JP2001093467A - Flash discharge tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flash discharge tube in which a discharge route between a pair of main electrodes which are arranged at an open end of a glass bulb whose one end is sealed is extended, and to prevent cracks from being generated in the glass bulb even when the flash discharge tube is lighted many times. SOLUTION: In a flash discharge tube relating to the invention, an inside of a glass bulb is divided at least into two rooms owing to a discharge route extending material, a trigger lead wire for supplying trigger voltage is attached to a place in the range of a trigger electrode on an outer surface of the glass bulb relating to one divided room in the glass bulb where a second main electrode is arranged so as to be connected to a low potential side of a luminous condenser. The flash discharge tube relating to the invention can prevent cracks from generating in the glass bulb even when the flash discharge tube is lighted many times for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flash discharge tube which is incorporated in, for example, a camera for photographing or an electronic flash device and is useful as an artificial light source for photographing, and in particular, an opening of a glass bulb having one end sealed. The present invention relates to a flash discharge tube formed by extending a discharge path between a pair of main electrodes disposed at the ends.

[0002]

2. Description of the Related Art In recent years, flash discharge tubes which have been useful as artificial light sources for photography have been required to be further miniaturized in recent years with the downsizing of photographic cameras and electronic flash devices in which they are mounted. ing. As the shape, a straight tube type, a U-shaped shape, a spiral shape, and the like have been used for a long time, but a flash discharge tube which has recently been proposed in Japanese Utility Model Publication No. 4-36051 has been proposed. .

In this device, the inside of an envelope of a glass bulb having an open end is divided into a plurality of spaces connected in series, and a pair of main electrodes is hermetically sealed to hermetically seal the open end. The brightness and the luminous efficiency are increased by extending the discharge path between the two electrodes with the divided body.

[0004]

By the way, the bulb of the discharge tube is required to have impact resistance and heat resistance of ions and electrons at the time of discharge. It is necessary to use a material that can withstand long-term use without adversely affecting the light-emitting characteristics and is suitable for mass production. Hard glass is generally used as a material satisfying such conditions. Many.

However, even if such a glass material is used, the impact on the glass bulb at the time of discharge is extremely large. In particular, while a large number of lights are emitted over a long period of time, minute cracks frequently occur in the glass bulb, and the characteristics are deteriorated. In particular, adverse effects such as a decrease in light emission amount and an increase in discharge voltage occur. The cracks occur more frequently as the size of the discharge tube is reduced, and the cracks occur more remarkably in the above-described small discharge tube and have a large influence on the characteristics.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to eliminate such a problem, and provides a flash discharge tube which emits a large amount of light, has almost no cracks even when used for a long time, and has stable characteristics. It is.

[0007]

In order to achieve the object of the present invention, a first main electrode connected to a high-potential side of a light-emitting capacitor as a light-emitting energy source and a low-potential side of the light-emitting capacitor are connected to a first main electrode. A base portion holding a second main electrode to be connected and hermetically sealed to the other end of the glass bulb;
The inside of the glass bulb attached to the base portion is divided into at least two chambers, a discharge path between the first and second main electrodes is formed, and the discharge path is extended by a discharge path extending member for extending the discharge path. A trigger lead wire is provided which is fixed and electrically connected to a position within the range of the trigger electrode on the outer surface of the glass bulb opposite to the division chamber of the glass bulb where the main electrode is disposed.

