JP2017168367A - Short arc type discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a short arc type discharge lamp in which a cylindrical retaining body does not rotate relatively with an electrode core rod in stages that include a lamp manufacturing stage.SOLUTION: In a short arc type discharge lamp, a metal member exists between a cylindrical retaining body and an electrode core rod, the metal member being fixed to the electrode core rod and engaging to the cylindrical retaining body in such a manner that a relative rotation therebetween is not caused.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a short arc type discharge lamp used for a light source for digital cinema, semiconductor exposure, infrared or ultraviolet curing.

  In such a short arc type discharge lamp, a pair of opposed electrodes are disposed in the arc tube, and a discharge gas is sealed therein. The discharge gas is a gas mainly composed of a rare gas such as xenon, and the brightness is increased by making the discharge gas pressure inside the arc tube very high. Since mercury is not sealed inside the arc tube, the current supplied to the electrode when the lamp is turned on becomes a large current. Therefore, a pair of electrode core rods that support the pair of electrodes are protruded to the outside from a sealing tube that is connected to both ends of the arc tube.

  In order to stably support the electrode core rod in the sealing tube, a holding cylinder made of quartz glass is interposed between the electrode core rod and the sealing tube. The holding cylinder is a cylinder having a shaft hole through which an electrode core rod passes at the center, and a metal body that prevents welding between the sealing tube and the holding cylinder is conventionally interposed on the outer peripheral surface thereof ( Patent Documents 1 to 4).

  In particular, the holding cylinder of Patent Document 3 has a small-diameter portion formed on the outer peripheral surface, a metal foil is wound around the outer peripheral surface of the holding cylinder, and the sealing tube follows the small-diameter portion of the holding cylinder. Thus, the holding cylinder is prevented from moving in the axial direction within the sealing tube.

JP-A-11-135067 JP 2000-306549 A Japanese Patent Laid-Open No. 2003-242932 JP 2005-11671 A

  However, the axial position of the holding cylinder in Patent Document 3 is restricted when the sealing tube is thermally deformed, and the holding cylinder is in the lamp manufacturing stage (before the diameter of the sealing tube is reduced). There was a possibility that the axial position of the body was shifted. Specifically, in the sealing step, when the holding cylinder inserted through the electrode core rod is inserted into the sealing tube, the holding cylinder moves in the axial direction with respect to the electrode core rod by vibration or the like, The metal foil on the outer peripheral surface rubs against the inner peripheral surface of the sealing tube, which may cause cracks in the sealing tube. Further, in the above structure, even when the sealing tube is thermally deformed and the axial movement of the holding cylinder is restricted, the holding cylinder is displaced in the rotation direction (circumferential direction) (that is, the electrode core rod and There was a possibility of relative rotation with respect to the sealing tube), and there was a possibility that cracks would occur in the sealing tube as well.

The present invention is based on the above problem awareness, and in particular, the problem caused by the relative rotation of the holding cylinder relative to the electrode core, including the lamp manufacturing stage and the electrode cylinder. An object of the present invention is to obtain a short arc type discharge lamp that does not rotate relative to each other.
Another object of the present invention is to obtain a short arc type discharge lamp in which the holding cylinder and the electrode core rod do not move relative to each other in the axial direction.

  The present invention includes an arc tube having a pair of electrodes therein, a sealing tube connected to both ends of the arc tube, a pair of electrode core rods respectively connected to the pair of electrodes, and at least one of them In the short arc type discharge lamp having a holding cylinder positioned between the electrode core rod and the sealing tube inside the sealing tube, the holding cylinder body and the electrode core rod In the meantime, there is a metal member that is fixed to the electrode core rod and engages the holding cylinder without causing relative rotation.

  In a preferred embodiment, the holding cylinder is formed with a communicating portion along the radial direction of the holding cylinder that connects the inner peripheral surface and the outer peripheral surface of the holding cylinder. At least a part of the metal member is inserted into the communication portion.

