JPH11339723A - High-pressure discharge lamp and light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold the distance from a heating part to a sealing part in a desired length while constituting the sealing part by pinch sealing method by providing an intermediate chamber held in vacuum state or having a rare gas sealed therein between a first sealing part and a second sealing part. SOLUTION: A pair of electrodes is provided in the discharge space within a spherical airtight vessel 1 so as to be mutually opposed. In use, one of the electrodes discharging under a DC power source forms a negative electrode 2, and the other forms a positive electrode 3. The other end of the negative electrode 2 having one end facing the discharge space within the airtight vessel 1 is extended into a first sealing part 4. Similarly, the other end of the positive electrode 3 having one end facing the discharge space within the airtight vessel 1 is extended into a first sealing part 5. A hollowed intermediate chamber 10 is provided adjacent to the first sealing part 5. The other end of a lead wire 9 having one end fixed to a metal foil conductor 8 is extended into a second sealing part 11 through the intermediate chamber 10.

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 and a light source device used in an image projection device for projecting an image, such as a liquid crystal projector.

[0002]

2. Description of the Related Art At present, the spread of image display devices is remarkable, but a high-pressure discharge lamp is widely used as a light source. Even among these high-pressure discharge lamps, light sources for liquid crystal projectors, which have become particularly popular recently, are close to point light sources and short arc-type high-pressure discharge lamps with easy light distribution control, such as xenon lamps and metal halide lamps Is often used.

A liquid crystal projector is a device for projecting an image on a screen, and is capable of projecting not only a still image but also a moving image as a clear image.
Image signals for projection can be either analog signals or digital signals, and since various images can be projected, they are used today as tools for presentations, for simple theaters, It is used for large-screen TVs, and is expected to greatly develop in the future.

[0004] Incidentally, this liquid crystal projector is extremely expensive as an image display device as compared with an inexpensive CRT display device or the like. For this reason, cost reductions are being promoted by downsizing each component aiming at a cheaper liquid crystal projector, and since there is still room for improvement in brightness, it is necessary to use a special optical system. Is being improved.

As described above, a high-pressure discharge lamp is preferably used for a light source device for a liquid crystal projector, but the demand for a high-pressure discharge lamp is to shorten the gap, increase the efficiency, and extend the life. In addition to these demands, high pressure discharge lamps are required to reduce costs, which is an immediate target of liquid crystal projectors, while ensuring reliability.

[0006] Also, high-pressure discharge lamps used in such video equipment are often mounted inside the equipment so as to be lit horizontally. Therefore, the temperature inside the arc tube increases due to convection, and the temperature distribution in the entire arc tube is in a state of being biased. In order to eliminate such a non-uniform temperature distribution, an air cooling device such as a fan is provided.

[0007]

An important step in manufacturing a high-pressure discharge lamp is a sealing step in which the interior of the arc tube is hermetically sealed. This step is currently performed by a pinch seal method in which the processing time is short and efficient work can be performed. The portion sealed by the pinch seal method can maintain sufficient airtightness against high internal pressure, and can secure desired performance for a long time.

[0008] Sealing of the arc tube is required at two places on the cathode and anode sides. A metal foil conductor made of molybdenum and a metal foil conductor connected to the cathode and anode are attached to the sealed portions. A lead wire made of molybdenum extends from the metal foil conductor to the outside. The metal foil conductor and the lead wire are welded in the sealing portion, and this welded portion is in the same state as the atmosphere has entered and is exposed to fire. For this reason, when the high temperature is maintained for a long time, the oxidation is likely to proceed and the fracture occurs, so that an effective measure for keeping the temperature lower in this portion is required.

As a countermeasure, there is a method of reducing the heat transmitted from the heat generating part by some method, or a method of cooling to suppress a rise in temperature. However, when the cooling method is adopted, noise generated by a blower or the like is generated. Therefore, noise reduction is not achieved, and the cooling method is rarely adopted.
For this reason, a method that is recently used is to increase the length of a sealing portion that makes it difficult to transmit heat from a heat generating portion. FIG.
Is a characteristic diagram showing the relationship between the distance from the front side of the arc tube and the temperature. When the distance exceeds 30 mm from the arc tube surface, the allowable temperature range is reached.

