JP5661375B2 - Flash lamp - Google Patents

Description

  The present invention relates to a flash lamp.

  As a conventional flash lamp, there is known a flash lamp including a sealed container in which a discharge gas is sealed, a cathode and an anode for generating arc discharge in the sealed container, and a plurality of trigger electrodes for generating preliminary discharge in the sealed container. (See, for example, Patent Documents 1 and 2). In such a flash lamp, when a trigger voltage is applied to the trigger electrode in a state where a predetermined voltage is applied between the cathode and the anode, a preliminary discharge is first generated by the trigger electrode, and then the cathode And an arc is generated by the anode. Thus, when a pulse voltage is applied to the trigger electrode as a trigger voltage, arc discharge occurs in a pulsed manner, and as a result, the flash lamp emits pulses.

Japanese Patent Publication No. 56-001746 US Pat. No. 3,356,888

  The flash lamp as described above is used as a light source for spectroscopic analysis equipment, emission analysis equipment, and the like. In such a case, the flash lamp emits light with an aperture installed at a predetermined position with respect to the flash lamp. Often cut out. Therefore, when fluctuations occur in the arc discharge, the light output cut out by the aperture or the like varies for each pulse emission.

  Then, this invention makes it a subject to provide the flash lamp which can suppress generation | occurrence | production of the fluctuation | variation of arc discharge.

In order to solve the above problems, a flash lamp according to the present invention includes a sealed container in which a discharge gas is sealed, a cathode and an anode that are disposed in the sealed container, and causes arc discharge, and is disposed in the sealed container. A first trigger electrode and a second trigger electrode for generating a preliminary discharge prior to the discharge, the cathode tip portion and the anode tip portion facing each other on a predetermined reference line; The tip portion of the trigger electrode is positioned on the cathode side with respect to the tip portion of the second trigger electrode in a direction parallel to the reference line, and the tip portion of the first trigger electrode is a predetermined reference including the reference line. On one side of the surface, the tip end portion of the second trigger electrode is tapered so as to be closer to the reference line in a state of being away from the reference line. On the side End of the tip portion is formed so as to be nearer tapered baseline while away from the reference line, the end of the tip portion of the termination and the second trigger electrodes of the tip portion of the first trigger electrode , When viewed from a direction parallel to the reference line, it is located inside the cathode and the anode, and the start end of the tip portion of the first trigger electrode and the start end of the tip portion of the second trigger electrode are at the reference line When viewed from a parallel direction, it is located outside the cathode and anode .

In this flash lamp, the tip portion of the cathode and the tip portion of the anode face each other on the reference line, and the tip portion of the first trigger electrode is located on one side with respect to the reference plane including the reference line. The tip portion of the second trigger electrode is located on the other side. Further, the end of the tip portion of the first trigger electrode and the end of the tip portion of the second trigger electrode are separated from the reference line, and the tip portion of the first trigger electrode and the tip portion of the second trigger electrode are It is formed so as to taper as it gets closer to the reference line. As a result, arc discharge occurs from the terminal end of the tip of the cathode (the terminal and its vicinity) through the terminal end of the first trigger electrode and the terminal of the second trigger electrode. This is a stable path with a limited path to the end of the tip. Therefore, according to this flash lamp, the occurrence of fluctuations in arc discharge can be suppressed. Furthermore, the start end of the tip portion of the first trigger electrode and the start end of the tip portion of the second trigger electrode are located outside the cathode and the anode when viewed from a direction parallel to the reference line. According to this configuration, the arc discharge becomes more difficult to pass through the start end portion (start end portion and the vicinity thereof) of the tip portion of the first trigger electrode and the start end portion of the tip portion of the second trigger electrode. The occurrence of fluctuations can be more reliably suppressed.

