JP2006019099A - Fluorescent lamp, fluorescent lamp unit, backlight unit, and liquid crystal television - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dielectric barrier discharge lamp provided with an outside electrode in which a crack and peeling-off are hard to occur, and in which corona discharge is hard to occur, and which has lifetime compared favorably with the lifetime of the other portions. <P>SOLUTION: This is the dielectric barrier electric discharge lamp 100 provided with the outside electrode at the circumference of the end part of a tubular glass tube 101, the outside electrode has a metal member (metal cap 105, metal cap 106) at the outer shell, and an adhesive material 107 containing a low melting point glass is filled in a gap between the glass tube 101 and the metal member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dielectric barrier discharge lamp including an external electrode on the outer periphery of an end portion of a tubular glass bulb, and more particularly to a structure and a manufacturing method 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.
FIG. 9 is a view showing an outline of a conventional typical dielectric barrier discharge lamp 90.
As shown in FIG. 9, a conventional dielectric barrier discharge lamp 90 includes a straight glass tube 91 which is a discharge envelope, a phosphor 92 applied to the inner surface of the tube, mercury 93 sealed in the tube, Buffering rare gas 94 such as neon and argon, external electrodes 95 and 96 made of a metal foil tape wound around the outer peripheral surface of both ends of the tube, and an acrylic resin member were mixed with metal powder. It is comprised from the electroconductive adhesive 97 (refer patent document 1).

Moreover, the structure which used the metal cap instead of metal foil as an external electrode may be sufficient (refer patent document 2 and patent document 3).
In addition, since acrylic conductive adhesive materials are locally deteriorated and carbonized, and the external electrodes are easily peeled off, there is a technology using a conductive adhesive made of any of silicon resin, fluororesin, polyimide resin, and epoxy resin. It is disclosed in Patent Document 4.

Moreover, since a high voltage of 1.0 to 3.0 kV is applied between the external electrodes of the dielectric barrier discharge lamp, in order to suppress the occurrence of corona discharge at the discharge space side end of the external electrode, Patent Document 5 discloses a technique in which the discharge space side end portion is tightly surrounded by an insulating member made of a resin such as a silicon rubber tube.
Note that there is a demand for extending the life of LCBL units.
JP 2003-168392 A Japanese Patent Laid-Open No. 2002-8408 JP 2002-358933 A JP 2003-229092 A JP 2003-257377 A

When the external electrode of the dielectric barrier discharge lamp is formed of a metal foil or a silver paste, scratches or peeling are likely to occur when the electrode is attached to or detached from the electrode socket.
When the external electrode of the dielectric barrier discharge lamp is scratched or peeled off, the electrode area is reduced, so that not only the light emission efficiency is lowered but also corona discharge is likely to occur.
Further, as in Patent Document 2 and Patent Document 3, when a metal cap is used as the external electrode, corona discharge is likely to occur if there is a gap between the glass tube and the metal cap.

In addition, as a result of the experiment, the conventional conductive adhesive used when sticking the external electrode to the end of the lamp tube is not limited to any resin member as disclosed in Patent Document 4. It was also found that the lifetime was shorter than in other parts.
In addition, as a result of the experiment, the insulating member made of a resin such as a silicon rubber tube as disclosed in Patent Document 5 deteriorates earlier than the life of other parts, and corona discharge over the entire life. It has been found that the occurrence of the above cannot be suppressed.

When corona discharge occurs, ozone is generated, and the ozone rapidly deteriorates the resin member around the lamp, and even a trace amount may have a great adverse effect.
The present invention is a fluorescent lamp provided with an external electrode on the outer periphery of the end of a tubular glass bulb, which is less likely to be scratched or peeled off, less likely to generate corona discharge, and has a life comparable to the life of other parts. An object is to provide a fluorescent lamp, a fluorescent lamp unit, a backlight unit, and a liquid crystal television including an external electrode.

In order to achieve the above object, a fluorescent lamp according to the present invention is a fluorescent lamp having an outer electrode on an outer periphery of an end portion of a tubular glass bulb, the outer electrode having a metal member on an outer shell, and the glass bulb And an adhesive material containing low-melting glass is filled in the gap between the metal member and the metal member.
In order to achieve the above object, a fluorescent lamp unit according to the present invention is a fluorescent lamp unit for holding and lighting a fluorescent lamp, wherein the fluorescent lamp is electrically connected to the external electrode and the fluorescent lamp is connected to the fluorescent lamp. An electrode socket for holding is provided.

