discharge lamp exhibiting good life characteristics is provided.

A high pressure discharge lamp according to a second aspect of the present invention is the high pressure discharge lamp according to the first aspect, wherein the transparent ceramic discharge vessel is made of alumina ceramic containing a rare earth oxide as an additive.

As the rare earth oxide, for example, oxides such as lanthanum La, scandium Sc and dysprosium Dy can be used.

Since the translucent alumina ceramic containing a rare earth oxide as an additive does not form a spinel structure, the entire translucent ceramic discharge vessel can be free of a spinel structure. .

According to a third aspect of the present invention, there is provided the high-pressure discharge lamp according to the first aspect, wherein the translucent ceramic discharge vessel contains magnesium oxide as an additive. It is characterized by being made of alumina ceramic without spinel.

Although the inner surface of the bulging portion surrounds the discharge space, no spinel is present in the inner surface, so that the spinel in the ceramic does not significantly corrode the translucent ceramic discharge vessel.

A high pressure discharge lamp according to a fourth aspect of the present invention is the high pressure discharge lamp according to any one of the first to third aspects, wherein the getter means includes a base end portion of the halide-resistant portion in at least one end portion. It is characterized by being arranged in the vicinity.

According to the present invention, not only is the getter means directly supported near the base end of the halide-resistant part, but also a ceramic sleeve is arranged around the power supply conductor, and the getter means is supported by the ceramic sleeve. Good. In this case, a specific means for supporting the getter means on the ceramic sleeve is not limited. For example, a groove is formed in a getter supporting portion on the outer surface of the ceramic sleeve, and a wire of the getter means is wound around the groove. To support. However, the getter may be formed in a plate shape.

[0047] Even if the getter means is supported by the ceramic sleeve, the getter means will exhibit the desired action. Further, the above configuration facilitates the support of the getter means.

On the other hand, the getter means can be supported on the halide-resistant part by, for example, winding the getter means on the halide-resistant part in a linear form. Further, the getter means may be welded to the halide-resistant portion, but need not be welded unless it moves only by winding.

The getter means may be plate-shaped or the like.

According to a fifth aspect of the invention, there is provided a high-pressure discharge lamp according to any one of the first to third aspects, wherein the getter means is a sealing portion of the power supply conductor. .

In order to use the sealing portion as getter means, the portion is preferably made of niobium and / or tantalum.

Further, in order for the sealing portion to also function as getter means, an embodiment in which hydrogen and oxygen are removed during the manufacturing process of the high pressure discharge lamp and an embodiment in which hydrogen and oxygen are removed during operation of the high pressure discharge lamp Any of these may be adopted.

First, an example of the former embodiment will be described. For example, a ring of a ceramic sealing compound containing dysprosium oxide is placed on the end portion of the translucent ceramic discharge vessel and heated and melted, and a part of the sealing portion is placed in the end portion of the translucent ceramic discharge vessel. Make an exposed state, and in this state, place the translucent ceramic discharge vessel
Heat to a temperature of 1100 ° to release hydrogen and oxygen in the translucent ceramic discharge vessel. The released hydrogen and oxygen pass through the sealing portion and are removed.

Next, a ring of the ceramic sealing compound containing, for example, magnesium oxide is placed on the end portion and heated and melted again, so that the ceramic sealing compound containing dysprosium oxide is in the end portion of the sealing portion. When the exposed portion is completely covered, a continuous seal of the two ceramic sealing compounds is formed.

The latter embodiment will be described. In order to act as getter means during operation of the high-pressure discharge lamp, the sealing part of the power supply conductor must be exposed in the end part of the translucent ceramic discharge vessel. However, care must be taken to prevent corrosion by halides. To this end, the halide-resistant portion of the power supply conductor extends into the end portion by a distance equal to or greater than the value obtained by adding 2 mm to the inner diameter of the end portion.

In the present invention, since the sealing portion of the power supply conductor is also used as the getter means, the number of parts and the number of assembling steps are reduced, so that the cost can be reduced.