However, when the length of the portion to be sealed exceeds 30 mm, it is difficult to seal such a small high-pressure discharge lamp by a pinch seal method, so that the distance from the arc center as a heat source is difficult. Can not take longer.

Accordingly, an object of the present invention is to provide a high-pressure discharge lamp and a light source device in which the distance from the heat generating portion to the sealing portion is maintained at a desired length while the sealing portion is formed by a pinch seal method. Is to do.

In the case of horizontal lighting, an air-cooling device such as a fan is provided as described above in order to equalize the temperature distribution of the entire arc tube, or if there is a problem of noise from the air-cooling fan or if it is cooled too much by air cooling. Since it is not possible to obtain the necessary light emitting characteristics, there is a problem that the control is difficult. In order to solve this, it is conceivable to light vertically, but in this case, since the temperature of the sealing portion located above rises significantly, the oxidation of the sealed metal foil is promoted and further fracture occurs. It will be easier. Therefore, another object of the present invention is to provide a high-pressure discharge lamp and a light source device capable of suppressing breakage of a metal foil even when the lamp is lit vertically.

[0013]

A high-pressure discharge lamp according to the first aspect of the present invention includes: a hermetic container having a discharge space; a pair of electrodes provided with one ends facing each other in the discharge space of the hermetic container; A pair of first sealing portions for maintaining the airtightness by crush-sealing the other end of the electrode, and the other end of the lead wire provided along at least one of the first sealing portions and drawn out from the first sealing portion. A second sealing portion which is crushed and sealed to maintain airtightness; and an intermediate chamber between the first sealing portion and the second sealing portion which is kept in a vacuum state or in which a rare gas is sealed. Things.

The definitions or technical meanings of the terms are as follows.

The high-pressure discharge lamp is a high-pressure mercury lamp, a high-pressure gas discharge lamp (for example, a xenon lamp) or a metal halide lamp. Accordingly, the discharge medium is configured to correspond to the high pressure discharge lamp. The high-pressure mercury lamp may be filled with, for example, a metal halide as an additive.

The airtight container means a container constituting the arc tube, and the shape, size, material and the like are not limited.

The mode of the discharge may be either DC discharge or AC discharge. The electrodes are configured to correspond to the mode of discharge.

The rare gases sealed in the intermediate chamber are argon, krypton, and xenon. Alternatively, nitrogen gas may be used. Further, when no rare gas is filled, it is necessary to exhaust air in the hollow portion until a vacuum is created during the manufacturing process.

According to the present invention, the distance between the heat generating portion and the second sealing portion can be maintained at a desired length in a small high-pressure discharge lamp, and the transfer of heat to the welding portion of the lead wire is suppressed. It is possible to reliably prevent breakage from occurring at the portion.

According to a second aspect of the present invention, in the high pressure discharge lamp according to the first aspect, the intermediate chamber is provided along only one of the first sealing portions, and the intermediate chamber is connected to the other of the other. It is characterized in that it is lit relatively higher than one sealing portion.

According to the present invention, since the intermediate chamber is disposed so as to be located relatively upward, the intermediate chamber is easily heated by the heat generated during the operation of the high-pressure discharge lamp up to the second sealing portion located above. The distance from the heat-generating portion can be increased, and the conduction of heat to the welded portion of the lead wire can be suppressed, so that breakage at the welded portion can be suppressed.

According to a third aspect of the present invention, in the high pressure discharge lamp according to the second aspect, one of the electrodes is configured as a cathode and the other is configured as an anode, and the anode is configured to be lit at a relatively upper position. It is characterized by the following.

