JP2008192416A - External electrode type rare gas fluorescent lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an external electrode type rare gas fluorescent lamp which prevents the impairment of the adhesion function of external electrodes by the electric discharge between external electrodes. <P>SOLUTION: The external electrode type rare gas fluorescent lamp concerning the invention which keeps a rare gas enclosed in the interior of an arc tube, phosphor incorporated in the arc tube, a pair of external electrodes mutually estranged and arranged along the pipe axial direction outside the arc tube, has the external electrodes consisting of aluminum, nickel, iron or cooper, and adhesion bodies installed between the arc tube and the external electrodes is characterized in that the adhesion bodies consist of ceramic materials. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rare gas fluorescent lamp for backlights of liquid crystals and advertisements / signboards, and more particularly to an external electrode type rare gas fluorescent lamp in which an electrode is provided on the outer peripheral surface of an arc tube.

A conventional external electrode type rare gas fluorescent lamp 9 will be described with reference to FIG. FIG. 8A is a perspective view of a conventional external electrode type rare gas fluorescent lamp 9, and FIG. 8B is a view perpendicular to the tube axis direction of the conventional external electrode type rare gas fluorescent lamp 9 of FIG. It is sectional drawing (DD sectional drawing of (a)). FIG. 8C is a cross-sectional view perpendicular to the tube axis direction of the conventional external electrode type rare gas fluorescent lamp 9 of FIG. 8A (cross-sectional view taken along line EE of FIG. 8A). .
A conventional external electrode type rare gas fluorescent lamp 9 shown in FIG. 8 includes a tubular arc tube 91, a phosphor 92, a plate-like external electrode 93, a power supply terminal 95, and a heat shrinkable tube 96.
As shown in FIG. 8B, a phosphor 92 is applied to the inner peripheral surface of the tubular arc tube 91. The arc tube 91 is filled with a rare gas such as xenon gas as the luminescent gas, and both ends of the arc tube 91 in the tube axis direction are sealed.
A power supply terminal 95 is electrically connected to the end of the plate-like external electrode 93 in the longitudinal direction. An adhesive 94 made of acrylic resin is applied to the external electrode 93 connected to the power supply terminal 95 with a thickness of 40 to 50 μm. A pair of external electrodes 93 are arranged on the arc tube 91 so as to be separated along the longitudinal direction of the outer peripheral surface thereof. The external electrode 93 is disposed at a desired position on the outer peripheral surface of the arc tube 91 by the applied acrylic resin 94. However, since the adhesive force of the acrylic resin 94 at a high temperature is weak, the external electrode 93 is stably attached to the arc tube 91 over a long period of time in a situation where the arc tube 91 is hotter than room temperature as when the lamp 9 is lit. It is difficult to maintain a desired position on the outer peripheral surface of the. Therefore, in order to maintain the external electrode 93 at a desired position on the outer peripheral surface of the arc tube 91, the conventional external electrode type rare gas fluorescent lamp 9 has a light-shrinkable heat shrinkable tube 96 as shown in FIG. The outer peripheral surfaces of the arc tube 91 and the external electrode 93 are covered while being in contact with each other (Patent Document 1). Thereby, the external electrode 93 is disposed at a desired position on the outer peripheral surface of the arc tube 91 and bonded thereto. The power supply terminal 95 at the end in the longitudinal direction of the external electrode 93 is covered with a heat-shrinkable tube 96 similarly to the external electrode 93 as shown in FIG.
A power supply (not shown) is connected to the power supply terminal 95 in the longitudinal direction of the external electrode 93.
The conventional external electrode type rare gas fluorescent lamp 9 as described above is supplied with power from a power source (not shown), and due to the potential difference between the external electrodes 93, vacuum ultraviolet rays are emitted by the xenon gas, which is a luminescent gas, The phosphor 92 is excited. The arc tube 91 between the external electrodes 93 functions as a dielectric.
In the above description, the positioning and adhesion function of the external electrode 93 on the outer peripheral surface of the arc tube 91 in the conventional external electrode type rare gas fluorescent lamp 9 has been described with the heat shrinkable tube 96, but the translucency described in Patent Document 2 is used. There is also a method that uses sheets.

