CN1574185A - Short arc discharging lamp - Google Patents

Abstract

The present invention provides a short-arc discharge lamp in which the glass tube of the holding cylinder does not move, the concentration of force does not occur on the sealing part, and the short-arc discharge lamp does not break. A short-arc discharge lamp, wherein the cathode and the anode are arranged oppositely in a luminous tube, and the electrode core rods of the cathode and the electrode core rods of the anode are held through a holding cylinder, and the holding cylinder is connected to the light emitting tube. The drawing part of the side pipe on the pipe is supported, and the outer peripheral surface of the above-mentioned holding cylinder is covered with a coating material formed of a high-melting point metal, and it is characterized in that the above-mentioned holding cylinder has a small diameter in the direction of the pipe axis. The above-mentioned cladding material has a plurality of protrusions extending continuously toward the tube axis direction of the holding cylinder, and the cross-sectional shape of the cladding material in the circumferential direction of the holding cylinder is wavy and/or zigzag .

Description

short arc discharge lamp

technical field

The present invention relates to short-arc discharge lamps used in light sources for projectors, semiconductor exposure, ultraviolet curing, and the like.

Background technique

For example, as a light source for a projector, a short-arc discharge lamp in which xenon gas is sealed has been frequently used in the past. Recently, the demand for higher brightness of transmitted images from projectors has become more intense. Therefore, there is a tendency to increase the gas volume of xenon gas to be enclosed. Therefore, in recent short-arc discharge lamps, the gas pressure inside the arc tube becomes extremely high when the lamp is turned on.

In such a short-arc discharge lamp, xenon gas is sealed in a spherical or ellipsoidal luminescent tube made of quartz glass, and a cathode and an anode are arranged facing each other. Moreover, the electrode core rods of the cathode and the anode are sealed at the ends of the side tubes extending along both sides of the luminous tube. In addition, in order to hold the electrode core rods of the cathode and the anode, the end of the side tube on the arc tube side is heated and drawn, and the diameter is reduced to form the drawn portion. However, in order to directly hold the cathode by the drawn portion of the side pipe and the electrode mandrel of the anode, it is necessary to increase the amount of drawing.

Therefore, in the past, the electrode core rods of the cathode and the anode were inserted into a cylindrical body made of quartz glass for holding the electrode core rods, and the drawn part of the side pipe was welded to the cylindrical body for holding. Electrode mandrel technology for cathode and anode.

If the drawn portion of the side pipe is welded to the holding cylinder, a small wedge-shaped gap may be generated at the welded end. Therefore, it becomes the cause of a crack at the time of lighting. As a technique that does not weld the drawn portion of the side pipe to the holding cylinder, JP-A-51-148274 discloses that molybdenum, molybdenum, and Technology for thin layers of refractory metal foils such as tantalum, tungsten, and titanium.

FIG. 1 is a schematic diagram showing an anode-side side tube of a conventional short-arc discharge lamp using the technology of the same publication as the prior art. Some of them are shown in cross-section. The electrode core rod 23 is penetrated and held in a holding cylinder 30 made of quartz glass for holding the electrode core rod. The outer peripheral surface of the holding cylinder 30 is covered with a covering material 40 . It also discloses a technique in which a recess 70 is provided on the side pipe 11 so that the holding cylinder 30 cannot move in the axial direction. 14 is lamp holder.

However, in the technique disclosed in JP-A-51-148274, there is a possibility that the holding cylinder 30 may move axially toward the arc tube 10, and the anti-vibration performance of the lamp is reduced, which easily causes damage to the lamp. . In addition, the tungsten coil 60 is provided to prevent the holding cylinder 30 from moving toward the arc tube 10, but this not only increases the number of components, but also requires additional tungsten coils 60 of different sizes for lamps of different sizes. the inconvenience.

