JP4525305B2 - Fluorescent lamp, backlight unit and LCD TV - Google Patents

Description

  The present invention relates to a dielectric barrier discharge lamp provided with an external electrode on the outer periphery of an end of a tubular glass bulb, and more particularly to the structure of the external electrode.

  In recent years, the spread of large-sized liquid crystal televisions is remarkable, and the demand for direct-type backlight units (hereinafter referred to as “LCBL units”) used in large-sized liquid crystal televisions is increasing.

  A cold cathode tube is generally used as the light source for the LCBL unit, but the use of other light sources is being studied due to various circumstances such as the need for the same number of high-frequency electronic ballasts to light multiple lamps. Yes.

  Here, the dielectric barrier discharge lamp has a merit that a plurality of lamps can be lit by a single high-frequency electronic ballast, and thus is suitable as a light source of an LCBL unit in which, for example, 16 lamps are used.

As shown in FIG. 10, a conventional dielectric barrier discharge lamp 90 is enclosed in a straight glass bulb 91 which is a discharge envelope, a phosphor 92 applied to the inner surface of the glass bulb, and a direct glass bulb 91. Mercury 93, a rare gas for buffer 94 such as neon and argon, and conductive resin layers 96a and 96b formed in cylindrical shapes on outer peripheral surfaces 95a and 95b at both ends of the glass bulb, and conductive resin layer 96a , 96b, and C-shaped metal conductors 97a and 97b having spring elasticity and connected to surround the outer peripheral surface (see Patent Document 1).
JP 2003-17005 A

  However, according to the study by the present inventors, ozone is generated in the conductive resin layers 96a and 96b when the lamp is lit when a high voltage of 1.0 to 3.0 kV is applied between the external electrodes. Became clear.

  That is, in order to form the conductive resin layers 96a and 96b in the cylindrical shape on the outer peripheral surfaces 95a and 95b at both ends of the glass bulb, generally, the glass bulb 91 in the region other than the areas where the conductive resin layers 96a and 96b are formed. It is conceivable that the outer peripheral surface is masked with a tape or the like and the glass bulb 91 is rotated and applied to the outer peripheral surface of the glass bulb 91 by a spray method or a brush coating method.

  In these methods, as shown in FIG. 11, the conductive resin layers 96a and 96b are unevenly coated in the tube axis direction of the glass bulb 91, and spring elasticity is applied to the outer peripheral surfaces of the conductive resin layers 96a and 96b. When the C-shaped metal conductors 97a and 97b are attached, the outer peripheral surfaces of the conductive resin layers 96a and 96b are not uniformly distributed, but a partly concentrated load is applied to the conductive resin layers 96a and 96b. The conductive resin layers 96a and 96b were foamed layers containing air.

  As a result, in the cracked portion A and the foamed layer B of the conductive resin layers 96a and 96b, there is an air layer gap h between the inner surfaces of the metal conductors 97a and 97b and the outer peripheral surface of the glass bulb 91. It is considered that corona discharge occurs between the inner surfaces of the metal conductors 97a and 97b and the outer peripheral surface of the glass bulb 91 (a gap h). When corona discharge occurs, ozone is generated, and ozone rapidly deteriorates the conductive resin layers 96a and 96b and a resin member around the lamp (not shown), and even a small amount may cause a great adverse effect. is there. As a result, there has been a problem that resin members used in ozone fluorescent lamps, backlight units, liquid crystal televisions, and the like deteriorate and have a short life.

  The present invention has been made in view of the above-described problems, and suppresses generation of ozone when the lamp is lit, and a fluorescent lamp including an external electrode having a lifetime comparable to the lifetime of other portions, and a fluorescent lamp An object is to provide a lamp unit, a backlight unit, and a liquid crystal television.

To achieve the above object, a fluorescent lamp according to the present invention is a fluorescent lamp comprising an external electrode formed of a conductive layer on an outer peripheral surface of an end of a glass bulb sealed at both ends, A cap-shaped or sleeve-shaped metal member that surrounds and is connected to surround at least a part of the outer peripheral surface, and the external electrode, or a blocking layer that surrounds the external electrode and the metal member and blocks the external electrode from outside air. The blocking layer is formed of a metal film .

