JP2001357817A - Flashing discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flashing discharge lamp capable of obtaining a big radiant intensity in a far ultraviolet area, having a long life, and also capable of easily forming a highly reliable airtight structure. SOLUTION: This flashing discharge lamp has a feature that a pair of discharge electrodes are disposed face to face in a discharge container of quartz glass, noble gas is sealed in it, a hollow tube of translucent ceramic is disposed in the discharge container, and the discharge electrodes are provided so as to be positioned inside the hollow tube. In this lamp, a protruding part protruding inward is formed on the inner peripheral surface of at least one end of the discharge container, and the movement of the hollow tube in the axial direction of the tube is preferably regulated by this protruding part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flash discharge lamp, and more particularly to a flash discharge lamp suitably used for, for example, a sterilization process, a toner fixing process, an adhesive curing process, and a semiconductor RTP process.

[0002]

2. Description of the Related Art At present, for example, in a sterilizing process, a fixing process of a toner, a curing process of an adhesive, a RTP process of a semiconductor, etc., light in a far ultraviolet region can be obtained with high efficiency. A flash discharge lamp filled with gas is preferably used, and in many cases, quartz glass is used as a material for forming a discharge vessel.
In such a flash discharge lamp, for example, 40 times,
It is required to be able to withstand lighting of 100,000 times or more.

In recent years, a flash discharge lamp capable of obtaining light having a higher radiation intensity in the far ultraviolet region has been desired. In order to obtain light having a large radiation intensity in the far ultraviolet region, for example, the flash pulse width is reduced and the current density is increased, and for example, the pulse width is set to 0.
It is necessary to operate under high load lighting conditions such as ² to 1 ms and a current density of ² kA / cm ² or more.

[0004] However, when the lamp is lit under a high load lighting condition, the quartz glass constituting the discharge vessel is subjected to the action of discharge plasma to produce silicon oxide (SiO 2).
x) becomes remarkable, and in addition to the discharge vessel being colored yellow, the electrode material constituting the cathode in particular evaporates and the discharge electrodes become more depleted. As a result, the light emitted from the flash discharge lamp is reduced. The output is reduced, resulting in a very short service life.

On the other hand, there is known a flash discharge lamp in which a discharge vessel is formed of a light transmitting material other than quartz glass. For example, "ITC Technical Bull"
Letin No. 3, 1965 "describes a flash discharge lamp in which a discharge vessel is formed of sapphire, and Japanese Utility Model Laid-Open No. 63-60265 discloses a flash discharge lamp in which a discharge vessel is formed of aluminum oxide. Has been described.

According to such a flash discharge lamp, sapphire or aluminum oxide constituting the discharge vessel is more resistant to discharge plasma than quartz glass. However, it is said that the deterioration of the discharge vessel is suppressed and the consumption of the electrodes is small.

However, since it is practically impossible to process sapphire or aluminum oxide by melting it, the discharge vessel and the external lead are usually integrated with a sealing material comprising niobium and a predetermined frit. It is necessary to form a hermetic sealing structure by temporarily fixing, and when high temperature is applied, niobium oxidizes and becomes brittle, and it is difficult to form a sealing structure with high reliability against breakage. Is a problem.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to provide:
An object of the present invention is to provide a flash discharge lamp which can obtain a large radiation intensity in a far ultraviolet region, has a long service life, and can easily form a highly reliable hermetic sealing structure.

[0009]

According to the present invention, there is provided a flash discharge lamp comprising a discharge vessel made of quartz glass, a pair of discharge electrodes opposed to each other and a rare gas sealed therein. A hollow tube made of a translucent ceramic is disposed therein, and the discharge electrode is provided so as to be located inside the hollow tube.

In the flash discharge lamp described above, at least one end of the discharge vessel is provided with an inwardly projecting projection on an inner peripheral surface thereof. The projection allows the hollow tube to move in the tube axis direction. Is preferably regulated. The outer end of the hollow tube is 5 m from the inner end of the discharge vessel.
It is preferable to be arranged in a state of being located at least m or more inside. Further, the discharge vessel has a straight tubular shape,
The difference between the inner diameter of the discharge vessel and the outer diameter of the hollow tube is preferably 1 mm or less. Further, the thickness of the hollow tube is 0.3 to
It is preferably 1.0 mm.

