JP2006260785A - Flashing discharge tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flashing discharge tube that secures an effective emission region and can be miniaturized, and improves the strength of sealing sections at both the ends of a glass valve to a mechanical load to main electrodes at both the ends. <P>SOLUTION: Planar members 9, 10 are formed on both sealed main electrodes 2, 5 at both the ends of the glass valve 1, and both the ends of the glass valve 1 and the planar members 9, 10 are closely installed. As a result, even if a mechanical load is applied to both the main electrodes 2, 5, the load is dispersed to the entire adhesion surface between both the ends of the glass valve 1 and the planar members 9, 10, thus greatly reducing cracks at the sealing sections 13, 14. Additionally, even if the sealing sections 13, 14 are thinned and miniaturized, the strength of the sealing sections 13, 14 is secured fully for miniaturization. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a flash discharge tube that is attached to or incorporated in an electronic flash device that is attached to or incorporated in various imaging devices such as a camera or a camera-equipped mobile phone or the like. The present invention relates to a flash discharge tube with improved strength.

  In this type of flash discharge tube, as shown in FIG. 7, main electrodes 18 and 21 are sealed at both ends of a glass bulb 17, and a trigger electrode 22 of a transparent conductive film is provided over the entire outer surface of the glass bulb 17. The glass bulb 17 is filled with a required amount of a rare gas such as xenon, and the main electrode 18 is formed by sintering a metal body 19 of tungsten or Kovar, a single body of refractory metal or a mixed powder thereof, and a metal body. It consists of a sintered metal body 20 attached to the tip of 19. The main electrodes 18 and 21 are sealed by attaching bead glasses 23 and 24 to both the main electrodes 18 and 21 and welding them at both ends of the glass bulb 17 (for example, Patent Document 1).

By the way, in recent years, various imaging apparatuses have been remarkably miniaturized, and further miniaturization is required for the electronic flash device used therefor. In order to meet these requirements, it is necessary to shorten the longitudinal dimension of the flash discharge tube. However, if the glass bulb 17 is simply shortened to reduce the size, the effective light emission area of the flash discharge tube, that is, the distance between the main electrodes 18 and 21 in the flash discharge tube is shortened, and the amount of emitted light is reduced. End up. Therefore, in order to reduce the size while ensuring such an effective light emitting region, it is effective to reduce the thickness in the tube axis direction of the sealing portions at both ends of the glass bulb 17.
JP 2000-315475 A

  However, if the sealing portions at both ends of the glass bulb 17 are made thin, the strength of the sealing portion may be reduced. If the flash discharge tube is transported or incorporated in the flash light emitting device in this state, both the main electrodes 18 are used. , 21 is likely to crack. When cracks enter the sealing portion in this way, the noble gas cannot be kept airtight, resulting in a decrease in the amount of emitted light and a shortened life of the flash discharge tube.

  Therefore, the present invention achieves miniaturization while ensuring an effective light emitting area, and further improves the strength of the sealing portions at both ends of the glass bulb against the mechanical load on the main electrodes at both ends. The purpose is to provide.

  The flash discharge tube of the present invention includes a glass bulb sealed at both ends, a trigger electrode provided on the outer surface of the glass bulb, a pair of main electrodes sealed at both ends of the glass bulb, and the glass A rare gas filled in a required amount in the bulb, and at least one of the main electrodes is a first electrode portion sealed in the glass bulb, and a glass bulb attached to the first electrode portion A second electrode portion exposed to the outside, and a plate-like member provided between the first electrode portion and the second electrode portion, and the first plate-like member is in close contact with the end portion of the glass bulb. It is characterized by being installed.

  According to this configuration, since the end of the glass bulb and the plate-like member attached to the main electrode are in close contact with each other, the main electrode is mechanically connected to the main electrode when the flash discharge tube is incorporated into the flash discharge device or during transportation. Even if a load is applied, the load is received at the intimate contact between the end portion of the glass bulb and the plate-like member. It is possible to greatly reduce the occurrence of cracks or breakage in the part.

  The first electrode part and the second electrode part may be integrally formed continuously, or both may be connected by welding or the like. As the material for the plate-like member, any material such as a conductive material such as a metal, an insulating material such as a resin or a ceramic can be applied. Further, the plate-like member may be attached to both main electrodes, or may be attached to only one of them.

  Moreover, the said plate-shaped member may be inserted by said 2nd electrode part. In this case, the plate-like member may be attached before the first electrode portion is sealed, or after such sealing. In order to prevent the plate member from coming out of the second electrode portion and to make sure that the plate member is in close contact with the end portion of the glass bulb, the plate member is inserted into the second electrode portion by interference fit. Is preferred.

