Short arc discharge lamp and method for manufacturing short arc discharge lamp

Abstract

The invention provides a short arc discharge lamp and a manufacturing method of the short arc discharge lamp. In a short arc discharge lamp in which a metal foil is sealed in a sealing tube, foil peeling of the metal foil is suppressed. In the short arc discharge lamp (10), a mounting member is sealed in sealing tubes (13A, 13B) connected to both sides of a discharge tube (12). A metal film (40) is formed on the sealing tube (13A). The metal film (40) is electrically connected via a metal wire (50) to a joint (19A) provided in the sealing tube (13A). The platinum (60) is wound around the metal wire (50).

Description

Technical Field

[0001] The present invention relates to a short arc discharge lamp, and more particularly to a sealing structure of the lamp. Background Art

[0002] In a short arc type discharge lamp, a foil sealing structure is adopted for sealing tubes connected to both ends of the discharge tube. Here, mounting components including a cylindrical glass component for holding an electrode support rod and a strip of metal foil for electrically connecting the electrode support rod to an external lead rod are inserted into the sealing tube and sealed to maintain airtightness.

[0003] The strip-shaped metal foil is separated from each other in the circumferential direction of the glass member and extends along the lamp axis, and is in close contact with the sealing tube and the glass member in a state of being sandwiched between the sealing tube and the glass member. In order to improve the pressure resistance performance of the discharge lamp, it is necessary to improve the adhesion of the metal foil.

[0004] On the other hand, alkali metals exist as impurities in the electrode parts and glass parts. When the lamp is lit, the alkali metals dissolved in the glass parts are ionized, electrically attracted to the direction of the same potential as the cathode, and deposited. The alkali metals are deposited around the metal foil, causing the metal foil to float and peel off, and the adhesion strength is reduced.

[0005] To prevent this, for example, a conductive film or other conductive member is formed on the outer circumference of the sealing tube and a lead wire is connected (see Patent Document 1). The lead wire is connected to the cathode side lead bar and has the same potential as the cathode, thereby preventing the alkali metal ions from moving near the metal foil.

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-118166

[0007] However, in the lead connection described in Patent Document 1, it is difficult to fully suppress the migration of alkali metal ions to the vicinity of the metal foil, and as the lamp is lit, the alkali metal ions migrate to the vicinity of the metal foil of the sealing tube, which may cause foil peeling and reduce the voltage resistance of the lamp. Summary of the invention

[0008] Therefore, in a short arc discharge lamp in which a metal foil is sealed in a sealing tube, it is required to suppress the peeling of the metal foil.

[0009] The short arc type discharge lamp of the present invention comprises: a discharge tube, a pair of electrodes disposed opposite to each other in the discharge tube, and a sealing tube connected to both sides of the discharge tube, wherein a metal film is formed on the outer surface of at least one of the sealing tubes, and a metal wire is disposed corresponding to the metal film disposed on at least one of the sealing tubes to electrically connect the metal film and at least one of the electrodes.

[0010] The electrical connection between the metal film and the electrode may be of various structures. For example, the metal film may be electrically connected to a joint provided on at least one of the sealing tubes. Alternatively, the metal film may be electrically connected to a lead rod extending from the end of the sealing tube.

[0011] In the present invention, a metal component that contacts at least a portion of the metal wire is provided around the sealed tube on which the metal film is formed. Here, "around the sealed tube on which the metal film is formed" means that the metal component is provided for the sealed tube on which the metal film is formed. For example, when the metal film is formed on only one side of the sealed tube, the metal component is provided around the sealed tube. In the sealed tube, the metal component may be provided in the area where the metal film is formed, the area of ​​the outer surface where the metal film is not formed, or both areas.

[0012] The structure of the metal component is various, and at least a part of it can be configured as a line. In addition, the entire metal component can be configured as a line. Regarding the structure related to the contact between the metal wire and the metal component, various contact methods are possible.

[0013] For example, the metal component may be configured to have a linear winding portion wound around the metal wire. When the metal wire has a portion extending along the lamp axis direction, the linear metal may be wound around the metal wire as the winding portion and in contact with the metal wire.

[0014] For example, the metal member may be configured to have a linear winding portion wound around the metal film. In the case where the metal wire has a portion wound around the sealing tube, a linear metal may be wound as the winding portion and in contact with the metal wire.