  The cathode has a cathode discharge facing surface from which electrons are emitted at the tip portion of the cathode, and the anode has an anode discharge facing surface from which electrons are absorbed at the tip portion of the anode. The terminal end of the electrode and the terminal end of the second trigger electrode are preferably located outside the cathode discharge facing surface and the anode discharge facing surface when viewed from a direction parallel to the reference line. . According to this configuration, the arc discharge is more likely to pass through the end portion of the tip portion of the first trigger electrode and the end portion of the tip portion of the second trigger electrode, so that the occurrence of fluctuations in the arc discharge can be more reliably performed. Can be suppressed.

  According to the present invention, the occurrence of fluctuations in arc discharge can be suppressed.

It is a partially cutaway perspective view of the flash lamp of one embodiment of the present invention. It is sectional drawing of the flash lamp along the II-II line | wire of FIG. It is an enlarged view of the front-end | tip part of the cathode of FIG. It is a top view of the part containing the cathode of FIG. 1, an anode, and a trigger electrode. It is a top view of the part containing the cathode of the comparative example 1, an anode, and a trigger electrode. It is a top view of the part containing the cathode of the comparative example 2, an anode, and a trigger electrode. It is a top view of the part containing the cathode of the comparative example 3, an anode, and a trigger electrode.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 1, the flash lamp 1 includes a sealed container 2 in which xenon gas (discharge gas) is sealed. The sealed container 2 includes a circular plate-shaped stem 3 made of metal, a cylindrical cap 4 made of metal, and a circular plate-shaped light transmission window 5 made of glass. The light transmission window 5 closes an opening 4 a having a circular cross section provided at a position facing the inner surface 3 a of the stem 3 in the cap 4. The stem 3 is provided with a sealing tube 11 that is sealed after the sealed container 2 is filled with xenon gas.

  In the sealed container 2, a cathode 60 and an anode 70 for generating arc discharge, a trigger electrode (first trigger electrode) 80 and trigger electrode (second trigger electrode) 90 for generating preliminary discharge prior to arc discharge, In addition, a sparker electrode 10 for stably generating arc discharge is disposed. The cathode 60 and the anode 70 are fixed to the end of the lead pin 13 that penetrates the stem 3 through the insulating member 12. The trigger electrodes 80 and 90 are fixed to the end portion of the lead pin 14 that penetrates the stem 3 through the insulating member 12. The sparker electrode 10 is fixed to the end portion of the lead pin 15 that penetrates the stem 3 through the insulating member 12.

  As shown in FIG. 2, the cathode 60 includes a cylindrical main body portion 61 constituting a base end portion to which the end portion of the lead pin 13 is fixed, and a conical tip portion 62 that tapers away from the main body portion 61. have. The main body portion 61 and the tip portion 62 are made of tungsten, for example, and are integrally formed with the same straight line as a center line. Similarly, the anode 70 has a cylindrical main body portion 71 constituting a base end portion to which the end portion of the lead pin 13 is fixed, and a conical tip portion 72 that tapers away from the main body portion 71. . The main body portion 71 and the tip portion 72 are made of, for example, tungsten, and are integrally formed with the same straight line as a center line.

  The cathode 60 and the anode 70 are arranged such that the respective center lines (that is, connecting the apexes of the conical tip portions 62 and 72) substantially coincide with the reference line RL. The tip portion 62 of the cathode 60 and the tip portion 72 of the anode 70 are opposed to each other on the reference line RL (that is, facing each other). The reference line (predetermined reference line) RL is a straight line substantially parallel to the inner surface 3a of the stem 3 here.

  The trigger electrode 80 has a cylindrical needle-shaped main body portion 81 that forms a base end portion to which the end portion of the lead pin 14 is fixed, and a conical needle-shaped distal end portion 82 that tapers away from the main body portion 81. . The main body portion 81 and the tip portion 82 are made of, for example, molybdenum, and are integrally formed with the same straight line as a center line. Similarly, the trigger electrode 90 has a cylindrical needle-like main body portion 91 that forms a base end portion to which the end portion of the lead pin 14 is fixed, and a conical needle-like tip end portion 92 that tapers away from the main body portion 91. doing. The main body portion 91 and the tip portion 92 are made of, for example, molybdenum, and are integrally formed with the same straight line as a center line.