[0011]

According to the flash discharge lamp configured as described above,
The discharge plasma generated by the flash discharge generated between the pair of discharge electrodes is regulated by the inner peripheral wall surface of the hollow tube, thereby preventing direct contact with the inner wall surface of the discharge vessel. As a result, the discharge vessel is protected from the discharge plasma. The light transmittance of the discharge vessel is maintained over a long period of time, and the hollow tube is made of a light-transmitting ceramic. As a result,
It can be operated with stable operation characteristics many times, and therefore, even when operated under high load lighting conditions, a flash operation having a sufficiently high radiation intensity in the far ultraviolet region can be operated many times. Can be done.

Further, since the discharge vessel is formed of quartz glass, the hermetic sealing structure of the discharge vessel is extremely easy to form, and a highly reliable hermetic sealing structure can be reliably formed.

[0013]

Embodiments of the present invention will be described below in detail. FIG. 1 is an explanatory cross-sectional view showing one embodiment of the flash discharge lamp of the present invention, and FIG. 2 is an enlarged cross-sectional view showing the configuration of one end of the flash discharge lamp shown in FIG. The flash discharge lamp 10 includes a straight tubular discharge vessel 11 made of quartz glass, both ends of which are sealed. In the discharge vessel 11, a cathode 12 and an anode 13 are arranged to face each other. Electrode rods 14 and 15 having the cathode 12 or the anode 13 at the tip thereof have outer ends thereof at the discharge vessel 11.
Are disposed so as to protrude outward through the electrode rod seal portions S at both ends of the first electrode. And in the discharge vessel 11,
Noble gas is enclosed. In FIG. 1, reference numeral 16 denotes a trigger electrode mounted on the outer peripheral surface of the discharge vessel 11, and reference numeral 17 denotes a remaining portion of the exhaust pipe.

Inside the discharge vessel 11 of the flash discharge lamp 10, a hollow tube 20 made of a circular translucent ceramic having an outer diameter slightly smaller than its inner diameter is provided.
1, the cathode 12 and the anode 13 are provided so as to protrude from both ends of the hollow tube 20 and to be located inside. Here, hollow tube 2
The positions of the cathode 12 and the anode 13 with respect to 0 are not particularly limited, and may be any positions as long as they are hidden inside the hollow tube 20. In practice, however, the distance a from the outer edge 22 of the hollow tube 20 Is preferably arranged at a position where the distance is 5 to 10 mm.

The light-transmitting ceramics constituting the hollow tube 20 include, for example, alumina, sapphire, YAG (yttrium-aluminum-garnet), yttria, zirconia and the like.

The inner peripheral surface of the discharge vessel 11 has protrusions 24, 2, which protrude inward over the entire circumference, at both ends.
5 are formed, and the movement of the hollow tube 20 in the tube axis direction is restricted by the protrusions 24 and 25. Specifically, the protrusion 2 of the discharge vessel 11
4 and 25 are formed so as to have inner diameters smaller than the outer diameter of the hollow tube 20 at positions slightly outside the both ends of the hollow tube 20, whereby the hollow tube 20 is connected to the discharge vessel 11. Although it is not fixed integrally with the tube, the movement in the tube axis direction is substantially restricted.

In this flash discharge lamp 10, the outer edge 22 of the hollow tube 20 is preferably arranged at a position where the distance b from the inner edge 11A of the discharge vessel 11 is 5 mm or more. Thereby, as will be described later, when the outer end portion of the discharge vessel material is heated and melted to form a hermetic sealing structure, the thermal influence on the hollow tube 20 is reduced, and the hollow tube 20 20 can be reliably prevented from being damaged.

The difference between the inner diameter of the discharge vessel 11 and the outer diameter of the hollow tube 20 is preferably 1 mm or less. When the difference between the inner diameter of the discharge vessel 11 and the outer diameter of the hollow tube 20 exceeds 1 mm, the main discharge by the cathode 12 and the anode 13 is:
It may occur through a gap between the inner peripheral surface of the discharge vessel 11 and the outer peripheral surface of the hollow tube 20. Also, the discharge vessel 11
Since the heat transfer coefficient in the gap between the inner peripheral surface of the hollow tube 20 and the outer peripheral surface of the hollow tube 20 becomes smaller, the heat of the hollow tube 20 is
It becomes difficult to radiate heat to the outside of the tube 1 and the hollow tube 20 may be damaged.

The thickness of the hollow tube 20 is 0.3-1.
It is preferably 0 mm. Thereby, the hollow tube 20
The hollow tube 20 can be prevented from being damaged during the lighting operation, and the desired operating characteristics can be maintained many times. Becomes

Next, an example of a method for manufacturing such a flash discharge lamp will be described. First, as shown in FIG.
A discharge vessel material 30 is provided in which a straight quartz glass tube 301 is provided with an exhaust pipe 302 communicating with the internal space, and a predetermined position close to one end 30A of the discharge vessel material 30 is, for example, burner. The one protruding portion 24 is formed by heating by, for example, the above. Here, protrusion 2
The formation of 4 is performed, for example, by heating the discharge vessel material 30 while rotating it at a constant speed about its tube axis.

