JP6634597B2 - Tempered glass tube for discharge tube, method for manufacturing the same, flash discharge tube using the tempered glass tube, and light irradiation device provided with the flash discharge tube - Google Patents

Description

  The present invention relates to a translucent glass tube used as an envelope of a discharge tube, and in particular, a tempered glass tube for a discharge tube having greatly improved discharge resistance, a method of manufacturing the same, and a flash discharge tube using the tempered glass tube. And a light irradiation device provided with the flash discharge tube.

  2. Description of the Related Art Conventionally, a flash discharge tube has been used as an artificial light source for illuminating a subject in photographing, for example, a strobe device, an aircraft obstacle light installed at a high place such as a bridge or a high-rise building, or an emergency vehicle such as an aircraft or a police car. It is useful as a light source of a light irradiation device such as a warning light mounted.

  Further, in the case of the above-mentioned strobe device, the digitalization of the camera for taking the above-mentioned photograph has been advanced, and therefore, the number of shots has increased drastically. It is well known that there is a strong need. It should be noted that such a demand for a significant improvement in the durability against light emission life is no exception in the other light irradiation devices described above.

  By the way, in order to improve the light emission lifetime durability characteristics of a light irradiation device such as the above-mentioned strobe device, it is essential to improve the durability characteristics of a flash discharge tube which is a light source. Needless to say, it is necessary to reinforce this.

  Here, looking at the configuration of the flash discharge tube, when the xenon gas is sealed at both ends of the glass tube constituting the translucent envelope of the flash discharge tube, the electrode pin and this electrode It is well known that a pair of discharge electrodes composed of a cathode formed mainly of a sintered body attached to a pin and an anode formed mainly of an electrode pin itself are hermetically sealed to each other. There has been a strong demand for reinforcement of constituent materials including glass tubes. As the material of the electrode pins, since the light emission of the flash discharge tube is an arc discharge phenomenon and a large current flows instantaneously, it is necessary to select a material that can withstand this large current. Generally, tungsten, which is a high melting point metal which is relatively easy to process into an electrode pin state, is generally used.

On the other hand, as a strengthening means of a glass tube which is a conventional envelope, a well-known tungsten sealing glass conventionally used as a glass tube for an envelope, that is, the coefficient of thermal expansion is approximated to that of the foregoing tungsten, and The so-called borosilicate glass tube designed to contain a suitable amount of alkali metal oxides such as sodium oxide and potassium oxide, which are alkali metal oxides, to lower the softening point. Means for forming a transparent insulating film of silicon or the like are well-known, and by such means, the generation of impurity gas due to ion collision at the time of electric discharge is prevented to improve durability and start-up characteristics, and further prevent blackening. There has been proposed a flash discharge tube having improved resistance to discharge operation (discharge resistance). (Patent Document 1)
Another example of improving discharge resistance in a discharge tube using silicon dioxide is to form a coating of 0.05 μm to 0.11 μm silicon dioxide on the inner surface of a glass bulb constituting an envelope of the discharge tube. Means for improving the light emission life durability characteristics of the flash discharge tube are also known. (Patent Document 2)

JP-A-62-206761 Japanese Patent No. 3977259

  As described above, Patent Documents 1 and 2 disclose a part (inner wall) of a borosilicate glass tube by forming a silicon dioxide film on a borosilicate glass tube which is a glass tube for a discharge tube, both of which constitute an envelope. The discharge resistance of the borosilicate glass tube, that is, only the glass tube for the discharge tube constituting the envelope of the flash discharge tube, which is the so-called thermal shock such as ion collision against the inner wall of the glass tube at the time of arc discharge and the thermal expansion of the sealed gas Durability characteristics (heat resistance characteristics, thermal shock resistance characteristics) against the phenomenon that has occurred can be improved and strengthened as compared with the case where the silicon dioxide film is not formed.

  However, compared to the case where quartz glass tubes with low thermal expansion coefficient, high thermal shock resistance and high mechanical strength, which have been widely recognized in the glass field as measures to strengthen glass tubes for discharge tubes, are used as glass for discharge tubes. Then, aside from the cost aspect, it was inevitable that the level of enhancement of the discharge resistance was still insufficient, and improvement was demanded.

  For example, when comparing the number of times of light emission life to which the thermal shock resistance greatly contributes, the number of times when a silicon dioxide film is formed on a borosilicate glass tube is twice as large as that when only a borosilicate glass tube is used. Although it can be increased to an extremely large number, the number of times is about 1/10 compared to a quartz glass tube, which is overwhelmingly small. In other words, when a quartz glass tube is used, the internal electrode is deteriorated earlier than the quartz glass tube due to thermal shock at the time of discharge, thereby limiting the number of times of emission life. When a silicon film is formed, the deterioration of the borosilicate glass tube and the silicon dioxide film itself, in addition to the deterioration of the internal electrode, also becomes an element limiting the number of times of light emission life, and as a result, the light emission is overwhelmingly smaller than that of a quartz glass tube. Only the number of lifetimes could be obtained.

  In order to further improve and enhance the discharge resistance of the borosilicate glass tube, it is conceivable to increase the thickness of the silicon dioxide film to increase the quartized region. As described above, in order to lower the softening point, an appropriate amount of an alkali oxide such as sodium oxide which is an alkali metal oxide is contained, while the alkali metal oxide has a property of cutting the crystal lattice of glass. It is also known as a substance, and it has been confirmed by the inventors of the present application that the thicker the silicon dioxide film, the higher the frequency of occurrence of a crack (crack) in the formed film, and the more the cracks occur. Since quartification cannot be achieved, the durability performance depends on the borosilicate glass tube, and in addition, some of the coating on the crack generating part generates heat during discharge. The glass tube deteriorates due to the melting and the presence of foreign matter in the tube, so it is not possible to obtain the expected improvement and strengthening of the discharge resistance, as well as to reduce the specific light amount due to the change in the light transmission state of the crack generation part. It has been confirmed that it would be caused.