  Moreover, the flat part facing the said plate-shaped member may be provided in the edge part of the said glass bulb | bulb, and the said plate-shaped member may be closely installed in this flat part. According to this configuration, the end of the glass bulb and the plate-like member are in contact with each other on the surface, and even if the mechanical load as described above is applied to the main electrode, the load is applied to the flat portion of the end of the glass bulb. Since it is distributed and received over the entire contact surface with the plate-like member, it is further advantageous for preventing cracks and breakage of the sealing portion. In addition, what is necessary is just to form a plane part by applying a jig | tool etc., when sealing both the main electrodes to the both ends of a glass bulb, for example.

  Moreover, the said plate-shaped member is good also as a structure which consists of an insulating material and is larger than the outer diameter of the said glass bulb. According to this configuration, since the plate-like member made of an insulating material partitions the space between the main electrode and the trigger electrode at a portion where both the main electrode and the trigger electrode are close to each other outside the glass bulb, This is advantageous in preventing the so-called trigger jump in which the current is short-circuited between the electrodes.

  As described above, according to the flash discharge tube of the present invention, the end of the glass bulb and the plate-like member attached to the main electrode are in close contact with each other. Even when a mechanical load is applied to the main electrode, stress does not concentrate on a specific part of the sealing part of the glass bulb, and cracking or breakage of the sealing part is greatly reduced. be able to.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIGS.

  In FIG. 1, 1 is a glass bulb, 2 is a main electrode including a sintered metal body 4 sealed at one end of the glass bulb and made of a sintered body such as tungsten powder, and 5 is the other side of the glass bulb 1. The main electrode 6 sealed at the end of the glass bulb 1 is a trigger electrode which is a transparent conductive film applied to the outer surface of the glass bulb 1, and is applied over the entire circumference of the outer surface of the glass bulb 1. Reference numerals 7 and 8 denote bead glasses which are attached to the main electrode 2 and the main electrode 5 and used for sealing both the main electrodes to the glass bulb 1. Further, the glass bulb 1 is filled with a required amount of rare gas such as xenon gas.

  In the flash discharge tube having the above-described configuration, the main electrodes 2 and 5 are disposed in the respective openings of the glass bulb 1 having both ends opened, and the bead glasses 7 and 8 are heated from the outside of the glass bulb 1 by heating the vicinity of the bead glasses 7 and 8. 8 and the glass bulb 1 are melted to form the sealing portions 13 and 14, and the main electrodes 2 and 5 are sealed at both ends of the glass bulb 1.

  In the present embodiment, a pair of plate-like members 9 and 10 formed in a disk shape are provided at both ends of the glass bulb 1. Specifically, both the main electrodes 2 and 5 are respectively connected to the first electrode portions 2a and 5a sealed in the glass bulb 1 and exposed to the outside of the glass bulb by being connected to the first electrode portions 2a and 5a, respectively. It consists of second electrode portions 2b and 5b, and flange-like plate-like members 9 and 10 are integrally formed on the second electrode portions 2b and 5b on the side facing the first electrodes 2a and 5a, respectively. ing. Hereinafter, the cathode side will be described in detail as an example.

  In FIG. 3, the first electrode part 2a is a metal body obtained by cutting a tungsten or Kovar metal rod having an expansion coefficient close to that of the glass bulb 1, and the second electrode part 2b is a solder such as nickel. It is composed of a metal body with good adhesion. The second electrode portion 2b is formed by, for example, pressing a metal wire body such as nickel into a mold and pressing it at room temperature to form the plate member 10 at one end.

  As shown in FIG. 3, the first electrode portion 2a and the second electrode portion 2b formed in this way are connected to one end 25 of the first electrode portion 2a of the plate-like member 10 of the second electrode portion 2b. The main electrode 2 is manufactured by fitting in a recess 26 provided in the center and welding the fitted part to connect them.

  Such a sealing process of the main electrode 2 will be described. That is, as shown in FIG. 4A, first, the main electrode 2 is installed in the opening 12 of the glass bulb 1 before sealing, and the vicinity of the bead glass 8 is heated from the outside of the glass bulb 1. Then, as shown in FIG. 4B, a sealing portion 14 is formed in the opening 12 of the glass bulb 1, and the main electrode 2 is sealed with the sealing portion 14. At that time, the molten sealing portion 14 flows and comes into close contact with one surface of the plate-like member 10.