  In a preferred embodiment, the metal member includes an electrode core rod winding portion disposed between the holding cylinder and the electrode core, and between the holding cylinder and the sealing tube. And the electrode core rod winding portion and the holding cylinder winding portion are integrally connected via the communication portion.

  At least one of the electrode core winding part and the holding cylinder winding part preferably has a metal member along the axial end surface of the holding cylinder at both ends in the lamp axial direction.

  It is preferable that the communication part has a communication path for communicating spaces on both sides in the axial direction of the holding cylinder.

  Since the short arc type discharge lamp of the present invention can prevent relative rotation of the holding cylinder with respect to the electrode core rod by the metal member fixed to the electrode core rod, damage to the sealing tube due to the relative rotation is prevented. Can be prevented. Furthermore, the metallic member prevents the holding cylinder and the electrode core bar from moving relative to each other in the axial direction, thereby preventing the sealing tube from being damaged due to the axial movement.

1 is a longitudinal sectional view showing an embodiment of a light source device including a short arc type discharge lamp and a reflecting mirror according to the present invention. It is the II section expanded sectional view of FIG. It is sectional drawing which follows the III-III line of FIG. (A), (B), (C) and (D) are perspective views showing a process of winding a metal foil around an electrode core rod and coupling the electrode core rod to a holding cylinder. It is sectional drawing corresponding to FIG. 2 which shows another embodiment of this invention. It is a perspective view corresponding to FIG. 4 (B) which shows another embodiment of the short arc type discharge lamp by this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 4 show a first embodiment of a short arc type discharge lamp (hereinafter “lamp”) 100 according to the present invention.

  FIG. 1 shows the entire light source device having a lamp 100 and a concave reflecting mirror 1. FIG. 2 shows an enlarged section taken along the line II in FIG. 1, and FIG. 3 shows a section taken along the line III-III in FIG. The lamp 100 includes an arc tube 3 and a sealing tube 4 connected to both ends of the arc tube 3. The arc tube 3 and the sealing tube 4 are each made of quartz glass, and the arc tube 3 is filled with xenon gas as a discharge gas at atmospheric pressure or higher. Inside the arc tube 3, a pair of electrodes 5 (anode 5a and cathode 5b) are arranged, and an electrode core rod 6 having one end projecting outward from the end of the sealing tube 4 is disposed on the pair of electrodes 5. Each is connected. The concave reflecting mirror 1 is usually an ellipsoidal mirror or a parabolic mirror, and the pair of electrodes 5 are disposed opposite to each other with the focal position of the concave reflecting mirror 1 as a center. In FIG. 1, a base 9 that is connected to the electrode core 6 is provided at the end of the sealing tube 4, and the base 9 is provided with air-cooling vent holes 9 a that communicate between the inside and the outside. The base 9 may be omitted.

  At the outer end of the sealing tube 4 in the lamp axis direction, an end wall portion 4a that continues to the sealing tube 4 and contracts in the lamp radial direction, and an inner tubular portion 4b that continues from the end wall portion 4a to the arc tube side. A step glass 7 for sealing the electrode core 6 is integrally formed at the end (inner end) of the inner tubular portion 4b on the arc tube 3 side. In general, the thermal expansion coefficient of the sealing tube 4 employing quartz glass is smaller than that of the electrode core bar 6 made of a metal material such as tungsten, so that the electrode core bar 6 and the sealing tube 4 are in direct contact with each other. If it does, there exists a possibility that the sealing tube 4 may be damaged by the thermal expansion of the electrode core rod at the time of lamp lighting (at the time of electricity supply). Such a step glass sealing, in which, for example, a step glass 7 made of glass whose coefficient of thermal expansion changes stepwise due to different components contained, is interposed between the sealing tube 4 and the electrode core 6. By adopting the structure, the step glass 7 can buffer the difference in thermal expansion between the sealing tube 4 and the electrode core 6, and can appropriately seal the sealing tube 4 and the electrode core 6.

A holding cylinder between one electrode core rod 6 (the electrode core rod of the anode 5a in the illustrated example) and the sealing tube 4 on the inner side in the lamp axial direction (on the arc tube 3 side) from the step glass 7. A body (bead tube) 10 is interposed. The holding cylinder 10 is a substantially cylindrical cylinder (details will be described later), and the holding cylinder 10 is arranged coaxially with the electrode core 6 by inserting the electrode core 6 into the holding cylinder 10. Is done.
The holding cylinder 10 is not a perfect cylinder, but has a communication cylinder (radial slit) 13 that communicates the inner space and the outer space of the holding cylinder 10 along the radial direction in the radial cross section. The communication portion 13 communicates the inner peripheral surface 11 and the outer peripheral surface 12 of the holding cylinder 10 with each other. The communication portion 13 is formed from one end surface to the other end surface along the axial direction of the holding cylinder, and the spaces on both sides in the holding cylinder axial direction communicate with each other via the communication portion 13. . Both the inner peripheral surface 11 and the outer peripheral surface 12 are formed of a simple cylindrical surface partially missing by the communication portion 13. The holding cylinder is made of, for example, the same quartz glass as the sealing tube 4 (the arc tube 3).

  As shown in FIG. 2, a metal member 20 a exists between the holding cylinder 10 and the electrode core bar 6. The metal member 20a is formed, for example, by winding a metal foil (for example, a molybdenum foil) around the electrode core rod 6. By fixing a part of the metal foil to the electrode core rod 6, the metal member 20a is an electrode core rod. 6 is fixed.

  A metal member 20 b exists between the holding cylinder 10 and the sealing tube 4. The metal member 20b is disposed along the outer peripheral surface 12 of the holding cylinder 10 and covers the outer peripheral surface 12, thereby preventing the holding cylinder 10 and the sealing tube 4 from being welded. Further, a metal member 20e extending in the electrode radial direction along the holding cylinder axial end surface 14 is connected to the arc tube side end and the lamp end side end of the metal member 20b. That is, the holding cylinder 10 is covered with the metal member 20b and the metal member 20e at the outer peripheral surface 12 and a part of the axial end surface 14 respectively. As a result, the holding cylinder 10, the metal member 20b, and the metal member 20e have a concave-convex relationship in the lamp axis direction cross section, and are fitted in the lamp axis direction.

  A metal member 20c along the communication portion 13 is provided in the communication portion 13 of the holding cylinder 10. The metal member 20c is integrated with the metal member 20a and the metal member 20b at both ends in the radial direction of the communication portion 13, respectively. Connected to. Thereby, the metal member 20c is fixed to the electrode core bar 6 via the metal member 20a, and the metal member 20b is fixed to the electrode core bar 6 via the metal member 20a and the metal member 20c. By fixing the metal member 20 c in the communication portion 13 to the electrode core bar 6, it is possible to prevent the holding cylinder 10 from rotating relative to the electrode core bar 6 in the circumferential direction. Further, the holding member 10 is fixed to the electrode core 6 in the lamp axis direction by fixing the metal member 20 b to the electrode core 6.

  Further, in the communicating portion 13, the space on both sides in the lamp axis direction of the holding cylinder 10, that is, the space on the arc tube side from the holding cylinder 10 and the space on the lamp end side from the holding cylinder 10 are communicated. A communication gap 13S is provided. By providing the communication gap 13S, even if the holding cylinder 10 and the sealing tube 4 are thermally expanded by lighting the lamp, the communication state between the arc tube side space and the lamp end side space is maintained. An extreme pressure difference does not occur in the spaces on both sides, and the occurrence of breakage and displacement of the holding cylinder 10 can be prevented.

  FIG. 4 shows an example of the manufacturing method according to the first embodiment, in which a metal member (metal foil) 20 is wound around the electrode core 6 and the electrode core 6 and the holding cylinder 10 are connected. It is a perspective view. The manufacturing method of the first embodiment will be described with reference to FIGS. 4 and 4 in addition to FIGS.