  The present invention has been made in view of the above problems, and realizes a significant improvement in discharge resistance to a borosilicate glass tube formed with a silicon dioxide film, that is, a high heat resistance property, as well as an improvement in high heat shock resistance. The tempered glass tube for a discharge tube using a silicon dioxide film that can be made closer to the discharge resistance of a quartz glass tube in consideration of the discharge resistance of the glass tube, a method for manufacturing the same, a flash discharge tube using the tempered glass tube, and It is an object to provide a light irradiation device provided with a flash discharge tube.

  In detail, the present invention has an object to form a denser and stronger silicon dioxide film with less occurrence of cracks, and to solve such an issue as a base material of a discharge tube glass tube which has conventionally been a borosilicate glass tube. By adopting a glass tube which hardly contains an alkali metal oxide having a property of cutting the crystal lattice of glass, and has a property of containing an alumina component and having a property of forming a crystal lattice serving as a glass skeleton together with silicon dioxide. Is the solution.

  More specifically, it has a property of containing an aluminosilicate as a main component, containing almost no alkali metal oxide, containing an alumina component and forming a crystal lattice serving as a glass skeleton together with silicon dioxide, and further having a softening point of HO. The object is solved by adopting an aluminosilicate glass tube higher than a silicate glass tube as a base material of a glass tube for a discharge tube.

  The tempered glass tube for a discharge tube according to the present invention contains almost no alkali metal oxide having a property of cutting the crystal lattice of glass, and contains an alumina component and can form a crystal lattice that forms a glass skeleton together with silicon dioxide. A glass tube provided with a base material, and a silicon dioxide film is coated on the inner wall of the base material glass tube, and a lattice forming region portion where silicon dioxide is diffused into the inner wall of the base material glass tube to form the crystal lattice. Is formed.

  According to such a configuration, the silicon dioxide film is diffused into the inner wall of the base glass tube, with almost no cutting of the crystal lattice of the glass by the alkali metal oxide on the inner wall of the base glass tube. Since the silicon dioxide film is formed to include a lattice forming region portion, the silicon dioxide film thus formed is different from a silicon dioxide film formed on a borosilicate glass tube containing an alkali metal oxide in that a crystal lattice is formed in a partial region. The formed denser and stronger film is obtained, and as a result, a tempered glass tube for a discharge tube having a denser and stronger silicon dioxide film formed thereon can be obtained. Further, since the silicon dioxide film is formed including the lattice-forming region, even if the film thickness is increased, the film becomes a dense film with less occurrence of cracks. It is possible to obtain a tempered glass tube for a discharge tube in which a suitable silicon dioxide film can be formed.

  In the present invention as set forth in claim 1, the base glass tube contains aluminosilicate as a main component, hardly contains an alkali metal oxide, contains an alumina component, and forms a crystal lattice which serves as a glass skeleton together with silicon dioxide. Aluminosilicate glass tube having a softening point higher than that of a borosilicate glass tube.

  According to this configuration, the silicon dioxide film is formed on the inner wall of the aluminosilicate glass tube as the base material, including the lattice-forming region formed by diffusion of silicon dioxide inside the inner wall of the aluminosilicate glass tube. The formed silicon dioxide film becomes a dense and strong film having a crystal lattice formed in a partial region, and as a result, a tempered glass tube for a discharge tube in which a denser and stronger silicon dioxide film can be formed can be obtained. Will be.

  In the present invention described in claims 1 and 2, the silicon dioxide film has a thickness of 50 nm to 400 nm.

  According to this configuration, the formed silicon dioxide film is a dense and strong film having a crystal lattice formed in a partial region, unlike the silicon dioxide film formed on a borosilicate glass tube containing an alkali metal oxide. At the same time, by setting the film thickness to 130 nm or more, a thicker, denser and stronger film with less occurrence of cracks can be obtained.

  The method for producing a tempered glass tube for a discharge tube according to the present invention contains, at least, almost no alkali metal oxide having a property of cutting the crystal lattice of glass, and contains an alumina component to form a glass skeleton together with silicon dioxide. An application step of applying a silanol solution that becomes a silicon dioxide film by firing to form an silanol coating film on an inner wall of a base glass tube having a property capable of forming a crystal lattice, and a silanol applied to the inner wall. A drying regulation step of drying the coating film and regulating the formation area of the silanol coating film to a desired area, and the base glass tube on which the silanol coating film is formed at a temperature equal to or higher than the annealing point of the base glass tube Is calcined, and on the inner wall of the base material glass tube, silicon dioxide is diffused into the base material glass tube and between the alumina component contained in the glass tube. Characterized in that a firing step of forming dioxide formation film containing a grating forming region portion by forming a crystal lattice.

  According to such a configuration, the crystal lattice of the glass is hardly cut by the alkali metal oxide, and the silicon dioxide diffuses into the inner wall of the base glass tube, and the glass together with the alumina component contained in the base glass tube. Can form a lattice-forming region portion formed by forming a crystal lattice that serves as a skeleton of. It is needless to say that this lattice-forming region is an extremely dense and strong film-forming region in which silicon dioxide forms a crystal lattice that forms a glass skeleton together with the above-mentioned alumina component. A tempered glass tube for a discharge tube in which a denser and stronger silicon dioxide film is formed on the inner wall can be manufactured.

  In the present invention according to claim 4, in the firing step, the base material glass tube contains aluminosilicate as a main component and contains almost no alkali metal oxide, and contains an alumina component and serves as a glass skeleton together with silicon dioxide. By using an aluminosilicate glass tube having a property capable of forming a lattice and having a softening point higher than that of a borosilicate glass tube, the firing temperature of the silanol coating film applied to the inner wall of the aluminosilicate glass tube was increased. Features.