Japanese Patent No. 2783448 JP 09-223485 A

  However, the acrylic resin is deteriorated such as carbonization by heating due to the discharge between the external electrodes when the lamp is turned on. Although the adhesive for the external electrode of the conventional external electrode type rare gas fluorescent lamp described above has been described using an acrylic resin, deterioration such as carbonization is a problem common to organic adhesives such as an acrylic resin.

  Accordingly, an object of the present invention is to provide an external electrode type rare gas fluorescent lamp in which deterioration of the adhesion function of the external electrode due to discharge between the external electrodes is prevented.

  In the external electrode type rare gas fluorescent lamp according to the present invention, a rare gas is sealed inside an arc tube, a phosphor is provided in the arc tube, and a pair of external electrodes are connected to each other along the tube axis direction outside the arc tube. In the external electrode type rare gas fluorescent lamp, the external electrode is made of aluminum, nickel, iron, or copper, and the adhesive is provided between the arc tube and the external electrode. It is characterized by comprising.

  2. The external electrode type rare gas fluorescent lamp according to claim 1, wherein the thickness of the adhesive is thinner than the thickness of the external electrode and the thickness of the arc tube. .

  2. The external electrode type rare gas fluorescent lamp according to claim 1, wherein the ceramic material includes vitreous. 3.

  4. The external electrode type rare gas fluorescent lamp according to claim 3, wherein a crystalline material is added to the ceramic material.

  2. The external electrode type rare gas fluorescent lamp according to claim 1, wherein the external electrode has a hole.

In the external electrode type rare gas fluorescent lamp according to the present invention, a rare gas is sealed inside an arc tube, a phosphor is provided in the arc tube, and a pair of external electrodes are connected to each other along the tube axis direction outside the arc tube. In the external electrode type rare gas fluorescent lamp, the external electrode is made of aluminum, nickel, iron, or copper, and the adhesive is provided between the arc tube and the external electrode. Accordingly, the external electrode and the arc tube can be firmly bonded, and the external electrode can be disposed and held at a desired position of the arc tube. Furthermore, since the ceramic material is made of an inorganic material, carbonization of the bonded body can be prevented when the lamp is lit, and deterioration of the bonding function of the bonded body can be prevented.
Further, the metal element of the external electrode may cause diffusion called migration on the outer peripheral surface of the arc tube, and if the metal element diffuses into the arc tube between the external electrodes, a short circuit may occur between the external electrodes. As in the external electrode type rare gas fluorescent lamp according to the present invention, by using a ceramic material for the adhesive body, diffusion (migration) of the metal element of the external electrode to the arc tube can be prevented. A short circuit can be prevented.

  Since the thickness of the adhesive is thinner than the thickness of the external electrode and the arc tube, the discharge distance between the pair of external electrodes is shortened, and the thickness of the dielectric composed of the arc tube and the adhesive is reduced. Further, it is possible to prevent a decrease in the amount of discharge between the external electrodes when the lamp is lit, and to prevent a decrease in illuminance of the external electrode type rare gas fluorescent lamp.

  When the ceramic material contains glassy material, the adhesive body is translucent. When the lamp is turned on, visible light passes through the translucent adhesive body and is irradiated to the external electrode. Since the external electrode is made of aluminum, nickel, iron, or copper, visible light applied to the external electrode can be reflected and sent into the arc tube by having a metallic luster. Thereby, the illumination intensity fall of visible light can be prevented.

  By adding a crystalline material to the glass-containing ceramic material, the thermal expansion coefficient of the adhesive can be matched with the material of the external electrode, and the bondability between the adhesive and the external electrode can be improved.

When the adhesive body is heated at the time of joining the external electrode and the arc tube, bubbles may be generated from the adhesive body. Bubbles generated from the adhesive between the external electrode and the arc tube that do not have a hole like a plate cannot escape from the arc tube side or the external electrode side, so the completed external electrode type rare gas fluorescence Bubbles remain between the arc tube of the lamp and the external electrode, and this bubble causes a decrease in the dielectric constant between the external electrode and the arc tube, so that sufficient discharge can be generated between the external electrodes when the lamp is lit. However, the illuminance of the external electrode type rare gas fluorescent lamp may be lowered.
For this reason, since the external electrode has a hole, bubbles generated from the adhesive when the external electrode and the arc tube are joined are discharged from the hole of the external electrode. The dielectric constant can be prevented from being lowered, and sufficient discharge can be generated between the external electrodes when the lamp is lit, and the illuminance reduction of the external electrode type rare gas fluorescent lamp can be prevented.

