JP2000090877A - High-pressure discharge lamp and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce sputtering in glow/arc transfer, to shorten transfer time and to miniaturize a lighting device by lowering starting voltage. SOLUTION: A power supply conductor 2 sealed at both the ends of a translucent discharge container 1 is constituted of a sealing part 2a and a halide- resistant part 2b and an electrode 4 disposed at a tip of the power supply conductor 2 is mainly constituted of a plate. The electrode 4 can be compactly constituted for an increase in surface area by curving the plate part around a shaft of the power supply conductor 2 in a cylindrical shape, for instance. As a result, because surface area of the electrode 4 is increased and electrode surface current density is lowered, sputtering is reduced. By making it possible to reduce heat capacity of the electrode 4, glow arc transfer time is shortened. Further, electron radiation performance is improved and starting voltage is lowered by an edge effect by an edge at an end face of the plate of the electrode 4.

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 discharge vessel and a lighting device using the same.

[0002]

2. Description of the Related Art In recent years, high-pressure discharge lamps having a translucent ceramics discharge vessel having advantages of longer life and higher efficiency than conventional quartz glass discharge vessels have been developed and are being widely used.

Further, the present inventors have disclosed a technique relating to a small high-pressure discharge lamp having a rated power consumption of about 20 W utilizing the above characteristics.

[0004] With the downsizing of the high pressure discharge lamp described above, downsizing of the high pressure discharge lamp lighting device is also required.

[0005]

However, in the prior art, when the high pressure discharge lamp lighting device is downsized,
If the characteristics of the high-pressure discharge lamp are hindered, and if the characteristics of the high-pressure discharge lamp are prioritized, there is a contradictory problem that the lighting device cannot be downsized.

That is, miniaturization of the high pressure discharge lamp lighting device is actually governed by reducing the size of the rising pressure transformer. In order to reduce the size of the step-up transformer, the number of secondary windings must be reduced, thereby lowering the secondary open-circuit voltage. With this, the high-pressure discharge lamp becomes difficult to start or, depending on the circuit system, in the transition period when the transition from the starting state to the arc discharge, which is a normal lighting state, the lamp power supplied to the high-pressure discharge lamp increases, so that The electrode of the high-pressure discharge lamp is transiently locally heated, causing sputtering or the like, and the transparent ceramics discharge vessel is blackened.

[0007] The present invention reduces sputtering at the glow-arc transition, shortens the transition time,
It is an object of the present invention to provide a high-pressure discharge lamp capable of reducing the starting voltage to reduce the size of the lighting device, and a lighting device using the same.

[0008]

A high-pressure discharge lamp according to the present invention comprises a light-transmitting discharge vessel, a sealing portion and a halide-resistant portion projecting from the sealing portion. A power supply conductor sealed at both ends of the light-transmitting discharge vessel at a transparent portion; an electrode disposed at the tip of the power supply conductor and mainly composed of a plate located inside the light-transmitting discharge vessel; An ionizing medium containing a metal halide and sealed in a translucent discharge vessel.

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

(Transparent Discharge Vessel) The translucent discharge vessel is made of quartz glass or translucent ceramics.
A discharge space is formed inside. Here, the term “light-transmitting” means that the light emitted by the discharge is transmitted to such an extent that the light can be emitted to the outside, and may be not only transparent but also light-diffusing.

[0011] Translucent ceramics include single crystal metal oxides such as sapphire, polycrystalline metal oxides such as translucent and airtight aluminum oxide, yttrium-aluminum-garnet (YAG), yttrium oxide. (YOX) means a material having light transmittance and heat resistance, such as a polycrystalline non-oxide such as aluminum nitride (AlN).

When quartz glass is used for the light-transmitting discharge vessel, the quartz glass softens when heated, so that it has workability. Known sealing means such as a pinch seal can be used by utilizing the workability of quartz glass.

On the other hand, since the translucent ceramics are difficult to melt and have no workability, they are sealed by a seal using a ceramic sealing compound.

(Regarding Power Feeding Conductor) "Power feeding conductor"
A voltage is applied between the internal electrodes by hermetically penetrating the translucent discharge vessel through a ballast means from a power source, a high-pressure discharge lamp is started, a current is introduced to light the lamp, and in some cases, the electrodes are turned on. It works to support.

The power supply conductor includes a sealing portion and a halide-resistant portion, regardless of whether the translucent discharge vessel uses quartz glass or translucent ceramics.

The sealing portion is mainly sealed to the light-transmitting discharge vessel, thereby sealing the light-transmitting discharge vessel and fixing the power supply conductor.

The halide-resistant portion extends from the tip of the sealing portion and reaches the electrode. Therefore, since a part of the halide resistant part is exposed to the high-temperature halide and free halogen present in the discharge vessel during operation of the high-pressure discharge lamp, a part of the part is exposed to the discharge space. Composed of substances that do not occur at all. For example, it is formed of tungsten, molybdenum, or an alloy containing these as main components.

The halogen-resistant part can be formed of a hollow pipe of tungsten or an alloy containing tungsten as a main component and having a thickness of 10 to 300 μm. Small, for example, rated power consumption 30 W or less, preferably 2
In a high-pressure discharge lamp of about 0 W, a wall thickness of 10 to 10
0 μm is appropriate. In addition, rated power consumption 150 ~
300μm maximum for 400W high pressure discharge lamp
A hollow pipe having a thickness of up to 100 mm can be used.