[0008] By connecting a trigger lead wire within a trigger electrode area on the outer surface of the glass bulb opposite to the division chamber of the glass bulb provided with the second main electrode connected to the low potential side of the light emitting capacitor, It is possible to provide a flash discharge tube in which the generation of cracks in the glass bulb is suppressed as much as possible even when a large number of lights are emitted for a long time.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a first main electrode connected to a high potential side of a light emitting capacitor and a second main electrode connected to a low potential side of the light emitting capacitor. A base portion which holds the main electrode and is hermetically sealed to the other end of the glass bulb, and divides the inside of the glass bulb into at least two chambers and forms a discharge path between the first and second main electrodes. A discharge path extending member that extends the discharge path, a trigger lead wire that is electrically connected to a trigger electrode provided on the outer surface of the glass bulb and that supplies a high trigger output voltage output from a trigger circuit to the trigger electrode, The trigger lead wire is made of a rare gas sealed in a glass bulb, and the trigger lead wire is divided by the discharge path extending member into a glass opposed to a divided chamber in which the second main electrode is disposed. Is obtained by electric connection to the trigger electrode scope of Lube outer surface, it is possible to suppress the occurrence of cracks in the glass bulb by electrically connecting the trigger lead wire fixed to the position within the trigger electrode range.

According to a second aspect of the present invention, a trigger lead wire is provided at one point within the trigger electrode range on the outer surface of the glass bulb opposite to the division chamber in the glass bulb provided with the second main electrode. The occurrence of cracks can be suppressed only by electrically connecting the trigger lead wires in a point-like manner within the trigger electrode range.

According to a third aspect of the present invention, the glass bulb is provided at a position within the range of the trigger electrode on the outer surface of the glass bulb opposite to the division chamber in the glass bulb provided with the second main electrode. Since the trigger lead wire is attached to be elongated in the circumferential direction linearly, the occurrence of cracks in the glass bulb can be suppressed.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 is a perspective view showing a flash discharge tube according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a glass bulb made of, for example, borosilicate glass material and having one end sealed and the other end opened. Reference numeral 2 denotes a base portion made of an insulating material such as hard glass or ceramic and sealed at the open end of the glass bulb 1. Reference numeral 3 denotes a discharge path extending member which is welded to the base portion or molded integrally with the base portion and is attached to the base portion to divide the inside of the glass bulb 1 into two chambers. Used. Reference numeral 4 denotes a first main electrode electrically connected to the high-potential side of the light-emitting capacitor. For example, a known metal rod made of tungsten alone is used. Reference numeral 5 denotes a second main electrode electrically connected to the low-potential side of the light-emitting capacitor. For example, a well-known structure is used. The main electrode includes a tungsten metal rod 7 and a sintered metal body 6 obtained by sintering a fine powder of a high melting point tungsten alone or a mixture of tungsten and hafnium. The sintered metal body 6 is attached to a metal rod 7 by caulking, welding, or the like.
The second main electrodes 4 and 5 are hermetically mounted in the mounting holes of the base portion 2 through the mounting holes (not shown) of the base portion 2. Reference numeral 8 denotes a known trigger lead wire, and 9 denotes a trigger lead wire 8 which is firmly fixed to a trigger electrode (not shown) which is a transparent conductive film formed on the outer surface of the glass bulb 1 with a conductive adhesive and is electrically connected. This is a fixing portion to be connected. The trigger electrode made of the transparent conductive film has a trigger voltage of the first main electrode 4 or the second main electrode 4 when a high-frequency trigger voltage which is an output voltage of a known trigger circuit described later is supplied.
So as not to be applied to the metal rod 6 of the main electrode 5 of
It is applied above the position which is far away from the first and second main electrodes and over the entire outer surface of the glass bulb. In addition,
A predetermined amount of a rare gas such as xenon is sealed in the glass bulb 1.

FIG. 2 is a cross-sectional view taken along line AA of FIG.
A high-frequency trigger output voltage of a known trigger circuit (not shown) is supplied through a trigger lead wire 8 to excite the flash discharge tube, and at the same time, a first light emitting circuit (not shown) is connected to the first and second main electrodes 4 and 5. When the charging energy stored in the large-capacity light-emitting capacitor is supplied, the charge energy of the light-emitting capacitor is instantaneously discharged between the main electrodes 4 and 5 in the direction of the arrow shown in the figure, whereby the flash discharge tube emits light. If the discharge path extending member 3 is not provided,
Since the discharge path between the main electrodes 4 and 5 is extremely short, a sufficient amount of light cannot be generated. However, since the discharge path can be lengthened by the discharge path extending member 3, the amount of light can be increased.