A first embodiment of an external electrode type rare gas fluorescent lamp 1 according to the present invention will be described with reference to FIGS.
FIG. 1 is an explanatory view of an external electrode type rare gas fluorescent lamp 1 according to the present invention. FIG. 1A is a perspective view of the external electrode type rare gas fluorescent lamp 1, and FIG. 1B is a cross-sectional view perpendicular to the tube axis direction of the external electrode type rare gas fluorescent lamp 1 of FIG. It is AA sectional drawing of a).

As shown in FIG. 1B, the phosphor 3 is applied to the inner peripheral surface of the tubular arc tube 2. That is, in the phosphor 3, a layer of the phosphor 3 is formed over the entire axial length of the inner surface of the arc tube 2. For example, a rare gas mainly composed of xenon gas is sealed in the arc tube 2 as a main component, and both ends of the arc tube 2 are sealed.
On the outer peripheral surface of the arc tube 2, a pair of external electrodes 4 made of, for example, aluminum foil are disposed so as to be separated along the longitudinal direction of the outer peripheral surface of the arc tube 2.

FIG. 2 is an enlarged view of one of the pair of external electrodes 4 in FIG. The same reference numerals are given to the same components as those shown in FIG.
Since the thermal expansion coefficient of the external electrode 4 is often larger than the thermal expansion coefficient of the arc tube 2, the thickness L1 of the external electrode 4 is preferably a foil shape that is thinner than the thickness L3 of the arc tube 2. This is because the external electrode 4 is foil-like, and when the lamp is lit, the stress due to the difference in expansion between the heated external electrode 4 and the arc tube 2 is plastically deformed by the foil-like external electrode 4. This is because it can be absorbed. As the external electrode 4 that can be formed into a foil shape, a metal material made of aluminum, nickel, iron, or copper can be used. For example, pure metal made of aluminum, or stainless steel (iron alloy) obtained by adding nickel and chromium to iron can be given. It is done.

  A low melting point glass 51 (hereinafter referred to as frit glass), which is a ceramic material made of an inorganic compound, is disposed between the outer peripheral surface of the arc tube 2 and the external electrode 4. Therefore, the frit glass 51 is sandwiched between the outer peripheral surface of the arc tube 2 and the external electrode 4 and is disposed so as to be separated along the longitudinal direction of the outer peripheral surface of the arc tube 2. The frit glass 51 has a bonding function by heating as described later, and can be bonded so that the external electrode 4 and the arc tube 2 are not peeled off.

The joining of the arc tube 2 and the external electrode 4 by the frit glass 51 will be described.
The frit glass 51 is made of Bi—B—O as a main component, the external electrode 4 is made of aluminum, and the arc tube 2 is made of a glass tube. As the frit glass 51, a frit glass 51 having a softening point lower than the melting point of the external electrode 4 is used. The frit glass 51 is a frit glass 51 having a softening point lower than that of the arc tube 2.
A frit glass 51 paste that is made into a paste by mixing a binder substance with the frit glass 51 is applied to a desired position on the outer peripheral surface of the arc tube 2 where the external electrode 4 is disposed. Therefore, the frit glass 51 paste is applied to a desired position where the external electrode 4 that is separated along the longitudinal direction of the outer peripheral surface of the arc tube 2 is desired. The frit glass 51 paste is temporarily baked to remove the binder material, and the external electrode 4 is disposed on the frit glass 51 paste. The frit glass 51 is softened above the softening point of the frit glass 51, below the melting point of the external electrode 4, and softened the arc tube 2. Heated below point.
The frit glass 51 paste has been described as being applied to the outer peripheral surface of the arc tube 2. However, after the frit glass 51 paste is applied to the external electrode 4 and pre-baked, it is disposed at a desired position on the outer peripheral surface of the arc tube 2. It doesn't matter.