According to a sixth aspect of the present invention, there is provided a lighting device comprising: a lighting device main body; and the high-pressure discharge lamp according to any one of the first to fifth aspects mounted on the lighting device main body. I have.

The present invention is applicable to all devices that use the high-pressure discharge lamp of the present invention as a light source for any purpose, and these devices are collectively referred to as lighting devices. For example, various lighting fixtures, display devices, light projecting devices, and the like. Lighting equipment includes outdoor and indoor lighting equipment. The light projecting device can be applied to a liquid crystal projector, an overhead projector, a search light, a head lamp for a moving object, and the like.

[0059]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an enlarged sectional view of a main part of a first embodiment of the high-pressure discharge lamp of the present invention.

In the figure, 1 is a translucent ceramic discharge vessel, 2 is a ceramic sleeve, 3 is a power supply conductor, 4 is an electrode, 5 is getter means, 6 is a ceramic sealing compound seal, and 7 is a slight gap. is there.

The translucent ceramic discharge vessel 1 is made of translucent alumina ceramic containing lanthanum oxide as an additive, and has a bulging portion 1a and end portions 1b, 1b.

The bulging portion 1a has an inner diameter of 13 mm and a total length of 35 m.
m, a wall thickness of about 1 mm, and comprises a cylindrical portion and a pair of conical portions located at both ends thereof.

The end portion 1b has an inner diameter of 2.2 mm and a length of 1.
It has a cylindrical shape with a thickness of 5 mm and a thickness of about 1 mm.

The ceramic sleeve 2 is made of alumina and has a cylindrical shape having an outer diameter of 2 mm, an inner diameter of 1 mm, and a length of 15 mm. Then, at a position 5 mm from the outer end of the ceramic sleeve 2, a width of about 1 mm and a depth of about 0.
A 3 mm groove 2a is formed.

The power supply conductor 3 comprises a sealing portion 3a and a halide-resistant portion 3b.

The sealing portion 3a is made of a niobium rod having an outer diameter of 0.9 mm and a length of 4 mm.

The halide-resistant part 3b has an outer diameter of 0.7 m.
m, and is welded to the tip of the sealing portion 3a by laser.

The electrode 4 is constituted by winding a tungsten wire having an outer diameter of 0.5 mm twice around the tip of the halide-resistant part 3b.

The getter means 5 is made of a niobium wire having an outer diameter of 0.5 mm, and is supported by being wound three to four turns in a groove 2 a formed around the ceramic sleeve 2.

Sealing compound 6 for ceramic sealing
Is obtained by melting and solidifying Al ₂ O ₃ —SiO ₂ —Dy ₂ O ₃ -based glass frit and sealing the end portion 1 b of the translucent ceramic discharge vessel 1, the ceramic sleeve 2 and the power supply conductor 3. The part 3a is hermetically sealed.

Thus, there is a slight gap 7 between the halide-resistant portion 3b and the inner surface of the ceramic sleeve 2, and between the outer surface of the ceramic sleeve 2 and the inner surface of the end portion 1b of the translucent ceramic discharge vessel 1. Are formed.

Further, a starting gas, a halide of a luminescent metal and mercury for buffering are sealed as a discharge medium in the translucent ceramic discharge vessel 1.

The starting gas is 50 torr of argon.

The luminescent metal halide is 30 mg of a mixture of dysprosium iodide, thallium iodide and sodium iodide.

The obtained high-pressure discharge lamp was 100 V AC.
Operates at 250 W lamp power at the power supply.

The lighting test of the high-pressure discharge lamp of this embodiment and the high-pressure discharge lamp of the comparative example having the same specifications as above except that no getter was provided showed that the luminous efficiency for 100 hours was 90 lm / W, and the correlated color was 100 hours. Although the temperature was 4000K, after 6000 hours had elapsed, the present embodiment provided a value of 8 for 100 hours.
5%. In contrast, the comparative example was also 75%.