  According to this configuration, since the firing temperature can be increased, more silicon dioxide is diffused into the inner wall of the aluminosilicate glass tube, and the crystal lattice that forms the glass skeleton together with the alumina component contained in the aluminosilicate glass tube is formed. Many can be formed. Therefore, it is needless to say that the lattice forming region portion is an extremely dense and strong film forming region in which many crystal lattices are formed. As a result, the denser and stronger film is formed on the inner wall of the aluminosilicate glass tube. A tempered glass tube for a discharge tube having a silicon dioxide film formed thereon can be manufactured.

  The flash discharge tube according to the present invention is a flash discharge tube in which a pair of discharge electrodes including an anode and a cathode are hermetically sealed at both ends of a light-transmitting envelope with xenon gas sealed therein. Further, a tempered glass tube for a discharge tube according to the present invention is employed as the envelope.

  According to such a configuration, for example, a denser and more rigid body is formed on the inner wall of the aluminosilicate glass tube as the base material, including the lattice-forming region portion formed by diffusion of silicon dioxide inside the inner wall of the aluminosilicate glass tube. Since a tempered glass tube for a discharge tube on which a silicon dioxide film is formed is provided as an envelope, durability characteristics (heat resistance, heat resistance) against the phenomenon that occurred only in the envelope of the flash discharge tube due to thermal shock during arc discharge Thus, it is possible to obtain a flash discharge tube capable of realizing a significant improvement in impact characteristics.

  Further, in the present invention according to claim 6, at least the cathode of the discharge electrode is formed of an electrode pin and borosilicate glass, and is directly formed on the electrode pin so as to have an outer diameter less than the inner diameter of the aluminosilicate glass tube. A cathode bead wound and formed, hermetically sealed, and a sintered body fixed to the tip of the electrode pin. A substantially central portion of the side surface of the cathode bead and the vicinity of the end of the aluminosilicate glass tube are formed. By locally heating and melting, the tube end is sunk into the substantially central portion of the side surface of the cathode bead, and a concave portion is formed in the substantially central portion of the side surface of the cathode bead, so that the tube end is hermetically sealed with the aluminosilicate glass tube. It is characterized by that.

  According to this configuration, the welding between the cathode and the aluminosilicate glass tube heats and melts only the vicinity of the tube end including the substantially central portion of the side surface of the cathode bead and the end surface of the aluminosilicate glass tube, and this tube end is placed on the side surface. Since it is realized by being sunk so as to form a concave portion at a substantially central portion, it is possible to reduce the influence of heating to portions other than the substantially central portion of the side portion, thereby causing a problem that may occur due to a difference in thermal expansion coefficient. Can be suppressed, and as a result, a simple process can be performed, whereby the flash discharge tube can be formed at low cost.

  The light irradiation device according to the present invention uses the flash discharge tube according to the present invention as a light source, that is, a durability characteristic against a thermal shock phenomenon or the like at the time of arc discharge that occurs only in the envelope of the flash discharge tube ( Since the flash discharge tube according to the present invention which can realize a great improvement in heat resistance and thermal shock resistance at a low cost is used, the light emitting device, for example, a light emitting life durability characteristic and a short-time repetitive light emission durability characteristic as a strobe device can be obtained. An excellent light irradiation device can be provided.

  According to the tempered glass tube for a discharge tube of the present invention and the method for manufacturing the same, the base material contains almost no alkali metal oxide having a property of cutting the crystal lattice of the glass, and the crystal lattice serving as a skeleton of the silicon dioxide and the glass. Since a glass tube having a property that can be formed is adopted, a silicon dioxide film is formed on the inner wall of the base glass tube, and the silicon dioxide is applied to the base glass tube with almost no cutting of the crystal lattice of the glass by the alkali metal oxide. It can be formed so as to include a lattice-forming region formed by forming a crystal lattice serving as a skeleton of glass together with an alumina component contained in the base glass tube by diffusion into the inner wall.

  Therefore, unlike the silicon dioxide film formed on the borosilicate glass tube containing the alkali metal oxide, the formed silicon dioxide film becomes a dense and strong film having a crystal lattice in a partial region, and as a result, It is possible to obtain a tempered glass tube for a discharge tube on which a dense and strong silicon dioxide film is formed. Further, since the silicon dioxide film is formed including the lattice forming region as described above, even if the film thickness is increased, it becomes a dense film with less occurrence of cracks. Thus, a tempered glass tube for a discharge tube in which a thicker and stronger silicon dioxide film can be formed can be obtained.

  According to the flash discharge tube of the present invention, a silicon dioxide film is formed on the inner wall of a base material glass tube, for example, an aluminosilicate glass tube, and a lattice forming region formed by diffusion of silicon dioxide inside the inner wall of the aluminosilicate glass tube. In other words, the strengthened glass tube for a discharge tube according to the present invention in which a thicker, more dense, and stronger silicon dioxide film including a lattice forming region portion formed with a crystal lattice is formed as an envelope is included. It is possible to greatly improve the durability characteristics (heat resistance, thermal shock resistance) against the phenomenon that occurred only in the envelope of the flash discharge tube, which is the thermal shock at the time of arc discharge. This has the effect of providing a flash discharge tube having excellent light emission durability characteristics over time.

  According to the light irradiation device of the present invention, since the flash discharge tube according to the present invention having significantly improved heat resistance and thermal shock resistance is used as a light source, it has excellent light emission lifetime durability and short-time repeated light emission durability. This has an effect that a light irradiation device can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic including one part enlarged schematic sectional drawing which shows one Embodiment of the tempered glass tube for discharge tubes concerning this invention. The schematic diagram which shows the example of a manufacturing process of the tempered glass tube for discharge tubes concerning the embodiment. Schematic view showing one embodiment of a flash discharge tube using a tempered glass tube for a discharge tube according to the present invention. Schematic showing an example of the manufacturing process of the flash discharge tube according to the same embodiment Schematic showing an example of the manufacturing process of the flash discharge tube according to the same embodiment Schematic showing an example of the manufacturing process of the flash discharge tube according to the same embodiment Schematic diagram including a partial cross section showing another embodiment of a flash discharge tube using a tempered glass tube for a discharge tube according to the present invention. 1 is a schematic configuration diagram illustrating an embodiment of a strobe device as an example of a light irradiation device using a flash discharge tube according to the present invention.