Since the external electrode 4 is made of a metal material made of aluminum, nickel, iron, or copper, the frit glass 51 brings the external electrode 4 and the arc tube 2 to a desired position by matching the thermal expansion coefficient of the material of the external electrode 4. Can be placed and glued. Adjustment of the thermal expansion coefficient of the frit glass 51 can be realized by adding a transition metal oxide such as zinc oxide (ZnO) or a crystalline material such as silicon dioxide (SiO ₂ ).

  FIG. 3 is an explanatory diagram for the power supply terminal 41 arranged at one end of the external electrode 4 in the longitudinal direction. 3A is a view showing one end of the external electrode type rare gas fluorescent lamp 1 of FIG. 1A in the tube axis direction, and FIG. 3B is an external electrode of FIG. 3A. It is a cross-sectional enlarged view (enlarged view of the BB cross section of FIG. 3A) perpendicular to the tube axis direction of the type rare gas fluorescent lamp 1. The same reference numerals are given to the same components as those shown in FIG.

  At one end in the longitudinal direction of the external electrode 4, for example, a power supply terminal 41 in which the surface of phosphor bronze is nickel-plated is electrically connected by, for example, a solder 42 mainly composed of Bi—Sn. As shown in FIG. 3B, the external electrode 4 is sandwiched between the frit glass 51 and the power supply terminal 41. On the outer surface of the power supply terminal 41, an insulating member 6 made of, for example, ABS resin having a substantially U-shaped cross section that conforms to the outer surface of the power supply terminal 41 is disposed. When the insulating member 6 is arranged to engage with the outer surface of the power supply terminal 41, a gap is formed between the arc tube 2 and the insulating member 6, and the gap is filled with an insulating adhesive 8 made of, for example, epoxy resin. The power supply terminal 41 protrudes from the end of the arc tube 2 in the tube axis direction, and the power supply line 43 is electrically connected to the protruded power supply terminal 41. A connector 44 is connected to the end of the power supply line 43, and the connector 44 is connected to a power supply device (not shown).

In the external electrode type rare gas fluorescent lamp 1 described above, when the lamp 1 is turned on, electric power is supplied to the external electrode 4 from a power supply device (not shown), and a potential difference occurs between the pair of external electrodes 4. The frit glass 51, which is an adhesive 51 between the external electrode 4 and the arc tube 2, functions as a dielectric together with the arc tube 2. Discharge occurs in the arc tube 2 due to the potential difference between the external electrodes 4 and the dielectric between the external electrodes 4, and the xenon gas enclosed in the arc tube 2 is excited to emit vacuum ultraviolet rays. The phosphor 3 applied to the inner peripheral surface of the arc tube 2 is excited by vacuum ultraviolet rays and radiates visible light to the outside of the arc tube 2.
By disposing the frit glass 51 as the adhesive 51 between the external electrode 4 and the arc tube 2, the external electrode 4 can be placed at a desired position even in a situation where the arc tube is heated when the lamp 1 is lit. It can be placed and held. Further, since the frit glass 51 as the adhesive 51 is a ceramic material, it does not carbonize even when heated by the discharge between the external electrodes 4. Thereby, the external electrode type rare gas fluorescent lamp 1 can be irradiated with visible light for a long time when the lamp 1 is lit without being deteriorated by the adhesive 51.

Since the frit glass 51, which is the adhesive 51 provided between the external electrode 4 and the arc tube 2, is a dielectric, the smaller the thickness L2 of the frit glass 51 is, as shown in FIG. It is possible to prevent a decrease in the discharge amount. For this reason, the thickness L2 of the frit glass 51 is preferably thinner than the thickness L1 of the external electrode 4 and the thickness L3 of the arc tube 2.
Taking a numerical example of the external electrode type rare gas fluorescent lamp 1 with reference to FIG. 2, the thickness L1 of the external electrode 4 in the radial direction of the arc tube 2 is 20 to 100 μm, and the frit glass 51 in the radial direction of the arc tube 2. The thickness L2 is 1 to 10 μm, and the radial thickness L3 of the arc tube 2 is 0.3 to 2 mm.