Further, the hollow pipe may be a pipe having no joint or a pipe having a joining line with a slight gap at the joint. The latter can be obtained at a low cost because the pipe can be easily formed. Also, when connecting the pipe by inserting it into the sealing part, since it has a joint line, it fits flexibly with the other member,
Good connection can be obtained.

In the case where the tungsten-based hollow pipe is used for the halide-resistant part, the tip of the pipe can be used as an electrode. For this reason, the structures of the power supply conductor and the electrode can be significantly simplified. In addition, even if quartz glass adheres to the base end side of such a hollow pipe by sealing or a ceramic sealing compound seal adheres, the hollow pipe absorbs the stress caused by the difference in thermal expansion, Cracks are less likely to occur.

Also, by molding into a hollow pipe,
Since the mechanical strength is improved, it sufficiently exhibits its function as a halide-resistant part.

When quartz glass is sealed with a pinch seal, the sealing portion is preferably made of a metal foil such as molybdenum.

On the other hand, when sealing a translucent ceramic, the sealing portion is generally made of a sealing metal having a coefficient of thermal expansion similar to that of a translucent ceramic such as niobium and a sealing compound for a ceramic sealing compound. Use empty sticks.
In the present invention, an empty rod or a hollow pipe of a sealing metal can be used as the sealing portion. The power supply conductor is hermetically sealed in the small-diameter cylindrical portion of the translucent discharge container by means described later.

(Electrode) The electrode has the characteristic configuration of the present invention. That is, the electrode is disposed at the tip of the halide-resistant portion of the power supply conductor and located inside the light-transmitting discharge vessel, but is mainly composed of a plate, so that the surface area is increased and the heat capacity is reduced as much as possible. I'm making it smaller. However, the plate portion can adopt various shapes. For example, the part of the board is flat,
Can be curved. The curved shape may be cylindrical, U-shaped, semicircular, cylindrical, that is, pipe-shaped, or the like.

In order to support the electrode and connect it to the power supply conductor, the electrode can be formed separately from the halide-resistant part of the power supply conductor and fixed to the tip of the halide-resistant part. However, it may be formed integrally with the halide-resistant part of the power supply conductor. In this case, if the halide-resistant portion is a hollow pipe, the tip may be used directly as an electrode. Further, even if the halide-resistant part and the electrode are integrated, the tip of the halide-resistant part made of, for example, an empty rod may be pinched and formed into a plate. Further, in the case of an AC lighting high pressure discharge lamp, a pair of electrodes can be formed integrally with a halide-resistant part, but in the case of a DC lighting type, a cathode is formed integrally and an anode is separately provided. It can also be formed.

A preferred construction when the electrode is formed integrally with the halide-resistant part is that the transparent ceramic discharge vessel is formed by making at least the tip part of the halide-resistant part into tungsten or an alloy mainly containing tungsten as a hollow pipe. This is a structure for projecting into the bulging portion of the. that way,
An electrode mainly composed of a plate in which the tip of the halide-resistant portion is curved in a cylindrical shape as it is is constituted.

(Ionizing Medium) In the present invention, the ionizing medium is not particularly limited. A high-pressure mercury vapor discharge lamp (a so-called mercury lamp) can be obtained using mercury and a rare gas as an ionizing medium. By enclosing a metal halide containing at least a luminescent metal, a high-pressure metal halide discharge lamp (a so-called metal halide lamp) can be obtained. In this case, an appropriate amount of mercury can be sealed together with a rare gas at an appropriate pressure as a buffer medium.

(Regarding the operation of the present invention) In the present invention, the surface area of the electrode is increased by constituting the electrode mainly by a plate. When the surface area of the electrode increases, the electrode surface current density (A / cm ² ), which is one of the factors determining the sputtering rate in the glow discharge mode in the glow-arc transition, decreases, and the cathode drop voltage decreases accordingly. Therefore, sputtering is reduced.

Further, since the heat capacity of the electrode can be reduced,
Glow-arc transition time is reduced.

Further, since the electrode is mainly composed of a plate, the electron emission performance is remarkably improved by an edge effect due to the edge of the end face of the plate of the electrode. As a result, the starting voltage of the high-pressure discharge lamp decreases.

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 ionizing medium is:
It is characterized by containing a metal halide.

The present invention defines a configuration as a so-called metal halide lamp.

As the halogen constituting the metal halide, one or more of iodine, bromine, chlorine and fluorine can be used.

The metal halide of the luminescent metal has a luminescent color,
In order to obtain radiation having desired luminous characteristics with respect to the average color rendering index Ra and luminous efficiency, etc., any of the known metal halides can be arbitrarily selected according to the size and input power of the transparent ceramic discharge vessel. You can choose. For example, sodium Na, lithium Li,
One or more halides selected from the group consisting of scandium Sc and rare earth metals can be used.

Further, an appropriate amount of mercury can be sealed as a buffer metal. Instead of mercury, a metal having a relatively high vapor pressure and little light emission in the visible light region, or a metal that does not emit light, for example, a halide such as aluminum can be sealed.

As the rare gas, argon, xenon, neon or the like can be used.

The high-pressure discharge lamp according to the third aspect of the present invention is the high-pressure discharge lamp according to the first or second aspect, wherein the electrodes are:
The plate portion is curved around the axis of the power supply conductor.