  Hereinafter, a tempered glass tube for a discharge tube according to the present invention, a method for manufacturing the same, a flash discharge tube using the tempered glass tube, and the like will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view including a partially enlarged schematic cross-sectional view showing one embodiment of a tempered glass tube for a discharge tube according to the present invention. As shown, the tempered glass tube for a discharge tube 1 is a base material. A silicon dioxide coating 3 is formed on the inner wall of the glass tube 2, including the lattice forming region 4. At both ends of the inner wall of the glass tube 2, non-formed portions 2a and 2b where the silicon dioxide film 3 is not formed are provided in order to hermetically seal a pair of discharge electrodes (not shown).

  The glass tube 2 serving as a base material contains almost no alkali metal oxide having a property of cutting a crystal lattice of glass, and has a property of containing an alumina component and forming a crystal lattice serving as a glass skeleton together with silicon dioxide. In this embodiment, a softening point is higher than that of a borosilicate glass tube because it contains an aluminosilicate as a main component and hardly contains an alkali metal oxide, and also contains silicon dioxide because it contains an alumina component. It is composed of an aluminosilicate glass tube having the property of forming a crystal lattice serving as a skeleton of glass.

  The aluminosilicate glass tube containing almost no alkali metal oxide is an alkali oxide-free aluminosilicate glass tube having a composition of about 20% by weight of aluminum oxide, about 60% by weight of silicon dioxide, and the balance of It is a conventionally well-known glass which contains an alkaline earth metal which occupies most as a main composition and the alkali oxide which is an alkali metal oxide is less than 0.03 w%.

  Looking at the composition of SCHOTT Glass8253 as a specific example, 16.5 w% of aluminum oxide, 61 w% of silicon dioxide, 13 w% of calcium oxide as an alkaline earth metal oxide, 8 w% of barium oxide, and alkali oxidation It is configured to contain less than 0.02 w% of sodium oxide or the like, and alkali oxides are set to be less than 0.03 w% in total. The glass 8253 has a softening point of about 1000 degrees, which is higher than about 700 to 830 degrees of borosilicate glass conventionally known as a discharge tube glass tube containing an alkali metal oxide. I have.

  Hereinafter, the details of the tempered glass tube for a discharge tube 1 according to the present invention will be briefly described with reference to FIGS.

  2A, 2B, and 2C are schematic views showing an example of a manufacturing process of a tempered glass tube for a discharge tube according to an embodiment of the tempered glass tube for a discharge tube according to the present invention, and FIG. 3 shows a schematic cross-sectional view of an application step of applying a silanol solution 5 that becomes a silicon dioxide film 3 by being fired on the inner wall surface of the glass tube 2 that becomes a base material.

  FIG. 2B is a schematic cross-sectional view of a drying regulation step of drying the silanol solution applied to the inner wall of the glass tube 2 and regulating the application area of the silanol solution to a desired area to form a silanol coating film 5a. FIG. 2C is a schematic sectional view of a firing step of firing the glass tube 2 on which the silanol coating film 5a has been formed.

  That is, the method for manufacturing the strengthened glass tube for a discharge tube 1 according to the present invention includes at least the respective manufacturing steps shown in FIGS. 2 (a), 2 (b) and 2 (c). In the application step, a silanol solution 5 that forms the silicon dioxide film 3 by being fired is applied to the inner wall of the aluminosilicate glass tube 2 described above, which is used as a base material.

  Specifically, as shown in FIG. 2A, one end of the aluminosilicate glass tube 2 is immersed in a silanol solution 5 placed in a container C, and is connected to the other end of the glass tube 2. The silanol solution 5 is sucked by a vacuum pump that has not been pulled up and raised to a predetermined position except for the portion where the discharge electrode is sealed, and the silanol solution is supplied to the inner wall surface of the glass tube 2, and then the vacuum pump is released. By taking out the glass tube 2 from the silanol solution 5 and discharging the silanol solution 5 therein, the silanol solution 5 is applied to the inner wall surface of the glass tube 2.

  Next, in a drying regulation step shown in FIG. 2B, the silanol solution applied to the inner wall of the aluminosilicate glass tube 2 is dried by, for example, a fan 6, and the silanol solution applied to the lower end portion of the glass tube 2 is dried. The solution is removed by, for example, a brush (not shown). As a result, the above-mentioned non-formed portions 2a and 2b are formed on the inner wall surface of the aluminosilicate glass tube 2, and the silanol coating film 5a whose formation region is restricted to a desired region is formed.

  Thereafter, in the firing step shown in FIG. 2C, the aluminosilicate glass tube 2 on which the silanol coating film 5a has been formed is cooled, for example, using an appropriate firing furnace 7 to a temperature lower than the annealing point of the aluminosilicate glass tube 2. Sintering at the temperature described above causes silicon dioxide to diffuse into the aluminosilicate glass tube 2 inside the aluminosilicate glass tube 2 and form a glass framework between the aluminosilicate glass tube 2 and the alumina component contained in the glass tube 2. Thus, a tempered glass tube for a discharge tube according to the present invention in which a dioxide formation film 3 including a lattice forming region portion 4 formed by forming a crystal lattice is completed.