Patent Document 1

Japanese Patent Laid-Open No. 51-148274

Contents of the invention

Therefore, an object of the present invention is to provide a short-arc discharge lamp capable of preventing axial movement of a holding cylinder made of quartz glass for holding an electrode core rod, having good vibration resistance, and preventing lamp breakage.

In order to solve the above problems, in the short-arc discharge lamp of the present invention, the cathode and the anode are arranged oppositely in the luminous tube, the electrode core rod of the cathode and the electrode core rod of the anode are penetrated and held in the holding cylinder, and the holding The cylindrical body is supported by the drawing part of the side pipe connected to the luminous tube, and the outer peripheral surface of the holding cylindrical body is coated with a cladding material made of metal, and it is characterized in that: the above-mentioned holding cylindrical body is in the direction of the tube axis The above-mentioned cladding material has a plurality of protrusions extending continuously in the tube axis direction of the holding cylinder, and the cross-sectional shape of the cladding material in the circumferential direction of the holding cylinder is wavy and / or jagged.

The short-arc discharge lamp of the present invention is characterized in that when 1/2 of the maximum difference in diameter between the small-diameter portion of the above-mentioned holding cylinder and the portion other than the small-diameter portion is a (mm), 0.2≤a≤ 2.

The short-arc discharge lamp of the present invention is characterized in that the covering material is a foil or a thin plate made of molybdenum, and is processed into a zigzag shape.

The short-arc discharge lamp of the present invention is characterized in that the bending height of the zigzag processing is 2 mm or less, and the pitch is 2 mm or less.

effect

In the present invention, the holding cylinder has a small-diameter portion in the tube axis direction, and the inside of the side pipe is decompressed and heated from the outer peripheral surface of the side pipe of the positioning and holding cylinder. The side pipe is specially cauterized at the corresponding position, thereby, the small-diameter part of the holding cylinder is pressed and fixed, thereby preventing the movement of the holding cylinder in the axial direction, and there is no need to - Parts other than the retaining cylinder disclosed in Publication No. 148274. However, in order to prevent welding between the holding cylinder and the side pipe, it is necessary to provide a covering material made of a high melting point metal on the outer peripheral surface of the holding cylinder. Therefore, when heating and reducing the diameter from the outer peripheral surface of the side tube of the holding cylinder having the small-diameter portion, if the covering material is in the shape of a flat foil or thin plate, it is wound on the holding cylinder. And cover the cladding material, when burning from the outer peripheral surface of the side tube, the cladding material is extruded on the inner wall of the side tube, and the surface of the cladding material may locally produce wrinkles with curved sharp corners. Such wrinkles not only deteriorate the appearance of the lamp and reduce the commercial value of the lamp, but also cause stress concentration at the tip of the bent portion of the wrinkle, which may cause the lamp to break.

Therefore, even if the holding cylinder has a small-diameter portion and the coating material made of a high melting point metal is provided on the outer peripheral surface of the holding cylinder, since the coating material has a continuous The plurality of protruding strips extending, the cross-sectional shape of the cladding material in the circumferential direction of the holding cylinder is wavy or saw-toothed. Since it is a mixed shape of wavy and saw-toothed, it is heated and shrunk from the outer peripheral surface of the side pipe. After the diameter, the cladding material expands and contracts, thereby preventing local bending and wrinkling of the cladding material.

Description of drawings

Fig. 1 is a schematic diagram showing a side tube on the anode side of a conventional short-arc discharge lamp;

Fig. 2 is the schematic diagram representing the side tube of the anode side of the short-arc discharge lamp of the present invention;

Fig. 3 shows an embodiment of the holding cylinder used in the short-arc discharge lamp of the present invention;

Fig. 4 is an enlarged view and a cross-sectional view of the vicinity of the holding cylinder portion of the short-arc discharge lamp of the present invention;

Figure 5 is an enlarged view of a cladding material made of a refractory metal;

Fig. 6 is a perspective view showing a state in which molybdenum foil after zigzag processing is wound around a holding cylinder.