  The tip portion 82 of the trigger electrode 80 is located closer to the cathode 60 than the tip portion 92 of the trigger electrode 90 in a direction parallel to the reference line RL. The tip portion 82 of the trigger electrode 80 has a pointed shape that tapers on one side of the reference surface RS so that the end (that is, the tip) 82a of the tip portion 82 is away from the reference line RL and becomes closer to the reference line RL. It is formed to become. On the other hand, the tip end portion 92 of the trigger electrode 90 has a pointed shape that tapers on the other side of the reference plane RS as the end 92a of the tip end portion 92 is away from the reference line RL and becomes closer to the reference line RL. Is formed. Note that the reference plane (predetermined reference plane) RS is a plane including the reference line RL, and is a plane substantially perpendicular to the inner surface 3a of the stem 3 here. In addition, the trigger electrodes 80 and 90 are arranged here so that the respective center lines are substantially perpendicular to the reference plane RS and are located on the same plane including the reference line RL and substantially perpendicular to the reference plane RS. ing.

  As shown in FIG. 3, the start end (that is, the base end) 82b of the distal end portion 82 of the trigger electrode 80 and the start end 92b of the distal end portion 92 of the trigger electrode 90 are viewed from a direction parallel to the reference line RL. It is located outside the cathode 60 and the anode 70. That is, the start ends 82 b and 92 b are cylindrical shapes defined by the bottom surface of the tip portion 62 of the cathode 60, the bottom surface of the tip portion 72 of the anode 70, and the surface formed by the straight line that connects the outer peripheral lines of the bottom surfaces. Located outside the space.

  When viewed from a direction parallel to the reference line RL, the end 82a of the tip portion 82 of the trigger electrode 80 and the end 92a of the tip portion 92 of the trigger electrode 90 have the cathode discharge facing surface 63 and the anode 70 that the cathode 60 has. It is located outside the anode discharge facing surface 73. That is, the end points 82a and 92a are formed in a cylindrical shape defined by the cathode discharge facing surface 63, the anode discharge facing surface 73, and a surface formed by a straight bus that connects the outer peripheral lines of the both discharge facing surfaces 63 and 73. Located outside the space. The ends 82a and 92a are located inside the cathode 60 and the anode 70 when viewed from a direction parallel to the reference line RL (preferably, the end 62a of the cathode 60 and the end 72a of the anode 70 are separated from the reference line RL). It is located within a range up to 1/4 of the distance (distance between discharge electrodes).

  Here, the cathode discharge facing surface 63 is a surface from which electrons are emitted in the tip portion 62 of the cathode 60, and the anode discharge facing surface 73 is a surface in which electrons are absorbed in the tip portion 72 of the anode 70. More specifically, as shown in FIGS. 4A and 4B, the cathode discharge facing surface 63 has tangents L and L ′ along the shape of the tip portion 62 at the tip portion 62 of the cathode 60. Corresponds to a portion (shaded portion in FIG. 4) closer to the terminal end 62a than the contacts a and a ′. Similarly, the anode discharge facing surface 73 is a portion of the end portion 72 of the anode 70 that is closer to the end 72a than the contact points a and a ′ of the tangent lines L and L ′ along the shape of the end portion 72 (shaded line in FIG. 4). Part).

  However, the cathode discharge facing surface 63 and the anode discharge facing surface 73 are in a range from the electrode center to 150 μm because of the current density of the discharge. Therefore, as shown in FIG. 4C, when the contacts a and a ′ are separated by 150 μm or more from the terminal 62a that is the center of the electrode, the cathode discharge facing surface 63 is a portion within 150 μm from the terminal 62a. become. Similarly, when the contacts a and a ′ are separated by 150 μm or more from the terminal end 72a which is the center of the electrode, the anode discharge facing surface 73 is a portion within 150 μm from the terminal end 72a.