FIG. 3 is a perspective view of a flash discharge tube according to a second embodiment of the present invention.
The interior of the glass bulb 1 is divided into four chambers at 1, 12, 13, and 14, and when the charging energy of the light-emitting capacitor is supplied, the space between the main electrode 4 and the main electrode 5 is discharged in the direction of the arrow shown in the drawing. Each of the four chambers is connected in series to form a main electrode 4 and a main electrode 5.
FIG. 4 is a cross-sectional view taken along a line BB of FIG. By further extending the discharge interval as in this embodiment, even if the same amount of rare gas as the rare gas sealed in the discharge tube of the previous embodiment is used, a larger amount of light can be obtained than in the previous embodiment.
The trigger lead wire 8 according to the present embodiment is divided by the discharge path extending member and opposed to the divided chamber in which the second main electrode 5 is provided, and at a position within the range of Z of the trigger electrode on the outer surface of the glass bulb. It is attached by the fixing part 9.

The first and second embodiments of the flash tube according to the present invention have been described above. Next, cracks in the glass bulb occur depending on the mounting position of the trigger lead wire of the flash tube based on those embodiments. The suppression will be described based on the results of actually manufacturing and testing five samples A to F described below. Sample (A) A flash discharge tube based on the embodiment of FIG. 1 of the present invention, in which a trigger lead wire 8 is attached at one point within a range of X in the drawing where the trigger electrode shown in FIG. 2 is provided. Sample (B) A flash discharge tube based on the embodiment of FIG. 3 of the present invention, in which a trigger lead wire 8 is attached at one point within the range of Z shown in FIG. 4 where the trigger electrode shown in FIG. 4 is provided. Sample (C) A flash discharge tube having the same configuration as that of the embodiment of FIG. 1 of the present invention, and having a trigger lead wire 8 attached to a point within a range indicated by Y in FIG. 2 where a trigger electrode is provided. . Sample (D) A flash discharge tube having the same configuration as that of the embodiment of FIG. 3 of the present invention, having a trigger lead wire 8 attached to a point within a range W shown in FIG. 4 where a trigger electrode shown in FIG. 4 is provided. . Sample (E) A flash discharge tube having the same configuration as that of the embodiment of FIG. 1 of the present invention. As shown in FIG. 6, which is a cross-sectional view taken along line CC of FIG. The glass bulb 1 is wound around and fixed to the entire outer surface of the glass bulb 1 as shown at 15, and the ends are fixed with an adhesive or the like. Sample (F) A flash discharge tube having the same configuration as that of the embodiment of FIG. 3 of the present invention. As shown in FIG. 5, a trigger lead wire is provided around the entire outer surface of the glass bulb 1 on which a trigger electrode is provided, as shown in FIG. And fixed by winding, and the ends are fixed with an adhesive or the like.

The materials of the glass bulb, the base, the discharge path extending member, and the first and second main electrodes are the same for all the samples, and the dimensions of the glass bulb and the base are all the same. Samples of the same dimensions were used, and the amount of rare gas sealed in the glass bulb was the same for all samples. Incidentally, the glass bulb is a hard glass having an outer diameter of 5.0 mmφ, an inner diameter of 4.0 mmφ, and a total length of 6.5 mm, and the filling gas in the glass bulb is 1100 Torr of Xe gas. Then, each sample was made to emit light under the same light-emitting conditions using the light-emitting circuit diagram shown in FIG. 7 to confirm the occurrence of cracks in the glass bulb. The light emitting circuit diagram of FIG.
Is a light emitting capacitor having a capacity of 120 μF for supplying luminous energy to the flash tube P, which is a sample, and charged to 330 V during light emission; and 17, a high-frequency trigger output to a trigger electrode of the flash tube P via a trigger lead wire. This is a trigger circuit for supplying a voltage. The light emission conditions of the flash tubes of Samples A to F are as follows.
The light emission interval for causing the flash discharge tube to emit light at a charging voltage of V is 30
Each sample was emitted 1000 times in seconds, and the following results were obtained for the occurrence of cracks. The number of cracks in the table is an average value of five samples.