Detailed ways

Embodiments of the present invention will be specifically described below with reference to the drawings. Fig. 2 is a schematic view showing an anode-side side tube of the short-arc discharge lamp of the present invention. Some of them are shown in cross-section. An example of a short-arc discharge lamp of the present invention is a xenon short-arc discharge lamp. In the arc tube 10 made of quartz glass, an anode 22 and a cathode (not shown) fixed to the tips of a pair of electrode core rods 23 formed of tungsten rods are arranged facing each other. In addition, xenon gas is sealed in the arc tube 10 . The side tube 11 extends from both sides of the arc tube 10, and the electrode core rod 23 is sealed at the end of the side tube 11. 14 is a lamp cap covering the sealed part.

The holding cylinder 30 is made of quartz glass and has a small diameter portion at the center in the longitudinal direction on the outer peripheral surface, and the electrode core rods 23 are respectively penetrated so that the electrode core rods 23 are held by the holding cylinder 30 . The holding cylinder 30 has a small-diameter portion 31 in its longitudinal direction, and by heating from the outer peripheral surface of the side pipe, the portion of the side pipe 11 corresponding to the small-diameter portion 31 is burned in particular, and the holding cylinder 30 is pressed. Tight fix. In addition to the shape shown in FIG. 2 , the holding cylinder 30 may have, for example, the shapes shown in FIGS. 3( a ), ( b ), and ( c ), but the shape is not limited thereto. FIG. 3( b ) shows a holding cylinder 30 having protrusions 32 at both ends in the longitudinal direction. The protrusions 32 are not limited to both ends, and may be located on the outer peripheral surface of the holding cylinder. The appearance of Fig. 3(c) is roughly drum-shaped, especially the glass is easy to form (easy to manufacture) and thus is more suitable. 33 is a through hole that runs through the electrode core rod.

As shown in Fig. 3 (a), (b), (c), 1/2 of the maximum difference in diameter between the narrow diameter portion 31 of the cylindrical body 30 and the portion other than the small diameter portion is a (mm ), when a is 0.1 mm, the depression of the small-diameter portion 31 is too small, and even if the outer peripheral surface of the side pipe 11 is heated to reduce the diameter, the holding cylinder 30 cannot be sufficiently fixed. If it exceeds 2 mm, the glass may be warped due to excessive diameter reduction when heated from the outer peripheral surface of the side pipe 11 to reduce the diameter. Therefore, 0.2≦a≦2 is preferable.

Fig. 4 (a), (b), (c) have shown that each holding cylinder 30 shown in Fig. 3 (a), (b), (c) is put into side pipe 11, and from side pipe 11The state of external heating and drawing. Furthermore, the inside of the arc tube 10 is in a decompressed state, and by heating the end portion of the side tube 11 on the arc tube 10 side, the diameter of the side tube 11 is reduced to form the drawn portion 12 . Between the holding cylinder 30 and the drawing part 12, as shown in FIG. 2, a covering material 50 made of a high melting point metal is covered. With this covering, the holding cylinder 30 and the drawn portion 12 can be fixed by welding without being integrated.

Fig. 4(d) shows the A-A' sectional view of Fig. 4(c). This figure shows that the cross-sectional shape of the covering material 50 is wavy or zigzag, or a mixed shape of wavy and zigzag across the entire circumference of the holding cylinder.

Specifically, as shown in FIG. 5 , it is suitable to use a corrugated molybdenum foil or thin plate as the covering material 50 . A molybdenum foil or thin plate is folded in a certain direction to form the protrusions 50a, 50b and alternately form peaks, valleys, peaks, and valleys, that is, so-called zigzag processing.