  The operation of the flash lamp 1 configured as described above will be described. First, a predetermined voltage is applied between the cathode 60 and the anode 70 by the main power supply unit electrically connected to the lead pin 13. In this state, a pulse voltage is applied to the sparker electrode 10 and the trigger electrodes 80 and 90 by the trigger power supply unit electrically connected to the lead pins 13 and 14.

  By applying such a voltage, the following phenomenon occurs in a pulsed manner. First, preliminary discharge occurs at the sparker electrode 10 and ultraviolet rays are emitted. Due to this ultraviolet radiation, photoelectrons are emitted from the cathode 60 and the trigger electrodes 80 and 90, and the xenon gas in the sealed container 2 is ionized. When the preliminary discharge by the sparker electrode 10 is completed, as shown in FIG. 3, the end portion (the end portion 82a and the vicinity thereof) of the tip portion 62 of the trigger electrode 80 from the end portion (the end portion 62a and the vicinity thereof) of the cathode 60. And a path R that reaches the end portion of the tip portion 72 of the anode 70 (the end portion 72a and the vicinity thereof) via the end portion of the tip portion 92 of the trigger electrode 90 (the end portion 92a and the vicinity thereof). Discharge occurs, and then arc discharge occurs along the path R. Thereby, the flash lamp 1 emits white light in pulses.

  As described above, in the flash lamp 1, the tip portion 62 of the cathode 60 and the tip portion 72 of the anode 70 face each other on the reference line RL, and the trigger electrode is located with respect to the reference plane RS including the reference line RL. The tip portion 82 of 80 is located on one side, and the tip portion 92 of the trigger electrode 90 is located on the other side. Further, the end 82a of the tip portion 82 of the trigger electrode 80 and the end 92a of the tip portion 92 of the trigger electrode 90 are separated from the reference line RL, and the tip portions 82 and 92 taper as they approach the reference line RL. Is formed. As a result, the arc discharge is terminated from the end portion of the tip portion 62 of the cathode 60 to the end portion of the tip portion 82 of the trigger electrode 80 and the end portion of the tip portion 92 of the trigger electrode 90. This occurs stably in the path R formed in a limited region reaching the part. Therefore, according to the flash lamp 1, the occurrence of fluctuations in arc discharge can be suppressed. Therefore, when the light emitted from the flash lamp 1 is cut out at a predetermined position with respect to the flash lamp 1 (here, the position corresponding to the central portion of the light transmission window 5), the light is cut out at the aperture. The light output will be stabilized.

  Further, the start end 82b of the tip end portion 82 of the trigger electrode 80 and the start end 92b of the tip end portion 92 of the trigger electrode 90 are located outside the cathode 60 and the anode 70 when viewed from a direction parallel to the reference line RL. . With this configuration, the start end portion (start end 82b and the vicinity thereof) of the trigger electrode 80, which is the edge of each trigger electrode 80, 90, and the start end portion (start end 92b and its end portion) of the tip end portion 92 of the trigger electrode 90 are provided. It becomes difficult for arc discharge to pass through the vicinity). Therefore, even with this configuration, the occurrence of fluctuations in arc discharge is suppressed.

  Further, the terminal end 82a of the tip portion 82 of the trigger electrode 80 and the terminal end 92a of the tip portion 92 of the trigger electrode 90 are viewed from a direction parallel to the reference line RL, and the cathode discharge facing surface 63 and the anode 70 included in the cathode 60. Is located outside the anode discharge facing surface 73. With this configuration, the end portions 82 a and 92 a of the end portion 82 of the trigger electrode 80 and the end portion 92 of the trigger electrode 90 are compared to the case where the end portions 82 a and 92 a are positioned inside the cathode discharge facing surface 63 and the anode discharge facing surface 73. Arc discharge easily passes through the end portion. Therefore, even with this configuration, the occurrence of fluctuations in arc discharge is suppressed.

