JP2021047985A - Short arc type discharge lamp and light irradiation device - Google Patents

Abstract

To provide a short arc type discharge lamp capable of cooling a sealed portion with high efficiency without lowering the temperature of the arc tube, and a light irradiation device having the short arc type discharge lamp.SOLUTION: A short arc type discharge lamp 10 includes an arc tube 11 in which a sealed portion 14 is formed to be continuous with one end of a light emitting portion 12, and a mouthpiece 30 into which the sealed portion 14 is inserted and fixed. In the short arc type discharge lamp 10 in which a foil seal structure is formed in the sealed portion 14, an internal space S2 is formed between an outer end surface portion 31 of the mouthpiece 30 and an outer end surface 14a of the sealed portion 14, and the outer end surface portion 31 of the mouthpiece 30 has a ventilation port 33 for allowing cooling air to flow into and out of the internal space S2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a short arc type discharge lamp having a base attached to a sealing portion of an arc tube and a light irradiation device provided with the short arc type discharge lamp.

For example, a short arc type discharge lamp is used as a light source in an exposure apparatus used in a manufacturing process of a semiconductor element, a liquid crystal display element, or the like, or in various projectors. This short arc type discharge lamp is configured such that an anode and a cathode are arranged in an arc tube so as to face each other, and a luminescent substance such as mercury or xenon gas is sealed in the arc tube. Further, in a short arc type discharge lamp, when high pressure resistance is required for the sealing portion of the arc tube, a foil sealing structure using a conductive foil for sealing is adopted as the sealing structure of the sealing portion. ing.

In such a short arc type discharge lamp, the arc tube becomes extremely hot when lit, and the sealing portion of the arc tube also becomes hot accordingly. When the temperature of the sealing portion becomes high, the conductive foil embedded in the sealing portion is oxidized, which may damage the sealing portion and make it unusable.

In order to solve such a problem, a first opening is formed in the peripheral surface portion of the mouthpiece attached to the sealing portion, and a second opening is formed in the outer end surface portion of the mouthpiece, so that the first opening in the mouthpiece is formed. A technique (see Patent Document 1) in which cooling air is blown into a portion where an opening is formed so that cooling air flows into the mouthpiece from the first opening and flows out from the second opening to the outside of the mouthpiece (see Patent Document 1). , The inflow air hole and the outflow air hole are formed on the peripheral surface of the mouthpiece attached to the sealing part, and the cooling air is blown to the portion of the mouthpiece where the inflow air hole is formed, so that the inflow air port There is known a technique (see Patent Document 2) in which cooling air flows into the mouthpiece and the cooling air flows out from the outflow air hole to the outside of the mouthpiece.

Japanese Unexamined Patent Publication No. 2001-216938 JP-A-2002-75282

However, in the short arc type discharge lamps described in Patent Document 1 and Patent Document 2, since the external reed is directly exposed to the cooling air, it is possible to cool the external reed with high efficiency, but the sealing portion is provided. It is difficult to cool with high efficiency.
Further, when a large flow rate of cooling air is blown to cool the sealing portion, a part of the cooling air hits the outer peripheral surface of the base and then flows toward the arc tube, so that the temperature of the arc tube drops. As a result, there is a risk of malfunction in lighting.
Further, in the short arc type discharge lamp described in Patent Document 2, it is difficult to connect the exhaust port to the outflow air hole because the outflow air hole is formed on the outer peripheral surface portion of the mouthpiece. Therefore, there is a problem that the inside of the device on which the short arc type discharge lamp is mounted is contaminated as a result of the contaminants such as the adhesive that joins the sealing portion and the mouthpiece flowing out from the outflow air holes together with the cooling air. ..

The present invention has been made based on the above circumstances, and an object of the present invention is a short arc type discharge lamp capable of cooling a sealed portion with high efficiency without lowering the temperature of the arc tube. And to provide a light irradiation device provided with this short arc type discharge lamp.