In the external electrode type rare gas fluorescent lamp 1 according to the present invention, a rare gas is sealed inside an arc tube 2, a phosphor 3 is provided inside the arc tube 2, and a pair of outside the arc tube 2 along the tube axis direction. In the external electrode type rare gas fluorescent lamp 1 in which the external electrodes 4 are arranged apart from each other, the external electrodes 4 are made of aluminum, nickel, iron or copper, and an adhesive 51 is provided between the arc tube 2 and the external electrodes 4. Since the adhesive 51 is made of a ceramic material, the external electrode 4 and the arc tube 2 can be firmly bonded, and the external electrode 4 can be disposed and held at a desired position of the arc tube 2. Furthermore, since the ceramic material is made of an inorganic material, carbonization of the bonded body can be prevented when the lamp is lit, and deterioration of the bonding function of the bonded body can be prevented.
Further, the metal element of the external electrode 4 may cause diffusion called migration on the outer peripheral surface of the arc tube 2, and if the metal element diffuses into the arc tube 2 between the external electrodes 4, a short circuit may occur between the external electrodes 4. . As in the external electrode type rare gas fluorescent lamp 1 according to the present invention, by using a ceramic material such as the frit glass 51 for the adhesive 51, diffusion (migration) of the metal element of the external electrode 4 to the arc tube 2 can be achieved. It is possible to prevent the short circuit between the external electrodes 4.
Further, since the thickness L2 of the adhesive 51 is thinner than the thickness L1 of the external electrode 4 and the thickness L3 of the arc tube 2, the discharge distance between the pair of external electrodes 4 is shortened and the arc tube 2 and the adhesive 51 are included. Since the thickness of the dielectric is reduced, it is possible to prevent a decrease in the amount of discharge between the external electrodes 4 when the lamp 1 is lit, and to prevent a decrease in illuminance of the external electrode type rare gas fluorescent lamp 1.
In addition, since the frit glass 51 is a ceramic material containing glass, the adhesive 51 has translucency, so that when the lamp 1 is turned on, visible light passes through the translucent adhesive 51, The external electrode 4 is irradiated. Since the external electrode 4 is made of aluminum, nickel, iron, or copper, the visible light applied to the external electrode 4 can be reflected and sent into the arc tube 2 by having a metallic luster. Thereby, the illumination intensity fall of visible light can be prevented. In addition, when a crystalline material is added to the bonded body 51, that is, when a crystalline material such as a transition metal oxide such as zinc oxide (ZnO) or silicon dioxide (SiO ₂ ) is added, the thermal expansion coefficient of the bonded body 51. Can be matched with the thermal expansion coefficient of the material of the external electrode 4, and the bondability between the adhesive 51 and the external electrode 4 can be improved.

  FIG. 4 shows another embodiment of the present embodiment, which is different from FIG. 2 in that the external electrode 4 is a net having holes. FIG. 4 is an enlarged view of one of the pair of external electrodes 4. The same reference numerals are given to the same components as those shown in FIG.

When the adhesive 51 is heated during the joining of the external electrode 4 and the arc tube 2, bubbles may be generated from the frit glass 51 that is the adhesive 51. As shown in FIGS. 1 and 2, bubbles generated from the adhesive 51 between the external electrode 4 and the arc tube 2 that do not have the plate-like hole 45 are on the arc tube 2 side or the external electrode 4 side. Therefore, bubbles remain between the arc tube 2 and the external electrode 4 of the completed external electrode type rare gas fluorescent lamp 1. Since the bubbles are gases, the bubbles have a dielectric constant lower than that of the frit glass 51, causing a decrease in the dielectric constant between the external electrode 4 and the arc tube 2. For this reason, when the lamp 1 is turned on, sufficient discharge cannot be generated between the external electrodes 4, and the illuminance of the external electrode type rare gas fluorescent lamp 1 may be lowered.
For this reason, since the external electrode 4 has the hole 45, bubbles generated from the adhesive 51 when the external electrode 4 and the arc tube 2 are joined can be discharged from the hole of the external electrode 4. 4 and the arc tube 2 can be prevented from lowering the dielectric constant, and when the lamp 1 is lit, sufficient discharge can be generated between the external electrodes 4, and the illuminance reduction of the external electrode type rare gas fluorescent lamp 1 can be prevented.