  Since the anode side is the same as the cathode side, description thereof is omitted. Of course, such a structure may be applied only to either the cathode side or the anode side as necessary.

  According to the above flash discharge tube, the end portions of the sealing portions 13 and 14 of the glass bulb 1 and the plate-like members 9 and 10 formed on the main electrodes 2 and 5 are in close contact with each other. Even when a mechanical load is applied to both the main electrodes 2 and 5 when the lamp is incorporated into a flash discharge device or during transportation, the load is distributed over the entire contact surface between the both ends of the glass bulb 1 and the plate-like members 9 and 10. It will be accepted. Therefore, stress is not concentrated on specific portions of the sealing portions 13 and 14 of the glass bulb, and the occurrence of cracks or breakage in the sealing portions 13 and 14 can be greatly reduced.

Further, in response to today's needs for miniaturization, even if the sealing portions 13 and 14 are made thin to realize miniaturization, the miniaturization can be achieved while sufficiently securing the strength of the sealing portions 13 and 14. Become.
(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIG.

  In the present embodiment, both the main electrodes 2 and 5 are respectively integrated integrally with the first electrode portions 2a and 5a sealed in the glass bulb 1 and the first electrode portions 2a and 2b, respectively. The second electrode portions 2b and 5b are formed and exposed to the outside of the glass bulb. The plate-like members 9 and 10 are inserted into the second electrode portions 2b and 5b of the main electrodes 2 and 5, respectively. The sealing portions 13 and 14 at both ends of the glass bulb 1 are provided with flat portions 13a and 14a at portions facing the plate-like members 9 and 10, and the flat members 9a and 14a are provided with flat plate portions 9a and 14a. , 10 are installed closely. The manufacturing process of such a flash discharge tube will be described taking the cathode side as an example.

  That is, as shown in FIG. 5A, first, before sealing the glass bulb 1, the main electrode 2 is installed in the opening 12 of the glass bulb 1, and the vicinity of the bead glass 8 is heated from the outside of the glass bulb 1. To do. At that time, a jig 11 is placed on the opening 12 of the glass bulb 1. Then, as shown in FIG. 5B, the sealing portion 14 is formed in the opening 12 of the glass bulb 1, and the main electrode 2 is sealed with the sealing portion 14. At that time, the flat portion 14 a is formed by the jig 11 in the sealing portion 14 in a molten state. Thereafter, as shown in FIG. 5C, the plate-like member 10 is inserted into the main electrode 2 and brought into close contact with the flat portion 14a. At this time, the plate-like member 10 is fitted into the main electrode 2 by interference fit so that the plate-like member 10 does not come out of the main electrode 2 and is surely brought into close contact with the flat portion 14a.

  The anode side is the same as the cathode side, and may be applied only to either the cathode side or the anode side as necessary, as in the first embodiment.

  As the material for the plate-like members 9 and 10, any material such as a conductive material such as a metal, an insulating material such as a resin or ceramic can be applied. The first electrode portions 2a, 5a and the second electrode portions 2b, 5b may be made of the same material, or may be made of different materials and connected by welding or the like. For example, in the case of the same material, a material close to the expansion coefficient of the glass bulb 1 such as tungsten is used, and nickel exposed to the outside of the glass bulb 1 is covered with nickel that is easily soldered. In the case of another material, the first electrode portions 2a and 5a are made of a material close to the expansion coefficient of the glass bulb 1 such as tungsten, and the second electrode portions 2b and 5b are made of nickel or the like that can be easily soldered.

According to the above flash discharge tube, the flat portions 13a and 14a of the sealing portions 13 and 14 of the glass bulb 1 and the plate-like members 9 and 10 inserted into both the main electrodes 2 and 5 are in close contact with each other. Even when a mechanical load is applied to both the main electrodes 2 and 5 when the flash discharge tube is incorporated into the flash discharge device or during transportation, the load is applied to the flat portions 13a and 14a of the glass bulb 1 and the plate-like member 9 and 10 is dispersed and received over the entire close contact surface. Therefore, stress does not concentrate on specific portions of the sealing portions 13 and 14 of the glass bulb, and the occurrence of cracks or breakage in the sealing portions 13 and 14 can be greatly reduced.
(Embodiment 3)
A third embodiment of the present invention will be described with reference to FIG.

  In the present embodiment, the plate-like members 15 and 16 are made of an insulating material with respect to the configuration of the second embodiment, and are made larger than the outer diameter of the glass bulb 1. Other configurations are the same as those of the second embodiment.