In this embodiment, the lamp voltage is +15.
V or less, but +25 V in the comparative example.

Hereinafter, a method of manufacturing the high-pressure discharge lamp will be described.

The power supply conductor 3 is manufactured by welding the sealing portion 3a and the halide-resistant portion 3b having the electrode 4 attached to the tip, and this is inserted into the ceramic sleeve 2 to form the sealing structure M. Constitute.

Next, the sealing structure M is inserted into one end portion 1b of the translucent ceramic discharge vessel 1, and a ceramic sealing compound previously formed into a ring shape is inserted into the end of the translucent ceramic discharge vessel 1. The ceramic sealing compound is melted by being placed on the end face of the part 1b and heated in a vacuum or rare gas atmosphere, and is extended to a predetermined position to form the seal 6.

Thereafter, the halide pellets and mercury are introduced into the translucent ceramic discharge vessel 1 from the other end portion in the dry box, and then the sealing structure M is inserted into the other end portion. The ring-shaped ceramic sealing compound is placed on the end face of the end portion, and heated in an argon atmosphere to hermetically seal the translucent ceramic discharge vessel 1 to form a high-pressure discharge lamp. obtain.

In the above steps, the sealing portion of the power supply conductor 2 is completely surrounded by the ceramic sealing compound seal 6.

Next, in a vacuum atmosphere at 650 ° C.
The high pressure discharge lamp is heated for about 2 hours. In this step, the halide pellets in the translucent ceramic discharge vessel 1 are melted, and the moisture contained therein is released into the translucent ceramic discharge vessel 1. Then, since the released moisture is absorbed by the getter means 5, the inside of the translucent ceramic discharge vessel 1 is cleaned up.

The higher the heating temperature, the sooner the impurity gas is absorbed, but if the heating temperature exceeds 750 ° C., the seal of the ceramic sealing compound may be damaged. 700 ° C. is desirable.

Further, the cleanup in the translucent ceramic discharge vessel is also performed by heat generated by the subsequent discharge.

FIG. 2 is an enlarged sectional view of a main part of a high-pressure discharge lamp according to a second embodiment of the present invention.

In the following, the same parts as those in FIG.

The present embodiment is different from the first embodiment in that the power supply conductor 3 and the ceramic sleeve 2 are easily fixed.

That is, in order to position the sealing portion 3 a with respect to the ceramic sleeve 2, a caulked portion k is formed at a position in contact with the ceramic sleeve 2.

On the other hand, a peripheral step s is formed on the inner surface of the outer end of the end portion 1 b of the translucent ceramic discharge vessel 1, and a circumferential projection p is formed on the outer surface of the outer end of the ceramic sleeve 2.

Then, the power supply conductor 3 is inserted into the ceramic sleeve 2 so that the caulked portion k comes into contact with the end face of the ceramic sleeve 2. Further, the ceramic sleeve 2 is inserted into the end portion 1b, and the peripheral convex portion p is brought into contact with the peripheral step s of the end portion 1b. In this state, the ceramic sealing compound seal 6 is formed to make the translucent ceramic discharge vessel 1 airtight. With this configuration, the power supply conductor 3 and the ceramic sleeve 2 can be fixed at predetermined positions by gravity. In addition, the falling position of the seal of the ceramic sealing compound can be regulated by the locking of the peripheral step portion s and the peripheral convex portion p.

FIG. 3 is an enlarged sectional view of a main part showing a third embodiment of the high-pressure discharge lamp of the present invention.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description is omitted.

This embodiment is different in that the ceramic sleeve is divided into two parts.

That is, the first ceramic sleeve 2 _A
Contributes to the seal 6 of the compound for ceramic sealing,
The second ceramic sleeve 2 _B is a halide-resistant part 3
This contributes to forming a small gap 7 around b.

[0097] wound are disposed in the halogen-resistant portion 1b getter means 5 by using a between both the ceramic sleeve 2 _A and 2 _B.

[0098] is used stopper 8 to position the second ceramic sleeve 2 _B.

