JP2017182928A - Discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp capable of preventing start failure.SOLUTION: A discharge lamp according to an embodiment comprises: an airtight container which has a sealing part provided with a pair of electrodes embedded in its both ends in a manner facing each other, and whose inside is airtightly sealed by the sealing part; mercury and rare gas sealed in the airtight container; a lead wire provided on a side, of the pair of electrodes, facing the airtight container; and a conductive film provided on an outer face of the sealing part so as to be connected to the lead wire. The discharge lamp emits ultraviolet light.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a discharge lamp.

  For example, a discharge lamp is disclosed as a light source used in applications such as exposure, curing, and drying by irradiating an object with ultraviolet rays in the field of liquid crystal panel production and printing.

JP 2009-259790 A

  When a discharge lamp is left in a dark place for a long time, there is no supply of initial electrons due to excitation of natural light, so that the time until dielectric breakdown increases and the start failure of the lamp occurs, so-called dark start It is known that the characteristics deteriorate. For the purpose of improving the dark starting characteristics, there are methods of turning on the auxiliary light source before lighting the lamp and applying an emitter material having a low work function to the electrode coil portion of the lamp. However, there is a concern that when there is no space for installing the auxiliary light source or when the emitter material scatters, it reacts with the arc tube, and the reaction part with the leak or emitter becomes high temperature, leading to arc tube blackening. Is done.

  Embodiments of the present invention provide a discharge lamp that suppresses starting failure.

  According to an embodiment of the present invention, the discharge lamp has a sealed portion in which a pair of electrodes are embedded oppositely at both ends, and an airtight container whose inside is hermetically sealed by the sealed portion; and Mercury and rare gas sealed inside the hermetic container, lead wires provided on the side of the pair of electrodes facing the hermetic container, and provided on the outer surface of the sealing portion connected to the lead wires And an ultraviolet ray is emitted.

  According to the embodiment of the present invention, it is possible to provide a discharge lamp that suppresses starting failure.

FIG. 1 is a schematic view illustrating a discharge lamp according to the first embodiment. FIG. 2 is an enlarged schematic view of the sealing portion 16 of the discharge lamp 1 according to the first embodiment. FIG. 3 is a schematic diagram for explaining suppression of starting failure of the discharge lamp 1 according to the first embodiment. FIG. 4 is a schematic view illustrating a modified example of the discharge lamp 1 according to the first embodiment. FIG. 5 is a diagram illustrating a result of a difference in starting voltage (V) depending on the presence / absence of the conductive film 60 and the presence / absence of connection of the conductive film 60 to the lead wire 28 in the discharge lamp 1 according to the first embodiment.

  An airtight container having a sealed portion in which a pair of electrodes are embedded opposite to each other at both ends according to the embodiment described below, and the inside is hermetically sealed by the sealed portion, and is enclosed in the inside of the airtight container Mercury and a rare gas, a lead wire provided on the side of the pair of electrodes facing the hermetic container, and a conductive film provided on the outer surface of the sealing portion so as to be connected to the lead wire. Release.

  According to this embodiment, start-up failure can be suppressed.

  In the discharge lamp according to the embodiment described below, the conductive film is connected to the lead wire by a metal conductor.

  According to the present embodiment, it is possible to more reliably suppress the starting failure.

  In the discharge lamp according to the embodiment described below, the conductive film extends to the lead wire.

  According to the present embodiment, it is possible to more reliably suppress the starting failure.

  Embodiments of the present invention will be described below with reference to the drawings.

  (First embodiment)

  FIG. 1 illustrates a discharge lamp 1 according to a first embodiment with reference to FIG. FIG. 1 illustrates a discharge lamp 1.

  As shown in FIG. 1, the discharge lamp 1 according to the present embodiment includes an airtight container 10 and a pair of discharge electrodes 20 and 20.

  In the present embodiment, an embodiment using a high-pressure mercury lamp as the discharge lamp 1 is illustrated.

  The airtight container 10 is formed in a straight tube shape and has a discharge space 12 therein. Moreover, the sealing parts 16 and 16 are formed in the both ends of the airtight container 10, and the discharge space 12 is kept airtight. The airtight container 10 is made of a material that transmits ultraviolet rays, and is made of, for example, quartz glass. The airtight container has an outer diameter of 25 mm and an overall length of 1260 mm.