  Next, an example of each dimension in the flash lamp 1 will be described. First, the diameter (discharge electrode diameter) of the main body portions 61 and 71 of the discharge electrode (that is, the cathode 60 and the anode 70) is 2.4 mm, and the distance between the terminal end 62a of the cathode 60 and the terminal end 72a of the anode 70 (discharge electrode). The distance) is 1.5 mm. That is, the end 82a of the trigger electrode 80 and the end 92a of the trigger electrode 90 are arranged within the range of the distance between the discharge electrodes smaller than the discharge electrode diameter. The diameters of the cathode discharge facing surface 63 and the anode discharge facing surface 73 are 200 μm.

  The diameters (trigger electrode diameters) of the main body portions 81 and 91 of the trigger electrodes 80 and 90 are 0.4 mm, and in the direction parallel to the reference line RL, the end 82a of the trigger electrode 80 and the end 92a of the trigger electrode 90 are (Distance between trigger electrodes) is 0.4 mm to 0.7 mm. In this way, by making the distance between the trigger electrodes larger than the trigger electrode diameter, a path (a part of the path R) from the end portion of the tip portion 82 of the trigger electrode 80 to the end portion of the tip portion 92 of the trigger electrode 90 It is possible to prevent the arc discharge from fluctuating. In the direction parallel to the reference line RL, the distance between the end 62a of the cathode 60 and the end 82a of the trigger electrode 80 is 0.3 mm to 0.5 mm.

  Furthermore, the distance between the reference line RL and the terminal ends 82a and 92a of the trigger electrodes 80 and 90 is 0.2 mm to 0.3 mm. In this way, by making the distance between the reference line RL and the end points 82a and 92a of the trigger electrodes 80 and 90 larger than ½ of the trigger electrode diameter, the trigger electrode can be moved from the end portion of the tip end portion 82 of the trigger electrode 80 to the trigger electrode. It is possible to suppress the arc discharge from fluctuating other than the route (a part of the route R) reaching the end portion of the tip portion 92 of the 90.

  Next, a flash lamp of a comparative example will be described. FIG. 5 is a plan view of a portion including a cathode and an anode and a trigger electrode of Comparative Example 1. As shown in FIG. 5, the flash lamp of Comparative Example 1 is the above-described flash lamp in that the tip portion 82 of the trigger electrode 80 and the tip portion 92 of the trigger electrode 90 cross the reference line RL and the reference plane RS. 1 and different. Due to this difference, the distance between the end 62a of the cathode 60 and the tip portion 82 of the trigger electrode 80, the distance between the tip portion 82 of the trigger electrode 80 and the tip portion 92 of the trigger electrode 90, and the tip portion 92 of the trigger electrode 90 The distance from the terminal end 72 a of the anode 70 is smaller than that of the flash lamp 1. Therefore, in the flash lamp of Comparative Example 1, the path R in which arc discharge can occur is wider than that of the flash lamp 1.

  Further, in the flash lamp of Comparative Example 1, when the start end 82b of the tip end portion 82 of the trigger electrode 80 and the start end 92b of the tip end portion 92 of the trigger electrode 90 are viewed from a direction parallel to the reference line RL, the cathode 60 and It is located inside the anode 70. Therefore, in the flash lamp of Comparative Example 1, the tip ends of the trigger electrodes 80 that are the edges of the trigger electrodes 80 and 90 are compared to the flash lamp 1 in which the start ends 82 b and 92 b are located outside the cathode 60 and the anode 70. The arc discharge easily passes through the start end of the portion 82 and the start end of the tip end portion 92 of the trigger electrode 90.