  As a material of the metal member 20, for example, a metal foil having a rectangular shape (band shape) with a thickness of about 0.1 mm is used (hereinafter, the metal member 20 is referred to as a metal foil 20). As shown in FIGS. 4 (A) and 4 (B), one end of the metal foil 20 is wound around the electrode core rod 6 to form a metal member (electrode core winding portion) 20a. The rod winding part 20a is fixed to the electrode core bar 6 by spot welding W. The electrode core rod 6 to which the metal foil 20 is fixed is inserted into the holding cylinder 10 (FIG. 4C), and the metal foil 20 is held through the communicating portion (radial slit) 13 of the holding cylinder 10. A metal member (internal / external connection portion) 20 c is formed in the radial slit 13 by being guided to the outer peripheral surface of the cylinder 10 for use. The metal foil 20 guided to the outer periphery of the holding cylinder 10 is wound around the outer peripheral surface 12 of the holding cylinder to form a metal member (holding cylinder winding portion) 20b. The holding cylinder winding portion 20b is fixed by folding the holding cylinder circumferential end of the metal foil 20 wound around the cylindrical outer peripheral surface 12 into the radial slit 13 (inserting portion 20d). (FIG. 4D). The diameter of the holding cylinder 10 is, for example, about 12 to 23 mm.

  Further, the width S of the metal foil 20 is longer than the axial length L of the holding cylinder 10, and after inserting the free end wound around the outer peripheral surface 12, that is, the insertion portion 20 d into the radial slit 13, The metal member (folded end portion) 20e is formed by bending the portions protruding from both axial ends of the holding cylinder 10 along the axial end surface 14 of the holding cylinder 10 (FIG. 2, FIG. 4 (D) arrow X).

  As shown in FIG. 3 and FIG. 4, in the state where the radial slit 13 of the holding cylinder 10 has the inner / outer connection part 20 c and the insertion part 20 d of the metal foil 20 (also), A communication gap 13 </ b> S that communicates the space on both sides in the axial direction (the arc tube side space and the lamp end side space) is formed. The communication gap 13 </ b> S is a communication path that communicates the arc tube side space partitioned by the holding cylinder 10 in the sealing tube 4 and the lamp end side space.

  The electrode core rod 6, the holding cylinder 10 and the metal foil 20 are welded and fixed to the electrode core rod 6 and the electrode core rod winding portion 20 a of the metal foil 20, and the holding cylinder winding portion of the metal foil 20 is fixed. 20b is wound around the outer peripheral cylindrical surface 12 of the holding cylinder 10, and the inner / outer connection part 20c and the insertion part 20d of the metal foil 20 are positioned in the radial slit 13 of the holding cylinder 10 so that the electrode core 6 and the holding cylinder 10 do not move relative to each other in the rotational direction. And by arrange | positioning the bending edge part 20e along the axial direction end surface 14 of the cylinder 10 for a holding | maintenance, the cylinder 10 for a holding | maintenance and the metal foil 20 are fitted to an axial direction, respectively, There is no relative movement of the holding cylinder 10 in the axial direction. That is, the metal foil 20 functions as a member (element) that prevents relative movement in the rotational direction and the axial direction of the electrode core 6 and the holding cylinder 10.