The short arc type discharge lamp of the present invention includes an arc tube in which a sealing portion is continuously formed at one end of a light emitting portion, and a mouthpiece into which the sealing portion is inserted and fixed. A short arc type discharge lamp with a foil seal structure formed on it.
An internal space is formed between the outer end surface portion of the mouthpiece and the outer end surface portion of the sealing portion.
The outer end surface portion of the mouthpiece is characterized by having a ventilation port for allowing cooling air to flow in and out of the internal space.

In the short arc type discharge lamp of the present invention, it is preferable that a plurality of the ventilation ports are formed on the outer end surface portion of the mouthpiece.

Further, in the short arc type discharge lamp of the present invention, at least one or more of the plurality of ventilation ports is an inflow ventilation port.
It is preferable that the length of the line segment defining the maximum length of the inflow vent is smaller than the length of the line segment defining the maximum length of the air outlet arranged to face the outer end surface portion of the mouthpiece. ..

Further, in the short arc type discharge lamp of the present invention, at least one or more of the plurality of ventilation ports is an outflow ventilation port.
A line segment having a line segment length defining the maximum length of the outflow vent is arranged to face the outer end surface of the mouthpiece and defines the maximum length of the outlet corresponding to the outflow vent. It is preferably smaller than the length of a minute.

Further, in the short arc type discharge lamp of the present invention, the plurality of ventilation ports are arranged along a virtual circle coaxial with the outer peripheral surface of the mouthpiece.
At least one or more of the plurality of ventilation openings is an inflow ventilation port.
The total length of the arcs of the virtual circle overlapping the inflow ventilation port is smaller than the total length of the arcs of the virtual circle overlapping the air outlets arranged so as to face the outer end surface portion of the mouthpiece. preferable.

Further, in the short arc type discharge lamp of the present invention, at least one or more of the plurality of ventilation ports is an outflow ventilation port.
The total length of the arcs of the virtual circle overlapping the outflow ventilation port is smaller than the total length of the arcs of the virtual circle overlapping the discharge port arranged to face the outer end surface portion of the mouthpiece. preferable.

The light irradiation device of the present invention includes the above-mentioned short arc type discharge lamp and
A lamp holding portion that holds the base of the short arc type discharge lamp, and a lamp holding portion.
It is characterized by including a ventilation mechanism for allowing cooling air to flow in and out of the internal space through the ventilation port on the outer end surface portion of the mouthpiece.

In the light irradiation device of the present invention, it is preferable that the lamp holding portion has an air outlet for blowing cooling air and an exhaust port for discharging cooling air, which are arranged so as to communicate with the ventilation port, respectively.

According to the present invention, since the ventilation port for allowing the cooling air to flow in and out of the internal space of the mouthpiece is formed on the outer end surface portion of the mouthpiece, the cooling air can be directly applied to the outer end surface of the sealing portion of the arc tube. As a result, the efficiency with which the sealing portion is cooled is improved.
Further, since the ventilation port is formed on the flat outer end surface portion of the mouthpiece, it is possible to connect the ventilation port and the exhaust port of the cooling air to the ventilation port. Therefore, the arc tube is not cooled by the cooling air.
Therefore, the sealing portion can be cooled with high efficiency without lowering the temperature of the arc tube, and as a result, the sealing portion is suppressed from being damaged due to the temperature rise of the sealing portion, resulting in a short arc. A long service life can be obtained in a type discharge lamp.
In addition, by connecting the air outlet and the exhaust port of the cooling air to the ventilation port, it is possible to prevent the inside of the device on which the short arc type discharge lamp is mounted from being contaminated by contaminants such as the joint layer. it can.

In addition, the length of the line segment that defines the maximum length of the inflow vent is the line that defines the maximum length of the air outlet corresponding to the inflow vent, which is arranged so as to face the outer end surface of the mouthpiece. According to the configuration smaller than the length of the minute, when the short arc type discharge lamp is attached to the light irradiation device, even if the short arc type discharge lamp is slightly displaced in the direction of rotation about the tube axis as the central axis. Since the inflow vent is located within the vent, the required connection between the inflow vent and the vent is easily achieved.
Further, according to the configuration in which the total length of the arcs of the virtual circle overlapping the inflow ventilation port is smaller than the total length of the arcs of the virtual circle overlapping the air outlets arranged facing the outer end surface of the mouthpiece. , When the short arc type discharge lamp is attached to the light irradiation device, the inflow vent is located inside the air outlet even if the short arc type discharge lamp is slightly displaced in the direction of rotation about the tube axis. Therefore, the connection between the inflow vent and the air outlet can be easily achieved.