  FIG. 5 shows another embodiment of the present embodiment, which is different from FIG. 2 in that an insulating film 7 is formed. FIG. 5 is a cross section perpendicular to the tube axis direction of the external electrode type rare gas fluorescent lamp 1, and is an enlarged view of the periphery of one external electrode 4 in the pair of external electrodes 4. The same reference numerals are given to the same components as those shown in FIG.

For the insulating coating 7, for example, an insulating resin or frit glass 51 made of silicone resin or epoxy resin is used. The insulating film is provided so as to cover the external electrode 4 provided on the outer peripheral surface of the arc tube 2. Thereby, the outer surface of the external electrode 4 can be covered with the frit glass 51 and the insulating coating 7.
In the external electrode type rare gas fluorescent lamp 1, the thickness L4 of the insulating coating 7 in the radial direction of the arc tube 2 is, for example, about 1 mm.

FIG. 6 shows another embodiment of the present embodiment, and the structure around the power feeding terminal 41 is different from that in FIG. FIG. 6A is a perspective view of the end portion of the external electrode type rare gas fluorescent lamp 1, and FIG. 6B is a cross section perpendicular to the tube axis direction of the external electrode type rare gas fluorescent lamp 1 in FIG. It is an enlarged view (enlarged view of CC section of (a)). The same reference numerals are given to the same components as those shown in FIG.
A linear power supply terminal 41 is electrically connected to the outer surface of the external electrode 4. As shown in FIG. 6 (b), the cross section of the insulating member 6 is substantially U-shaped, and the cross section in which the linear power supply terminal 41 is disposed on the inner surface of the recess that forms the approximately U-shape is substantially C-shaped. Shaped holes are formed. The concave portion having a substantially C-shaped cross section is filled with, for example, solder 42 or conductive adhesive 42. When the insulating member 6 is arranged to engage with the outer surface of the power supply terminal 41, a gap is formed between the arc tube 2 and the insulating member 6, and the insulating adhesive 8 is filled in the gap.
The external electrode type rare gas fluorescent lamp 1 according to the present invention may have a peripheral structure of the power supply terminal 41 shown in FIG.

Further, the solder 42 used for connecting the external electrode 4 and the power supply terminal 41 shown in FIG. 3 and FIG. 6 is not limited to the solder 42 mainly composed of Bi—Sn. For example, Ag, Cu, Al or the like is used. A conductive adhesive 42 in which silver or the above-described solder 42 and epoxy are mixed in a resin can also be used.
Furthermore, the insulating member 6 is not limited to the ABS resin, and a phenol resin or an acrylic resin, a ceramic obtained by molding and firing mullite, calmlite, cordierite, alumina, or the like, or a glass member can also be used. .
In addition, the insulating adhesive 8 is not limited to an epoxy resin, but is a resin material mainly composed of a phenol resin or a silicone resin, or a ceramic adhesive mainly composed of a phosphoric acid adhesive. Can also be used.

A second embodiment of the external electrode type rare gas fluorescent lamp 1 according to the present invention will be described with reference to FIG.
FIG. 7 is an explanatory view of the external electrode type rare gas fluorescent lamp 1 according to the present invention. FIG. 7A is a perspective view of the external electrode type rare gas fluorescent lamp 1, and FIG. 7B is a cross section perpendicular to the tube axis direction of the external electrode type rare gas fluorescent lamp 1 in FIG. 4 is an enlarged cross-sectional view of the periphery of one of the pair of external electrodes 4. The same reference numerals are given to the same components as those shown in FIG.
FIG. 7 differs from the first embodiment in that a metal alcoholate is used for joining the external electrode 4 and the arc tube 2. As an explanation of the second embodiment, differences from the first embodiment will be described.