  That is, since the aluminosilicate glass tube 2 having a softening point higher than that of the borosilicate glass tube containing an alkali metal oxide and having a lowered softening point was employed as the base material, the firing temperature of the silanol coating film 5a in the firing step was reduced. Accordingly, silicon dioxide diffuses into the inner wall of the aluminosilicate glass tube 2 and is formed by a property capable of forming a crystal lattice serving as a glass skeleton together with the alumina component contained in the aluminosilicate glass tube 2. More crystal lattices can be formed.

  It goes without saying that the lattice-forming region portion 4 in which more crystal lattices are formed is an extremely dense and strong film-forming region. As a result, according to the method for producing a tempered glass for a discharge tube according to the present invention. For example, a strengthened glass tube for a discharge tube 1 in which a denser and stronger silicon dioxide film 3 is formed on the inner wall of the aluminosilicate glass tube 2 can be manufactured.

  As for the thickness of the silicon dioxide film 3, the thicker the film can be formed, the more the quartized region on the inner wall of the aluminosilicate glass tube 2 can be expanded. Therefore, the durability characteristics against the phenomenon that occurs only in the discharge tube glass tube (heat resistance, Thermal shock resistance), a so-called discharge resistance, can be greatly improved. However, the present inventors have confirmed that when the film thickness exceeds 400 nm, the frequency of occurrence of cracks in the formed film increases sharply. It has been confirmed that.

  Table 1 shows an embodiment of a flash discharge tube according to the present invention described below using an aluminosilicate glass tube as a base material glass tube, and a flash discharge according to a conventional configuration using a borosilicate glass tube as a base material glass tube described at the beginning. 1 is a summary of the evaluation of the film thickness, cracks and discharge resistance of a silicon dioxide film in a tube.

  In addition, the occurrence of cracks in the formed coating is nothing but the fact that the inner wall of the glass tube has not been made into quartz, and therefore, the durability of the film depends on the base material glass tube. Since the base material glass tube deteriorates due to the fact that a part of the coating melts due to heat generated during discharge and is present as a foreign substance in the tube, it will not be possible to expect a significant improvement in discharge resistance such as thermal shock resistance. Not even. In addition, it is apparent that a change in the light transmission state due to the presence of the crack itself also occurs, which causes a decrease in the specific light amount.

  As shown in Table 1, in the case of the present invention, the crack evaluation, which was not possible when the film thickness exceeds 110 nm in the conventional configuration, is not possible until the film thickness exceeds 400 nm. That is, in the present invention, the base glass tube contains almost no alkali metal oxide having a property of cutting the crystal lattice of the glass, and can form a crystal lattice which contains an alumina component and serves as a glass skeleton together with silicon dioxide. Since the aluminosilicate glass tube, which is a glass tube with properties, is used, the crack occurrence frequency is a good evaluation without any particular problem up to a film thickness of 400 nm, and is evaluated only when the film thickness exceeds 400 nm. The evaluation was unacceptable, so that the silicon dioxide film could be formed much thicker than the conventional configuration.

  For this reason, with respect to the discharge resistance, the conventional configuration is not evaluated when the frequency of crack occurrence is higher than 110 nm, but is not evaluated when it exceeds 400 nm in the case of the present invention.

  Further, looking at the discharge resistance in more detail, it has been confirmed that in the film thickness range of 50 nm to 110 nm, the present invention is evaluated as good, whereas the conventional structure is evaluated as evaluated. That is, according to the present invention, the silicon dioxide film is diffused into the inner wall of the base glass tube with almost no cutting of the crystal lattice of the glass by the alkali metal oxide on the inner wall of the base glass tube. Since the silicon dioxide film is formed including the lattice-forming region portion formed in this manner, the formed silicon dioxide film is different from the silicon dioxide film formed on the borosilicate glass tube containing the alkali metal oxide, which is a conventional structure, and is different from the silicon dioxide film. It becomes a dense and strong film with a crystal lattice formed in the partial region, and therefore, even with the same thickness, the case of the present invention in which a denser and stronger silicon dioxide film is formed is advantageous in terms of discharge resistance. Has also been confirmed.

  Further, since the silicon dioxide film of the present invention is formed including the lattice forming region as described above, even if the film thickness is increased, the film becomes a dense film with less occurrence of cracks. When the film thickness becomes 130 nm or more, the contribution and the contribution of the quartification based on the thickness increase as described as excellent evaluation in Table 1, and the previous discharge resistance is higher than the previous discharge resistance. Has been confirmed to be greatly improved.

  As described above, according to the present invention, the base glass tube contains almost no alkali metal oxide having a property of cutting the crystal lattice of glass, and contains an alumina component and serves as a glass skeleton together with silicon dioxide. Unlike the case where a borosilicate glass tube was used as the base glass tube, a denser and stronger silicon dioxide film can be formed because the glass tube has the property of forming a lattice. In the case of the structure, cracks in the silicon dioxide film, which frequently occur when the film thickness is 110 nm or more, are unlikely to occur. Therefore, the film thickness can be increased to a large value, preferably 130 nm or more. When the thickness exceeds 110, cracks occur in the rapidly formed film, as in the case of the film thickness of 110 nm or more in the borosilicate glass tube. It has confirmed that the frequency is increased.

  Therefore, it is desired that the thickness of the silicon dioxide film be set to 400 nm or less without unnecessarily increasing the thickness in the present invention.

  FIG. 3 is a schematic view showing an embodiment of a flash discharge tube using the tempered glass tube for a discharge tube 1 according to the present invention shown in FIG. 1, and as shown, the flash discharge tube 8 is an envelope. Electrode pins 12 forming a part of a discharge electrode A (anode) via an anode bead 10 in a state in which xenon gas 9 is sealed inside the glass tube 1 at both ends of the tempered glass tube 1 for a discharge tube constituting An electrode pin 13 forming a part of the discharge electrode C (cathode) is hermetically sealed via a cathode bead 11.