In addition, the length of the line segment that defines the maximum length of the outflow vent is the line that defines the maximum length of the outlet corresponding to the outflow vent, which is arranged so as to face the outer end surface of the mouthpiece. According to the configuration smaller than the length of the minute, when the short arc type discharge lamp is attached to the light irradiation device, even if the short arc type discharge lamp is slightly displaced in the direction of rotation about the tube axis as the central axis. Since the inflow vent is located within the vent, the required connection between the outflow vent and the outlet is easily achieved.
Further, according to the configuration in which the total length of the arcs of the virtual circle overlapping the outflow ventilation port is smaller than the total length of the arcs of the virtual circle overlapping the discharge port arranged facing the outer end surface of the mouthpiece. , When the short arc type discharge lamp is attached to the light irradiation device, even if the short arc type discharge lamp is slightly misaligned in the direction of rotation around the tube axis, the outflow vent is located inside the discharge port. Therefore, the required connection between the outflow vent and the outlet is easily achieved.

It is explanatory cross-sectional view which shows the structure in the example of the short arc type discharge lamp of this invention. It is explanatory drawing which shows the outer end surface part of the mouthpiece in the short arc type discharge lamp shown in FIG. It is explanatory drawing which shows the state which superposed the air outlet and the discharge port on the outer end surface portion of the mouthpiece in the short arc type discharge lamp shown in FIG. It is explanatory drawing which shows the structure in the example of the light irradiation apparatus of this invention. It is explanatory drawing which shows the structure in the example of the lamp holding part in the light irradiation apparatus of this invention. It is explanatory drawing which shows the flow of the cooling air in the internal space of a base. It is explanatory drawing which shows the state which when the short arc type discharge lamp shown in FIG. 1 is attached to a light irradiation apparatus, the short arc type discharge lamp is displaced in the direction of rotation about the tube axis as a central axis. It is explanatory drawing which shows the structure in another example of the base used for the short arc type discharge lamp of this invention. It is explanatory drawing which shows the modification of the mouthpiece used for the short arc type discharge lamp of this invention. It is explanatory drawing which shows the other modification of the mouthpiece used for the short arc type discharge lamp of this invention. It is explanatory drawing which shows the further modification of the mouthpiece used for the short arc type discharge lamp of this invention. It is explanatory drawing which shows the structure in another example of the lamp holding part used for the light irradiation apparatus of this invention.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is an explanatory sectional view showing a configuration in an example of a short arc type discharge lamp of the present invention. In this short arc type discharge lamp (hereinafter, also simply referred to as “discharge lamp”) 10, sealing portions 14 are formed at both ends of a substantially spherical light emitting portion 12 so as to continuously extend outward through a narrowed portion 13. The arc lamp 11 is provided. A light emitting space S1 is formed inside the light emitting portion 12 of the light emitting tube 11, and an anode 20 and a cathode 21 are arranged in the light emitting space S1 so as to face each other. Further, the light emitting space S1 is filled with a light emitting substance such as mercury and a buffer gas for starting assistance such as argon gas.

As the material constituting the arc tube 11, a light-transmitting material such as quartz glass can be used.
Further, tungsten can be used as the material constituting the anode 20, and triated tungsten can be used as the material constituting the cathode 21.
The amount of the luminescent substance, for example, mercury sealed in the light emitting space S1 is 2 to 6 mg / cm ³ , and the sealing pressure of the buffer gas, for example, argon gas is 0.09 to 0.5 MPa in static pressure.

Inside the arc tube 11, two rod-shaped internal leads 22 extending from the sealing portion 14 toward the light emitting space S1 along the tube axis are arranged. An anode 20 or a cathode 21 is fixed to each tip of the internal lead 22. Further, each base end portion of the internal lead 22 is fixedly supported by one end portion of a substantially columnar sealing insulator 15 made of, for example, glass, which is arranged in the sealing portion 14 along the pipe axis. .. In the illustrated example, one end of the sealing insulator 15 is formed in a tapered shape. Further, at the other end of the sealing insulator 15, two rod-shaped external leads 23 extending outward from the sealing portion 14 along the pipe axis are fixedly supported.
Tungsten can be used as the material constituting the inner lead 22 and the outer lead 23.