  In the discharge space 12, mercury 14 or a rare gas (not shown) enclosed in the discharge space 12 emits light when electric power is applied from the pair of discharge electrodes 20 and 20. The discharge space 12 has, for example, an inner diameter of 22 mm and a light emission length (distance between the discharge electrodes 20-20) of 1100 mm.

The mercury 14 is enclosed in the discharge space 12 and emits ultraviolet rays of, for example, 254 nm and 365 nm when electric power is applied from the outside of the discharge lamp 1. Further, the mercury 14 contributes to the maintenance of the discharge when electric power is applied from the outside of the discharge lamp 1. Mercury 16 is mostly present as liquid and partially present as gas in the hermetic container 10 when electric power is not supplied to the discharge lamp 1. The amount of mercury enclosed is, for example, 0.5 to 3.0 (mg / cm ³ ).

  The rare gas promotes discharge when starting the discharge lamp 1 and contributes to maintaining the discharge after the start of discharge. The enclosure pressure of the rare gas is, for example, 1 to 10 (kPa) at 25 (° C.). The rare gas may be any one of xenon, argon, neon, or a mixed gas of two or more.

  The sealing parts 16 and 16 are formed at both ends of the discharge space 12. The sealing portions 16 and 16 are made of the same quartz glass as the airtight container 10. The sealing parts 16, 16 are formed by so-called shrink seals in which the discharge electrodes 20, 20 are provided at desired positions and then melted and sealed by a melting means such as a gas burner (not shown) under reduced pressure. The sealing parts 16 and 16 may be made of quartz glass or the like different from the hermetic container 10. Moreover, the sealing parts 16 and 16 may be formed by what is called a pinch seal by forming means such as a pincher (not shown). The length of the sealing portions 16 is 16 mm, for example. A conductive film 60 is formed on the outer surfaces of the sealing portions 16 and 16. Details of the conductive film 60 will be described later.

  The pair of discharge electrodes 20, 20 introduces electric power applied from the outside of the discharge lamp 1 into the discharge space 12, and causes arc discharge in the discharge space 12. The pair of discharge electrodes 20, 20 are partly embedded in the sealing parts 16, 16 and are provided opposite to both ends of the discharge space 12. The pair of discharge electrodes 20 and 20 includes shaft members 22 and 22, coils 24 and 24, foils 26 and 26, and lead wires 28 and 28.

  The shaft members 22 and 22 apply electric power to the discharge space 12. The shaft members 22 and 22 are configured such that one end protrudes into the discharge space 12 and the other end is embedded in the sealing portions 16 and 16. In addition, coils 24 and 24 are provided at one ends of the shaft members 22 and 22 that protrude toward the discharge space 12. The shaft members 22 and 22 are connected to the foils 26 and 26 by welding at the other end. The shaft members 22, 22 are made of tungsten, for example.

  The coils 24, 24 are provided on one end side of the shaft members 22, 22, and radiate temperature from the tips of the shaft members 22, 22 during discharge, thereby suppressing the temperature rise of the shaft members 22, 22. The coils 24, 24 have one end provided on one end side of the shaft members 22, 22, that is, on the discharge space 12 side, and the other end provided on the other end side of the shaft members 22, 22. The coils 24 and 24 are made of tungsten, for example.

  The foils 26 and 26 are embedded and sealed in the sealing portions 16 and 16 to keep the airtight container 10 airtight. One end of the foils 26, 26 is welded to the other end of the shaft members 22, 22, and the other end is welded to one end of the lead wires 28, 28, and is embedded in the sealing portions 16, 16. The foils 26 and 26 are made of, for example, molybdenum.

  The lead wires 28 and 28 are partially embedded in the sealing portions 16 and 16 to electrically connect the inside of the airtight container 10 and the harnesses 40 and 40. One end of the lead wires 28 and 28 is welded to the foils 26 and 26, and the other end is connected to the harnesses 40 and 40. The lead wires 28 are made of molybdenum, for example.