Next, as shown in FIG. 4, an electrode rod 32 having a discharge electrode 31 at its tip and a disk-shaped electrode rod 32 integrally fixed so as to penetrate through an electrode rod seal portion S are formed. One electrode structure 34 made of glass material 33
After inserting and disposing from one end of the discharge vessel material 30,
By heating one end 30A of the discharge vessel material 30, the discharge vessel material 30 and the glass material 3 of the electrode structure 34 are heated.
3 and the peripheral portion of the discharge vessel material 30 are integrally fused.
Is hermetically sealed.

Then, as shown in FIG. 5, after inserting the hollow tube 20 from the other end of the discharge vessel material 30, the other end 20B of the hollow tube 20 in the other end 30B of the discharge vessel material 30 is used.
Is heated by a burner or the like to form the other protruding portion 25.

Thereafter, as shown in FIG. 6, the other electrode structure 35 similar to the one described above is inserted from the other end of the discharge vessel material 30 and arranged. By heating 30B, the discharge vessel material 30 and the glass material 33 of the electrode structure 35 are integrally fused, and the other end 30B of the discharge vessel material 30 is hermetically sealed. After the gas in the internal space of the discharge vessel material 30 is exhausted by the exhaust pipe 302, a predetermined amount of a rare gas is sealed, and the exhaust pipe 302 is completely sealed to form a hermetic sealing structure. The flash discharge lamp 10 having the configuration shown in FIG. 1 is manufactured.

According to the flash discharge lamp 10 having the above-described structure, the discharge plasma generated by the flash discharge generated between the cathode 12 and the anode 13 is regulated by the inner peripheral wall surface of the hollow tube 20 and As a result of preventing direct contact with the wall surface, the discharge vessel is protected from the discharge plasma, deterioration is suppressed, the light transmittance of the discharge vessel 11 is maintained for a long time, and the hollow tube 20 is transparent. Since it is made of conductive ceramics, it does not deteriorate its light transmittance and suppresses electrode wear.As a result, it can be operated with stable operation characteristics many times, and thus can be operated under high load lighting conditions. Even in this case, a flash operation having a sufficiently high radiation intensity in the far ultraviolet region can be stably performed many times.

Further, since the discharge vessel 11 is formed of quartz glass, the hermetic sealing structure of the discharge vessel 11 is extremely easy to form, and a highly reliable hermetic sealing structure can be reliably formed. it can.

Further, since the position of the hollow tube 20 is regulated by the protruding portions 24 and 25 formed at both ends of the discharge vessel 11, the main discharge by the cathode 12 and the anode 13 is reliably performed inside the hollow tube 20. Discharge vessel 1
1 can be reliably prevented from deteriorating. Moreover, the hollow tube 2 can be directly welded to the discharge vessel 11 without welding.
0, the discharge vessel 11 is caused by thermal stress caused by a difference in thermal expansion between the quartz glass constituting the discharge vessel 11 and the translucent ceramic constituting the hollow tube 20 during the lighting operation. No damage. Therefore, a flash operation having a sufficiently high radiation intensity in the far ultraviolet region can be stably performed many times.

Although the specific embodiments of the present invention have been described above, the present invention is not limited to the above examples, and various changes can be made to the specific configuration of each unit. For example, as shown in FIG. 7, instead of forming one protruding portion at one end of the discharge vessel 41, a part of the getter ring 27 fixed to the outer peripheral surface of the electrode rod 14 is partially connected to one end 20A of the hollow tube 20. By engaging the outer end of the hollow tube 20, the movement of the hollow tube 20 in the tube axis direction can be restricted.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the flash discharge lamp according to the present invention will be specifically described below, but the present invention is not limited to these embodiments. Example 1 and Comparative Example 1 A flash discharge lamp (10) was manufactured according to the structure shown in FIG. The specifications of the flash discharge lamp (10) are such that the distance between the electrodes is 100 mm, the inner diameter of the discharge vessel (11) is 10.5 mm, and the outer diameter is 13.0.
mm, length 160 mm, inner diameter of hollow tube (20) is 9.
Xenon, which is a rare gas, was sealed in the discharge vessel (11) in an amount such that the sealing pressure was 300 Torr, which was 0 mm, the outer diameter was 10.0 mm, and the length was 140 mm.

A flash lamp for comparison was manufactured in the same manner as in Example 1 except that the hollow tube was not arranged in the discharge vessel.