On the outer peripheral surface of the sealing insulator 15, a plurality of (for example, six) strip-shaped conductive foils 24 are arranged in the circumferential direction of the sealing insulator 15 at equal intervals, and the arc tube is provided. It is arranged so as to extend along the pipe axis direction of 11. One end of each of these conductive foils 24 is interposed between the disc-shaped conductive disc 25 and the disc-shaped auxiliary disc 26 stacked on one end surface of the sealing insulator 15. One end of each of the conductive foils 24 is integrally joined with the conductive disk 25 by welding. An internal lead 22 penetrates each of the conductive disk 25 and the auxiliary disk 26. As a result, the conductive foil 24 is electrically connected to the internal lead 22 via the conductive disk 25. Further, the other end of each of the conductive foils 24 is joined to the outer peripheral surface of the bottomed tubular metal member 27 that opens outward by welding. The external lead 23 penetrates the metal member 27 in a state of being electrically connected, whereby the conductive foil 24 is electrically connected to the external lead 23 via the metal member 27.
Then, the inner surface of the sealing portion 14 in the arc tube 11 and the sealing insulator 15 are welded via the conductive foil 24, so that the conductive foil 24 is airtightly embedded in the sealing portion 14. The structure is formed.

As the material constituting the conductive foil 24, for example, refractory metals such as tungsten, tantalum, ruthenium, and rhenium or alloys thereof can be used, but the ease of welding and the conductivity of welding heat are good. For this reason, it is preferable to use a metal containing molybdenum as a main component. The thickness of the conductive foil 24 is, for example, 0.02 to 0.06 mm, and the width of the conductive foil 24 is, for example, 6 to 12 mm.
As a material constituting the conductive disk 25 and the auxiliary disk 26, refractory metals such as tantalum, niobium, tungsten, and molybdenum can be used. The thickness of the conductive disk 25 in contact with one end surface of the sealing insulator 15 is, for example, 0.5 to 6 mm, and the thickness of the auxiliary disk 26 is, for example, 0.05 to 1 mm.
Molybdenum or the like can be used as the material constituting the metal member 27.

In the illustrated example, a tubular internal lead support member 16 made of glass, for example, through which the internal lead 22 is inserted is arranged in the narrowed portion 13 of the arc tube 11. Further, in the tubular hole of the metal member 27, for example, a glass tubular external lead support member 17 through which the external lead 23 is inserted is arranged.

The sealing portion 14 of the arc tube 11 is provided with a bottomed tubular base 30 in a state where the sealing portion 14 is inserted into the tubular hole. A bonding layer 40 made of an adhesive is formed between the outer peripheral surface of the sealing portion 14 and the inner peripheral surface of the base 30, and the base 30 is fixed to the sealing portion 14 by the bonding layer 40. There is.

As the material constituting the base 30, brass, aluminum, or the like can be used.
As the adhesive constituting the bonding layer 40, an inorganic adhesive typified by a ceramic adhesive can be used. The thickness of the bonding layer 40 is preferably 0.5 to 5 mm.

An internal space S2 is formed between the outer end surface portion 31 of the mouthpiece 30 and the outer end surface 14a of the sealing portion 14 in the mouthpiece 30. At the central portion of the outer end surface portion 31 of the base 30, a bottomed cylindrical terminal portion 32 that opens into the internal space S2 is formed so as to project outward from the outer end surface portion 31 of the base 30. The tip of the external lead 23 is inserted into the tubular hole of the terminal portion 32 and fixed by brazing or the like, so that the external lead 23 is electrically connected to the terminal portion 32 of the base 30.

As shown in FIG. 2, a plurality of (two in the illustrated example) circular ventilation ports 33 are formed in the outer end surface portion 31 of the base 30 to allow cooling air to flow in and out of the internal space S2. These ventilation ports 33 are arranged along a virtual circle C coaxial with the outer peripheral surface of the base 33. In the illustrated example, one ventilation port 33 is an inflow ventilation port 33a, and the other ventilation port 33 is an outflow ventilation port 33b.