In general, the anode has a large heat capacity so as to sufficiently withstand thermal shock caused by electron collision due to electric discharge, while the cathode has a small heat capacity to promote the emission of thermoelectrons. Have been. Also, mercury, metal halides, and the like, which are frequently used as a discharge medium, adhere to the coldest part of the arc tube at the beginning of lighting, but for example, such as vertical lighting, such that one electrode is located relatively above. When lit, the metals that create these discharge media condense near the lower electrode, where the temperature tends to be lower. In the above invention, a cathode having a small heat capacity is generally located below, and a large anode is located above. Since the temperature of the cathode located at the lower portion rises rapidly with the start of electric discharge due to the small heat capacity, the evaporation of the luminescent metal adhered to the lower portion can be promoted. Can be improved.

According to a fourth aspect of the present invention, in the high-pressure discharge lamp according to the third aspect, the airtight container has a bulging portion for forming a discharge space, and an upper end and a lower end of the bulging portion. , The distance between the lower end of the bulge and the intermediate position between the anode and the cathode is n, the distance between the anode and the cathode is L, and the inner diameter of the discharge space in the bulge is When the dimension is D, 0.29 ≦ ｛(a−n) /
L｝ ≦ 2.7

5L ≦ D

The size of each part is set so as to satisfy the following relationship.

According to the present invention, the bulging portion 3 at the time of vertical lighting is provided.
Swelling and rupture can be reduced, and lamp characteristics and life can be ensured. That is, {(a−n) / L}
When <0.29, the distance L is too long.
When the requirement of L ≦ D is satisfied, the inner diameter D of the discharge space 4 becomes too large, and it is difficult to reduce the size. If 5L> D is disregarded in this state, ignoring the requirement of 5L ≦ D, it is confirmed that the inner diameter D of the discharge space 4 is small for the long arc, so that the bulging portion 3 swells due to the heat of the arc. It is a thing.

On the other hand, if {(a−n) / L}> 2.7, the inter-electrode dimension L is too small, and the necessary light emitting characteristics cannot be obtained in order to satisfy 5L ≦ D. . Also, 5
If 5L> D, disregarding the requirement that L ≦ D, the arc and the tube wall of the bulging portion 3 are too close to each other, leading to bulging of the bulging portion 3 due to the heat of the arc.

Further, 0.29 ≦ {(a−n) / L} ≦
Even if the condition of 2.7 is satisfied, if the other condition of 5L ≦ D is not satisfied, the bulging portion 3 may swell and break.

[0030]

A high pressure discharge lamp according to a fifth aspect of the present invention is characterized in that a lead wire extending into the intermediate chamber is provided with a filament that blows during a designated service time.

According to the present invention, it is possible to effectively prevent an accidental rupture of the hermetic container at the end of the life of the high pressure discharge lamp and an unexpected accident occurring in a device incorporating the high pressure discharge lamp. . Further, the high pressure discharge lamp according to the invention of claim 6 is characterized in that the filament is made of a linear filament material. Claim 7
The high-pressure discharge lamp according to the invention is characterized in that the filament is made of a coiled filament material.

In the present invention, a linear filament material or a coil-shaped filament material can be made to function as a filament that is blown out during the service time. Therefore, the filament can be formed using an existing material, and an inexpensive discharge lamp can be provided.

Further, a light source device according to an eighth aspect of the present invention is characterized by comprising the high-pressure discharge lamp according to the present invention, and a reflector provided so as to keep the optical axis of the high-pressure discharge lamp concentric.

The high-pressure discharge lamp of the present invention can be widely used for a light source device. Particularly desirable are liquid crystal projectors, image projectors such as overhead projectors,
This is an application to a floodlighting device, a signal lamp device, and the like.

[0036]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a spherical airtight container 1 is formed hollow so that the inside is a discharge space. This airtight container 1 is made of quartz glass. A pair of electrodes are provided in the discharge space in the hermetic container 1 so as to face each other. In use, one of the electrodes that performs a DC discharge under a DC power supply (not shown) serves as a cathode 2 and the other serves as an anode 3. Cathode 2 is made of, for example, a thoriated tungsten alloy containing thorium, and has a thickness of 0.7 mm. The anode 2 is made of tungsten and has a thickness of 2.6 mm.