FIG. 4 is an enlarged sectional view of a main part of a high-pressure discharge lamp according to a fourth embodiment of the present invention.

In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals, and the description is omitted.

The present embodiment is different in that the sealing portion is constituted by the niobium cap 3a '.

That is, the seal 6 of the ceramic sealing compound is formed between the end portion 1b and the niobium cap 3a ', so that the translucent ceramic discharge vessel 1 is airtight.

The hydrogen and oxygen getters 5 are wound around the base end of the anti-halide portion 3b. An intermediate portion of the halide-resistant part 3b is inserted into the ceramic sleeve _2C and is fixed between the getter means 5 and the stopper 8. This ceramic sleeve 2 _C forms a slight gap 7.

FIG. 5 is an enlarged sectional view of a main part of a high-pressure discharge lamp according to a fifth embodiment of the present invention.

In the figure, the same parts as those in FIG.

The present embodiment is different in that the sealing portion 3a of the power supply conductor 3 is also used as getter means, and a ceramic tube is not used.

That is, the translucent ceramic discharge vessel 1 '
Has an inner diameter of 1.2 mm, a length of 15 mm,
It has a cylindrical shape with a thickness of 2.9 mm.

The anti-halide portion 3b of the power supply conductor 3 has entered the end portion 1b 'to a position of 10 mm.

The portion of the sealing portion 3a of the power supply conductor 3 on the side of the halide-resistant portion 3b is exposed from the seal 6 in the end portion and also serves as getter means.

During the operation, hydrogen and oxygen as impurity gases in the translucent ceramic discharge vessel 1 ′ are absorbed from the exposed sealing portion 3 a and pass through the sealing portion. And is excluded outside the translucent ceramic discharge vessel 1 '.

FIG. 6 is an enlarged sectional view of a main part of a high-pressure discharge lamp according to a sixth embodiment of the present invention.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description is omitted.

The present embodiment differs from the first embodiment in that the sealing portion 3a "of the power supply conductor 3" is also used as getter means, and the configuration of the translucent ceramic discharge vessel 1 "and the halide-resistant portion 3b 'is different.

That is, the translucent ceramic discharge vessel 1 ″
Although MgO is used as an additive, it is formed using a material in which the amount of addition is reduced and the temperature at the time of sintering is increased to sublime the spinel on the inner surface.

The bulging portion 1a ″ is closed by an end plate having a center hole formed at both ends of a cylinder having an inner diameter of 9.7 mm and a total length of 47 mm.

For the end portion 1b ", a translucent alumina ceramic tube having an outer diameter of 2.6 mm and an inner diameter of 1.0 mm is inserted into the center hole of the end plate, and the bulging portion 1a" and the end portion 1b are sintered. To form an integrated translucent ceramic discharge vessel 1 ″.

The sealing portion 3a ″ of the power supply conductor 3 ″ is formed of a niobium rod having a diameter of 0.5 mm. The halide-resistant part 3b ″ is composed of a tungsten rod A and a coil B having a diameter of 0.5 mm, and the base end of the rod A is sealed with a sealing part 3.
The tip of a ″ is welded by a laser. Coil B
Is formed by winding a molybdenum wire having a diameter of 0.2 mm around a rod A.

The electrode 4 ′ is formed by winding a tungsten wire having an outer diameter of 0.1 mm around the tip of the rod A.