[0018]

[Table 1]

As is evident from the above results, the present invention in which the trigger lead wire is mounted within the range of the trigger electrode on the outer surface of the glass bulb facing the division chamber in the glass bulb provided with the second main electrode. In the flash discharge tube, only one crack is generated on average even if the light is emitted 1000 times, and a position outside the range of the trigger electrode relative to the divided chamber of the glass bulb provided with the second main electrode is provided. The occurrence of cracks was extremely small, and very good results were obtained as compared with the case where the trigger lead wire was attached to the glass bulb and the case where the trigger lead wire was attached to the entire circumference of the glass bulb.

[0020]

As described above, the flash discharge tube of the present invention is connected to the low potential side of the light-emitting capacitor and is provided in the divided chamber of the glass bulb divided by the discharge path extending member. Since the trigger lead wire was attached at a position within the range of the trigger electrode on the outer surface of the glass bulb relative to the divided chamber of the main electrode, even if the number was repeatedly increased, cracks hardly occurred in the glass bulb, It is possible to provide a long-life flash discharge tube which is extremely stable against the occurrence of cracks and as a result has stable light emission characteristics such as discharge voltage and light emission amount.

In this embodiment, the trigger lead wire is fixed at one point in the range of the trigger electrode. However, the trigger electrode of the glass bulb facing the divided chamber of the glass bulb where the second main electrode is provided. If the position is within the range,
The glass bulb may be attached linearly and horizontally in the circumferential direction with an adhesive or the like.

[Brief description of the drawings]

FIG. 1 is a perspective view of a flash discharge tube according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the flash discharge tube of the embodiment of FIG.

FIG. 3 is a perspective view of a flash tube according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of the flash tube of the embodiment of FIG. 3;

FIG. 5 is a perspective view of a flash discharge tube showing another mounting state of the trigger lead wire.

FIG. 6 is a cross-sectional view of the flash discharge tube according to FIG. 5;

FIG. 7 is a schematic diagram of an electric circuit for causing a flash discharge tube to emit light.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass bulb 2 Base part 3 Discharge path extending member 4 1st main electrode 5 2nd main electrode 6 Sintered metal body 7 Metal rod 8 Trigger lead wire 9 Fixing part 10 Base part 11, 12, 13, 14 Discharge path Extension member 16 Light emitting capacitor 17 Trigger circuit

Claims (3)

[Claims] 1. A glass bulb having one end sealed and the other end open, a first main electrode connected to a high potential side of a light emitting capacitor, and a first main electrode connected to a low potential side of the light emitting capacitor. A base portion holding a second main electrode and hermetically sealed to the other end of the glass bulb; and dividing the interior of the glass bulb into at least two chambers attached to the base portion, wherein the first and second chambers are divided. A discharge path extending member for forming a discharge path between the main electrodes to extend the discharge path, and a trigger output voltage fixedly attached to a trigger electrode provided on the outer surface of the glass bulb and output from a trigger circuit. A trigger lead wire to be supplied to a trigger electrode and a rare gas sealed in the glass bulb, wherein the trigger lead wire is formed by dividing the second main electrode provided in any of the division chambers. Flash discharge tube formed by electrically connected in the trigger electrode scope opposed glass bulb outer surface. 2. The flash discharge tube according to claim 1, wherein the trigger lead wire is attached to a point within a range of the trigger electrode on the outer surface of the glass bulb opposite to the divided chamber provided with the second main electrode. 3. The trigger lead wire is linearly and horizontally attached in the circumferential direction of the glass bulb within the range of the trigger electrode on the outer surface of the glass bulb facing the division chamber provided with the second main electrode. The flash discharge tube according to claim 1, comprising: