Discharge lamp

Abstract

To provide a discharge lamp that can cope even with a situation where the arrangement of the discharge lamp and a stabilizer is different.SOLUTION: A discharge lamp is provided with: an arc tube; electrodes that are provided respectively at both ends of the arc tube; and cables that are electrically connected to the electrodes. Each cable has a coil part in which a linear member, which has a plurality of core wires and a coating part covering the plurality of core wires, is wound in a coil shape.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a discharge lamp.

Background Art

[0002] There is a discharge lamp that irradiates light such as ultraviolet light. The discharge lamp includes, for example, a cylindrical arc tube and a pair of electrodes provided at the ends of the cylindrical arc tube. In order to light such a discharge lamp, a dedicated ballast is required. The ballast mainly controls the values of the lamp current and lamp power of the discharge lamp so that they are within a predetermined range.

[0003] Generally, the discharge lamp and the ballast are electrically connected using a flexible cable. In this case, if the cable length is long, for example, the light irradiated from the discharge lamp may be blocked by the cable. On the other hand, if the cable length is short, it may be difficult to electrically connect the discharge lamp and the ballast, or the force applied to the terminals of the cable and the terminals of the ballast may increase.

[0004] In this case, it is also conceivable to use a cable having an appropriate length according to the arrangement of the discharge lamp and the ballast. However, in this case, it is necessary to set the cable length for each device in which the discharge lamp and the ballast are provided, or for each user. Therefore, it is necessary to manage the cable length for each device or each user. Also, when performing maintenance or the like, if the appropriate cable length is not known in advance, operations such as installing a relay terminal and adjusting the cable length are required at the maintenance site.

[0005] Therefore, there has been a demand for the development of a discharge lamp that can cope even when the arrangements of the discharge lamp and the ballast are different.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem to be solved by the present invention is to provide a discharge lamp that can cope even when the arrangements of the discharge lamp and the ballast are different.

Means for Solving the Problems

[0008] The discharge lamp according to the embodiment includes a light-emitting tube; electrodes provided at both ends of the light-emitting tube; and a cable electrically connected to the electrodes. The cable has a coil portion in which a linear member having a plurality of core wires and a covering portion covering the plurality of core wires is wound in a coil shape.

Effects of the Invention

[0009] According to the embodiment of the present invention, it is possible to provide a discharge lamp that can cope even when the arrangements of the discharge lamp and the ballast are different.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0011] Hereinafter, embodiments will be exemplified with reference to the drawings. In each drawing, the same components are denoted by the same reference numerals, and detailed descriptions thereof are omitted as appropriate.

[0012] The discharge lamp 1 according to the present embodiment can be, for example, a so-called high-intensity discharge lamp (HID: High Intensity Discharge lamp) such as a high-pressure mercury lamp, a metal halide lamp, a high-pressure sodium lamp, a xenon lamp, or a low-pressure mercury lamp. However, the type of the discharge lamp 1 is not limited to the exemplified ones. In the following, as an example, the case where the discharge lamp 1 is a long-arc type high-pressure mercury lamp will be described.

[0013] FIG. 1 is a schematic diagram for exemplifying the discharge lamp 1 according to the present embodiment. FIG. 2 is a schematic cross-sectional view of part A in FIG. 1. As shown in FIG. 1, the discharge lamp 1 includes, for example, a luminous tube 10, electrodes 20, conductive parts 30, outer leads 40, a base 50, a joint part 60, and a cable 70.

[0014] As shown in FIG. 1, the luminous tube 10 has, for example, a cylindrical part 11 and a sealing part 12. The cylindrical part 11 and the sealing part 12 can be integrally formed. The luminous tube 10 is formed of, for example, quartz glass. In this case, the luminous tube 10 is formed of, for example, transparent quartz glass, that is, quartz glass that is not colored.

[0015] The cylindrical part 11 has a cylindrical shape. The cylindrical part 11 has a form in which the overall length (the length in the tube axis direction) is longer than the outer diameter dimension d (mm) in the direction orthogonal to the tube axis direction. The outer diameter dimension d of the cylindrical part 11 is, for example, about 21.5 mm.

[0016] A discharge medium for generating light having a predetermined wavelength is enclosed in the internal space of the cylindrical part 11. The wavelength of the light irradiated from the luminous tube 10 (cylindrical part 11) can be changed by the composition of the discharge medium. For example, when generating ultraviolet light, the discharge medium can contain a noble gas such as argon gas and mercury. Further, the discharge medium can further contain a metal halide containing iron, tin, iodine, or the like.

[0017] The sealing portions 12 are provided at both ends of the cylindrical portion 11 in the tube axis direction. By providing the sealing portions 12 at both ends of the cylindrical portion 11, the internal space of the cylindrical portion 11 can be hermetically sealed. For example, the pair of sealing portions 12 are formed by crushing both end portions of the heated cylindrical portion 11. For example, the pair of sealing portions 12 can be formed using a pinch seal method or a shrink seal method. If the shrink seal method is used to form the sealing portion 12, a columnar sealing portion 12 as illustrated in FIGS. 1 and 2 can be formed. If the pinch seal method is used to form the sealing portion 12, a plate-like sealing portion 12 can be formed. In the tube axis direction, the dimension between the end portion of one sealing portion 12 on the side opposite to the cylindrical portion 11 side and the end portion of the other sealing portion 12 on the side opposite to the cylindrical portion 11 side is, for example, about 765 mm.

[0018] The electrodes 20 are provided at both ends of the arc tube 10. A pair of electrodes 20 are provided so as to face each other. The distance between the tips of the pair of electrodes 20 (the arc length of the discharge lamp 1) is, for example, about 665 mm.

[0019] As shown in FIG. 2, one end side of the electrode 20 is electrically connected to the conductive portion 30 inside the sealing portion 12. The other end side of the electrode 20 is provided inside the cylindrical portion 11.

[0020] The electrode 20 has, for example, a lead 21 and a coil 22. The lead 21 and the coil 22 mainly contain, for example, tungsten or thoriated tungsten.

[0021] The lead 21 is linear, and one end thereof is provided in the internal space of the cylindrical portion 11. The other end side of the lead 21 is electrically connected to the conductive portion 30 inside the sealing portion 12. The other end side of the lead 21 is, for example, laser welded or resistance welded to the conductive portion 30.

[0022] The coil 22 is provided on one end side of the lead 21. The coil 22 is provided in the internal space of the cylindrical portion 11. The coil 22 can be, for example, a linear member wound around the lead 21. Although the case where the coil 22 is attached to the lead 21 is exemplified, one end side of the lead 21 may be wound to form the coil 22. That is, the lead 21 and the coil 22 can also be integrally formed.

[0023] One conductive part 30 can be provided for one sealing part 12. The conductive part 30 is provided inside the sealing part 12. That is, the conductive part 30 is provided inside each sealing part 30. The planar shape of the conductive part 30 is, for example, a quadrilateral. The conductive part 30 is formed from, for example, molybdenum foil.

[0024] The outer lead 40 is electrically connected to the electrode 20 and a plurality of core wires 71 of a cable 70 described later. One outer lead 40 is provided, for example, for one conductive part 30. The outer lead 40 is linear. One end side of the outer lead 40 is electrically connected to the conductive part 30 inside the sealing part 12. For example, one end side of the outer lead 40 is laser welded or resistance welded to the conductive part 30. The other end side of the outer lead 40 is exposed from the sealing part 12. The outer lead 40 contains, for example, molybdenum as a main component.

[0025] The base 50 covers the connection part between the plurality of core wires 71 of the cable 70 and the outer lead 40. One base 50 is provided, for example, for one outer lead 40. As shown in FIG. 2, the base 50 has, for example, a main body part 51 and a flange 52. The main body part 51 and the flange 52 can be integrally formed. The base 50 (the main body part 51 and the flange 52) can be formed from, for example, a metal such as stainless steel. Note that the base 50 (the main body part 51 and the flange 52) can also be formed from a material having insulating properties and heat resistance. For example, the base 50 can be formed from ceramics such as aluminum oxide.

[0026] The main body portion 51 covers the connection portion between the plurality of core wires 71 of the cable 70 and the outer lead 40. The main body portion 51 has, for example, a cylindrical shape, with one end open and the other end closed. However, a hole 51a for passing one end of the cable 70 is provided at the other end of the main body portion 51. There is no particular limitation on the arrangement position of the hole 51a. For example, as shown in FIG. 2, the hole 51a can be a hole that penetrates the closed end of the main body portion 51 in the thickness direction.

[0027] As shown in FIG. 2, in the internal space of the main body portion 51, a joint portion 60, the vicinity of the end of the sealing portion 12, the portion of the outer lead 40 exposed from the sealing portion 12, and the tip portion of the cable 70 are provided.