The term “a portion of the plate is curved” means an arc, a semicircle, a partially open circle, or a complete circle along the axis of the power supply conductor. Note that “around the axis” means that the radial distance from the axis is within an appropriate range.

Thus, in the present invention, since the plate portion of the electrode is curved around the axis of the power supply conductor, the electrode can be made compact despite its large surface area.

According to a fourth aspect of the present invention, there is provided the high-pressure discharge lamp according to any one of the first to third aspects, wherein the translucent discharge vessel has a bulging portion surrounding the discharge space and a bulging portion. A light-transmitting ceramic having a small-diameter tubular portion disposed in communication with both ends and having an inner diameter smaller than the bulging portion; the power supply conductor is inserted into the small-diameter tubular portion of the light-transmitting discharge vessel; A ceramic sealing compound seal that seals between the small-diameter cylindrical portion of the container and the mainly sealing portion of the power supply conductor to form a small gap between the small-diameter cylindrical portion and the halide-resistant portion is provided. Is characterized by:

The present invention is characterized in that the translucent discharge vessel is made of translucent ceramics.

(Regarding Translucent Discharge Vessel) A translucent discharge vessel made of translucent ceramics seals the central bulge surrounding the discharge space and the translucent discharge vessel.
It is composed of a pair of small-diameter cylindrical portions located at both ends of the bulging portion for sealing the power supply conductor.

The bulging portion and the small-diameter cylindrical portion can be integrally formed from the beginning. Further, for example, a cylinder forming a bulging portion, a pair of end plates which are fitted and closed at both end surfaces of the cylinder, and a small-diameter tubular body which is fitted into a center hole of the end plate to form a small-diameter tubular portion are provided. It is also possible to form an integral discharge vessel by temporarily sintering each other, fitting them as required, and sintering them.

Further, the inner volume of the light-transmitting discharge vessel is not limited, but the present invention is particularly effective in a small-sized container having an inner volume of 0.05 cc or less, preferably 0.04 cc or less. . Such a small translucent discharge vessel can be formed to have an overall length of 30 mm or less.
Further, the rated lamp power is preferably set to 20 W or less.

(Regarding Power Feeding Conductor) The power feeding conductor is used for at least one small-diameter cylindrical portion of the translucent discharge vessel.

The sealing portion is formed by using a ceramic sealing compound seal described later to seal the light-transmitting discharge vessel, between the small-diameter cylindrical portion and the sealing portion, or further, if necessary, to the ceramic tube. Any structure suitable for sealing with intervening therebetween may be used, and niobium is used based on the idea that a material having a thermal expansion coefficient which is generally known in the past and which is relatively close to that of the light-transmitting discharge vessel is used. , Tantalum, titanium, zirconium, hafnium, vanadium and the like can be used. In this case, the sealing portion may be an empty rod or a hollow pipe.

However, the present invention is not limited to the above, and even if the sealing portion has a small coefficient of thermal expansion and a relatively large difference from that of the light-transmitting discharge vessel, the difference in thermal expansion causes A configuration that absorbs the generated stress may be used. As the latter configuration, for example, the thickness is 10 to 100.
μm molybdenum can be molded into a hollow pipe for use. Further, the above-mentioned so-called sealing metal having a thermal expansion coefficient close to the molybdenum hollow pipe may be further added.

The molybdenum hollow pipe constituting the sealing portion may be a complete pipe having no joint or a pipe having a joint line at the joint. Advantageously, the presence of a small gap in the joint line facilitates the manufacture of the pipe and facilitates and ensures connection by insertion of external feedthroughs and / or halide-resistant parts.

The halide-resistant portion can be constituted by a hollow pipe made of molybdenum, tungsten or an alloy containing these as a main component and having a thickness of 10 to 100 μm from the whole or from the base end to the middle. These metals have a coefficient of thermal expansion that is clearly smaller than that of the ceramic sealing compound seal and the translucent discharge vessel, but by reducing the thickness as described above, the stress caused by the difference in thermal expansion is reduced. Easy to absorb. By forming the hollow pipe together therewith, the mechanical strength is improved, and the connection of the electrode or other members such as the sealing portion is made easy, accurate and reliable. If a hollow pipe is used in which the above-mentioned thin metal plate is bent into a cylindrical shape to form a joining line with a slight gap at the joint, the connection with the electrode and / or the sealing portion is further improved.

A small gap called a capillary is formed between the halide-resistant portion and the inner surface of the small-diameter cylindrical portion. A part of the small gap on the end side is filled with the sealing material of the ceramic sealing compound, but in the remaining part, the excess halide stays in a liquid phase state during lighting. Then, the temperature of the liquid surface on the discharge space side becomes the coldest part. By appropriately setting the width and length of the small gap and the amount of the ionized medium to be filled, a desired coldest part temperature can be obtained.

If the sealing part and the halide-resistant part are separate, the connection between them is shrink-fitted in advance,
It can be performed by welding or the like. However, when a hollow pipe is used for the sealing portion and / or the halide-resistant portion, the other member may be inserted and connected to one of the hollow pipes.