To achieve the above object, a backlight unit according to the present invention is characterized by comprising the fluorescent lamp.

To achieve the above object, a liquid crystal television according to the present invention is characterized by comprising the backlight unit.

  According to the configuration described in the means for solving the problem, it is possible to suppress the generation of ozone due to corona discharge at the time of lamp lighting, a fluorescent lamp including an external electrode having a life comparable to the life of other parts, A backlight unit and a liquid crystal television can be provided.

(Embodiment 1)
FIG. 1 is a diagram showing an outline of a liquid crystal television according to Embodiment 1 of the present invention.

  A liquid crystal television 10 shown in FIG. 1 is, for example, a 32-inch liquid crystal television, and includes a liquid crystal screen unit 11 and a backlight unit 12.

  The liquid crystal screen unit 11 includes a color filter substrate, a liquid crystal, a TFT substrate, a drive module and the like (not shown), and forms a color image based on an image signal from the outside.

  The backlight unit 12 is an LCBL unit and includes one high-frequency electronic ballast 13 and 16 dielectric barrier discharge lamps 100. Further, the socket base 50 as shown in FIG. 2 holds both ends of the 16 dielectric barrier discharge lamps 100 on the electrode socket 51 and the electrode socket 52 made of elastic stainless steel, phosphor bronze or the like to light the lamp. Is.

  The high-frequency electronic ballast 13 is a lighting circuit that lights all 16 dielectric barrier discharge lamps 100.

  FIG. 3A is a diagram showing an outline of the dielectric barrier discharge lamp 100 according to Embodiment 1 of the present invention.

As shown in FIG. 3 (a), the dielectric barrier discharge lamp 100 according to the first embodiment of the present invention is an external electrode 102 formed of a conductive layer on the outer peripheral surface of both ends of a tubular glass bulb 101 by a dipping method. , 103, surrounding the at least part of the outer peripheral surfaces of the external electrodes 102, 103 and having good electrical conductivity and a thermal expansion coefficient close to that of the glass bulb 101, such as Fe—Ni—Co (Kovar). ), And end portions 104a and 105a of the metal members 104 and 105 on the center side of the glass bulb are positioned at the end of the glass bulb from the positions of the external electrode ends 102a and 103a on the center side of the glass bulb. On the part 101b side, for example, an interval L is set at 1 mm. The blocking layers 110 and 111 formed of a solder layer that blocks the external electrodes 102 and 103 from the outside air are provided so as to surround the external electrodes 102 and 103 and the metal members 104 and 105. The glass bulb 101 has a substantially circular cross section when cut along a plane perpendicular to the tube axis. On the inner surface of the glass bulb 101, red (Y ₂ O ₃ : Eu ³⁺ ), green (LaPO ₄ : Ce ³⁺ , Tb ³⁺ ) and blue (BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ) phosphors The mixed rare earth phosphor is applied to form a phosphor film 106 having a thickness of about 20 μm. The glass bulb 101 is filled with a rare gas 107 such as argon and neon having a pressure of about 8 kPa and about 2 mg of mercury 108.

  The glass bulb 101 is a discharge envelope, and is made of, for example, borosilicate glass. In the present embodiment, the glass bulb 101 is a straight glass bulb having an outer diameter of 4.0 mm, an inner diameter of 3.0 mm, and a total length of 720 mm.

  FIG. 3B is a diagram illustrating an appearance of the metal member 104.

  The metal member 105 is the same as the metal member 104. The metal member 104 is formed in such a shape that a cylindrical hemisphere is covered with a hemispherical dome. In order to give the metal member 104 an elastic force, for example, two slits 109 in the longitudinal direction are provided. , And the metal member 104 is connected to the external electrode using the elastic force of the slit 109.

  The metal member 104 and the metal member 105 are mounted from the end portion 101 b of the glass bulb 101. Since the end portions 104a and 105a of the metal members 104 and 105 are chamfered so as not to have an acute angle portion as shown in FIG. 3, it is easy to mount from the end portion of the glass bulb 101 and the external electrode 102 is provided. , 103 is less likely to damage the outer peripheral surface.

  The metal members 104 and 105 do not have a fixed shape, such as a metal foil or a metal tape, considering the reduction of damage on the outer peripheral surfaces of the external electrodes 102 and 103, and change shape when force is applied from the outside. Unlike a plastic member that retains its shape even when the force is removed, a non-plastic metal member that has a fixed shape and does not easily change its shape when a force is applied from the outside is preferable.

  In the present embodiment, the metal member 104 and the metal member 105 have, for example, a total length of 23.0 mm, an outer diameter φ4.5 mm of the cylindrical portion, an inner diameter φ4.1 mm, and a wall thickness of 0.2 mm. Thus, since it is not necessary to have plasticity, it can be set thick so that scratches do not easily occur.

  Here, since the outer diameter of the glass bulb 101 is 4.0 mm and the inner diameter of the metal members 104 and 105 is 4.1 mm, the average clearance between the glass bulb 101 and the metal members 104 and 105 is 0.05 mm.

  The external electrodes 102 and 103 are electrically conductive paste, for example, silver paste at both ends of the sealed glass bulb 101 by a dipping method in advance to a predetermined length from one end of the glass bulb 101, for example, 25.0 mm in total length. It is formed and attached.

Note that the conductive paste of the external electrodes 102 and 103 is not limited to silver paste, and nickel paste, gold paste, palladium paste, or carbon paste may be used. Further, the conductive paste of the external electrodes 102 and 103 is preferably low melting glass as a binder in the conductive paste in consideration of strong adhesion to the surface of the glass bulb 101, and the amount thereof is included in an amount of 1 to 10% by weight. The specific resistance is preferably about 10 ⁻¹ to 10 ⁻⁶ Ω · cm.

  The blocking layers 110 and 111 are formed on both ends of the sealed glass bulb 101 by a dipping method so that solder is formed to a predetermined length from one end of the glass bulb 101, for example, a total length of 25.0 mm or more. In addition, the metal members 104 and 105 are surrounded.

  The blocking layers 110 and 111 surround the entire region C of the external electrodes 102 and 103 and the metal members 104 and 105, but are not limited to this, the region where the external electrodes 102 and 103 are in contact with the outside air, For example, as shown in FIG. 4, in order to reduce the amount of the material used for the blocking layers 110 and 111, a part of the slit 109 portion and the external electrode end portions 102a and 103a from the position of the gap L portion on the glass bulb end portion 101b side. The region D may be surrounded by the blocking layers 110 and 111. In the case of the entire region C, the blocking layers 110 and 111 are made of solder, nickel plating, gold plating, silver plating, copper plating, etc. in consideration of conduction with the electrode socket 51 and the electrode socket 52 shown in FIG. In the case of a partial film D, in addition to the metal film, the metal members 104 and 105 can be electrically connected to the electrode socket 51 and the electrode socket 52 shown in FIG. An insulating film such as a continuous film of a metal oxide made of at least one selected from the group consisting of alumina, hafnium oxide, zirconium oxide, vanadium oxide, niobium oxide and yttrium oxide can also be used.

  Next, the procedure of the bonding process of the glass bulb, the external electrode, the metal member, and the blocking layer will be described with reference to FIGS.

  (1) As shown in FIG. 5 (a), a silver paste is diluted with a diluent such as hexane, the diluted silver paste solution is accommodated in a container 60, and both ends are sealed by dipping. A portion in the vicinity of the bulb 101 excluding one end portion (center portion side) is sandwiched by the first jig 61, the one end portion of the glass bulb 101 is lowered, and a predetermined length is placed in the container 60 containing the silver paste liquid. Mmm is immersed, and the silver paste 62a is attached to one end of the glass bulb 101 (step S1). At this time, the external electrode 102 of the silver paste 62a formed on the glass bulb 101 can directly contact the silver paste liquid with a constant pressure on the outer peripheral surface of the glass bulb 101, as compared with the spray method or the brush coating method of the prior art. It is possible to stably reduce unevenness in the tube axis and the radial direction.

  (2) As shown in FIG. 5B, after raising the glass bulb 101, the glass bulb 101 is held between the first jig 61, for example, a tunnel-type heating furnace 63 (conditions of the heating furnace) Is passed through a processing temperature of 100 ° C. for a processing time of about 1.5 minutes, and the silver paste 62a is temporarily fixed to one end of the glass bulb 101 (step S2).

  (3) After returning to normal temperature, the glass bulb 101 is removed from the first jig 61. Next, as shown in FIG.5 (c), the part (center part side) of the vicinity except the other end part is clamped with the 1st jig | tool 61, and the other end part of this glass bulb 101 is attached by the dipping method. The predetermined length Mmm is immersed in the container 60 in which the silver paste liquid is accommodated, and the silver paste 62b is attached to the other end of the glass bulb 101 (step S3). At this time, since the external electrode 103 of the silver paste 62b formed on the glass bulb 101 can directly contact the silver paste liquid at a constant pressure on the outer peripheral surface of the glass bulb 101 as compared with the spray method or brush coating method of the prior art. It is possible to stably reduce unevenness in the tube axis and the radial direction.

  (4) As shown in FIG. 5D, with the glass bulb 101 held between the first jig 61, for example, a tunnel-type heating furnace 63 (conditions of the heating furnace is a processing temperature of 620 ° C. and a processing time of About 1 minute), and the silver pastes 62a and 62b adhering to both ends of the glass bulb 101 are permanently fixed (step S4).

(5) As shown in FIG. 6, a second jig 64 having a protrusion 65 having a width slightly larger than the opening width on the slit 109 side is used, and the protrusion 65 is used to make a hemispheric dome-shaped metal. The metal member 104 is held by the second jig 64 by widening the opening end of the member 104 on the slit 109 side. While maintaining this state, the glass bulb 101 is then lowered and one end of the glass bulb 101 is inserted into the opening of the metal member 104 held by the second jig 64, and then the second jig 64. Thus, the metal member 104 is removed, and the metal member 104 is fixed to one end of the glass bulb 101 (step S5). At this time, since an evenly distributed load due to the elastic force of the cap-shaped metal member 104 is applied to the outer peripheral surface of the silver paste 62a, it is possible to prevent the silver paste 62a from cracking.

  (6) Similarly, the second jig 64 is used to widen and hold the opening end of the hemispherical dome-shaped metal member 105 on the slit 109 side. After the other end of the glass bulb 101 is inserted into the held opening of the metal member 105, the metal member 105 is removed by the second jig 64 and the metal member 105 is fixed to the other end of the glass bulb 101 ( Step S6). At this time, if a cap-shaped metal member 105 is attached to the outer peripheral surface of the silver paste 62b, an equally distributed load is applied to the outer peripheral surface of the silver paste, so that the silver paste 62b can be prevented from cracking.

  (7) Next, as shown in FIG. 7 (a), the molten solder is accommodated in the container 70, and a portion in the vicinity of the glass bulb 101 provided with the external electrode 102 and the metal member 104 (the center) Part of the glass bulb 101 is sandwiched between the first jig 61 and one end of the glass bulb 101 is immersed in a container 70 containing molten solder by a dipping method. (Immersion time is 1 to 2 seconds) The external electrode 102 and the metal member 104 at one end of the glass bulb 101 are surrounded and adhered by the solder layer 72a (step S7). At this time, even if a part of the silver paste 62b of the external electrode 102 is a crack or a foamed layer containing air, the external electrode 102 can be blocked from the outside air by the solder layer. Occurrence can be suppressed.

  (8) After returning to normal temperature, the glass bulb 101 is removed from the first jig 61 (see FIG. 7B). Next, as shown in FIG. 7 (c), a portion (the center portion side) in the vicinity excluding the other end portion is sandwiched by the first jig 61, and the other end portion of the glass bulb 101 is melted by the dipping method. A predetermined length Nmm (Mmm or more) is dipped in the container 70 containing the solder (immersion time is 1 to 2 seconds), and the external electrode 103 and the metal member 105 at the other end of the glass bulb 101 are It is surrounded and attached by the solder layer 72a (step S8). At this time, even if a part of the silver paste of the external electrode 103 is a crack or a foamed layer containing air, the external electrode 102 can be blocked from the outside air by the solder layer, so that ozone is generated. Can be suppressed. Thereby, a straight dielectric barrier discharge lamp 100 can be manufactured (see FIG. 7D).

  In the steps S7 and S8, solder may be interposed between the outer surfaces of the external electrodes 102 and 103 and the inner surfaces of the metal members 104 and 105. The solder further surrounds the surface of the external electrode 102 and is blocked from the outside air. Therefore, generation of ozone can be further suppressed.

  Next, the function and effect of the dielectric barrier discharge lamp 100 will be described.

  The first embodiment of the present invention surrounds the external electrodes 102 and 103 formed on the outer peripheral surfaces of both ends of the glass bulb 101 or the external electrodes 102 and 103 and the metal members 104 and 105. By providing the blocking layers 110 and 111 for blocking the outside air, a part of the conductive paste which is the external electrodes 102 and 103 is cracked, a foamed layer containing air, and the gap h described in the prior art (see FIG. 11). Even if it has a reference), it is possible to suppress the generation of ozone due to corona discharge when the lamp is lit between the metal members 104, 105 and the glass bulb 101, which is inferior to the lifetime of other parts. It is possible to provide a fluorescent lamp, a backlight unit, and a liquid crystal television each having an external electrode with no lifetime.

  In addition, since the external electrodes 102 and 103 are formed on the outer peripheral surface of the end portion of the glass bulb 101 by a dip method using a conductive paste, the tube axis and the radial direction are compared with the conventional spray method or brush coating method. The unevenness of coating can be reduced. As a result, when the cap-shaped metal members 104 and 105 are attached to the outer peripheral surface of the conductive paste that is the external electrodes 102 and 103, an evenly distributed load is applied to the outer peripheral surface of the conductive paste, so that the conductive paste is cracked. It becomes difficult, and generation | occurrence | production of the corona discharge at the time of lamp lighting can be suppressed further.

  When the blocking layers 110 and 111 are formed of a metal film, the external electrodes 102 and 103 and the metal members 104 and 105 can be easily covered by the dipping method, and the metal members 104 and 105 and the electrodes shown in FIG. The socket 51 and the electrode socket 52 can be easily connected.

  Further, when the blocking layers 110 and 111 are formed of a metal film or an insulating film and a part of the metal members 104 and 105 is provided so as to be in contact with the outside air, the amount of material used for the metal film or the insulating film is reduced. can do.

  Further, the end portions 104a and 105a of the metal members 104 and 105 on the center side of the glass bulb 101 are spaced from the positions of the external electrode end portions 102a and 103a on the center side of the glass bulb 101 toward the glass bulb end portion 101b. Since it is installed, it is possible to suppress the occurrence of corona discharge when the lamp is lit between the end portions 104a and 105a of the metal members 104 and 105 and the glass bulb 101.

  In addition, since the end portions 104a and 105a of the metal members 104 and 105 on the center side of the glass bulb 101 are installed with a gap L of 1 mm or more, the metal member 104 can be mounted even if the metal members 104 and 105 are attached unevenly. , 105 can suppress the occurrence of corona discharge when the lamp is lit between the end portions 104a and 105a and the glass bulb 101.

  Further, since the metal members 104 and 105 surround the external electrodes 102 and 103 with a length of 3 mm or more, the metal members 104 and 105 at both ends of the dielectric barrier discharge lamp 100 are the electrode sockets 51 of the socket base 50. The electrode socket 52 can be stably connected and held, and the lamp can be turned on.

  In addition, since the end portions 104a and 105a of the metal members 104 and 105 on the center side of the glass bulb 101 are chamfered, the metal members 104 and 105 can be easily attached from the end portion of the glass bulb 101, and the external portions are attached at the time of attachment. It is possible to make it difficult to damage the outer peripheral surfaces of the electrodes 102 and 103.

  Further, since the metal members 104 and 105 are formed with two or more slits 109 in the longitudinal direction and are connected to the external electrodes 102 and 103 by the elastic force of the metal members 104 and 105, the metal members 104 and 105 are connected to the metal member 104 from the end of the glass bulb 101. 104 and 105 can be easily mounted, and the outer peripheral surfaces of the external electrodes 102 and 103 can be hardly damaged during the mounting.

  Further, by forming the conductive layers as the external electrodes 102 and 103 with a conductive paste of silver paste, nickel paste, gold paste, palladium paste, or carbon paste, the adhesion with the glass bulb 101 is improved, and the glass bulb 101 is improved. Generation of corona discharge between the external electrodes 102 and 103 and the glass bulb 101 interposed between the external electrode 102 and the discharge space of the external electrode 103 is equivalently The capacitances of the first capacitor and the second capacitor can be made substantially equal.

  In addition, by including 1 to 10% by weight of low melting point glass in the conductive paste as the external electrodes 102 and 103, the metal members 104 and 105 are attached to the outer peripheral surfaces of the external electrodes 102 and 103 from the end of the glass bulb 101. In this case, it is possible to make it difficult to damage the outer peripheral surfaces of the external electrodes 102 and 103.

(Embodiment 2)
FIG. 8 shows an outline of the dielectric barrier discharge lamp 200 according to the second embodiment of the present invention. This embodiment is different from the first embodiment in that the external electrodes 202 and 203 are arranged on the outer peripheral surfaces at both ends of the glass bulb 101. For example, the silver paste is formed in a cylindrical shape by a dip method by masking the end of the glass bulb 101, and the metal members 204 and 205 are formed in a sleeve shape (cylindrical shape). The metal members 204 and 205 are inserted from the end of the glass bulb 101, the metal members 204 and 205 are closely connected to the external electrodes 202 and 203, and both ends 204a and 204b of the sleeve-shaped metal member 204 (or sleeve-shaped Both ends 205a and 205b of the metal member 205 are connected to both ends 202a and 202b of the external electrode 202 (or both ends 2 of the external electrode 203). 3a and 203b), the outer electrodes 202 and 203 and the metal members 204 and 205 are surrounded by solder (blocking layers 110 and 111) by the dipping method shown in FIG. The difference is that it is formed in a cylindrical shape. The reason why the blocking layers 110 and 111 are formed in a cylindrical shape is that the adhesion of solder to the outer peripheral surface of the glass bulb 101 is poor.

  In addition, the same number is attached | subjected to the component similar to the dielectric barrier discharge lamp 100 in Embodiment 1, and the description is abbreviate | omitted.

  According to this embodiment, since the gap h (see FIG. 11) described in the prior art is not provided between the metal members 204 and 205 and the glass bulb 101, the metal members 204 and 205 and the glass bulb 101 are not provided. The occurrence of corona discharge when the lamp is lit can be suppressed. Further, even if the conductive paste that is the external electrodes 202 and 203 has a part of the conductive paste that is cracked and includes a foamed layer containing air and the gap h (see FIG. 11) described in the prior art, the blocking layer 110 , 111 surrounds the external electrodes 202 and 203 and the metal members 204 and 205, so that generation of ozone due to corona discharge when the lamp is lit can be suppressed.

  Further, both end portions 204a, 204b (or both end portions 205a, 205b of the metal member 205) of the metal member 204 are attached to both ends 202a, 202b (or the external electrode) of the external electrode 202 even when the mounting variation is in the tube axis direction X. When the lamp is lit between the both ends 204a and 204b of the metal member 204 (or both ends 205a and 205b of the metal member 205) and the glass bulb 101, since there is a distance L from both ends 203a and 203b) of the 203. The generation of corona discharge can be suppressed. Further, since the cylindrical metal members 204 and 205 are connected to the external electrodes 202 and 203 by the shrinking method, the adhesion of the cylindrical metal members 204 and 205 to the external electrodes 202 and 203 is improved, and the electric Connection is stabilized.

(Embodiment 3)
FIG. 9 shows an outline of a dielectric barrier discharge lamp 300 according to the third embodiment of the present invention. This embodiment is different from the second embodiment in that the thin metal member 304 winds the external electrode 202 around. And the point which is formed in the shape of a sleeve differs by crushing the part of the thin-body near the both ends. The metal member 304 is the same as the metal member 305 provided at the opposite end. In addition, the same number is attached | subjected to the component similar to the dielectric barrier discharge lamp 200 in Embodiment 2, and the description is abbreviate | omitted.

  According to this embodiment, since the gap h (see FIG. 11) described in the prior art is not provided between the metal member 304 and the glass bulb 101, between the metal member 304 and the glass bulb 101, Thus, it is possible to provide a fluorescent lamp, a backlight unit, and a liquid crystal television each having an external electrode that can suppress the occurrence of corona discharge when the lamp is turned on and has a life that is inferior to that of other parts. Further, even if the conductive paste that is the external electrodes 202 and 203 has a part of the conductive paste that is cracked and includes a foamed layer containing air and the gap h (see FIG. 11) described in the prior art, the blocking layer 110 , 111 surrounds the external electrodes 202 and 203 and the metal members 304 and 305, so that generation of ozone due to corona discharge during lamp lighting can be suppressed.