The ratio of the area of the ventilation port 33 to the outer end surface of the base 30 (hereinafter, referred to as “opening ratio”) is preferably 5% or more and 80% or less, and more preferably 10% or more and 40% or less. If the opening ratio of the ventilation port 33 is too small, the cooling air does not sufficiently flow in and out of the internal space S of the base 30, and therefore it becomes difficult to sufficiently cool the sealing portion 14. There is. On the other hand, when the opening ratio of the ventilation port 33 is excessive, the strength of the outer end surface portion 31 of the mouthpiece 30 is low, and the outer end surface portion 31 may be easily damaged.

Of the plurality of ventilation ports 33, in the inflow ventilation port 33a, as shown in FIG. 3, the total length of the arc C1 of the virtual circle C overlapping with the inflow ventilation port 33a (in the illustrated example, the inflow ventilation port). Since there is only one 33a, the length of the arc C2 of the virtual circle C where the length of the arc related to the inflow ventilation port 33a) overlaps with the air outlet 52 arranged to face the outer end surface portion 31 of the mouthpiece 30. It is preferable that it is smaller than the total sum (in the illustrated example, since there is only one air outlet 52, the length of the arc related to the air outlet 52).
The ratio of the total length of the arc C1 related to the inflow ventilation port 33a and the total length of the arc C2 related to the ventilation port 52 is preferably 1: 1.05 to 1: 1.3. It is preferably 1: 1.1 to 1: 1.2.

Further, in the outflow ventilation port 33b among the plurality of ventilation ports 33, the total length of the arc C3 of the virtual circle C overlapping with the outflow ventilation port 33b (in the illustrated example, the outflow ventilation port 33b is one). Therefore, the total length of the arc C4 of the virtual circle C in which the length of the arc related to the outflow ventilation port 33b) overlaps with the discharge port 53 arranged to face the outer end surface portion 31 of the mouthpiece 30 (illustrated). In the example of, since there is only one discharge port 53, it is preferably smaller than the length of the arc related to the discharge port 53).
The ratio of the total length of the arc C3 related to the outflow ventilation port 33b and the total length of the arc C4 related to the discharge port 53 is preferably 1: 1.05 to 1: 1.3. It is preferably 1: 1.1 to 1: 1.2.

The light irradiation device of the present invention blows cooling air into the internal space S2 via the discharge lamp 10, the lamp holding portion for holding the base 30 of the discharge lamp 10, and the ventilation port 33 of the outer end surface portion 31 of the base 30. It is equipped with a ventilation mechanism that allows inflow and outflow.

FIG. 4 is an explanatory diagram showing a configuration in an example of the light irradiation device of the present invention. This light irradiation device includes a discharge lamp 10 shown in FIG. 1, a lamp holding portion 50 for holding the discharge lamp 10, and a concave reflector 55 arranged so as to surround the light emitting portion 12 in the discharge lamp 10. These are housed in the lamp house 60.
As shown in FIG. 5, the lamp holding portion 50 is formed of, for example, a rectangular plate-like body made of metal. In the lamp holding portion 50, a circular terminal connection opening 51, an air outlet 52, and an exhaust port 53 penetrating in the thickness direction correspond to the terminal portion 32 and the two ventilation ports 33 in the base 30 of the discharge lamp 10. It is formed.
The air outlet 52 of the lamp holding portion 50 is connected to the air blowing mechanism 65 provided outside the lamp house 60 by a pipe 61. On the other hand, the discharge port 53 of the lamp holding portion 50 is connected to the filter 63 provided outside the lamp house 60 by a pipe 62.

In the lamp holding portion 50, the terminal connection opening 51 has an inner diameter slightly larger than the outer diameter of the terminal portion 32 in the base 30. When the discharge lamp 10 is attached to the lamp holding portion 50, it is used for terminal connection in a state where each of the ventilation ports 33 of the base 30 is aligned so as to face the ventilation port 52 and the discharge port 53 of the lamp holding portion 50. The terminal portion 32 of the base 30 is inserted into the opening 51, whereby the air outlet 52 and the discharge port 53 are in a state of communicating with the ventilation port 33 of the base 30. On the side surface of the lamp holding portion 50, a fixing member 54 made of a screw for fixing the terminal portion 32 of the base 30 is provided (FIG. 5).