  The electrode core rod 6, the holding cylinder 10, and the metal foil 20 are formed in the sealing tube 4 before forming the end wall portion 4 a, the inner tubular portion 4 b, and the step glass 7 of the sealing tube 4. Is inserted at the position. That is, the inner diameter of the sealing tube 4 before forming the end wall portion 4a and the inner tubular portion 4b is larger than the outer diameter of the holding cylinder winding portion 20b wound around the outer peripheral surface 12 of the holding cylinder. . In the inserted state, the holding cylinder 10 is wound by heating the area (the reduced diameter area 4c (FIG. 1)) of the sealing tube 4 facing the holding cylinder 10 in the lamp radial direction to reduce the diameter. The holding cylinder 10 is held by the sealing tube 4 through 20b. The reduced diameter region 4c may be only a part of a region where the sealing tube 4 and the holding cylinder winding portion 20b face each other in the lamp radial direction. When the diameter of the sealing tube 4 is reduced by heating, the metal foil 20 (the holding cylinder winding portion) is provided between the outer peripheral surface 12 of the holding cylinder 10 and the inner surface of the sealing tube 4 (reduced diameter region 4c). Since 20b) is located, the sealing tube 4 and the holding cylinder 10 are not welded. Since the holding cylinder 10 is fixed to the electrode core 6 by the metal foil 20 in both the axial direction and the rotation direction, the holding cylinder 10 moves relative to the electrode core 6. There is no possibility that cracks (breakage) occur in the sealing tube 4. In addition, being fixed in the rotation direction and the axial direction (relative movement does not occur) does not mean that the relative movement in the same direction is strictly zero. A slight relative movement may occur due to the flexibility (stretchability) of the metal foil 20, and the fact that the relative movement does not occur (fixed) in the present invention is harmful to damage to the sealing tube 4. This means that relative movement does not occur.

  In addition, the holding cylinder 10 including the metal foil 20 is formed with a communication gap 13 </ b> S that allows communication between spaces on both sides in the axial direction of the holding cylinder 10. This communication gap 13S is maintained even if the holding cylinder 10 and the sealing tube 4 are thermally expanded during lamp lighting, and the space on both sides in the axial direction of the holding cylinder 10 is formed by this gap (communication gap 13S). By being connected, an extreme pressure difference does not occur in the space on both sides in the axial direction of the holding cylinder 10, and the holding cylinder 10 is prevented from being damaged or displaced.

  Although the metal member 20 can use a metal foil having a constant thickness, it is more preferable to use an embossed metal foil. By using the embossed metal foil, a space is generated around the metal foil. As a result, the thermal expansion difference between the electrode core 6 or the metal member 20 and the holding cylinder 10 is buffered, the damage to the holding cylinder 10 can be prevented, and the metal member 20 in the communication gap 13S. A space can be easily secured around the area.

  For example, in Patent Document 1, it is necessary to sufficiently reduce the diameter of the sealing tube in order to fix the holding cylinder in the axial direction by reducing the diameter of the sealing tube. Therefore, thermal processing for the sealing tube is increased, and thermal distortion is likely to occur. Further, when the lamp is lit, the spaces on both sides in the axial direction of the holding cylinder are easily divided by the thermal expansion of the sealing tube and the holding cylinder. Further, in Patent Document 3, it is necessary to (complexly) reduce the diameter of the sealing tube in accordance with the holding cylinder, and infrared rays and ultraviolet rays that propagate through the sealing tube during lighting are irregularly reflected at the reduced diameter portion. By doing so, there is a possibility that the lamp may be damaged due to embrittlement of the sealing tube or heating of the metal foil. On the other hand, in the above embodiment, the holding cylinder 10 is fixed to the electrode core 6 and the outer peripheral cylindrical surface 12 of the holding cylinder 10 is a simple cylindrical shape. The diameter condition (heat processing condition) can be minimized so that the sealing tube 4 can hold the holding cylinder 10, and damage to the sealing tube 4 can be suppressed. However, in the present invention, the outer peripheral surface of the bead tube 10 can be formed in a shape other than a simple cylindrical shape.

  FIG. 5 shows another embodiment of a short arc discharge lamp according to the present invention. In the above embodiment, the bent end portion 20e is formed by bending the axial end portion of the holding cylinder winding portion 20b of the metal member 20 along the axial end surface 14 of the holding cylinder 10 respectively. However, in this embodiment, the metal member (bending end portion) 20f is formed by bending the axial end portion of the electrode core winding portion 20a along the end surface 14 respectively.