The other end of the cathode 2, one end of which faces the discharge space in the hermetic container 1, extends to the first sealing portion 4. Similarly, the other end of the anode 3 having one end facing the discharge space in the hermetic container 1 extends toward the first sealing portion 5. First sealing part 4
Is embedded with a metal foil conductor 6 made of molybdenum.

The metal foil conductor 6 is welded on the one hand to the cathode 2 and on the other hand to the lead wire 7 made of molybdenum. The size of the metal foil conductor 6 is 3 mm in width and 13 in length.
mm. Similarly, a metal foil conductor 8 made of molybdenum is embedded in the first sealing portion 5. The metal foil conductor 8 is welded on one hand to the anode 3 and on the other hand to a straight lead wire 9 made of molybdenum. This metal foil conductor 8
Is 3 mm wide and 13 mm long. The length of the first sealing portion 5 is 23 mm, and is sealed by a pinch seal method.

Further, the intermediate chamber 1 is located adjacent to the first sealing portion 5.
0 is provided. This intermediate chamber 10 is formed hollow. The other end of the lead wire 9 having one end fixed to the metal foil conductor 8 extends through the intermediate chamber 10 to the second sealing portion 11. A metal foil conductor 12 made of molybdenum is embedded in the second sealing portion. The metal foil conductor 12 is welded on one hand to the lead wire 9 and on the other hand to the lead wire 13 made of molybdenum. The size of the metal foil conductor 12 is 3 mm in width and 10 mm in length. The length of the second sealing portion 11 is 13 mm, and is sealed by a pinch seal method.

In this embodiment, the distance from the center of the arc serving as a heat source to the end of the second sealing portion 11 is about 65 mm.

In this high-pressure discharge lamp, a sufficient amount of mercury is sealed in the discharge space of the hermetic container 11 to obtain a predetermined lamp voltage. Also, argon gas at a pressure of about 40 kpa is sealed. Further, the intermediate chamber 10 is filled with an argon gas.

This embodiment has the above configuration.
The second sealing portion is sealed by a pinch seal method, and complete airtightness for preventing the flow of the argon gas sealed in the intermediate portion 10 is maintained. The distance from the arc center, which is the heat source, to the end of the second sealing portion 111 is about 65 mm, which is much longer than that of a conventional small high-pressure discharge lamp, and the distance between the heating portion and the heat generating portion can be increased. it can. This makes it difficult for the heat from the heat-generating portion to be transmitted to the welded portion between the metal foil conductor 12 and the lead wires 9 and 13, so that the temperature rise is greatly reduced, and oxidation is less likely to occur even when the welded portion comes into contact with the atmosphere.

On the other hand, since the distance of the first sealing portion 5 from the heat generating portion is basically the same as that of the conventional one, when the arc tube is used for a long period of time, the anode rises in accordance with the temperature rise of the metal foil conductor 8. 3 and the temperature of the welding portion with the lead wire 9 increases.
However, only chemically stable argon sealed in the intermediate chamber 10 enters this portion, and the atmosphere does not enter, and corrosion proceeds at the welded portion between the metal foil conductor 8 and the lead wire 9. Never.

As described above, in the present embodiment, the distance from the heating portion to the second sealing portion 11 can be maintained at a desired length in a small high-pressure discharge lamp, and the lead wires 9 and 1 can be maintained.
Thus, it is possible to suppress the transmission of heat to the welded portion 3 and reliably prevent the occurrence of breakage in the welded portion.

Next, another embodiment of the present invention will be described. In FIG. 2, most of the configuration of the high-pressure discharge lamp is the same as that of the above-described embodiment, and the same components are denoted by the same reference numerals and description thereof will be omitted. The difference from the above embodiment is that the lead wire 9 having the linear filament 14 passes through the intermediate chamber 10 and the metal foil conductors 8, 12
It is to be provided over. The filament 14 is made of tungsten, and has a capacity determined so that the filament 14 is blown during a service time shorter than a predetermined lamp rated life time.