Further, the air outlet 52 and the discharge port 53 are formed within a range covered by the outer end surface of the mouthpiece 30 when the discharge lamp 10 is held by the lamp holding portion 50. In the example shown in FIG. 5, the air outlet 52 and the exhaust port 53 are formed so that the distance L is smaller than the outer diameter of the outer end surface of the base 30. As a result, it is possible to prevent the cooling air from leaking to the outside from the ventilation port 52 of the lamp holding portion 50 or the ventilation port 33 of the base 30.

In the above light irradiation device, the ventilation mechanism 65 is operated when the discharge lamp 10 is lit, so that the cooling air flows from the ventilation port 52 into the internal space S2 through the inflow ventilation port 33a of the base 30. The flow rate of the cooling air flowing into the internal space S2 is, for example, 1.0 to 2.5 L / min.

Then, as shown in FIG. 6, the cooling air flowing into the internal space S2 from the inflow ventilation port 33a directly hits the outer end surface 14a of the sealing portion 14 of the arc tube 11 facing the inflow ventilation port 33a. As a result, the efficiency with which the sealing portion 14 is cooled is improved. Further, the cooling air that hits the outer end surface 14a of the sealing portion 14 flows out from the outflow ventilation port 33b. After that, the cooling air is discharged through the discharge port 53.
Further, since the air outlet 52 and the discharge port 53 for the cooling air are connected to the ventilation port 33 of the base 30, the arc tube 11 is not cooled by the cooling air.
Therefore, the sealing portion 14 can be cooled with high efficiency without lowering the temperature of the arc tube 11, thereby suppressing damage to the sealing portion 14 due to the temperature rise of the sealing portion 14. As a result, a long service life can be obtained in the discharge lamp 10.
Further, since the cooling air ventilation port 52 and the discharge port 53 are connected to the ventilation port 33 of the base 30, it is possible to prevent the inside of the light irradiation device from being contaminated by contaminants such as the bonding layer 40. ..

Further, the total length of the arc C1 of the virtual circle C overlapping the inflow ventilation port 33a is the length of the arc C2 of the virtual circle C overlapping the air outlet 52 arranged to face the outer end surface portion 31 of the base 30. As shown in FIG. 7, even if the discharge lamp 10 is slightly displaced in the direction of rotation about the tube axis when the discharge lamp 10 is attached to the light irradiation device because it is smaller than the total of the above. Since the inflow vent 33a is located inside the air outlet 52, the required connection between the inflow vent 33a and the air outlet 52 can be easily achieved.

Further, the total length of the arc C3 of the virtual circle C overlapping the outflow ventilation port 33b is the length of the arc C4 of the virtual circle C overlapping the discharge port 53 arranged to face the outer end surface portion 31 of the base 30. When the discharge lamp 10 is attached to the light irradiation device, the outflow ventilation port 33b is exhausted even if the discharge lamp 10 is slightly displaced in the direction of rotation about the tube axis. Since it is located in the outlet 53, the required connection between the outflow ventilation port 33b and the discharge port 53 can be easily achieved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications such as the following can be made.

(1) As shown in FIG. 8, the base 30 may have a positioning portion 34 formed by, for example, a D-cut shaped notch. By providing such a positioning portion 34, when the discharge lamp 10 is attached to the lamp holding portion 50, the ventilation port 33, the ventilation port 52, and the discharge port 53 can be easily and surely aligned with each other. .. Further, the positioning portion 34 is not limited to the one formed by the D-cut shape notch, and various forms can be adopted.

(2) The shape of the ventilation port 33 of the base 30 is not limited to a circular shape, and for example, as shown in FIG. 9A, a rectangular ventilation port 33 may be formed, as shown in FIG. 9B. As shown, a bow-shaped ventilation port 33 may be formed.