(Regarding the Seal of the Ceramic Sealing Compound) The seal of the ceramic sealing compound is formed of a sealing portion at the end face of the small-diameter cylindrical portion and at least a sealing portion between the small-diameter cylindrical portion of the light-transmitting discharge vessel. If some or all of the sealing metal is used for
The sealing portion is surrounded so as to seal the light-transmitting discharge container so that the sealing portion is not exposed to the discharge space side in the light-transmitting discharge container. When no sealing metal is used other than the thin molybdenum hollow pipe in the sealing portion, the sealing portion may not be surrounded so as not to be exposed to the discharge space side. .

On the other hand, when the high-pressure discharge lamp is sealed in the evacuated outer bulb and turned on, the sealing metal may be exposed to the outside from the seal. However, when the high-pressure discharge lamp is lit while being exposed to the atmosphere, it is surrounded by a ceramic sealing compound seal without exposing the sealing metal to the outside so as not to be oxidized. Then, an external lead wire made of an oxidation-resistant metal is connected to the sealing portion in advance, and is exposed to the outside from the seal of the ceramic sealing compound.

In order to form the seal of the ceramic sealing compound at a predetermined position, the translucent discharge vessel is fixed with the portion to be sealed facing upward, and a solid ceramic sealing material is placed outside the portion to be sealed. Apply compound and heat. Then, the ceramic sealing compound melts by heating and enters between the small-diameter cylindrical portion and the sealing portion, and the tip of the molten ceramic sealing compound is further positioned at a predetermined position in the middle of the halide-resistant portion. Cool down when you enter.

Thus, the power supply conductor is fixed at a predetermined position by the sealing of the ceramic sealing compound, and the translucent discharge vessel is sealed.

Furthermore, in the case of a small high-pressure discharge lamp, the halide-resistant portion of the power supply conductor can be covered over a distance of 0.2 to 3 mm by the sealing of the ceramic sealing compound. When the covering distance of the halide-resistant portion is less than 0.2 mm, the tubular sealing portion is easily corroded by the halide during lighting, and when it exceeds 3 mm, cracks are not easily generated. However, when the halide-resistant portion is made of a hollow pipe made of tungsten, molybdenum, or an alloy containing these as a main component having a thickness of 10 to 300 μm, the pipe absorbs the stress caused by the difference in thermal expansion, so that cracks may occur. There is no fear.

(Other Configurations) The width of the small gap formed between the inner surface of the small-diameter cylindrical portion of the translucent discharge vessel and the power supply conductor is not particularly limited in the present invention, but is relatively small. For high pressure discharge lamps, 0.21
mm or more.

According to the studies made by the present inventors, it has been found that, in the case of a small high-pressure discharge lamp, even if the prior art is scaled down and applied, a good lamp cannot be obtained. That is, when the lamp power is reduced, it is necessary to secure an appropriate coldest part temperature in order to secure luminous efficiency, and it is essential to reduce the heat capacity of the entire light-transmitting discharge vessel. At this time, if the shape and electrode dimensions of the light-transmitting discharge vessel are simply and proportionately reduced in the case where the lamp power is relatively large, a leak occurs in the sealed portion in a short time after lighting. It is considered that this is because when the translucent discharge vessel is made smaller, the form of heat transfer from the heating element including the discharge plasma to the sealed portion, that is, the balance of heat conduction, convection, and radiation is lost.

As described above, the high-pressure discharge lamp can be turned on in the atmosphere by forming the external lead wire exposed from the light-transmitting discharge vessel to the outside with an oxidation-resistant conductor. However, if necessary, the high-pressure discharge lamp is housed in an envelope, the interior of the envelope is evacuated, and an inert gas is sealed at an appropriate pressure, thereby forming a cylindrical seal as an external lead wire in the envelope. Even if the adhesive portion is directly exposed to the outside, or if another sealing conductor is inserted at the base end of the cylindrical sealing portion and connected to be exposed to the outside, the sealing conductor is not exposed. Oxidation can be prevented.

By evacuating the inside of the envelope,
The temperature gradient on the surface of the translucent discharge vessel can be reduced. Thereby, when the discharge vessel is formed of a translucent ceramic, cracks are less likely to occur.

According to a fifth aspect of the present invention, there is provided a high-pressure discharge lamp according to the fourth aspect, wherein the sealing portion comprises a hollow pipe; and the halide-resistant portion is inserted into a tip of the sealing portion. Connected.

According to the present invention, the sealing portion is constituted as described above, so that connection can be made by inserting a halide-resistant portion into the sealing portion.

Further, by forming an opening on the side surface of the pipe at the sealing portion, the molten ceramic sealing compound can flow into the pipe from the opening to form a sealing film therein. . Since the temperature of the power supply conductor is transiently higher than the temperature of the translucent discharge vessel during heating in the sealing step, it is considered that the ceramic sealing compound in a molten state flows into the opening preferentially. Thus, an airtight cross section including a translucent discharge vessel made of a translucent ceramic, a seal, and a sealing portion can be formed in the cross section in which the seal film is formed.

Further, the film of the seal can be extended to the connection portion of the halide-resistant portion. Then, the connection can be surrounded by the seal film.
Prevents halides and free halogens from penetrating and corroding the sealing part pipe even when the connection between the halide resistant part and the sealing part is not airtight. can do.

Thus, in the present invention, the connection between the sealing portion and the halide-resistant portion is easy, accurate and reliable.

The high-pressure discharge lamp according to the sixth aspect of the present invention is the high-pressure discharge lamp according to the fourth or fifth aspect, wherein the sealing portion comprises:
Consisting of a hollow pipe; the halide-resistant part consisting of a hollow pipe whose base end is connected to the sealing part via a halide-free hollow rod conductor inserted at the tip of the sealing part; It is characterized by:

The empty rod conductor is made of a halogen-resistant metal or a cermet of the metal whose coefficient of thermal expansion is close to that of the sealing portion. For example, molybdenum or a cermet of molybdenum and ceramics constituting a translucent ceramics discharge vessel are used.

The empty rod conductor only needs to be long enough to connect the hollow pipe of the halide-resistant part to the sealing part.

Thus, according to the present invention, since the empty rod conductor is interposed between the sealing portion of the hollow pipe and the hollow pipe of the halide-resistant portion, the empty rod conductor is double hollow. Since the space between the pipes can be air-tightly shut, leakage through the hollow pipe can be reduced.

Further, by using the above cermet as the empty rod conductor, the low thermal conductivity of cermet
Heat conduction from the electrode to the sealing part through the hollow pipe and the hollow rod conductor of the halide-resistant part is reduced, so the temperature rise of the sealing part is reduced, and the reliability of sealing by sealing is improved. I do.

According to a seventh 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 sixth aspects supported by the lighting device main body. I have.

In the present invention, the illuminating device is a concept including any device that uses the light emitted from the high-pressure discharge lamp for some purpose, such as a lighting fixture, a headlight for a moving object, a light source for an optical fiber, an image projection device, a photochemical device, and the like.
The present invention can be applied to a fingerprint discrimination device and the like. Note that the lighting device body refers to the remaining portion of the lighting device excluding the high-pressure discharge lamp.

It is well known to use a discharge lamp lighting device for lighting a high pressure discharge lamp. However, a discharge lamp lighting device having a high frequency lighting circuit using an inverter and a current limiting means is known. It is preferable in terms of size reduction and weight reduction. However, if necessary, a configuration in which a low-frequency alternating current is directly applied to the high-pressure discharge lamp via the current limiting means may be adopted. In this case, the current limiting means can use an inductor, a resistor or a capacitor.

Further, according to the present invention, the high-pressure discharge lamp is provided inside the reflector, the discharge lamp lighting device is provided on the back of the reflector, and the power receiving means is provided on the back of the discharge lamp lighting device. Lighting device, that is, a bulb-type high-pressure discharge lamp. In this case, by housing the discharge lamp lighting device in an appropriate case, the appearance can be satisfactorily adjusted, and the handling can be made easy and safe. The power receiving means receives power from a power supply in order to supply power to the discharge lamp lighting device. As a power receiving means, a mode in which a conducting wire is connected to a power source, a mode in which a well-known base or hooking sealing cap structure is provided, and a mode in which the power source is attached to a lamp socket or a hooking sealing body on the power source side can be appropriately selected and adopted.

By adopting the latter mode of the power receiving means, the lighting device can be mounted in a lamp socket for a general incandescent lamp or a hook-up sealing body, and can be subjected to a high-pressure discharge with the same feeling as an incandescent lamp. The lamp can be turned on.

The bulb-type fluorescent lamp has come to be used with the same feeling as described above, but is not suitable for the purpose of illumination that requires directivity.

On the other hand, in the above-described lighting device, the light emitting portion is close to the ideal point light source, so that a light distribution with a desired directivity can be obtained by the reflecting mirror.

Further, there is a concern that the lighting of the high-pressure discharge lamp may cause a rise in temperature due to heat generation. However, the radiation of heat to the discharge lamp lighting device by the reflector can be reduced.
It is also possible to divert a discharge lamp lighting device for a compact fluorescent lamp.

[0079]

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

FIG. 1 is a front view showing a high-pressure discharge lamp according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the main part.

FIG. 3 is an enlarged perspective view showing the sealing portion.

In each figure, 1 is a translucent discharge vessel, 2 is a power supply conductor, 3 is an external lead wire, 4 is an electrode, and 5 is a seal.

The light-transmitting discharge vessel 1 is made of a light-transmitting alumina oxide and has a bulging portion 1a and small-diameter cylindrical portions 1b and 1b.

The bulging portion 1a has a hollow substantially elliptical spherical shape whose both ends are narrowed by continuous curved surfaces.

The small-diameter cylindrical portion 1b is connected to the bulging portion 1a by a curved surface continuous with the bulging portion 1a.
Is formed.

The power supply conductor 2 comprises a sealing portion 2a and a halide-resistant portion 2b.

The sealing portion 2a functions to seal the translucent discharge vessel 1 between the power supply conductor 2 and the small-diameter cylindrical portion 1b. As shown in FIG. 3, the sealing portion 2a is formed of a niobium hollow pipe, and has openings 2a1 and 2a1 on the side surface near the distal end.

The sealing portion 2a is formed by bending a niobium plate into a cylindrical shape so that there is a slight gap at the joint, and a joining line 2a2 parallel to the axis is provided.

The halide-resistant portion 2b is made of a tungsten pipe and is inserted into and connected to the tip of the sealing portion 2a, and extends into the bulging portion 1a of the translucent discharge vessel 1. To form the electrode 4.

The antihalide portion 2b is formed by bending a thin tungsten plate into a cylindrical shape so that there is a slight gap at the seam and a joint line 2b1 parallel to the axis.