  The bases 30 and 30 are provided on the outer periphery of the sealing portions 16 and 16, the lead wires 28 and 28, and the harnesses 40 and 40 of the airtight container 10, so that the connection portions of the lead wires 28 and 28 and the harnesses 40 and 40 are exposed. prevent. The bases 30 and 30 are made of ceramics, for example. Moreover, in order to make the fitting with the airtight container 10 stronger in the bases 30 and 30, for example, cement may be fixed to a part of the sealing parts 16 and 16.

  The harnesses 40 and 40 are electrically connected to a power supply circuit (not shown) inside the hermetic container 10. The harnesses 40, 40 have one end connected to the other end of the lead wires 28, 28 and the other end connected to a power supply circuit or the like. The harnesses 40 and 40 are made of, for example, annealed copper wire. In addition, in order to make a connection with a power supply circuit easy in the other end of the harnesses 40 and 40, the terminal which is not shown in figure may be provided.

  The discharge lamp 1 provided in this way is, for example, a so-called air-cooling method in which when the discharge lamp 1 is supplied with electric power and is lit, it is cooled by cooling air sent by a blower (not shown) or the like. The discharge lamp 1 employs a so-called water cooling method in which the discharge lamp 1 is covered with a water cooling jacket (not shown) provided so as to surround the discharge lamp 1 and is cooled by a liquid flowing inside the water cooling jacket, specifically water. May be.

  Here, the conductive film 60 will be described in more detail with reference to FIG. FIG. 2 is an enlarged schematic view of the electrode 20, the sealing portion 16, and the lead wire 28. In FIG. 2, only a part of the conductive film 60 is drawn in order to clarify the position of the electrode 20.

  One end of the conductive film 60 is provided in the vicinity of the position of the hermetic container 10 facing the shaft member 22 of the electrode 20. The other end of the conductive film 60 is provided over the entire sealing portion 16. Note that the other end of the conductive film 60 is preferably electrically connected to the lead wire 28. This is because the starting failure due to the dark starting characteristic can be suppressed by electrically connecting the conductive film 60 to the lead wire 28. The conductive film 60 is provided, for example, by applying tin oxide (SnO) and then drying it. Note that the conductive film 60 keeps both ends of the hermetic container 10 warmed to raise the temperature of mercury liquid or the like that may enter a slight gap generated between the sealing portions 16, 16 and the electrode 20. You may act as what is called a heat retention film | membrane returned to the discharge space 12. FIG. The conductive film 60 is not limited to tin oxide (SnO). For example, the conductive film 60 includes one or more of tin oxide (SnO), platinum (Pt), gold (Au), cesium oxide (CsO), zinc oxide (ZnO), and magnesium oxide (MgO). It may be.

  Here, a mechanism for suppressing start-up failure due to the provision of the conductive film 60 will be described with reference to FIG. FIG. 3 is a schematic diagram for explaining suppression of starting failure. In FIG. 3, only a part of the conductive film 60 is drawn in order to clarify the discharge mechanism.

  When power is supplied to the discharge lamp 1 from a power supply circuit (not shown), the shaft member 22 and the coil 24 of the electrode 20 are positively charged at the same time as shown in FIG. Is charged. When the conductive film 60 is positively charged, the inside of the discharge vessel 10 is polarized and negatively charged as shown in FIG. At this time, since the positively charged electrode 20 and the negatively charged discharge container 10 exist in the discharge vessel 10, a discharge occurs between the electrode 20 and the discharge vessel 10, and this discharge is caused by the discharge vessel 10. It reaches the other electrode 20 through the inside, and finally a discharge is formed from one electrode 20 to the other electrode 20. From the above, it is desirable that the outer surface of the sealing portion 16 of the discharge lamp 1 has the conductive film 60 provided connected to the lead wire.

  As described above based on the above embodiment, according to the present embodiment, the conductive film 60 provided in connection with the lead wire 28 is provided on the outer surface of the sealing portion 16 of the discharge lamp 1. Since discharge tends to occur from one electrode 20 to the other 20 when the lamp 1 is started, it is possible to provide a discharge lamp that can suppress start-up failure.