(3) The number of ventilation ports 33 of the base 30 is not limited to two, and for example, a single ventilation port 33 that is also used for the inflow and outflow of cooling air may be formed. When forming a single ventilation port 33, the ventilation port 33 may have the same inner diameter as the internal space S2 of the base 30 as shown in FIG. In the figure, the sealing portion 14, the external lead 23, and the bonding layer 40 on the end side of the discharge lamp 10 can be seen inside the ventilation port 33. When the base 30 having such a configuration is used, the lamp holding portion 50 is preferably sized to cover the ventilation port 33.

(4) In the base 30, three or more ventilation ports, for example, as shown in FIG. 11A, four ventilation ports 33 surround the central portion of the outer end surface portion 31 where the terminal portion 32 is formed. It may be formed, and as shown in FIG. 11B, a large number of ventilation openings 33 may be formed so as to surround the central portion where the terminal portion 32 is formed in the outer end surface portion 31.

(5) In the light irradiation device, the shapes of the air outlet 52 and the exhaust port 53 of the lamp holding portion 50 are not limited to a circular shape, and for example, as shown in FIG. 12A, the rectangular air outlet 52 and the exhaust port 52 and the exhaust port 53. The outlet 53 may be formed, and as shown in FIG. 12B, a truck-shaped air outlet 52 and an outlet 53 may be formed.

(6) The plurality of ventilation ports 33 may not be arranged along a virtual circle coaxial with the outer peripheral surface of the base 30. In such a case, the length of the line segment that defines the maximum length of the inflow ventilation port 33a among the ventilation ports 33 defines the maximum length of the ventilation port 52 corresponding to the inflow ventilation port 33a. It is preferably smaller than the length of the line segment. Of the ventilation ports 33, the length of the line segment defining the maximum length of the outflow ventilation port 33b is smaller than the length of the line segment defining the maximum length of the discharge port 53 corresponding to the outflow ventilation port 33b. Is preferable. Here, the length of the line segment that defines the maximum length means, for example, the diameter if the ventilation port 33 is circular, and the diagonal length if the ventilation port 33 is rectangular. According to such a configuration, when the discharge lamp 10 is attached to the light irradiation device, the ventilation port 33 is the ventilation port even if the discharge lamp 10 is slightly displaced in the direction of rotation about the tube axis thereof. Since it is located in the 52 or the discharge port 53, the required connection between the ventilation port 33 and the ventilation port 52 or the discharge port 53 can be easily achieved.

<Example 1>
A discharge lamp having the following specifications was produced according to the configurations shown in FIGS. 1 and 2.
[Expression tube (11)]
Material = quartz glass, total length = 90 mm,
Light emitting part (12): maximum outer diameter = 62 mm, maximum inner diameter = 55 mm,
Sealing part (13): Outer diameter = 30 mm
[Anode (20)]
Material = Tungsten, Outer diameter = 25 mm
[Cathode (21)]
Material = Triated Tungsten, Outer Diameter = 12mm
[Conductive foil (24)]
Material = molybdenum [base (30)]
Material = brass, overall length = 70 mm, inner diameter = 31.5 mm, outer diameter = 33.5 mm
Number of ventilation openings = 2, Diameter of ventilation openings = 7 mm
[Joint layer (40)]
Material = ceramic adhesive, thickness = 0.75 mm,

A cooling air supply nozzle having an outlet having an inner diameter of 2.5 mm was inserted into one of the ventilation openings of the base of the discharge lamp described above. This discharge lamp was lit with a lamp input of 2.7 kW (current = 25 A, voltage = 107 V), and cooling air was supplied into the base from a cooling air supply nozzle. Then, the temperature at a position about 20 mm away from the outer end of the sealing portion of the conductive foil was measured, and the flow rate of the cooling air required to maintain the temperature of the conductive foil at 350 ° C. was measured. It was 0 L / min.