The external lead wire 3 is made of an empty rod made of platinum, and is connected to the base end of the sealing portion 2a by inserting the distal end thereof. It protrudes.

Since the electrode 4 is constituted by the tip of the halide-resistant portion 2b as described above, the electrode 4
Has a cylindrical portion at the end of the plate.

Thus, the power supply conductor 2 has a light transmitting property such that a small gap g is formed between the inner surface of the small-diameter cylindrical portion 1b of the light transmitting discharge vessel 1 and the outer surface of the halide-resistant portion 2b. The discharge vessel 1 is inserted from the small-diameter cylindrical portion 1b into the inside.

The seal 5 comprises a small-diameter cylindrical portion 1b, a sealing portion 2a and a halide-resistant portion 2 of the light-transmitting discharge vessel 1.
In the slight gap g formed between the two portions b, the front end reaches the base end of the halide-resistant portion 2b and surrounds the entire sealing portion 2a. Further, the compound for ceramics sealing has a sealing portion 2a when in a molten state.
Flows into the pipe through the pair of openings 2a1 and 2a1 to form a seal film 5a that also surrounds the connection between the halide-resistant portion 2b and the sealing portion 2a. As a result, an airtight section is formed by the translucent discharge vessel 1, the sealing portion 2a, and the seal 5 in a cross section at a position where the seal film 5a is located.

In the translucent ceramics discharge vessel 1, a metal halide of a luminescent metal is introduced in a rare gas atmosphere before sealing.

[0097]

Embodiment 1 The high-pressure discharge lamp shown in FIGS. 1 to 3 has the following specifications.

Translucent ceramic discharge vessel 1: made of translucent aluminum oxide, having a maximum outer diameter of about 5.5 mm for the bulging portion 1a, an outer diameter of 1.7 mm for the small-diameter cylindrical portion 1b, and a total length of 30
mm, the internal volume is 0.03 cc.

Power supply conductor 2: sealing portion 2a has an outer diameter of 0.6
It is made of a niobium hollow pipe having a thickness of 8 mm, a wall thickness of 0.18 mm, and a total length of 3.5 mm. The halide-resistant part 2b is formed of a tungsten hollow pipe having an inner diameter of 0.29 mm, a thickness of about 50 nm, and a total length of 8 mm. Each of the sealing portion 2a and the halide-resistant portion 2b is provided with bonding lines 2a2 and 2b1 having a slight gap of about 2 μm on average.

Outer lead wire 3 is made of platinum and has an outer diameter of about 0.29 mm.

Electrode 4: constituted by the tip of halide-resistant part 2b.

Then, the translucent ceramics discharge vessel 1
The small gap g formed between the inner surface of the small-diameter cylindrical portion 1b and the outer surface of the halide-resistant portion 2b is 0.21 mm.

Seal 5: Al ₂ O ₃ —SiO ₂ —Dy ₂ O ₃
A solid ceramic sealing compound is used.

Ionizing medium: NaI, InI, TlI,
An appropriate amount of DyI ₃ and mercury are sealed in the translucent ceramics discharge vessel 1, and argon gas is added at about 13300 Pa
Enclosed.

The obtained high-pressure discharge lamp has a rated lamp power of 20 W.

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

In the figure, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the sealing portion 2a 'is constituted by a sealing metal hollow pipe 2aA and a molybdenum hollow pipe 2aB, and the halide-resistant portion 2b' is formed by a molybdenum hollow pipe 2bA and tungsten. Mainly in that it is constituted by the hollow pipe 2bB.

That is, the sealing portion 2a 'is formed by laminating a molybdenum hollow pipe 2aB having a thickness of 10 to 100 μm on the inner surface of a sealing metal hollow pipe 2aA.

The halide-resistant portion 2b 'is formed integrally with the molybdenum hollow pipe 2bA by extending the molybdenum hollow pipe 2aB of the sealing portion 2A as it is, and the tungsten-made hollow pipe 2bB is formed. The base end is inserted and connected to the front end of a hollow pipe 2bA made of a metal.

An opening 2bA1 is formed in the side surface of the middle part of the anti-halide part 2b '.

The end of the seal 5 reaches the vicinity of the opening 2bA1 of the molybdenum hollow pipe 2bA in the halide-resistant portion, and forms a seal film 5a inside the opening 2bA1.

The electrode 4 is formed of a tungsten hollow pipe tip of the halide-resistant portion 2b ', and a coil 4a is wound around a cylinder to improve heat dissipation.

FIG. 5 is a sectional view showing a power supply conductor and electrodes in a third embodiment of the high-pressure discharge lamp of the present invention.

In the figure, the same parts as those in FIG. 4 are denoted by the same reference numerals, and the description is omitted.

In the present embodiment, the sealing portion 2 of the power supply conductor 2 is used.
The main difference is that the hollow pipe 2aB 'made of molybdenum a' is laminated only up to the middle part of the hollow pipe 2aA made of sealing metal.

That is, since the molybdenum hollow pipe 2aB is not laminated at the base end side of the sealing metal hollow pipe 2aA of the sealing portion 2a ', the outer lead wire 3' has a large diameter. Can be used. For this reason, the mechanical strength of the external lead wire 3 'is improved by that amount, and the support of the high-pressure discharge lamp is ensured.

FIG. 6 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. 2 are denoted by the same reference numerals, and description thereof will be omitted.

The present embodiment is different in that the sealing portion 2a and the anti-halide portion 2b are connected via a molybdenum empty bar 2bC.

That is, an empty rod conductor 2b made of molybdenum
The proximal end of C is inserted into the distal end of the sealing portion 2a, and the distal end is also inserted into the proximal end of the halide-resistant portion 2b and connected to each other.

Thus, according to the present invention, the hollow rod conductor 2bC can hermetically block the halogen-resistant portion 2b formed of a hollow pipe and the sealing portion 2a formed of a hollow pipe.

Further, since the diameter of the tungsten hollow pipe in the halide-resistant portion can be increased, the diameter of the electrode 4 'can be relatively increased accordingly.

FIG. 7 is an enlarged perspective 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. 6 are denoted by the same reference numerals, and description thereof will be omitted.

The present embodiment is different in that an empty rod conductor 2bC 'made of cermet is used instead of the empty rod conductor 2bC.

That is, the cermet of this embodiment is a conductive sintered body obtained by mixing molybdenum and aluminum oxide ceramics, and has a low thermal conductivity, so that the cermet conducts the halide-resistant part from the electrode 4 '. Heat conduction to reduce heat conduction to the sealing portion.

FIG. 8 is an enlarged perspective view showing a halide-resistant part and electrodes in a sixth embodiment of the high-pressure discharge lamp of the present invention.

In the figure, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the electrode 4 ″ is formed in a flat plate shape and connected to the tip of the halide-resistant part 2b.

FIG. 9 is a sectional view showing a seventh embodiment of the high-pressure discharge lamp of the present invention.

In the figure, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the translucent discharge vessel 1 ″ is made of quartz glass, and the structure of the power supply conductor is different accordingly.

That is, the translucent discharge vessel 1 "has a bulging portion 1a" and a pair of sealing portions 1b "and 1b" connected to both ends of the bulging portion 1a ".

The bulging portion 1a ″ has a substantially elliptical spherical shape.

The sealing portion 1b ″ has a pipe shape before sealing, but is pinched at the time of sealing to form a sealing portion.

In the power supply conductor 2 ″, the sealing portion 2a ″ is formed of molybdenum foil, and the halide-resistant portion 2b ″ is formed of a hollow tungsten pipe.

The distal end of the sealing portion 2a "is welded to the base end of the halide-resistant portion 2b", and the base end is welded to an external lead wire in advance.

Then, the sealing portion 1 of the translucent discharge vessel 1 '
The power supply conductor 2 "is inserted into b", the sealing portion 1b "is pinch-sealed, the translucent discharge vessel 1" is sealed, and the power supply conductor 2 "is fixed.

FIG. 10 shows an eighth embodiment of the high-pressure discharge lamp of the present invention.
It is a front view which shows embodiment.

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

The present embodiment is different from the first embodiment in that it is surrounded by a protective tube and configured for a headlight of an automobile.

That is, 6 is an arc tube, 7 is a protective tube, 8
Reference numerals a and 8b denote connection wires, 9 denotes an insulating tube, and 10 denotes a base.

The arc tube 6 has the same structure as the high-pressure discharge lamp shown in FIG.

The protective tube 7 surrounds and supports the arc tube 6, but the inside is not airtight.

The connection wire 8a is connected to the upper external lead wire 3 in the figure, and is turned back to extend to the base 10 side. The connection line 8b is connected to the lower external lead wire 3.

The insulating tube 9 covers the folded portion of the connection line 8a.

The base 10 fixes the lower end of the protective tube 7 and connects the connection lines 8a and 8b to respective base terminals (not shown).
Connected to.

FIG. 11 is a perspective view showing a headlight for a vehicle as a first embodiment of the lighting device of the present invention.

In the figure, 21 is a headlight main body, and 22 is a front cover.

The headlight body 21 is formed by molding a synthetic resin, and has a reflective surface formed on the inner surface by aluminum evaporation.

The front cover 22 is formed by molding a transparent synthetic resin and is mounted on the front of the headlight body 20.
If necessary, light control means such as a lens and a prism are formed on the inner surface.

A metal halide discharge lamp having the same structure as the sixth embodiment of the high-pressure discharge lamp of the present invention shown in FIG. 10 is detachably mounted from the back of the headlight body 21.

FIG. 12 is a front view in central section showing a bulb-type high-pressure discharge lamp as a second embodiment of the lighting device of the present invention.

In the figure, 31 is a high-pressure discharge lamp, 32
Is a reflector, 33 is a discharge lamp lighting device, 34 is a power receiving means, and 35 is a case.

The high-pressure discharge lamp 31 has the same structure as that shown in FIG. 1 except that one small-diameter cylindrical portion of the translucent ceramics discharge vessel 1 is formed to be short and its external lead wires are provided. Connection lines 36a, 36b are connected to 3, 3, respectively.

The reflecting mirror 32 has the connection lines 36a and 36b fixed to the top opening 32a thereof through the inorganic adhesive 32b, so that the axis of the high-pressure discharge lamp 31 coincides with the axis of the reflecting mirror and the reflecting mirror 32 is focused. The light emitting center of the high-pressure discharge lamp 31 is supported so as to match. Also, the top opening 32a
Is provided. The short small-diameter cylindrical portion 1b 'of the high-pressure discharge lamp 31 is disposed on the opening end side of the reflecting mirror 32.

The discharge lamp lighting device 33 includes a high frequency inverter and a current limiting means, and lights the high pressure discharge lamp 31. The discharge lamp lighting device 33 includes a reflecting mirror 32.
It is arranged behind.

The power receiving means 34 is formed of an E26 type screw cap. When the screw cap is mounted on a lamp socket (not shown), the power receiving means 34 receives power and energizes the discharge lamp lighting device 33.

The case 35 houses the discharge lamp lighting device 33 inside. One end of the case 35 supports a cylindrical portion 32c at the top of the reflecting mirror 32 so that the reflecting mirror 32 is supported.
, And connection wires 36a and 36b are introduced therein, and a power receiving means 34 is attached to the other end.

[0161]

According to the first aspect of the present invention, since the electrode located in the light-transmitting discharge vessel is mainly composed of a plate, the surface area of the electrode increases and the electrode surface current density decreases. Along with this, the sputtering is reduced and the heat capacity of the electrode can be reduced, so that the glow-arc transition time is shortened. Thus, it is possible to provide a high-pressure discharge lamp that enables downsizing of the high-pressure discharge lamp lighting device.

According to the second aspect of the present invention, it is possible to provide a high-pressure discharge lamp which operates as a metal halide lamp by additionally containing the metal halide in the ionizing medium.

According to the third aspect of the present invention, in addition, since the plate portion of the electrode is curved around the axis of the power supply conductor, the high-pressure discharge lamp is configured to be compact despite the large surface area of the electrode. Can be provided.

According to the fourth aspect of the present invention, it is possible to provide a long-life, high-efficiency high-pressure discharge lamp in which the translucent discharge vessel is made of translucent ceramics.

According to the fifth aspect of the present invention, since the sealing portion is formed of a hollow pipe, and the halogen-resistant portion is inserted and connected to the hollow pipe, the connection of the power supply conductor is facilitated. An accurate and reliable high-pressure discharge lamp can be provided.

According to the sixth aspect of the present invention, in addition, the sealing portion and the halide-resistant portion are formed of hollow pipes, and are connected between the hollow pipes by the empty rod conductor. It is possible to provide a high-pressure discharge lamp in which a leak between the two pipes is hermetically blocked to prevent leakage through the inside of the pipes.

According to the seventh aspect of the present invention, it is possible to provide a lighting device having the effects of the first to sixth aspects of the present invention.

[Brief description of the drawings]

FIG. 1 is a front view showing a high-pressure discharge lamp according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the same.

FIG. 3 is an enlarged perspective view showing a sealing portion.

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

FIG. 5 is an enlarged sectional view of a main part showing a power supply conductor and electrodes in a third embodiment of the high-pressure discharge lamp of the present invention.

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

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

FIG. 8 is an enlarged perspective view showing a halide-resistant part and electrodes in a high-pressure discharge lamp according to a sixth embodiment of the present invention.

FIG. 9 is a sectional view showing a high-pressure discharge lamp according to a seventh embodiment of the present invention.

FIG. 10 is a front view showing an eighth embodiment of the high-pressure discharge lamp of the present invention.

FIG. 11 is a perspective view showing a headlight for an automobile as a lighting device according to a first embodiment of the present invention;

FIG. 12 is a front view in central section showing a bulb-type high-pressure discharge lamp as a second embodiment of the lighting device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Translucent discharge container 1a ... Swelling part 1b ... Small diameter cylinder part 2 ... Power supply conductor 2a ... Sealing part 2a1 ... Opening 2a2 ... Bonding line 2b ... Halide resistant part 2b1 ... Bonding line 2b2 ... Opening 3 ... External Lead wire 4 ... Electrode 5 ... Seal 5a ... Seal film g ... Small gap

Claims (7)

[Claims] 1. A light-transmitting discharge vessel, comprising: a sealing portion and a halide-resistant portion projecting from the sealing portion, wherein the sealing portion is mainly sealed at both ends of the light-transmitting discharge container. A power supply conductor; an electrode disposed at the tip of the power supply conductor and mainly composed of a plate positioned inside the translucent discharge vessel; and an ionization medium sealed in the translucent discharge vessel; A high-pressure discharge lamp comprising: 2. The high pressure discharge lamp according to claim 1, wherein the ionizing medium contains a metal halide. 3. The high-pressure discharge lamp according to claim 1, wherein the electrode has a plate portion curved around the axis of the power supply conductor. 4. A light-transmitting discharge vessel is made of a light-transmitting ceramic having a bulging portion surrounding a discharge space and a small-diameter cylindrical portion disposed in communication with both ends of the bulging portion and having an inner diameter smaller than the bulging portion. A power supply conductor is inserted into the small-diameter cylindrical portion of the light-transmitting discharge vessel; 4. The high-pressure discharge lamp according to claim 1, further comprising a ceramic sealing compound seal forming a slight gap between the halide-resistant parts. 5. The high-pressure discharge lamp according to claim 4, wherein the sealing portion comprises a hollow pipe; and the halide-resistant portion is inserted and connected to a tip of the sealing portion. . 6. The sealing part comprises a hollow pipe; and the halide-resistant part comprises a hollow pipe connected to the sealing part via a void-free conductor. Or the high-pressure discharge lamp according to 5. 7. A lighting device comprising: a lighting device main body; and the high-pressure discharge lamp according to claim 1 supported by the lighting device main body.