This embodiment has the above configuration.
During use of the high-pressure discharge lamp, the temperature of the metal foil conductor 8 rises due to the heat generated by the discharge arc, and accordingly, the temperature of the intermediate chamber 10 increases.
The temperature of the filament 14 inside increases. When the temperature of the metal foil conductor 8 rises and the service time of the filament material shorter than the lamp rated life time elapses, the filament 1
4 melts. Due to the fusing of the filament 14, the current flowing through the lead wire 9 is cut off, and the DC discharge in the hermetic container 1 performed under the DC power supply (not shown) is stopped.

Normally, the brightness of a high-pressure discharge lamp decreases with the elapse of the lighting time, but the brightness does not decrease rapidly but gradually. For this reason, in the long-term use of the high-pressure discharge lamp, the high-pressure discharge lamp is often used beyond the rated life time, and at the end of the life of the high-pressure discharge lamp, the airtight container 1 may burst.

In preparation for such a case, the filament 14, which is a part of the DC circuit, is blown at the designated service time of the filament material. By determining the service time of the filament 14 within the rated life time of the lamp, it is possible to prevent a sudden accident such as a burst of the airtight container 1 at the end of the life of the high pressure discharge lamp. That is, the user is notified that the high-pressure discharge lamp is approaching the end of its life.
The high pressure discharge lamp in use can be replaced with a new high pressure discharge lamp.

Conventionally, empirical values of the temperature and oxidation of a metal foil conductor mounted on a sealing portion that comes into contact with the atmosphere, for example, assuming a life of 2000 hours, and setting the metal foil conductor temperature to 300
Although a value such as ° C has been determined as a guide, there are variations in use conditions.

According to this arc tube, when an abnormal discharge occurs in the hermetic container 1, the generated current is sensed,
The high-pressure discharge lamp can be turned off safely without bursting.

As described above, in this embodiment, at the end of the life of the high-pressure discharge lamp, the airtight container 1 is suddenly ruptured, and an unexpected accident occurs in a device or the like incorporating the high-pressure discharge lamp. It is possible to prevent.

Next, another embodiment of the present invention will be described. In FIG. 3, most of the configuration of the high-pressure discharge lamp is the same as that of the above-described embodiment (see FIG. 1), and the same components are denoted by the same reference numerals and description thereof is omitted. The difference from the above embodiment is that the lead wire 9 provided with the coiled filament 15 is made of metal foil conductors 8 and 12.
It is to be provided over. The capacity of the filament 15 is also determined so that the filament 15 is blown during a service time shorter than a predetermined lamp rated life time. The filament 15 is manufactured using a tungsten filament material.

This embodiment is similar to the first embodiment. The high-pressure discharge lamp having the above-described configuration and having the filament 15 similar to the filament 14 of the above-described embodiment is used, when the specified filament material service time that is shorter than the lamp rated life time has elapsed. Then, the filament 15 is melted. The fusing of the filament 15 stops the DC discharge in the hermetic container 1 which has been performed by the DC power supply.

Thus, also in the present embodiment, it is possible to prevent the accidental rupture of the hermetic container 1 at the end of the life of the high pressure discharge lamp and the occurrence of an unexpected accident in a device incorporating the high pressure discharge lamp. Can be prevented.

Next, another embodiment of the present invention will be described. In FIG. 4, the liquid crystal projector includes a high-pressure discharge lamp 21 of the above-described embodiment (see FIG. 1) and a reflector 22.
The light source device 23 includes: Light emitted from the high-pressure discharge lamp 21 is condensed by the reflector 22 and is irradiated on the liquid crystal panel 24.

The high pressure discharge lamp 21 is provided with a lamp lighting device 25. The liquid crystal panel 24 includes an image control unit 26. The lamp lighting device 25 and the image control means 26 are connected to an AC power supply 27 so that required power is supplied. The lamp lighting device 25 has a built-in rectifier. A projection lens 28 is provided in front of the liquid crystal image display means 24. Light radiated forward from the reflector 22 irradiates the liquid crystal panel 24, and an image composed of the three primary colors R, G, and B created by the liquid crystal panel 24 is projected onto a screen 29 via a projection lens 28.
Project on top. Each device except the screen 29 is housed in the main body case 30.