<Comparative example 1>
A discharge lamp having the same specifications as in Example 1 except that a ventilation port is not formed in the base and the joint layer is formed so as to be filled between the outer end surface of the sealing portion and the bottom surface of the base. Was produced. A cooling air supply nozzle having an outlet having an inner diameter of 25 mm was arranged at a position 60 mm away from the outer peripheral surface of the base of the discharge lamp. This discharge lamp was lit with a lamp input of 2.7 kW (current = 25 A, voltage = 107 V), and cooling air was supplied from the cooling air supply nozzle toward the outer peripheral surface of the base. Then, the temperature at a position about 20 mm away from the outer end of the sealing portion of the conductive foil was measured, and the flow rate of the cooling air required to maintain the temperature of the conductive foil at 350 ° C. was measured. It was min.

From the above results, it was confirmed that the sealed portion can be cooled with high efficiency according to the discharge lamp according to the embodiment. Further, by connecting the cooling air discharged from the other ventilation port to the discharge port of the lamp holding portion in the light irradiation device, it is possible to cool the sealing portion without lowering the temperature of the arc tube. ..

10 Short arc type discharge lamp 11 Light emitting tube 12 Light emitting part 13 Constriction part 14 Sealing part 15 Sealing insulator 16 Internal lead support member 17 External lead support member 20 Anode 21 Electrode 22 Internal lead 23 External lead 24 Conductive foil 25 Conductive Disc 26 Auxiliary disk 27 Metal member 30 Mouthpiece 31 Outer end surface 32 Terminal part 33 Ventilation port 33a Inflow ventilation port 33b Outflow ventilation port 34 Positioning part 40 Joint layer 50 Lamp holding part 51 Terminal connection opening 52 Blower port 53 Outlet 54 Fixing member 55 Concave reflector 60 Lamp house 61, 62 Piping 63 Filter 65 Blower mechanism C Virtual circle C1, C2, C3, C4 Arc S1 Light emitting space S2 Internal space

Claims (8)

A short arc having a light emitting tube in which a sealing portion is continuously formed at one end of a light emitting portion and a mouthpiece into which the sealing portion is inserted and fixed, and a foil seal structure is formed in the sealing portion. It is a type discharge lamp
An internal space is formed between the outer end surface portion of the mouthpiece and the outer end surface portion of the sealing portion.
A short arc type discharge lamp characterized in that the outer end surface portion of the mouthpiece has a ventilation port for allowing cooling air to flow in and out of the internal space. The short arc type discharge lamp according to claim 1, wherein a plurality of the ventilation ports are formed on the outer end surface portion of the mouthpiece. At least one or more of the plurality of ventilation openings is an inflow ventilation port.
The length of the line segment defining the maximum length of the inflow vent is smaller than the length of the line segment defining the maximum length of the air outlet arranged to face the outer end surface portion of the mouthpiece. The short arc type discharge lamp according to claim 2. At least one or more of the plurality of ventilation openings is an outflow ventilation port.
A line segment having a line segment length defining the maximum length of the outflow vent is arranged to face the outer end surface of the mouthpiece and defines the maximum length of the discharge port corresponding to the outflow vent. The short arc type discharge lamp according to claim 3, wherein the length is smaller than a minute. The plurality of ventilation holes are arranged along a virtual circle coaxial with the outer peripheral surface of the mouthpiece.
At least one or more of the plurality of ventilation openings is an inflow ventilation port.
The total length of the arcs of the virtual circle overlapping the inflow ventilation port is smaller than the total length of the arcs of the virtual circle overlapping the air outlets arranged so as to face the outer end surface portion of the mouthpiece. The short arc type discharge lamp according to claim 2. At least one or more of the plurality of ventilation openings is an outflow ventilation port.
The total length of the arcs of the virtual circle overlapping the outflow ventilation port is smaller than the total length of the arcs of the virtual circle overlapping the discharge port arranged so as to face the outer end surface portion of the mouthpiece. The short arc type discharge lamp according to claim 5. The short arc type discharge lamp according to any one of claims 1 to 6.
A lamp holding portion that holds the base of the short arc type discharge lamp, and a lamp holding portion.
A light irradiation device including a ventilation mechanism for allowing cooling air to flow in and out of the internal space through the ventilation port on the outer end surface portion of the mouthpiece. The light irradiation device according to claim 7, wherein each of the lamp holding portions has a ventilation port for blowing cooling air and an exhaust port for discharging cooling air, which are arranged so as to communicate with the ventilation port.

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