The tempered glass tube for a discharge tube 1 constituting the envelope of the flash discharge tube 8 according to the present invention is formed of an aluminosilicate glass tube containing almost no alkali metal oxide (for example, Glass8253 from SCHOTT). The bead 10 and the cathode bead 11 are each formed of a borosilicate glass tube designed to have a low softening point. (For example, SCHOTT Glass8487 etc.)
The discharge electrode A, which is an anode, is composed of an electrode pin 12 to which an anode bead 10 is welded and an external pin 14 welded to the electrode pin 12, as shown in FIG. The outer pins 14 are made of tungsten having an extremely high melting point of about 3400 ° C., which is 4.4 to 4.5 × 10 ⁻⁶ · K ⁻¹ , and a nickel-based metal such as nickel is used as the external pins 14.

  The anode bead 10 has a first bead 10a directly welded to the electrode pin 12 and an outer diameter around the first bead 10a that is smaller than the inner diameter of the glass tube 1 and in the axial direction of the first bead 10a. The glass tube 1 is formed from a second bead 10b welded with a length shorter than the length, and the side surface of the second bead 10b and the inner wall surface of the glass tube 1 are melt-bonded to form the glass tube 1 and the electrode. Airtight sealing with the pin 12 is realized indirectly.

  The discharge electrode C serving as the cathode was welded to the electrode pin 13 to which the cathode bead 11 was hermetically welded, and the sintered electrode 15 and the electrode pin 13 attached to the electrode pin 13 by a method such as caulking as shown in the figure. The cathode bead 11, the electrode pin 13 and the external pin 16 are also made of borosilicate glass, tungsten, and a nickel-based metal, respectively, similarly to the discharge electrode A. I have.

  Like the anode bead 10, the cathode bead 11 also has a third bead 11a directly welded to the electrode pin 13, and an outer diameter less than the inner diameter of the glass tube 1 around the third bead 11a, and The fourth bead 11b is welded with a length shorter than the length of the third bead 11a in the axial direction. The fourth bead 11b is formed by melting and joining the side surface portion of the fourth bead 11b and the inner wall surface portion of the glass tube 1. In addition, the hermetic sealing between the glass tube 1 and the electrode pins 13 is indirectly realized.

  Next, the manufacturing process of the flash discharge tube 8 according to the first embodiment of the present invention will be briefly described with reference to FIGS. 4 to 6, which are schematic views showing an example of the manufacturing process of the flash discharge tube 8. .

  FIGS. 4A and 4B are schematic views showing steps of manufacturing a discharge electrode A as an anode, and FIGS. 5A and 5B are schematic views showing steps of manufacturing a discharge electrode C as a cathode. FIGS. 6A and 6B are schematic views showing the steps of manufacturing the flash discharge tube 8 according to the present invention using the respective process members manufactured in FIGS.

Each of the discharge electrodes A and C shown in FIGS. 4 and 5 has a hollow cylindrical shape on tungsten having a thermal expansion coefficient of 4.4 to 4.5 × 10 ⁻⁶ · K ^{−1 as} the electrode pins 12 and 13. An anode bead 10 (first bead 10a and second bead 10b) and a cathode bead 11 (third bead 11a and second bead 10) made of borosilicate glass having a coefficient of thermal expansion of 3.2 to 4.1 × 10 ⁻⁶ · K ⁻¹ . The four beads 11b) are moved in the directions indicated by arrows in FIGS. 4 (a) and 5 (a) and inserted, and then, for example, as shown in FIGS. 4 (b) and 5 (b). Heating is performed by the bead heating burners B1 and B2, so that the electrode pins 12 and 13 are melt-bonded.

  That is, the discharge electrode A has a first bead 10a made of borosilicate glass, and an electrode pin 12 made of tungsten, which is smaller than the inner diameter of the tempered glass tube 1 for a discharge tube according to the present invention, which forms the envelope of the flash discharge tube 8. The first bead 10a is wound directly around the first bead 10a so as to have an outer diameter smaller than the inner diameter of the glass tube 1 by directly winding the second bead 10b also made of borosilicate glass. It is formed by winding with a length shorter than the axial length.

  Similarly to the discharge electrode A, the discharge electrode C is provided with a third bead 11a made of borosilicate glass and an electrode pin 13 made of tungsten, and a tempered glass for a discharge tube according to the present invention constituting an envelope of the flash discharge tube 8. Directly wound so as to have an outer diameter less than the inner diameter of the tube 1, and further wrapped a fourth bead 11 b made of borosilicate glass around the third bead 11 a so as to have an outer diameter less than the inner diameter of the glass tube 1. The first bead 11a is formed by winding the first bead 11a with a length shorter than the length in the axial direction, and attaching the sintered electrode 15 to the electrode pin 13 through a known caulking step (not shown).

At this time, the difference in the coefficient of thermal expansion between the electrode pins 12 and 13 and the anode bead 10 and the cathode bead 11 is small, and specifically, is set to 1 × 10 ⁻⁶ · K ⁻¹ or less. This can prevent the occurrence of inconvenience due to the difference in the coefficient of thermal expansion at the time of fusion bonding by heating.

  Further, it will be described in detail that a transparent conductive film functioning as a trigger electrode to which a trigger voltage is applied as necessary may be formed on a predetermined region of an outer surface of the glass tube 1 by a known method. Not even.

  Next, as shown in FIG. 6, the discharge electrodes A and C manufactured as described with reference to FIGS. 4 and 5 are combined as follows to complete the flash discharge tube 8 according to the present invention.

  First, the discharge electrode A, which is the anode, is moved in the direction of the arrow in FIG. 6A, and the anode bead 10 is positioned inside one end of the glass tube 1. Thereafter, the anode bead 10 is heated by a burner B3, for example. The side surface of the second bead 10b forming the bead 10 and the inner wall surface at one end of the glass tube 1 are fusion-bonded, whereby the discharge electrode A as an anode is hermetically sealed to the glass tube 1 via the anode bead 10. I do.