Seal 6 for compound for ceramic sealing
Melts an Al ₂ O ₃ —SiO ₂ —Dy ₂ O ₃ system and coats it up to the base end of the halide-resistant portion 3b ″. Is exposed in the translucent ceramic discharge vessel 1 ''. That is, in forming the ceramic sealing compound seal 6, two-stage heating is performed. The first heating causes the ceramic sealing compound to be exposed. And the molten ceramic sealing compound enters a small gap 7 between the inner surface of the end portion 1b "and the outer surface of the sealing portion 3a". Stop with the tip exposed. With the tip of the sealing portion 3a "exposed, the translucent ceramic discharge vessel 1" is
Heat to 100 °. Thereby, hydrogen and oxygen in the translucent ceramic discharge vessel 1 "are released, and the exposed portion at the tip of the sealing portion 1a" absorbs hydrogen and oxygen. Thereafter, the seal 6 of the sealing ceramic compound is again heated and melted to completely cover the sealable portion 1a ", and further, the seal 6 covers the base end of the halide-resistant portion 1b". The hydrogen and oxygen absorbed by the sealing portion 3a "pass through the sealing portion 1a" and are discharged to the outside of the discharge vessel 1 ".

FIG. 7 is a front view showing a high-pressure discharge lamp according to a seventh embodiment of the present invention.

In the figure, 8 is an arc tube, 9 is a support conductor,
10 is a support band, 11 is an insulating tube, 12 is a conductor frame, 13 is a flare stem, 14 is an outer tube, 15 is a base, 1
6 is a conducting wire.

The arc tube 8 is a high-pressure discharge lamp having the same structure as the embodiment shown in FIG.

The support conductor 9 is welded to the upper sealing portion 3a in the figure of the arc tube 8 to support the arc tube 8 and introduce a current.

The support band 10 supports the lower sealing portion 3a in the figure of the arc tube 8 via the insulating tube 11 in an insulating manner.

The conductor frame 12 is disposed outside the arc tube 8 with a space therebetween, and supports both ends of the support conductor 9 and the support band 10 by welding, and has elastic contact pieces 12a, 12
a.

The flare stem 13 has a pair of internal leads 13a and 13b, and one of the internal leads 13a and 13b.
The lower end of the conductor frame 12 is welded to support the arc tube 8 at a predetermined position. The other internal lead wire 13b
Is connected to the lower sealing portion 3a in the figure of the arc tube 8 via a conducting wire 16.

The outer tube 14 is formed of a cylindrical T-shaped valve. The flare stem 13 is sealed at the lower neck portion in the figure, and the above-described members are hermetically housed therein. The contact piece 12a of the conductor frame 12 elastically contacts the inner surface near the distal end of the outer tube 14, protects the conductor frame 12 against an externally applied impact, and To hold it in place. Further, the inside of the outer tube 14 is evacuated to a vacuum state, or an inert gas is sealed after the evacuation.

The base 15 is fixed to the neck of the outer tube 14 and is electrically connected to the pair of internal lead wires 13a and 13b of the flare stem 13.

Although not shown, an initial getter and a performance getter are provided in the outer tube 14 if necessary.

Thus, the high pressure discharge lamp according to the fifth embodiment of the present invention described above can be used for general lighting.

FIG. 8 is a sectional view showing a ceiling-mounted downlight in an embodiment of the lighting apparatus of the present invention.

In the figure, 17 is a high-pressure discharge lamp, 18
Is a downlight body.

The high-pressure discharge lamp 17 has the same structure as that shown in FIG.

The downlight main body 18 includes a base 18a, a socket 18b, a reflector 18c, and the like.

The base 18a has a ceiling contact edge e at the lower end to be embedded in the ceiling.

The socket 18b is mounted on the base 18a.

The reflection plate 18c is supported by the base 18a and is surrounded so that the emission center of the high-pressure discharge lamp 17 is located substantially at the center.

[0138]

According to the first to fifth aspects of the present invention, at least the inner surface portion surrounding the discharge space of the translucent ceramic discharge vessel is constructed so that no spinel structure is present, and the translucent ceramic discharge vessel is formed. Equipped with getter means for removing impure gas in the vessel, there is little corrosion due to the reaction of the translucent ceramic discharge vessel with the halide, and there is little blackening due to the impure gas, resulting in lower luminous flux and abnormal temperature. It is possible to provide a high-pressure discharge lamp in which an airtight leak due to rising is unlikely to occur.