The joining of the arc tube 2 and the external electrode 4 by metal alcoholate will be described. Here, silicone alcoholate is used as the metal alcoholate in the description. The silicone alcoholate solution is a solution obtained by adding C ₂ H ₅ OH, H ₂ O, HCl, and the like to Si (OC ₂ H ₅ ) ₄ . After the arc tube 2 sealed at both ends in the tube axis direction is immersed in this silicone alcoholate solution, the arc tube 2 is pulled up from the silicone alcoholate solution. After drying the raised arc tube 2, for example, an external electrode 4 having a net-like hole is disposed, and heated to 400 ° C. or higher, below the melting point of the external electrode 4, and below the softening point of the arc tube 2. An adhesive body 51 made of a ceramic material is formed between 2 and the external electrode 4, and is bonded by the adhesive body 51. The adhesive 51 formed between the arc tube 2 and the external electrode 4 contains glass.
The metal alcoholate has been described as being applied to the outer peripheral surface of the arc tube 2. However, after the metal alcoholate solution is immersed in the external electrode 4, the external electrode 4 is pulled up from the silicone alcoholate solution, You may arrange | position in the desired position of an outer peripheral surface.

Since the external electrode 4 is made of a metal material made of aluminum, nickel, iron, or copper, the adhesive 51 is placed in a desired position by matching the thermal expansion coefficient of the material of the external electrode 4 with the external electrode 4 and the arc tube 2. Can be placed and glued. The adjustment of the thermal expansion coefficient of the bonded body 51 can be realized by adding a transition metal oxide such as zinc oxide (ZnO) or a crystalline material such as silicon dioxide (SiO ₂ ).

  When a numerical example of the external electrode type rare gas fluorescent lamp 1 is given, the thickness L5 of the external electrode 4 having the radial hole portion of the arc tube 2 is 50 to 100 μm, and the radial metal alcoholate of the arc tube 2 is used. The synthesized adhesive body 51 has a thickness L6 of 0.1 to 1 μm, and the arc tube 2 has a radial thickness L7 of 0.3 to 2 mm.

In the external electrode type rare gas fluorescent lamp 1 according to the present invention, a rare gas is sealed inside an arc tube 2, a phosphor 3 is provided inside the arc tube 2, and a pair of outside the arc tube 2 along the tube axis direction. In the external electrode type rare gas fluorescent lamp 1 in which the external electrodes 4 are arranged apart from each other, the external electrodes 4 are made of aluminum, nickel, iron or copper, and an adhesive 51 is provided between the arc tube 2 and the external electrodes 4. Since the adhesive 51 synthesized from the metal alcoholate is made of a ceramic material, the external electrode 4 and the arc tube 2 can be firmly bonded, and the external electrode 4 is disposed at a desired position of the arc tube 2. Can be held together. Furthermore, since the ceramic material is made of an inorganic material, carbonization of the bonded body can be prevented when the lamp is lit, and deterioration of the bonding function of the bonded body can be prevented.
Further, the metal element of the external electrode 4 may cause diffusion called migration on the outer peripheral surface of the arc tube 2, and if the metal element diffuses into the arc tube 2 between the external electrodes 4, a short circuit may occur between the external electrodes 4. . As in the external electrode type rare gas fluorescent lamp 1 according to the present invention, by using a ceramic material such as the frit glass 51 for the adhesive 51, diffusion (migration) of the metal element of the external electrode 4 to the arc tube 2 can be achieved. It is possible to prevent the short circuit between the external electrodes 4.
Furthermore, since the thickness L6 of the adhesive 51 is thinner than the thickness L5 of the external electrode 4 and the thickness L7 of the arc tube 2, the discharge distance between the pair of external electrodes 4 is shortened and the arc tube 2 and the adhesive 51 are included. Since the thickness of the dielectric is reduced, it is possible to prevent a decrease in the amount of discharge between the external electrodes 4 when the lamp 1 is lit, and to prevent a decrease in illuminance of the external electrode type rare gas fluorescent lamp 1.
In addition, since the adhesive 51 synthesized from the metal alcoholate is a ceramic material containing glass, the adhesive 51 has translucency, so that visible light has translucency when the lamp 1 is lit. The external electrode 4 is irradiated through the adhesive 51. Since the external electrode 4 is made of aluminum, nickel, iron, or copper, the visible light applied to the external electrode 4 can be reflected and sent into the arc tube 2 by having a metallic luster. Thereby, the illumination intensity fall of visible light can be prevented. In addition, when a crystalline material is added to the bonded body 51, that is, when a crystalline material such as a transition metal oxide such as zinc oxide (ZnO) or silicon dioxide (SiO ₂ ) is added, the thermal expansion coefficient of the bonded body 51. Can be matched with the thermal expansion coefficient of the material of the external electrode 4, and the bondability between the adhesive 51 and the external electrode 4 can be improved.