[0028] The internal space of the main body portion 51 is filled with a bonding material 53. The bonding material 53 has a function of fixing the base 50 (main body portion 51) to the arc tube 10 (sealing portion 12), and a function of insulating between the elements provided in the internal space of the base 50 (the joint portion 60, the outer lead 40, and the plurality of core wires 71 exposed from the covering portion 72 of the cable 70), the base 50, and the like. The bonding material 53 is formed from a material having insulation and heat resistance, such as aluminum oxide, for example.

[0029] The flange 52 has, for example, a function of supporting the arc tube 10. The flange 52 has, for example, a disc shape and is provided on the side surface of the main body portion 51 (the surface in the direction intersecting the direction in which the outer lead 40 extends). The outer dimension D (mm) of the flange 52 in the direction orthogonal to the tube axis direction is larger than the outer diameter dimension d of the cylindrical portion 11.

[0030] In addition, when the arc tube 10 is supported by the main body portion 51 or when the arc tube 10 is supported by a member provided outside the discharge lamp 1, the flange 52 can be omitted.

[0031] As shown in FIGS. 1 and 2, the discharge lamp 1 may be provided, for example, inside a protective tube 80. The protective tube 80 has, for example, a cylindrical shape with open ends on both sides. In the tube axis direction, the length of the protective tube 80 is longer than the length of the discharge lamp 1. The inner diameter dimension of the protective tube 80 is slightly larger than the outer dimension D of the flange 52. Therefore, when the discharge lamp 1 is provided inside the protective tube 80, at least a part of the outer peripheral end of the flange 52 can be brought into contact with the inner wall of the protective tube 80. In this way, the position of the discharge lamp 1 with respect to the protective tube 80 can be determined. In this case, the tube axis direction of the cylindrical portion 11 can be made substantially parallel to the tube axis direction of the protective tube 80.

[0032] Also, an inert gas such as nitrogen or a rare gas can be enclosed in the space between the inner wall of the protective tube 80 and the arc tube 10. In such a case, the space between the flange 52 and the inner wall of the protective tube 80 may be sealed airtight using a sealing material.

[0033] The protective tube 80 is formed of a material that transmits the light irradiated from the arc tube 10. The material of the protective tube 80 can be, for example, borosilicate glass or the same as the material of the arc tube 10.

[0034] Note that the protective tube 80 is not necessarily required and can be omitted. However, if the protective tube 80 is provided, for example, the discharge lamp 1 can be immersed in a liquid. Therefore, the light irradiated from the discharge lamp 1 can be efficiently incident on the liquid. As a result, the treatment of the liquid (for example, chemical reactions such as polymerization reactions, sterilization, decomposition of organic substances, etc.) can be efficiently performed.

[0035] As shown in FIG. 2, one joint portion 60 is provided, for example, for one outer lead 40. The joint portion 60 electrically and mechanically connects the end portion exposed from the sealing portion 12 of the outer lead 40 and the plurality of core wires 71 exposed from the covering portion 72 of the cable 70. The joint portion 60 can be, for example, a metal band that covers the contact portion between the end portion of the outer lead 40 and the plurality of core wires 71 of the cable 70.

[0036] The joint portion 60 is plate-shaped and formed of a metal such as nickel, stainless steel, or iron. The joint portion 60 is electrically and mechanically connected to the outer lead 40 and the core wire 71 of the cable 70 by, for example, resistance welding or laser welding.

[0037] Also, a bonding material 61 can be provided in the internal space of the joint portion 60. The bonding material 61 can be provided, for example, in the gaps between the core wires 71, the gaps between the core wire 71 and the inner wall of the joint portion 60, the gaps between the core wire 71 and the outer lead 40, and the gaps between the outer lead 40 and the inner wall of the joint portion 60. The bonding material 61 contains, for example, a metal as a main component and a resin as a sub-component. The metal is, for example, gold, silver, platinum, etc. The resin is, for example, an epoxy resin, etc.

[0038] The cable 70 is electrically connected to the electrode 20. As shown in FIGS. 1 and 2, the cable 70 has, for example, a plurality of core wires 71, a covering portion 72, and a terminal 73.

[0039] The plurality of core wires 71 are formed of a low-resistance metal such as copper or a copper alloy, for example. The covering portion 72 covers the plurality of core wires 71. The covering portion 72 bundles the plurality of core wires 71 and insulates between the members provided outside the base 50 and the discharge lamp 1 and the plurality of core wires 71. Further, light and heat radiated from the light-emitting tube 10 enter the covering portion 72. Also, the light radiated from the light-emitting tube 10 contains ultraviolet rays. Therefore, the covering portion 72 is preferably formed of a material having insulation, heat resistance, and resistance to ultraviolet rays. The covering portion 72 contains, for example, a fluororesin.

[0040] One end of the plurality of core wires 71 is exposed from the covering portion 72. One end of the plurality of core wires 71 is electrically connected to the outer lead 40 by the joint portion 60. The other end of the plurality of core wires 71 is exposed from the covering portion 72. The other end of the plurality of core wires 71 is electrically connected to the terminal 73.

[0041] The terminal 73 can be, for example, a crimp terminal or a connector. The terminal 73 illustrated in FIG. 1 is a bar terminal. The terminal 73 is not necessarily required and can be omitted. However, if the terminal 73 is provided, the attachment and detachment of the discharge lamp 1 can be facilitated. Therefore, the productivity during the manufacture of the discharge lamp 1 and the workability during maintenance can be improved.

[0042] As shown in FIG. 1, the terminal 73 provided on the cable 70 is detachably connected to the output terminal 100a of the ballast 100. Further, the input side of the ballast 100 is electrically connected to, for example, an AC power supply 101 provided in a factory or the like. The ballast 100 mainly controls so that values such as the value of the lamp current and the value of the lamp power of the discharge lamp 1 are within a predetermined range. For example, the rated lamp voltage is about 940V, the lamp current is about 3.8A, and the lamp power is about 3400W.

[0043] When a voltage is applied to the terminal 73 provided on the cable 70 by the ballast 100, discharge occurs between the pair of electrodes 20, and light (for example, ultraviolet light) having a predetermined wavelength is irradiated from the arc tube 10 according to the composition of the discharge medium enclosed in the internal space of the arc tube 10. When the light irradiated from the arc tube 10 is incident on the irradiation object, a predetermined process is performed on the irradiation object.

[0044] Here, generally, the discharge lamp 1 and the ballast 100 are electrically connected using a flexible cable. In this case, if the length of the cable is long, for example, the light irradiated from the discharge lamp 1 may be blocked by the cable. On the other hand, if the length of the cable is short, it may be difficult to electrically connect the discharge lamp 1 and the ballast 100, or the force applied to the terminal 73 of the cable and the output terminal 100a of the ballast 100 may increase.

[0045] In this case, it is also conceivable to use a cable having an appropriate length according to the arrangement of the discharge lamp 1 and the ballast 100. However, if this is done, it is necessary to set the length of the cable for each arrangement of the discharge lamp 1 and the ballast 100, or for each user. Therefore, it is necessary to manage the length of the cable for each device or for each user. Also, when performing maintenance or the like, if the appropriate length of the cable is not known in advance, operations such as installation of relay terminals and adjustment of the cable length are required at the site where maintenance is performed.

[0046] Therefore, a cable 70 is provided to the discharge lamp 1. As shown in FIG. 1, the cable 70 has a coil portion 70a. The coil portion 70a is a portion where a linear member having a plurality of core wires 71 and a covering portion 72 covering the plurality of core wires 71 is wound in a coil shape. That is, the cable 70 can be a coiled cable.

[0047] For example, the cross-sectional area of the plurality of core wires 71 can be about 1.25 sq, the outer diameter dimension (cross-sectional dimension) of the linear member can be about φ2.3 mm, and the length of the linear member before being wound can be about 0.5 m to 3 m.

[0048] Also, as shown in FIG. 1, it is preferable that the outer diameter dimension D1 (mm) of the coil portion 70a is smaller than the outer diameter dimension d of the cylindrical portion 11. As described above, the discharge lamp 1 may be provided inside the protective tube 80. If the outer diameter dimension D1 of the coil portion 70a is smaller than the outer diameter dimension d of the cylindrical portion 11, it becomes easier to pass the cable 70 inside the protective tube 80. Note that the outer diameter dimension D1 of the coil portion 70a can be, for example, the dimension when the coil portion 70 is in a close contact state.