Each of the flash discharge lamps manufactured as described above was subjected to a flash current having a peak current value of 1200 A, a flash pulse of 5 Hz, and a flash pulse width of 0.2 msec (half the pulse peak value). Width.) The operation was repeatedly performed under the condition that one light emission energy was 100 J, and the emission intensity of light emitted in the far ultraviolet region of each flash discharge lamp was measured. The results are shown in Table 1 below. Here, the distance between the radiation intensity measuring instrument and the flash discharge lamp was 500 mm.

[0031]

[Table 1]

From the above results, in the flash discharge lamp of the first embodiment, since the hollow tube is provided in the discharge vessel, the radiation intensity at the time of initial lighting is higher than the radiation intensity of the flash discharge lamp of the first comparative example. Although low, the ratio of the decrease in the radiation intensity to the number of times of lighting is small, and it can be seen that even when the number of times of lighting reaches 5 million times, the high radiation intensity is maintained and the operation can be stably performed many times. On the other hand, in the flash discharge lamp of Comparative Example 1, 1
Radiation intensity count lighting was 65μJ / cm ² is reduced to 45μJ / cm ² at the time of the 600,000 times, after all, the number of lighting times is no longer able to soon operate past 5,000,000.

[0033]

According to the flash discharge lamp of the present invention, the discharge plasma generated by the flash discharge generated between the pair of discharge electrodes is regulated on the inner peripheral wall surface of the hollow tube, and directly contacts the inner wall surface of the discharge vessel. As a result, the discharge vessel is protected from the discharge plasma, the deterioration is suppressed, the light transmittance of the discharge vessel is maintained for a long time, and the hollow tube is made of translucent ceramics. As a result, the light transmittance of the light-emitting element is not deteriorated, and the consumption of the discharge electrode is suppressed. As a result, the light-emitting element can be operated with stable operation characteristics many times, and therefore, even when operated under high load lighting conditions. In addition, a flash operation having a sufficiently high radiation intensity in the far ultraviolet region can be stably performed many times.

Further, since the discharge vessel is made of quartz glass, the hermetic sealing structure of the discharge vessel is extremely easy to form, and a highly reliable hermetic sealing structure can be reliably formed.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing one embodiment of a flash discharge lamp according to the present invention.

FIG. 2 is an enlarged sectional view showing a configuration of one end of the flash discharge lamp shown in FIG.

FIG. 3 is an explanatory sectional view showing a state in which one protruding portion is formed at one end of a discharge vessel material.

FIG. 4 is an explanatory sectional view showing a state where one end of a discharge vessel material is sealed.

FIG. 5 is an explanatory cross-sectional view showing a state in which a hollow tube is disposed inside a discharge vessel material and the other protrusion is formed at the other end.

FIG. 6 is an explanatory sectional view showing a state in which the other end of the discharge vessel material is sealed.

FIG. 7 is an explanatory sectional view showing another embodiment of the flash discharge lamp of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Flash discharge lamp 11 Discharge vessel 11A Inner edge 12 Cathode 13 Anode 14, 15 Electrode rod 16 Trigger electrode 17 Exhaust pipe remaining part 20 Hollow tube 20A One end 20B Other end 22 Outer edge 24, 25 Projection 27 Gettering Reference Signs List 30 discharge vessel material 301 quartz glass tube 302 exhaust pipe 30A one end 30B other end 31 discharge electrode 32 electrode rod 33 glass material 34, 35 electrode structure S electrode rod seal part

Claims (5)

[Claims] 1. A flash discharge lamp in which a pair of discharge electrodes are opposed to each other and sealed with a rare gas in a discharge vessel made of quartz glass, wherein a hollow tube made of a translucent ceramic is provided in the discharge vessel. A flash discharge lamp, wherein the discharge electrode is disposed so as to be located inside a hollow tube. 2. An inwardly projecting projection is formed on an inner peripheral surface of at least one end of the discharge vessel, and movement of the hollow tube in a tube axis direction is restricted by the projection. The flash lamp according to claim 1, wherein: 3. The flash according to claim 1, wherein the hollow tube is arranged so that an outer edge thereof is located at least 5 mm from an inner edge of the discharge vessel. Discharge lamp. 4. The discharge vessel according to claim 1, wherein a shape of the discharge vessel is a straight tube, and a difference between an inner diameter of the discharge vessel and an outer diameter of the hollow tube is 1 mm or less. The flash discharge lamp according to any one of the above. 5. The flash discharge lamp according to claim 1, wherein the thickness of the hollow tube is 0.3 to 1.0 mm.