  In addition, both end portions 304a and 304b of the metal member 304 have a distance L from the both end portions 202a and 202b of the external electrode 202 even if there is a variation in attachment in the tube axis direction X. Generation of corona discharge when the lamp is lit between 304a and 304b and the glass bulb 101 can be suppressed. Further, since the external electrode 202 provided on the glass bulb 101 is wound and attached, the metal member 304 can be easily attached with an inexpensive thin body even if the outer diameter of the glass bulb 101 varies.

  Note that the external electrodes and metal members provided at both ends of the glass bulb 101 are not limited to the same shape at both ends, and may be combined with any one of the first embodiment, the second embodiment, and the third embodiment. . In addition, the metal member is not limited to the first, second, and third embodiments, and for example, instead of the cap-shaped metal member 104 in the first embodiment, a slit is formed in the tube axis direction as shown in FIG. A sleeve-like metal member 104a having 109a or the like may be provided.

  Furthermore, in the said embodiment, although the cross section of the glass bulb | bulb 101 was circular shape, you may make it an elliptical shape etc. not only in this.

  The present invention can be widely applied as any lighting including a direct backlight unit used in a liquid crystal television. According to the present invention, it is possible to provide a dielectric barrier discharge lamp including an external electrode that is unlikely to generate corona discharge and has a lifetime comparable to that of other portions, which contributes to a longer lifetime of a liquid crystal television. And its industrial utility value is extremely high.

The figure which shows the outline | summary of the liquid crystal television in Embodiment 1 of this invention The figure which shows the outline | summary of the socket stand 50 in the same Embodiment 1. (A) is a figure which shows the outline | summary of the dielectric barrier discharge lamp 100 in Embodiment 1, (b) is a figure which shows the external appearance of the metal member 104, (c) is the external appearance of the metal member 104a of a modification. Figure showing The figure which shows the modification which attached the interruption | blocking layer only to the area | region D where the external electrodes 102 and 103 in Embodiment 1 are in contact with the outside air Diagram showing outline of glass bulb manufacturing process Diagram showing outline of glass bulb manufacturing process Diagram showing outline of glass bulb manufacturing process The figure which shows the outline | summary of the dielectric barrier discharge lamp 200 in Embodiment 2 of this invention. The figure which shows the outline | summary of the dielectric barrier discharge lamp 300 in Embodiment 3 of this invention. The figure which shows the outline | summary of the conventional typical dielectric barrier discharge lamp 90 The figure explaining the subject of the dielectric barrier discharge lamp 90

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Dielectric barrier discharge lamp 101 Tubular glass bulbs 102 and 103 External electrodes 102a and 103a End portions of external electrodes 104 and 105 on the central side of the glass bulb 101 Metal members 104a and 105a End portions of metallic members 104 and 105 on the central side of the glass bulb 110, 111 barrier layer

Claims (7)

A fluorescent lamp comprising an external electrode formed of a conductive layer on the outer peripheral surface of the end of a glass bulb sealed at both ends,
A cap-shaped or sleeve-shaped metal member surrounding and connecting at least a part of the outer peripheral surface of the external electrode, the external electrode, or the external electrode and the metal member are surrounded, and the external electrode is outside air. A blocking layer for blocking ,
The fluorescent lamp , wherein the blocking layer is formed of a metal film .   The fluorescent lamp according to claim 1, wherein the conductive layer of the external electrode is formed by a dip method using a conductive paste.   The fluorescent lamp according to claim 1 or 2, wherein the metal film is any one of solder, nickel plating, gold plating, silver plating, and copper plating. The fluorescent lamp according to any one of claims 1 to 3 , wherein the metal member has a slit in the longitudinal direction and is connected to an external electrode by an elastic force of the metal member. The fluorescent lamp according to any one of claims 1 to 4 , wherein the conductive layer contains 1% by weight or more of the low-melting glass. A backlight unit comprising the fluorescent lamp according to any one of claims 1 to 3 as a light source. A liquid crystal television comprising the backlight unit according to claim 6 .

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