  Next, as shown in FIG. 6A, the discharge electrode C is moved in the direction of the arrow, and a desired amount of the cathode bead 11 is placed inside the other end of the glass tube 1 inside the glass tube 1. The side wall of the fourth bead 11b forming the cathode bead 11 and the inner wall surface at one end of the glass tube 1 are melt-bonded by filling with a xenon gas 9 and heating by, for example, a burner B4, thereby forming a cathode. The discharge electrode C is hermetically sealed to the glass tube 1 via the cathode bead 11.

  Thereafter, although not shown, a step of setting the lengths of the external pins 14 and 16 to a desired length and a step of performing preliminary soldering on the external pins 14 and 16 are performed as necessary to obtain the configuration shown in FIG. The flash discharge tube 8 according to the present invention shown in FIG.

  In addition, the flash discharge tube according to the present invention is not limited to the above-described embodiment, and for example, the method of hermetically sealing the discharge electrodes A and C and the method of sealing xenon gas are variously changed as follows. It goes without saying that it can be done.

  That is, in the above-described embodiment, both side portions of the second bead 10b of the anode bead 10 and the fourth bead of the cathode bead 11 are formed on both ends of the glass tube 1 for both the discharge electrodes A and C, respectively. The electrode pins 12, 13 and the glass tube 1 are hermetically sealed by fusion bonding the side surface portion of the glass tube 1 to the side surface portion of the glass tube 1; for example, FIG. 7 shows a flash discharge according to the present invention. As shown in a schematic diagram including a partial cross section of another embodiment of the tube 8, each bead is configured as a unitary anode bead 17, cathode bead 18 instead of a double bead configuration as described above. A bead 17 and a cathode bead 18 are arranged in both ends of the glass tube 1 such that both tube ends of the glass tube 1 are located substantially at the center of each side. Above the middle part By locally heating the vicinity of the end of the glass tube 1 together with the vicinity of the end, the end of the glass tube 1 is sunk into the substantially central portion of the side surface portion, thereby forming a concave portion and hermetically sealing with the glass tube 1. Needless to say, the hermetic sealing between the glass tube 1 and the electrode pins 12 and 13 of the discharge electrode A and the discharge electrode C may be realized indirectly.

  In other words, each of the anode bead 17 and the cathode bead 18 is formed as a single unit, and has a side portion outer diameter smaller than the inner diameter of the glass tube 1 (aluminosilicate glass tube) as shown in the cross section in FIG. The electrode pins 12 and 13 are directly wound around the glass tube 1, and the respective sides of the glass tube 1 are heated substantially together with the glass tube 1 near the tube center. The tube end of the glass tube 1 is sunk into the substantially central portion of the side surface to form a concave portion, thereby realizing an air-tight seal between the beads 17, 18 and the glass tube 1, thereby achieving the glass tube 1 and the electrode pins. Needless to say, the hermetically sealed attachment with 12, 13 may be realized indirectly.

  Further, as another example of the method of realizing the hermetic sealing process while enclosing the xenon gas inside the glass tube 1 of the discharge electrode C, for example, a carbon heater is used in place of the burner B4. Except for the burner B4, a vacuum vessel equipped with a work space capable of evacuating the inside and filling a predetermined pressure of xenon gas with the glass tube 1, the discharge electrode C and the carbon heater sealed to the discharge electrode A shown in FIG. It is a matter of course that a method of filling the vessel with xenon gas and heating and melting and joining the cathode bead 11 of the discharge electrode C and the glass tube 1 by a carbon heater in the vacuum vessel can be adopted.

  In addition, the above-mentioned method is arranged such that the tube end of the glass tube 1 is positioned substantially at the center of the side surface of the cathode bead 18 of the discharge electrode C in the above-mentioned vacuum container, and the xenon gas is placed in the vacuum container. It is needless to say that the present invention can also be applied to the configuration example shown in FIG. 7, for example, by heating the cathode bead 18 of the discharge electrode C and the local portion near the end of the glass tube by a carbon heater.

  Next, an embodiment of the light irradiation device according to the present invention will be described.

  FIG. 8 is a schematic configuration diagram showing an embodiment of a strobe device S which is an example of a light irradiation device using the flash discharge tube 8 according to the present invention.

  As shown in the drawing, a strobe device S, which is an embodiment of the light irradiation device according to the present invention, includes a flash discharge tube 8 according to the present invention, which serves as a light source for illuminating a subject 20, and a flash discharge tube 8 according to the present invention. A reflector 21 for guiding the emitted light toward the subject 20, an optical member 22 disposed between the flash discharge tube 8 and the subject 20 to block light in a short wavelength region, for example, light of 400 nm or less, via an optical member 22. Optical control means 23 for controlling the emission direction, emission angle, and the like of the incident light, and light emission operation control means 24 for controlling the light emission operation of the flash discharge tube 8.

  For this reason, when the flash discharge tube 8 performs a light emission operation by the light emission operation control means 24, the emitted light emitted from the flash discharge tube 8 is reflected directly and by the reflector 21 to reach the optical member 22 and has a short wavelength. The light in the region is controlled to be blocked light (for example, light that does not include light having a wavelength of 400 nm or less), and the irradiation angle and the like are controlled by the optical control unit 23 to irradiate the subject 20.

  At this time, the above-mentioned strobe device, which is an example of the light irradiation device according to the present invention, has a crystal lattice on the inner wall of the flash discharge tube 8 according to the present invention, that is, a base material glass tube, for example, an aluminosilicate glass tube. A phenomenon that occurred only in the envelope of the flash discharge tube, that is, thermal shock during arc discharge, in which a thicker, more dense and stronger silicon dioxide film was formed, including the formed grid-forming region. The use of a flash discharge tube, which has greatly improved the durability characteristics (heat resistance and thermal shock resistance), has greatly improved the light emission lifetime durability and short-time repeated light emission durability of a strobe device. You can do it.