  Further, in the above embodiment, the conductive film 60 provided on the discharge lamp 1 extends to the lead wire 28, so that the conductive film 60 is polarized when the discharge lamp 1 is started. Since discharge between the electrode 20 and the electrode 20 is more likely to occur, it is possible to provide a discharge lamp capable of suppressing starting failure.

  (Modification of the first embodiment)

  A modification of the first embodiment is shown in FIG. FIG. 4 is a schematic diagram showing a modification of the first embodiment.

  FIG. 4 shows an example in which the conductive film 60 is connected to the lead wire 28 by the metal conductor 70. The metal conductor 70 electrically connects the conductive film 60 and the lead wire 28. The metal conductor 70 is, for example,

It is made of nickel or molybdenum. By connecting the conductive film 60 and the lead wire 28 with the metal conductor 70, there is an effect that the electrical connection can be stably performed as compared with the case where the conductive film 60 is formed extending to the lead wire 28.

  As described based on the above embodiment, according to this embodiment, the conductive film 60 provided on the outer surface of the sealing portion 16 of the discharge lamp 1 by being connected to the lead wire 28 using the metal conductor 70. Therefore, since discharge easily occurs from one electrode 20 to the other 20 when the discharge lamp 1 is started, a discharge lamp that can suppress a starting failure can be provided.

  Further, in the above embodiment, since the conductive film 60 provided in the discharge lamp 1 is connected to the lead wire 28 by the metal conductor 70, a more stable electrical connection can be secured, thereby suppressing start-up failure. A discharge lamp can be provided.

Here, in the discharge lamp 1, the difference in the starting voltage (V) depending on the presence / absence of the conductive film 60 and the presence / absence of connection of the conductive film 60 to the lead wire 28 was examined. The evaluation conditions are as follows. The starting voltage (V) was evaluated by measuring the dielectric breakdown voltage using a high voltage power supply HSX-3R5 manufactured by Matsusada Precision with the lamp left in the dark for one day.

Discharge lamp 1 (common): inner diameter = 23 mm, discharge space length = 1100 mm, overall length of the discharge lamp = 1260 mm, lamp starting voltage = 600 V, lamp current = 10 A, lamp power = 16 kW.
Conductive film 60 (Comparative Example 2, Example 1, Example 2): Tin oxide (SnO).
Example 1 The conductive film 60 was formed to extend to the lead wire 28 so as to be connected to the lead wire 28.
Example 2: A metal conductor 70 was provided so as to connect the conductive film 60 and the lead wire 28.
Number of comparison lamps: 10 each.

  The results are shown in FIG. As is clear from FIG. 5, compared with Comparative Examples 1 and 2, the average value of the starting voltage decreased by 200 (V) in Examples 1 and 2. In other words, compared to Comparative Examples 1 and 2, in Examples 1 and 2, the starting voltage (V) could be lowered by 200 (V), so it was found that starting failure was suppressed compared to Comparative Examples 1 and 2. did.

  In the above embodiment, the discharge lamp 1 has a so-called high-pressure mercury lamp configuration, but may be a so-called metal halide lamp in which metal halide is sealed in addition to mercury and a rare gas.

  Although several embodiments of the present invention have been described, 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, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1 ... discharge lamp,
10 ... an airtight container,
12 ... discharge space,
14 ... sealing part,
16 ... first inclusion,
18 ... second inclusion,
20 ... Electrode,
22 ... shaft material,
24 ... Coil,
26 ... foil,
28 ... Lead wire 30 ... Base,
40 ... Harness,
60 ... conductive film,
70: Metal conductor.

Claims (3)

An airtight container having a sealing portion in which a pair of electrodes are embedded oppositely at both ends, and the inside is hermetically sealed by the sealing portion;
Mercury and a rare gas sealed in the hermetic container;
A lead wire provided on a side of the pair of electrodes facing the hermetic container;
A conductive film provided on the outer surface of the sealing portion and connected to the lead wire;
A discharge lamp that emits ultraviolet rays.   The discharge lamp according to claim 1, wherein the conductive film is formed to extend to the lead wire. The discharge lamp according to claim 1, wherein the conductive film is connected to the lead wire by a metal conductor.

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