[0049] The number of turns of the coil portion 70a can be appropriately changed according to the outer diameter dimension D1 of the coil portion 70a and the length of the linear member before being wound. Further, at least any one of the length of the cable provided on one end side of the arc tube 10, the outer diameter dimension of the coil portion, and the number of turns of the coil portion may be the same as or different from at least any one of the length of the cable provided on the other end side of the arc tube 10, the outer diameter dimension of the coil portion, and the number of turns of the coil portion.

[0050] The coil portion 70a formed by winding the linear member in a coil shape is easy to expand / contract and bend. Therefore, as shown in FIG. 1, according to the arrangement of the discharge lamp 1 and the ballast 100, the dimension between the end portion on the joint portion 60 side of the cable 70 and the terminal 73 of the cable 70, and the shape between the end portion on the joint portion 60 side of the cable 70 and the terminal 73 of the cable 70 can be easily changed. That is, according to the arrangement of the discharge lamp 1 and the ballast 100, the length and shape of the cable 70 can be easily changed. Also, even if there are manufacturing variations in the length of the discharge lamp 1 in the tube axis direction, the coil portion 70a can absorb the variations in the length of the discharge lamp 1 by expanding and contracting. Further, since the coil portion 70a has a contraction force, the position of the cable 70 can be stabilized.

[0051] Therefore, for a plurality of types of devices with different arrangements of the discharge lamp 1 and the ballast 100, it is possible to make the cable 70 common or significantly reduce the types of the cable 70 lengths. If the cable 70 can be made common or the like, it is possible to facilitate inventory management, improve the workability of maintenance work, reduce manufacturing costs, and the like.

[0052] In addition, a support portion 102 for supporting the coil portion 70a of the cable 70 can also be provided on a housing or the like in which the discharge lamp 1 and the ballast 100 are provided. The support portion 102 can be, for example, a rod-shaped body or a plate-shaped body.

[0053] As shown in FIG. 1, the support portion 102 can be inserted into the space inside the coil portion 70a. If the support portion 102 is provided, when vibration or the like is applied to the coil portion 70a, it is possible to suppress a large movement of the position of the coil portion 70a.

[0054] In this case, the cross-sectional dimension of the support portion 102 can be made smaller than the inner diameter dimension of the coil portion 70a. In this way, a gap can be provided between the support portion 102 and the inner portion of the coil portion 70a, so that when vibration or the like is applied to the coil portion 70a, the position of the coil portion 70a can be shifted along the support portion 102.

[0055] When vibration or the like is applied to the coil portion 70a, if it is possible to suppress a large movement of the position of the coil portion 70a or shift the position of the coil portion 70a along the support portion 102, the force applied to the terminal 73 of the cable 70, the output terminal 100a of the ballast 100, and the joint portion 60 can be reduced. Therefore, it is possible to suppress their breakage or improve the reliability regarding the electrical connection between the discharge lamp 1 and the ballast 100.

[0056] As described above, some embodiments of the present invention have been illustrated. However, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, changes, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof. In addition, the above-described embodiments can be implemented in combination with each other.

Description of Reference Numerals

[0057] 1 Discharge lamp, 10 Light-emitting tube, 11 Cylindrical portion, 12 Sealing portion, 20 Electrode, 30 Conductive portion, 40 Outer lead, 50 Base, 51 Main body portion, 52 Flange, 60 Joint portion, 70 Cable, 70a Coil portion, 71 Core wire, 72 Coating portion, 73 Terminal, 80 Protection tube, 100 Ballast, 100a Output terminal, 101 AC power supply, 102 Support portion

Claims

1. A discharge lamp comprising: a discharge tube; electrodes provided at respective ends on both sides of the discharge tube; a cable electrically connected to the electrodes; wherein the cable has a coil portion in which a linear member having a plurality of core wires and a covering portion covering the plurality of core wires is wound in a coil shape.

2. The discharge tube has a cylindrical portion having a cylindrical shape, and the outer diameter dimension of the coil portion is smaller than the outer diameter dimension of the cylindrical portion. The discharge lamp according to Claim 1.

3. an outer lead electrically connected to the electrode and the plurality of core wires of the cable; a base covering a connection portion between the plurality of core wires of the cable and the outer lead; further comprising the base having a main body portion covering the connection portion; and a flange provided on a surface of the main body portion in a direction intersecting the direction in which the outer lead extends; wherein the outer dimension of the flange is larger than the outer diameter dimension of the cylindrical portion. The discharge lamp according to Claim 2.

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