As an example of dimensions, in FIG. 5 , the height c of the peaks of the coating material 50 is 0.2 mm, the pitch b of the peaks of the coating material 50 is 1.0 mm, and the thickness t is 15 μm. The bending height of the zigzag processing corresponds to the peak height c of the covering material 50, but if it is not less than 2mm, it is difficult to obtain the stretching effect of the foil. In addition, when the pitch is not less than 2mm, it is also difficult to obtain the expansion and contraction effect of the foil.

As the covering material 50, molybdenum foil as described above can be used. Molybdenum foil is suitable due to its good ductility. In addition to molybdenum, refractory metals such as tungsten, tantalum, zirconium, and titanium can also be used. The thickness of the covering material 50 is preferably 30 μm or less.

Next, a method of welding the holding cylinder portion in the case of using molybdenum foil as the covering material will be described. First, molybdenum foil, which is a zigzag-processed covering material 50, is wound around the outer peripheral surface of the holding cylinder 30 so that a plurality of protrusions continuously extend in the axial direction. The molybdenum foil is bent on both ends in the axial direction. As shown in FIG. 6 , a state in which the covering material 50 is wound around the holding cylinder 30 is shown in a perspective view. FIG. 6 corresponds to an example in which the holding cylinder 30 has a small-diameter portion 31 at approximately the central portion in the axial direction, and shows a molybdenum foil as the covering material 50 wound so that a plurality of protrusions continuously extend in the axial direction. .

Subsequently, in the side tube 11, insert the holding cylinder 30 that is penetrated by the electrode mandrel 23 with the electrode at the front end, and make the inside of the luminous tube connected to the side tube 11 be in a depressurized state. Heating can reduce the diameter of the side pipe 11 and form the drawn part 12. Since the covering material 50 formed of molybdenum foil exists in the middle, the holding cylinder 30 and the drawn part 12 can be fixed by welding without be integrated. At this time, the plurality of protrusions extending continuously in the axial direction of the cladding material 50 are deformed during the heating and diameter reduction process of the side pipe 11 , so that local bending and wrinkles can be suppressed. In addition, the holding cylinder 30 may not only be a complete cylinder, but may also be a polygonal cylinder having a pentagon or more.

Invention effect

As described above, in the short-arc discharge lamp of the present invention, the holding cylinder made of quartz glass has a small diameter portion, and the serrated refractory metal is wound around the outer peripheral surface of the holding cylinder. Therefore, even if the side pipe of the positioning holding cylinder is heated from the outside to shrink the side pipe, no bending wrinkles will occur on the surface of the covering material, and the contact between the foil and the glass will not occur. There will be no stress concentration on the part, so there will be no damage.

According to the present invention, even if the lamp is vibrated during transportation, etc., the glass tube of the holding cylinder does not move, and force does not concentrate on the sealing portion, so that a short-arc discharge lamp that does not break can be realized.

Claims (4)

1. A short-arc discharge lamp, the cathode and the anode are arranged oppositely in the luminous tube, the electrode mandrel of the cathode and the electrode mandrel of the anode are penetrated and held in a holding cylinder, and the holding cylinder is connected to the The drawing part of the side tube of the luminous tube is supported, and the outer peripheral surface of the holding cylinder is coated with a cladding material formed of a high-melting point metal, which is characterized in that: The holding cylinder has a small-diameter portion in the tube axis direction, the coating material has a plurality of protrusions extending continuously in the tube axis direction of the holding cylinder, and the coating material is formed on the holding tube. The cross-sectional shape of the body in the circumferential direction is wavy and/or saw-toothed. 2. The short-arc discharge lamp according to claim 1, wherein 1/2 of the maximum diameter difference between the narrow portion of the holding cylinder and the portion other than the small diameter portion is a( mm), 0.2≤a≤2. 3. The short-arc discharge lamp as claimed in claim 1 or 2, characterized in that the covering material is a foil or a thin plate made of molybdenum, which is processed in a saw-tooth shape. 4. The short-arc discharge lamp according to claim 3, characterized in that: the bending height of the zigzag processing is less than 2mm, and the bending distance is less than 2mm.

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