According to the second aspect of the present invention, the light-transmitting ceramic discharge vessel is formed of a light-transmitting alumina ceramic containing a rare-earth oxide as an additive. A high-pressure discharge lamp having no structure can be provided.

According to the third aspect of the present invention, the light-transmitting ceramic discharge vessel additionally contains magnesium oxide as an additive, but no spinel is present on the inner surface of the protruding portion surrounding the discharge space. A high-pressure discharge lamp provided with a light-transmitting ceramic discharge vessel having a small reaction with a halide without changing materials and equipment can be provided by using a transparent alumina ceramic.

According to the fourth aspect of the present invention, since the getter means is a sealing portion of the power supply conductor, it is possible to provide an inexpensive high-pressure discharge lamp having a simple structure.

According to the fifth aspect of the present invention, in addition, the getter means is disposed near the base end of the anti-halide portion of the power supply conductor, thereby providing a high-pressure discharge lamp in which the function of the getter means is effectively performed. Can be provided.

According to the invention of claim 6, it is possible to provide a lighting device having the effects of claims 1 to 5.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part showing a first embodiment of a high-pressure discharge lamp of the present invention.

FIG. 2 is an enlarged sectional view of a main part showing a second embodiment of the high-pressure discharge lamp of the present invention.

FIG. 3 is an enlarged sectional view of a main part showing a third embodiment of the high-pressure discharge lamp of the present invention.

FIG. 4 is an enlarged sectional view of a main part of a high-pressure discharge lamp according to a fourth embodiment of the present invention.

FIG. 5 is an enlarged sectional view of a main part showing a fifth embodiment of the high-pressure discharge lamp of the present invention.

FIG. 6 is an enlarged sectional view of a main part showing a sixth embodiment of the high-pressure discharge lamp of the present invention.

FIG. 7 is an enlarged sectional view of a main part of a high-pressure discharge lamp according to a seventh embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a ceiling-recessed downlight in one embodiment of the lighting device of the present invention.

[Description of Signs] 1 ... Translucent ceramic discharge vessel 1a ... Swelling part b ... End part 2 ... Ceramic sleeve 2a ... Groove 3 ... Power supply conductor 3a ... Sealable part 3b ... Halogen resistant part 4 ... Electrode 5 ... getter means 6 ... sealing of the compound for ceramic sealing 7 ... slight gap

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Ashida 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Litec Corporation (72) Inventor Tatsuo Otabe 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo No. Toshiba Litec Co., Ltd.

Claims (6)

[Claims] At least an inner surface portion surrounding a discharge space has a swelling portion configured so as not to have a spinel type structure and an end portion having an inner diameter smaller than that of the swelling portion and arranged at both ends of the swelling portion. A translucent ceramic discharge vessel comprising:
A sealing portion and a halide-resistant portion having a base end connected to the distal end of the sealing portion, penetrate the inside of the end portion of the light-transmitting ceramic discharge vessel, and A power supply conductor forming a small gap therebetween; an electrode disposed in the bulge portion and connected to the power supply conductor; a ceramic sealing compound seal for sealing an end portion and the power supply conductor; and a metal halide. A high-pressure discharge lamp, comprising: a discharge medium containing a discharge space and a getter means for removing impurity gas in the discharge space. 2. The high-pressure discharge lamp according to claim 1, wherein the translucent ceramic discharge vessel is made of alumina ceramic containing a rare earth oxide as an additive. 3. The high-pressure high-pressure ceramic discharge vessel according to claim 1, wherein the transparent ceramic discharge vessel contains magnesium oxide as an additive, but is made of alumina ceramic having no spinel on the inner surface of the bulging portion. Discharge lamp. 4. The high-pressure discharge according to claim 1, wherein the getter means is disposed near the base end of the halide-resistant part in at least one end part. lamp. 5. The high pressure discharge lamp according to claim 1, wherein the getter means is a sealing portion of the power supply conductor. 6. A lighting device comprising: a lighting device main body; and the high-pressure discharge lamp according to claim 1 mounted on the lighting device main body.