  In the metal member 20 of the above embodiment, the electrode core rod winding portion 20a around the electrode core rod 6 and the holding cylinder winding portion 20b around the outer peripheral surface 12 of the holding cylinder 10 are connected to the inside / outside connection portion 20c. There is an advantage that the single metal member 20 can prevent relative rotation and axial movement of the electrode core 6 and the holding cylinder 10. On the other hand, the metal member 20 in FIG. 6 includes a first metal member 201 having a winding portion 20a1 around the electrode core 6 and an insertion portion 20c1 inserted into the radial slit 131 of the holding cylinder 10. In this embodiment, the second metal member 202 is wound around the outer peripheral surface 12 of the holding cylinder 10. In this embodiment, the radial slit 131 may not be penetrated in the radial direction as long as it is connected to the inner peripheral surface, or may be a simple recess having a bottom portion on the radially outer side. Even in such a configuration, relative rotation between the electrode core bar 6 and the holding cylinder 10 can be prevented by the insertion portion 20c1.

  In the above embodiment, the present invention is applied to an aspect in which the holding cylinder 10 is provided between the electrode core 6 on the anode 5a side and the sealing tube 4 of the pair of electrodes 5 (the anode 5a and the cathode 5b). However, the present invention is also applicable to an embodiment in which the holding cylinder 10 is interposed between the electrode core 6 on the cathode 5 b side and the sealing tube 4.

DESCRIPTION OF SYMBOLS 1 Concave reflecting mirror 3 Light emission tube 4 Sealing tube 4a End wall part 4b Inner tubular part 4c Reduced diameter area | region 5 Electrode (a pair of electrodes)
5a Anode 5b Cathode 6 Electrode core rod 7 Step glass 9 Base 9a Vent hole 10 Holding cylinder 11 Inner peripheral surface 12 of holding cylinder Outer peripheral surface 13 of holding cylinder Communication portion (radial slit)
13S communication gap 14 axial end face 20 of holding cylinder 20 metal member (metal foil)
20a Metal member (electrode core winding part)
20b Metal member (cylinder winding part for holding)
20c Metal member (internal / external connection)
20d Metal member (insertion part)
20e Metal member (bent end)
20f Metal member (bent end)
201 1st metal member (1st metal foil)
20a1 Metal member (winding part)
20c1 Metal member (insertion part)
202 2nd metal member (1st metal foil)
100 lamp

Claims (5)

An arc tube with a pair of electrodes inside;
Sealing tubes connected to both ends of the arc tube;
A pair of electrode core rods respectively connected to the pair of electrodes;
Inside the at least one sealing tube, a holding cylinder positioned between the electrode core bar and the sealing tube;
In a short arc type discharge lamp having
Between the holding cylinder and the electrode core, there is a metal member that is fixed to the electrode core and engages the holding cylinder without causing relative rotation;
Short arc type discharge lamp. In the short arc type discharge lamp according to claim 1,
In the holding cylinder,
A communication portion is formed along the radial direction of the holding cylinder, which communicates the inner peripheral surface and the outer peripheral surface of the holding cylinder.
A short arc type discharge lamp in which at least a part of the metal member is inserted into the communication portion. The short arc type discharge lamp according to claim 1 or 2,
The metal member is
An electrode core rod winding portion disposed between the holding cylinder and the electrode core rod;
A holding cylinder winding portion disposed between the holding cylinder and the sealing tube;
A short arc type discharge lamp in which the electrode core winding part and the holding cylinder winding part are integrally connected via the communication part. In the short arc type discharge lamp according to claim 3,
At least one of the electrode core winding part and the holding cylinder winding part has a short arc type discharge lamp having a metal member along the axial end face of the holding cylinder at both ends in the lamp axial direction. The short arc type discharge lamp according to any one of claims 1 to 4,
The communication part is
A short arc type discharge lamp having a communication path for communicating spaces on both axial sides of the holding cylinder.

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