  6 is a plan view of a portion including a cathode and an anode and a trigger electrode of Comparative Example 2. FIG. As shown in FIG. 6, the flash lamp of Comparative Example 2 is the above-described flash in that the tip portion 82 of the trigger electrode 80 and the tip portion 92 of the trigger electrode 90 are located on one side of the reference plane RS. It is different from the lamp 1. Due to this difference, the distance between the tip portion 82 of the trigger electrode 80 and the tip portion 92 of the trigger electrode 90 becomes smaller than that of the flash lamp 1. Therefore, in the flash lamp of Comparative Example 2, the path from the end portion of the tip portion 82 of the trigger electrode 80 to the end portion of the tip portion 92 of the trigger electrode 90 among the paths R in which arc discharge can occur is in the flash lamp 1. It becomes wider than that.

  FIG. 7 is a plan view of a portion including a cathode and an anode and a trigger electrode of Comparative Example 3. As shown in FIG. 7, in the flash lamp of Comparative Example 3, the tip portions 82 and 92 that are tapered do not have the trigger electrodes 80 and 90, and the entire trigger electrodes 80 and 90 are formed in a cylindrical needle shape. This is different from the flash lamp 1 described above. Due to this difference, the end points 80a and 90a of the trigger electrodes 80 and 90 become surfaces. Therefore, in the flash lamp of Comparative Example 3, the path R in which arc discharge can occur is wider than that of the flash lamp 1.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, if the trigger electrode 80 and the trigger electrode 90 form a region including the center in the direction parallel to the reference line RL in the path R in which arc discharge can occur, the cathode 60 and the trigger electrode 80 Further trigger electrodes may be provided between the anode 70 and the trigger electrode 90. The trigger electrodes 80 and 90 may be arranged on different sides with respect to a plane that is substantially parallel to the reference line RL and substantially perpendicular to the reference plane RS, for example.

  DESCRIPTION OF SYMBOLS 1 ... Flash lamp, 2 ... Sealed container, 60 ... Cathode, 62 ... Tip part, 63 ... Cathode discharge opposing surface, 70 ... Anode, 72 ... Tip part, 73 ... Anode discharge opposing surface, 80 ... Trigger electrode (1st Trigger electrode), 82 ... tip portion, 82a ... end, 82b ... start end, 90 ... trigger electrode (second trigger electrode), 92 ... tip portion, 92a ... end, 92b ... start end, RL ... reference line, RS ... reference surface.

Claims (2)

A sealed container filled with discharge gas;
A cathode and an anode disposed within the sealed vessel for generating arc discharge;
A first trigger electrode and a second trigger electrode which are disposed in the sealed container and generate a preliminary discharge prior to the arc discharge;
The tip portion of the cathode and the tip portion of the anode are opposed on a predetermined reference line,
The tip portion of the first trigger electrode is located on the cathode side with respect to the tip portion of the second trigger electrode in a direction parallel to the reference line,
The tip portion of the first trigger electrode is tapered on one side of a predetermined reference plane including the reference line as the end of the tip portion is away from the reference line and approaches the reference line. Is formed as
It said distal portion of said second trigger electrode, the other side of the reference plane is formed as the end of the tip portion becomes nearer tapering to the reference line in a state apart from the reference line ,
The end of the tip portion of the first trigger electrode and the end of the tip portion of the second trigger electrode are located inside the cathode and the anode when viewed from a direction parallel to the reference line. The cathode and the anode are positioned when viewed from a direction parallel to the reference line, and the beginning of the tip of the first trigger electrode and the beginning of the tip of the second trigger electrode are viewed from a direction parallel to the reference line. A flash lamp characterized by being located on the outside of the lamp. The cathode has a cathode discharge facing surface from which electrons are emitted at the tip portion of the cathode, and the anode has an anode discharge facing surface from which electrons are absorbed at the tip portion of the anode;
The end of the tip portion of the first trigger electrode and the end of the tip portion of the second trigger electrode are the cathode discharge facing surface and the anode when viewed from a direction parallel to the reference line. claim 1 Symbol placement of the flash lamp and being located outside the discharge counter surface.

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