When the adhesive 51 is heated during the joining of the external electrode 4 and the arc tube 2, bubbles may be generated from the metal alcoholate that is the adhesive 51. As shown in FIGS. 1 and 2, bubbles generated from the adhesive 51 between the external electrode 4 and the arc tube 2 that do not have the plate-like hole 45 are on the arc tube 2 side or the external electrode 4 side. Therefore, bubbles remain between the arc tube 2 and the external electrode 4 of the completed external electrode type rare gas fluorescent lamp 1. Since the bubbles are gases, the bubbles have a dielectric constant lower than that of the adhesive 51, which causes a decrease in the dielectric constant between the external electrode 4 and the arc tube 2. For this reason, when the lamp 1 is turned on, sufficient discharge cannot be generated between the external electrodes 4, and the illuminance of the external electrode type rare gas fluorescent lamp 1 may be lowered.
For this reason, since the external electrode 4 has the hole 45, bubbles generated from the adhesive 51 when the external electrode 4 and the arc tube 2 are joined are discharged from the hole of the external electrode 4. It is possible to prevent a decrease in dielectric constant between the arc tube 2 and a sufficient discharge between the external electrodes 4 when the lamp 1 is turned on, thereby preventing a decrease in illuminance of the external electrode type rare gas fluorescent lamp 1.

  Further, the external electrode 4 having the holes of the external electrode type rare gas fluorescent lamp 1 according to the present embodiment is provided with an insulating film 7 covering the outer surface of the external electrode 4 as shown in FIG. 5 of the first embodiment. It does not matter if it is provided.

It is explanatory drawing of the external electrode type rare gas fluorescent lamp which concerns on this invention. It is explanatory drawing of the external electrode type rare gas fluorescent lamp which concerns on this invention. It is explanatory drawing of the external electrode type rare gas fluorescent lamp which concerns on this invention. It is explanatory drawing of the external electrode type rare gas fluorescent lamp which concerns on this invention. It is explanatory drawing of the external electrode type rare gas fluorescent lamp which concerns on this invention. It is explanatory drawing of the external electrode type rare gas fluorescent lamp which concerns on this invention. It is explanatory drawing of the external electrode type rare gas fluorescent lamp which concerns on this invention. It is explanatory drawing of the external electrode type rare gas fluorescent lamp which concerns on the past.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 External electrode type rare gas fluorescent lamp 2 Luminescent tube 3 Phosphor 4 External electrode 41 Feed terminal 42 Solder or conductive adhesive 43 Feed line 44 Connector 45 Hole 51 Adhesive body 6 Insulating member 7 Insulating film 8 Insulating adhesive

Claims (5)

A rare gas is sealed inside the arc tube, a phosphor is provided in the arc tube, and a pair of external electrodes are arranged apart from each other along the tube axis direction outside the arc tube,
The external electrode is made of aluminum, nickel, iron or copper,
In the external electrode type rare gas fluorescent lamp in which an adhesive is provided between the arc tube and the external electrode,
An external electrode type rare gas fluorescent lamp, wherein the adhesive is made of a ceramic material.
2. The external electrode type rare gas fluorescent lamp according to claim 1, wherein a thickness of the adhesive body is thinner than a thickness of the external electrode and a thickness of the arc tube.
The external electrode type rare gas fluorescent lamp according to claim 1, wherein the ceramic material includes glass.
The external electrode type rare gas fluorescent lamp according to claim 3, wherein a crystalline material is added to the ceramic material.
The external electrode type rare gas fluorescent lamp according to claim 1, wherein the external electrode has a hole.

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