[0015] The metal film formed around the sealing tube may be formed in a layered form. For example, a metal film may be further formed on a winding portion of a metal component wound around the metal film. That is, the metal film may be configured to include a metal film formed around the outer surface of the sealing tube and a metal film formed on the winding portion of the metal component.

[0016] The metal component may be made of various materials, and may be made of the same material as the metal wire or a different material from the metal wire. The metal component may be configured to have a lower resistance value than the metal wire at least at the contact portion with the metal wire. For example, the metal component may be configured to contain platinum at least partially.

[0017] The number of metal wires and the number of metal parts (for example, the number of metal wires in the case of linear metal) can vary, and a plurality of metal wires and a plurality of metal parts can be provided. For example, a plurality of metal wires and a plurality of metal parts (for example, linear metal wires) can be configured so that corresponding wires and parts are in contact with each other, or at least one group of wires and parts are in contact, or one or more metal wires are in contact with one metal part or a plurality of metal parts.

[0018] In another embodiment of the present invention, a method for manufacturing a short arc type discharge lamp is formed on the outer surface of at least one of the sealing tubes connected to the two sides of the discharge tube, and the metal film is electrically connected to a joint provided in the sealing tube on which the metal film is formed by a metal wire, so that a linear metal component is in contact with the metal wire. For example, the linear metal component can be wound around the metal wire. Furthermore, the linear metal component can be wound in a manner that contacts the portion of the metal wire wound around the sealing tube, and / or in a linear state that contacts the portion extending along the lamp axis. For example, the linear metal component can be wound around the sealing tube and contact the metal wire, and a metal film can be further formed on the metal component wound on the metal film.

[0019] According to the present invention, in a short arc discharge lamp in which a metal foil is sealed in a sealing tube, it is possible to suppress foil peeling of the metal foil. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic plan view of the short arc discharge lamp according to the present embodiment.

[0021] Figure 2 This is a diagram schematically showing a sealing portion on the cathode side of a short arc type discharge lamp.

[0022] Figure 3 It is a diagram showing a modified example of the short arc discharge lamp of the present embodiment.

[0023] Figure 4 It is a diagram showing another modified example of the short arc discharge lamp of the present embodiment.

[0024] Description of symbols

[0025] 10: short arc type discharge lamp; 13A: sealed tube; 19A: joint; 40: metal film; 50: metal wire; 60: platinum (metal part). DETAILED DESCRIPTION

[0026] Hereinafter, the short arc discharge lamp according to the present embodiment will be described with reference to the drawings.

[0027] Figure 1 It is a schematic plan view of the short arc discharge lamp according to the present embodiment.

[0028] The short arc type discharge lamp 10 has a discharge tube (light emitting tube) 12 made of transparent quartz glass, and a pair of electrodes 20 and 30 made of tungsten or the like are coaxially arranged in the discharge tube 12 along the lamp axis C. On both sides of the bulb-shaped discharge tube 12, sealing tubes 13A and 13B made of quartz glass are connected to the discharge tube 12 and formed integrally. Mercury and discharge gas (rare gas) are sealed together in the discharge space DS in the discharge tube 12.

[0029] The cathode electrode 20 is supported by the electrode support rod 17A. The sealed tube 13A contains a glass tube (not shown) through which the electrode support rod 17A is inserted, a lead rod 15A connected to an external power source, and a metal foil 16A connecting the electrode support rod 17A and the lead rod 15A.

[0030] The anode electrode 30 is also sealed with a glass tube (not shown) through which the electrode support rod 17B is inserted, a metal foil 16B, a lead rod 15B and other mounting components. Joints 19A and 19B are mounted on the end sides of the sealed tubes 13A and 13B, respectively.

[0031] When a voltage is applied to the pair of electrodes 20 and 30, arc discharge occurs between the electrodes 20 and 30, and light is radiated toward the outside of the discharge tube 12. The light radiated from the discharge tube 12 is guided in a predetermined direction by, for example, a reflective mirror (not shown).

[0032] Figure 2 This is a diagram schematically showing a sealing portion on the cathode side of the short arc type discharge lamp 10. However, components such as metal foil and electrode support rods are omitted from the diagram.

[0033] A metal film 40 is formed near the connection portion 13T of the sealed tube 13A on the cathode side with the discharge tube 12. In addition, a metal film 40 is also formed near the connection portion 12T of the outer surface of the discharge tube 12 with the sealed tube 13A. The metal film 40 provided on the outer surface of the sealed tube 13A functions as a heat-insulating film that maintains the temperature of the sealed tube 13A within an appropriate range when lighting. The metal film 40 provided on the outer surface of the discharge tube 12 has a function as a heat-insulating film that maintains the coldest point temperature during lighting at a high level. By forming such a metal film 40, it is possible to prevent mercury vapor from entering the sealed tube 13A and condensing when lighting.

[0034] Here, the metal film 40 provided on the outer surface of the sealing tube 13A and the discharge tube 12 is formed by applying a metal film liquid such as gold or platinum. The root portion of the anode side of the discharge tube 12 and the sealing tube 13B are also formed with a metal film.

[0035] like Figure 2As shown in FIG. 1 , the metal film 40 formed around the outer surface of the sealing tube 13A is electrically connected to the connector 19A through the metal wire 50. Specifically, the metal wire 50 is wound around the metal film 40 and extends along the lamp axis C, and one end is attached to a hole (not shown) formed at the discharge tube side end 19T of the connector 19A. Here, the metal wire 50 is wound around the metal film 40 only once, and the winding is fixed in a ring shape.

[0036] The metal wire 50 is made of a metal that is resistant to heat when the lamp is turned on. Here, the metal wire 50 is made of a Kanthal wire, but may be made of SUS or the like.

[0037] The metal wire 50 is in contact with platinum 60 (metal member) and connected to the joint 19A. Specifically, a part (hereinafter referred to as a winding part) 62 of the platinum 60 is wound around a linear part 52 extending along the lamp axis C of the metal wire 50 .

[0038] Here, the platinum 60 is wound around the metal film 40 in a ring shape and fixed in place similarly to the metal wire 50. The winding portion 62 of the platinum 60 is formed in a spiral shape along the lamp axis C so as to be in close contact with the metal wire 50.

[0039] Thus, the potential difference between the metal film 40 and the connector 19A side (cathode 20) is reduced by the electrical connection between the metal film 40 and the connector 19A by the metal wire 50 and the contact (entanglement) between the platinum 60 and the metal wire 50. In particular, the resistance value between the metal film 40 and the connector 19A is reduced by the platinum 60, and the potential approaches the same. As a result, during the lighting of the lamp, the movement of alkali metal ions to the metal foil 16A side is suppressed, and the metal foil 16A can be prevented from peeling off.

[0040] The resistance value of platinum 60 is lower than the resistance value of metal wire 50 composed of Kanthal wire or the like. Therefore, it is easy to further reduce the potential difference between metal film 40 and joint 19A (cathode 20), and it is possible to suppress the peeling of metal foil 16A caused by alkali metal ions. In addition, by winding platinum 60 around metal wire 50, platinum 60 is loosely in contact with sealing tube 13A, which can prevent devitrification.

[0041] In addition, metal parts other than platinum 60 may be used as long as the metal parts with lower resistance than the metal wire 50 composed of Kanthal wire or the like are used. In addition, it may be composed of a metal wire partially using platinum 60, or a metal that is not in a linear form (plate or foil form) may be used. On the other hand, a metal composed of the same raw material as the metal wire 50 may be used.

[0042] The short arc type discharge lamp described above can be manufactured, for example, as follows. That is, in the lamp manufacturing process, the lamp can be manufactured in a manner including the following steps: applying a metal film liquid to the outer surface of at least one of the sealing tubes connected to both sides of the discharge tube; and electrically connecting the metal film to a joint provided in the sealing tube on which the metal film is formed using a metal wire such as a Kanthal wire, and making a metal wire such as platinum contact (for example, winding) with a metal wire such as a Kanthal wire.

[0043] In this embodiment, a portion of the metal wire 50 and platinum 60 is wound around the metal film 40 to form a loop and fixed. If the loop portion is not in sufficient contact with the metal film 40, the electrical connection between the metal film 40 and the cathode side becomes unreliable.

[0044] Therefore, the lamp manufacturing can include the steps of winding the metal wire 50 and part of the platinum 60 around the sealing tube and then applying the metal film liquid thereon.

[0045] Figure 3 It shows Figure 1 , Figure 2 1 is a diagram of a modified example of the short arc type discharge lamp of the present embodiment described in . Here, platinum 60 is wound around only the straight portion 52 of the metal wire 50. Even with such a structure, the resistance value between the metal film 40 and the joint 19A is reduced, and the foil peeling of the metal foil can be suppressed.

[0046] Figure 4 1 is a diagram showing another modified example of the short arc discharge lamp of the present embodiment. Figure 4 2 in the middle) 50, multiple platinum 60 (in Figure 4 The plurality of wires are wound around the metal film 40 and fixed into a ring shape.

[0047] The plurality of metal wires 50 and platinum 60 are in contact at the portion where they are wound and fixed in a ring shape, and on the other hand, they extend along the lamp axis C and are connected to the joint 19A. Even with such a structure, the resistance value between the metal film 40 and the joint 19A is reduced, and the foil peeling of the metal foil can be suppressed. Alternatively, one metal wire 50 may be installed in a manner that it reciprocates between the metal film 40 and the joint 19A.

[0048] The above-described structure of the metal wire 50 and the platinum 60 can also be applied to the sealing tube 13B on the anode side.

[0049] [Example]

[0050] The following is an explanation of the embodiment. The short arc discharge lamp of this embodiment is Figure 1 , Figure 2The discharge lamp corresponding to the short arc type discharge lamp of the present embodiment shown has a rare gas (xenon) sealed in a discharge space DS, and performs arc discharge at a predetermined rated power (12 kW in the embodiment).

[0051] Kanthal wire (manufactured by Sakaguchi Electric Heater Co., Ltd.) was used as the metal wire, and platinum (manufactured by Nilaco Co., Ltd.) was wound around the metal wire. In the lamp manufacturing process, the metal wire and platinum were wound around the metal film applied to the sealing tube, and then the metal film was applied again from above.

[0052] On the other hand, as a comparative example, a discharge lamp using Kanthal wire as a metal wire and without platinum was prepared (hereinafter referred to as a comparative example). The comparative example has substantially the same structure as the short arc discharge lamp of the present embodiment except that platinum is not provided.

[0053] The resistance value of the short arc discharge lamp of this embodiment was measured to be 0.65Ω. On the other hand, the resistance value of the short arc discharge lamp of the comparative example was measured to be 1.33Ω. The resistance value was measured by a tester (manufactured by Kaise Co., Ltd.) at the metal film and the joint.

[0054] The short arc discharge lamp of the present example and the short arc discharge lamp of the comparative example were lit at 12 kW for 150 hours, and an experiment to confirm the peeling of the metal foil was performed.

[0055] In the comparative example, 8 mm of the metal foil peeled off after lighting for 150 hours, whereas in the present example, 1.6 mm of the metal foil peeled off, and the effect of the present example on the peeling of the metal foil was confirmed.

Claims

1. A short arc discharge lamp, characterized in that: The short arc discharge lamp has: A discharge tube, a pair of electrodes disposed opposite to each other in the discharge tube; A sealing tube connected to both sides of the discharge tube; a metal film formed on the outer surface of at least one of the sealing tubes; A metal wire electrically connecting the metal film to at least one of the electrodes; as well as A metal member is provided around the sealing tube on which the metal film is formed and is in contact with at least a portion of the metal wire.

2. The short arc discharge lamp according to claim 1, characterized in that: The metal member has a wire-shaped winding portion wound around the metal wire.

3. The short arc discharge lamp according to claim 1, characterized in that: The metal member has a linear winding portion wound around the metal film.

4. The short arc discharge lamp according to claim 3, characterized in that: The metal film includes a metal film formed on the winding portion.

5. The short arc discharge lamp according to claim 1, characterized in that: The metal member has a resistance value lower than a resistance value of the metal wire at least in a portion in contact with the metal wire.

6. The short arc discharge lamp according to claim 1, characterized in that: The metal component at least partially contains platinum.

7. The short arc discharge lamp according to claim 1, characterized in that: The metal member is made of the same raw material as the metal wire.

8. The short arc discharge lamp according to claim 1, characterized in that: A plurality of the metal wires and the metal component are provided.

9. The short arc discharge lamp according to claim 1, characterized in that: The metal wire is connected to a joint provided on the sealing tube formed with the metal film.

10. A method for manufacturing a short arc discharge lamp, characterized in that: A metal film is formed on the outer surface of at least one of the sealing tubes provided to connect both sides of the discharge tube. The metal film and a joint provided on a sealing tube on which the metal film is formed are electrically connected by a metal wire, and a linear metal member is brought into contact with the metal wire.

11. The method for manufacturing a short arc discharge lamp according to claim 10, characterized in that: A metal film is further formed on the metal member wound on the metal film.

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