  According to this configuration, in addition to the operations and effects described in the second embodiment, a plate-like member made of an insulating material in a portion where both the main electrodes 2 and 5 and the trigger electrode 6 are close to each other outside the glass bulb 1. 15 and 16 partition the space between the two electrodes 2 (5) and 6, which is advantageous in preventing so-called trigger jump that causes a short circuit between the electrodes.

  Of course, the present invention is not limited to the above-described embodiment, and can be applied to all other uses.

  Here, the flash discharge tube in the first embodiment will be described because the strength of the sealing portion 14 that supports the cathode-side main electrode 5 is verified by a static load test. Specifically, after the glass bulb 1 was fixed horizontally, a test was performed by hanging a weight on the main electrode 2 and applying a static load to the sealing portion 14. The prepared weights were 300 g, 500 g, 800 g, 1000 g, 1500 g, and 2000 g. These were attached in order from a lighter one, and the time when cracks and breakage occurred in the sealing portion 14 was confirmed.

  As a sample, the flash discharge tube according to the first embodiment was used as an example, and the flash discharge tube without the plate-like members 9 and 10 according to the first embodiment was used as a conventional example. In both the conventional example and the embodiment, a flash discharge tube having a glass bulb outer diameter φ1.8, inner diameter φ1.2, a distance between both main electrodes of 13 mm, and a bead length (axial thickness of the sealing portion 14) of 2 mm is used. It was. The results were as follows.

  As shown in Table 1, in the conventional example, no abnormality was found in the sealing portion 14 at any time of the loads 300 g, 500 g, 800 g, and 1000 g. However, when the load was 1500 g, cracks were observed in the sealing portion 14 for four of the five test specimens. Furthermore, at a load of 2000 g, cracks were confirmed in three of the five test specimens, and the sealing portion 14 was confirmed to be broken in one of the five specimens.

  On the other hand, in the examples, no abnormality such as a crack was observed in the sealing portion 14 at any time point of the load from 300 g to 2000 g.

  From the above, it has been found that with the same bead length, the example is less likely to crack in the sealed portion. That is, if the present invention is applied, it can be said that an improvement in the strength of the sealing portion can be expected and an excellent flash discharge tube with less fear of leakage can be provided. Moreover, even if the miniaturization is realized by thinning the sealing portion in response to today's miniaturization needs, it can be said that the miniaturization can be achieved while sufficiently securing the strength of the sealing portion.

  Since the present invention can be miniaturized without reducing the amount of light from the flash discharge tube, an electronic flash device mounted on various imaging devices such as digital cameras, which are remarkable in miniaturization, and devices with various imaging functions such as mobile phones with cameras. It is suitable as a flash discharge tube.

Sectional drawing of the flash discharge tube concerning Embodiment 1 of this invention 1 is a perspective view of the flash discharge tube of FIG. 1 is an exploded perspective view of the main electrode (anode side) of FIG. Partial sectional view showing the sealing process of the flash discharge tube of FIG. The fragmentary sectional view which showed the sealing process of the flash discharge tube concerning Embodiment 2 of this invention Sectional drawing of the flash discharge tube concerning Embodiment 3 of this invention Cross section of a conventional flash discharge tube

Explanation of symbols

1 Glass bulb 2 Main electrode (cathode side)
2a 1st electrode part 2b 2nd electrode part 4 Sintered metal body 5 Main electrode (anode side)
5a 1st electrode part 5b 2nd electrode part 6 Trigger electrode 7 Bead glass 8 Bead glass 9 Plate member 10 Plate member 11 Jig 12 Opening 13 Sealing part 14 Sealing part

Claims (4)

A glass bulb sealed at both ends, a trigger electrode provided on the outer surface of the glass bulb, a pair of main electrodes sealed at both ends of the glass bulb, and a required amount enclosed in the glass bulb Consisting of noble gases,
At least one of the main electrodes includes a first electrode portion sealed in a glass bulb, a second electrode portion attached to the first electrode portion and exposed outside the glass bulb, and the first electrode portion A flash discharge tube comprising: a plate-like member provided between the first electrode portion and the second electrode portion, wherein the first plate-like member is placed in close contact with an end portion of the glass bulb.   The flash discharge tube according to claim 1, wherein the plate-like member is fitted into the second electrode portion.   The flat part which opposes the said plate-shaped member is provided in the edge part of the said glass bulb, The said plate-shaped member is closely installed in this flat part, The Claim 1 or 2 characterized by the above-mentioned. Flash discharge tube. 4. The flash discharge tube according to claim 1, wherein the plate-like member is made of an insulating material and is larger than an outer diameter of the glass bulb. 5.

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