  Note that the light irradiation device according to the present invention is not limited to the above-described strobe device, and for example, an aircraft obstacle light installed on a high place such as a bridge or a high-rise building, or an emergency vehicle such as an aircraft or a police car. It is needless to say that the present invention can be applied to various light irradiation devices that use or can use a flash discharge tube as a light source, such as a warning light mounted on a vehicle.

  According to the tempered glass tube for a discharge tube of the present invention and the method for manufacturing the same, the base material contains almost no alkali metal oxide having a property of cutting the crystal lattice of the glass, and the crystal lattice serving as a skeleton of the silicon dioxide and the glass. Since a glass tube having a property that can be formed is adopted, the inner wall of the base glass tube is provided with a lattice-forming region portion that is a dense and strong region in which a crystal lattice is partially formed, and more preferably a film thickness of The present invention can be applied to obtaining a strengthened glass tube for a discharge tube on which a thick, denser and stronger silicon dioxide film is formed.

  The flash discharge tube of the present invention includes a lattice-forming region portion in which a crystal lattice is formed on the inner wall of a base material glass tube, for example, an aluminosilicate glass tube, and more preferably a thicker, more dense, stronger silicon dioxide. The provision of the tempered glass tube for a discharge tube according to the present invention having a coating formed thereon as an envelope makes it possible to withstand the heat shock at the time of arc discharge which has occurred only in the envelope of the flash discharge tube (heat resistance, heat resistance). As a result, the present invention can be applied to obtaining a flash discharge tube having excellent durability against light emission and durability against short-time repeated light emission.

  In addition, the light irradiation device of the present invention has excellent heat-resistance characteristics and light-emitting durability characteristics as well as short-time repetitive light-emitting durability characteristics, since the flash discharge tube according to the present invention having significantly improved heat resistance and thermal shock characteristics is used as a light source. It can be applied to obtaining a light irradiation device.

REFERENCE SIGNS LIST 1 tempered glass tube for discharge tube 2 aluminosilicate glass tube 3 silicon dioxide coating 4 lattice forming region 5 silanol solution 6 fan 7 firing furnace 8 flash discharge tube 9 xenon gas 10 anode bead 10a first bead 10b second bead 11 cathode bead 11a Third bead 11b Fourth bead 12 Electrode pin 13 Electrode pin 14 External pin 15 Sintered body 16 External pin 17 Anode bead 18 Cathode bead 19 Main body 20 Subject 21 Reflector 22 Optical member 23 Optical control means 24 Light emission operation control means

Claims (8)

A glass tube containing almost no alkali metal oxide having a property of cutting the crystal lattice of glass and containing an alumina component and having a property of forming a crystal lattice serving as a skeleton of glass together with silicon dioxide as a base material glass tube. Wherein a silicon dioxide film is formed on the inner wall of the base glass tube, including a lattice forming region where the silicon dioxide is diffused into the inner wall of the base glass tube to form the crystal lattice. Tempered glass tube for discharge tube. The base glass tube has a property of containing an aluminosilicate as a main component, containing almost no alkali metal oxide, and containing an alumina component and having a property of forming a crystal lattice serving as a glass skeleton together with silicon dioxide, and further has a softening point. 2. The tempered glass tube for a discharge tube according to claim 1, wherein the tempered glass tube is an aluminosilicate glass tube higher than a borosilicate glass tube. 3. The tempered glass tube for a discharge tube according to claim 1, wherein the silicon dioxide film has a thickness of 50 nm to 400 nm. 4. At least, a preform glass tube containing almost no alkali metal oxide having a property of cutting the crystal lattice of glass, and having a property of containing an alumina component and having a property of forming a crystal lattice serving as a glass skeleton together with silicon dioxide. An application step of applying a silanol solution to be a silicon dioxide film by being baked on the inner wall to form a silanol coating film, and drying the silanol coating film applied on the inner wall and forming a region of the silanol coating film. A drying regulation step of regulating to a desired area, and baking the base glass tube on which the silanol coating film is formed at a temperature equal to or higher than the annealing point of the base glass tube; Diacid containing a lattice-forming region formed by diffusion of silicon into the inside of the base material glass tube to form a crystal lattice with an alumina component contained in the glass tube. Method for manufacturing a discharge tube reinforced glass tube, characterized in that a firing step of forming a formation film. The firing step is characterized in that the base glass tube has a property that it contains an aluminosilicate as a main component, contains almost no alkali metal oxide, contains an alumina component, and can form a crystal lattice serving as a glass skeleton together with silicon dioxide, and is further softened. 5. The discharge according to claim 4, wherein the firing temperature of the silanol coating film applied to the inner wall of the aluminosilicate glass tube is increased by using an aluminosilicate glass tube having a point higher than that of the borosilicate glass tube. Manufacturing method of tempered glass tube for pipe. A flash discharge tube in which a pair of discharge electrodes comprising an anode and a cathode are hermetically sealed with xenon gas sealed therein at both ends of a translucent envelope, wherein the envelope is claimed. Item 4. A flash discharge tube using the tempered glass tube for a discharge tube according to any one of Items 1 to 3. At least the cathode of the discharge electrodes is an electrode pin, a cathode made of borosilicate glass and directly wound around the electrode pin so as to have an outer diameter less than the inner diameter of the aluminosilicate glass tube, and a hermetically sealed cathode. A bead, and a sintered body fixed to the tip of the electrode pin. The tube end is formed by locally heating and melting substantially the center of the side surface of the cathode bead and the vicinity of the end of the aluminosilicate glass tube. 7. An airtight seal with the aluminosilicate glass tube by forming a concave portion at a substantially central portion of the side surface of the cathode bead by sunk into a substantially central portion of the side surface of the cathode bead. Flash tube. A light irradiation device using the flash discharge tube according to the present invention according to claim 6 as a light source.