Next, another embodiment of the present invention will be described with reference to FIGS. The high-pressure discharge lamp is vertically lit in the direction shown in the figure, and includes an airtight container 1 formed of quartz glass, a discharge medium containing mercury sealed in a bulging portion 1 a of the airtight container 1, It comprises a pair of electrode assemblies, each having an anode 3 and a cathode 2 facing each other in the discharge space in the outlet 1a and arranged at both ends of the hermetic container 1.

The other end of the cathode 2, one end of which faces the discharge space in the hermetic container 1, extends to the first sealing portion 4. In this embodiment, a coil is wound around the outer periphery of the cathode 2 to prevent a temperature rise and prevent evaporation of a cathode material such as tungsten.

The other end of the anode 3 whose one end faces the discharge space in the hermetic container 1 extends to the first sealing portion 5. The first sealing portion 4 has a metal foil conductor 6 made of molybdenum.
Is buried. This metal foil conductor 6 is welded on the one hand to the cathode 2 and, on the other hand, to a lead wire 7 of a molybdenum wire.
And have been welded. Similarly, a metal foil conductor 8 made of molybdenum is embedded in the first sealing portion 5. The metal foil conductor 8 is welded on one hand to the anode 3 and on the other hand to a straight lead wire 9 made of molybdenum wire.

Further, the intermediate chamber 1 is located adjacent to the first sealing portion 5.
0 is provided. This intermediate chamber 10 is formed hollow. The other end of the lead wire 9 having one end fixed to the metal foil conductor 8 extends through the intermediate chamber 10 to the second sealing portion 11. A metal foil conductor 12 made of molybdenum is embedded in the second sealing portion. The metal foil conductor 12 is welded on one hand to the lead wire 9 and on the other hand to the lead wire 13 made of molybdenum.

The inner diameter of the bulging portion 1a, that is, the inner diameter of the discharge space is set to D, and its thickness is set to tl. Further, the thickness of the sealing portion where the electrode axis of the anode is sealed is set to t2. Further, the vertical length of the outer periphery of the bulging portion 1a is 2a, the distance between the anode 3 and the cathode 2,
That is, the separation dimension is L, and the dimension from the center between the poles to the outer lower end of the bulging portion 1a is n. In this state, the dimension of each part is 0.29 ≦ {(a−n) / L}.
≦ 2.7, 5L ≦ D.

A specific example will now be presented. The inner diameter D of the discharge space is 8 mm, the major axis is 12 mm, the thickness tl of the bulging portion 1a is 2 mm, and the tube wall load is 55 W / cm2. The electrode used is such that the cathode 2 has a diameter of 0.7 mm,
The anode 3 is made of tungsten having a diameter of 2.0 mm. The metal foil conductor 6 sealed by the first sealing portion 4 on the cathode 2 side is Mo, and its width is 2 mm and its length is 15 mm. The metal foil conductor 8 on the anode 3 side is also Mo, having a width of 2 mm and a length of 15 mm.
It is. The thickness t2 of the electrode shaft sealing portion is 3 mm and the width is 7 mm.
mm, and the relationship between the thickness tl of the bulging portion 1a and the thickness t2 of the electrode shaft sealing portion 26 is as follows.

Tl> (t2 / 2)

Is as follows. That is, 2> (3/2)
It is set to become a relationship.

The discharge space of the bulging portion 1a is filled with Hg in an amount capable of obtaining a predetermined lamp voltage, specifically, 40 mg / cc Hg per unit volume. In addition, about 40 kPa of Ar gas is sealed.

Therefore, as described above, tl> (t2
As a result of the setting of (/ 2), a chipless compact and high-efficiency short gap lamp by the pinch method, which was impossible in the past, can be manufactured.

In such a configuration, the high-pressure discharge lamp is used in a vertical state as shown in the figure. In this case, as described above, the cathode 2 is used in the vertical lighting with the cathode 2 facing down, but the distance between the upper end and the lower end of the bulging portion 1a is 2a, and the lower end of the bulging portion 1a is used. The distance between the part and the intermediate position between the anode 3 and the cathode 2 is n, the distance between the anode 3 and the cathode 2 is L, and the inner diameter of the discharge space in the bulging part 1a is D.
When

0.29 ≦ {(a−n) / L} ≦ 2.7

5L ≦ D

Since the following relationship is satisfied, it is possible to reduce the swelling and bursting of the bulging portion 1a at the time of vertical lighting, and to secure the lamp characteristics and the life. That is, if {(a−n) / L} <0.29, the gap L is too long, and if the requirement of 5L ≦ D is satisfied, the inner diameter D of the discharge space becomes too large. Smaller or more difficult. In this state, ignoring the requirement of 5L ≦ D, 5L>
Assuming that D, the inner diameter D of the discharge space is smaller than that of the long arc, so that the bulging portion 1a swells due to the heat of the arc.

On the other hand, if {(a−n) / L}> 2.7
, The gap L is too small, and 5L ≦
In order to satisfy D, required light emission characteristics cannot be obtained. If 5L> D is disregarded, ignoring the requirement of 5L ≦ D, the arc and the tube wall of the bulging portion 1a are too close to each other, leading to bulging of the bulging portion 1a due to the heat of the arc.

Also, 0.29 ≦ {(a−n) / L} ≦
Even if the condition of 2.7 is satisfied, if the other condition of 5L ≦ D is not satisfied, the bulging portion 1a swells and breaks. For example, D = 8.5, L = 1.5,
0.29 as a = 9, n = 7 (both in mm)
A type sample satisfying the conditions of ≦ {(a−n) / L} ≦ 2.7 and 5L ≦ D, and Di6.5, L =
Assuming that 1.5, a = 9, and n = 7 (the unit is mm), the condition of 0.29 ≦ {(a−n) / L} ≦ 2.7 is satisfied, but the requirement of 5L ≦ D is satisfied. Five types of B type samples that were not satisfied were prepared, and each of them was subjected to a life test. As shown in Table 1, the A type sample did not cause any trouble even after 2,000 hours. , B type samples,
No. The three samples No. 3 caused the bulging portion 1a to bulge in 100 hours. The sample of No. 4 failed in 300 hours, and no. In the sample No. 5, the bulging portion 1a bulged in 200 hours.

[0073]

[Table 1]

Note that the bulge 1
The temperature distribution at a tends to be uniform. That is, during lighting, the gas in the discharge space causes convection inside due to the heat of the arc. In the case of horizontal lighting, the arc bulges upward due to the convection, and approaches the tube wall above the bulge 1a. Therefore, the temperature distribution in the bulging portion 1a is not uniform, and inconveniences such as bulging occur. On the other hand, in the case of vertical lighting, the arc is linear even if gas convection occurs in the discharge space, and the bulging portion 1
The temperature distribution at a is symmetric with respect to the vertical center line.
Therefore, there is also an advantage that the pipe wall of the bulging portion 1a is not locally heated.

According to this embodiment, since the intermediate chamber 10 is disposed so as to be located relatively upward, the distance from the heat generating portion to the second sealing portion 11 can be increased, and the high pressure It is possible to suppress the transmission of heat to the welds between the metal foil conductor 12 and the lead wires 9 and 13 located above, which are easily heated by the heat generated during the lighting of the discharge lamp, thereby suppressing breakage at these welds. . In addition, since the anode 5 is configured to be lit at a relatively upper position, the temperature of the mercury solidified in the coolest part formed around the cathode 2 located at the lower position rises quickly at the start. The cathode promotes evaporation. As a result, the rising characteristics of the luminous flux of the high-pressure discharge lamp can be improved.

In carrying out the above embodiment, it is desirable to set the gap L between 1.0 and 3.0 mm and the lamp power between 150 and 250 W. By using this state for vertical lighting, a high-intensity high-pressure discharge lamp can be provided.

[0077]

According to the present invention as described above,
While the sealing portion is configured by the pinch seal method, the distance from the heat generating portion to the sealing portion can be maintained at a desired length,
It is possible to reliably prevent breakage of the welded part of the lead wire.

According to the second aspect of the present invention, since the intermediate chamber is disposed so as to be located relatively upward, the intermediate chamber is easily heated by the heat generated during operation of the high-pressure discharge lamp. (2) The distance from the heat generating portion to the sealing portion can be increased, and the conduction of heat to the welded portion of the lead wire can be suppressed, and the breakage at the welded portion can be suppressed.

According to the third aspect of the present invention, a cathode having a small heat capacity is generally located at a lower position and a large anode is located at an upper position. As the temperature rises, the temperature of the high-pressure discharge lamp can be improved by rapidly evaporating the luminescent metal adhered downward.

According to the fourth aspect of the present invention, it is possible to reduce the swelling and rupture of the bulging portion 3 at the time of vertical lighting, and to secure the lamp characteristics and the life.

Further, the high pressure discharge lamp according to the fifth aspect of the present invention is provided with a filament extending into the intermediate chamber and having a filament which is blown out during a designated service time. Can be prevented, and an unexpected accident can be effectively prevented from occurring in a device or the like incorporating the high-pressure discharge lamp.

Further, according to the invention of claim 6 or 7, since a linear filament material or a coil-shaped filament material can be made to function as a filament that is blown out in service time, an inexpensive discharge lamp is provided. It becomes possible.

According to the light source device of the eighth aspect, it is possible to provide a light source device having the effects obtained by the above inventions.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view illustrating another embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating another embodiment of the present invention.

FIG. 4 is a configuration diagram showing another embodiment of the present invention.

FIG. 5 is a front view of a high-pressure discharge lamp showing another embodiment of the present invention.

FIG. 6 is a side view of the high-pressure discharge lamp shown in FIG.

FIG. 7 is a characteristic diagram showing the relationship between the distance from the arc tube surface and the temperature.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hermetic container 2 Cathode 3 Anode 4, 5 First sealing part 6, 8, 12 Metal foil conductor 10 Intermediate chamber 11 Second sealing part 14, 15 filament 21 High-pressure discharge lamp

Claims (8)

[Claims] An airtight container provided with a discharge space, a pair of electrodes having one end provided in the discharge space of the airtight container so as to face each other, and the other end of each of the electrodes being crushed and sealed to form an airtight container. And a pair of first sealing portions provided along at least one of the first sealing portions, and the other end of the lead wire drawn from the first sealing portion is crushed and sealed to maintain airtightness. A second sealing portion, and an intermediate chamber between the first sealing portion and the second sealing portion, which is maintained in a vacuum state or in which a rare gas is filled. High pressure discharge lamp. 2. The intermediate chamber is provided along only one of the first sealing portions, and the intermediate chamber is located above the other first sealing portion and is turned on. A high pressure discharge lamp characterized by the above-mentioned. 3. The high-pressure discharge lamp according to claim 2, wherein one of the electrodes is configured as a cathode and the other is configured as an anode, and the anode is configured to light up at a relatively upper position. 4. The airtight container has a bulge for forming a discharge space, and a distance between an upper end and a lower end of the bulge is two.
a, the distance between the lower end of the bulging portion and the intermediate position between the anode and the cathode is n, the distance between the anode and the cathode is L,
When the inner diameter of the discharge space in the bulging portion is D, the dimensions of each portion are set so as to satisfy the following relationship: 0.29 ≦ {(a−n) / L} ≦ 2.75L ≦ D The high-pressure discharge lamp according to claim 3, wherein: 5. The high-pressure discharge lamp according to claim 1, wherein said lead wire extending into said intermediate chamber is provided with a filament which melts at a designated service time. 6. The high pressure discharge lamp according to claim 1, wherein the filament is made of a linear filament material. 7. The high pressure discharge lamp according to claim 1, wherein said filament is made of a coiled filament material. 8. A high-pressure discharge lamp according to claim 1, further comprising: a reflector provided concentrically with an optical axis of the high-pressure discharge lamp. Light source device.