In order to achieve the above object, a backlight unit according to the present invention is a direct-type backlight unit used in a liquid crystal television, and turns on a plurality of fluorescent lamps and all of the plurality of fluorescent lamps. And a plurality of high-frequency electronic ballasts.
In order to achieve the above object, a liquid crystal television according to the present invention is a liquid crystal television including a direct backlight unit, and the backlight unit includes a plurality of fluorescent lamps and a plurality of fluorescent lamps. One high frequency electronic ballast that is all lit is included.

  Due to the configuration described in the means for solving the problems, the outer electrode is made of a metal member so that scratches and peeling are unlikely to occur, and the gap between the glass bulb and the metal member is filled with adhesive material, so corona discharge occurs. In addition, since the adhesive material is a low-melting glass and is not inferior to the material of the glass bulb, it can have a life comparable to that of the glass bulb.

Here, in the fluorescent lamp, the adhesive material may include 15% by weight or more of the low melting point glass.
Thereby, since the adhesive material contains 15% by weight or more of the low melting point glass, it is clear from the experimental results that no flaws or peeling occurs even if it is inserted and removed about 5 times as specified.
Here, in the fluorescent lamp, the low-melting glass contained in the adhesive material has a lower melting point than the glass bulb, the dielectric constant of the adhesive material is comparable to the dielectric constant of the glass bulb, and the adhesive material is The glass bulb may be integrated with the glass bulb by a melting process.

Accordingly, since the low melting point glass has a lower melting point than the glass bulb, the melting treatment can be performed at a temperature not lower than the melting point of the low melting point glass and lower than the melting point of the glass bulb.
In addition, since the adhesive material having a dielectric constant similar to that of the glass bulb is integrated with the glass bulb by a melting process to become one dielectric, the external electrode and the integrated dielectric are in close contact with each other. No corona discharge occurs.

Here, in the fluorescent lamp, a dielectric constant of the adhesive material may be equal to or higher than a dielectric constant of the glass bulb.
Thereby, since the dielectric constant of the adhesive material is higher than the dielectric constant of the glass bulb, corona discharge does not occur.
Here, in the fluorescent lamp, the adhesive material may include a conductive substance.

Accordingly, since the adhesive material includes the glass bulb and the conductive substance, the dielectric constant becomes equal to or higher than the dielectric constant of the glass bulb.
Here, the fluorescent lamp may be characterized in that the metal member and the adhesive material are electrically coupled and integrated to form the external electrode.
As a result, the adhesive material having a dielectric constant as high as that of the conductor is integrated with the metal member to form the external electrode, and the glass bulb and the integrated external electrode are in close contact with each other, so that corona discharge does not occur.

Here, in the fluorescent lamp, the metal member may be a cap-shaped metal cap and is fitted into the glass bulb.
Thereby, since the metal member has a bottom, the shape is stable and strong.
Here, in the fluorescent lamp, the metal cap may be characterized by not having an acute angle portion within a range where corona discharge around the outer periphery of the glass bulb can occur.

Thereby, corona discharge does not generate | occur | produce in the discharge space side edge part of a metal cap.
Here, in the fluorescent lamp, a discharge space side end portion in the tube axis direction of the metal cap is extended outward from the outer periphery of the glass bulb, and a tip thereof is out of the range. .
As a result, the end portion of the metal cap is located outside the range where corona discharge around the outer periphery of the glass bulb can occur, and therefore there cannot be an acute angle portion within this range.

Here, in the fluorescent lamp unit, the metal member may be higher in hardness than the electrode socket.
Thereby, a metal member is hard to be damaged.
Here, in the fluorescent lamp unit, the metal member includes a convex portion having a barb for preventing removal, and the electrode socket includes a concave portion for locking the barb and fitting with the convex portion. You can also

As a result, it is possible to prevent the fluorescent lamp from falling off.
Here, in the fluorescent lamp unit, there are two external electrodes at both ends of the fluorescent lamp, two electrode sockets are provided for two external electrodes, and the two convex portions have the same size. And one of the concave portions is positioned in the longitudinal direction of the fluorescent lamp and fits with the convex portion, and the other is large enough to fit with the convex portion leaving a gap in the longitudinal direction of the fluorescent lamp. It can also be characterized by being.

  Thereby, even if the space | interval of two external electrodes and the space | interval of two electrode sockets generate | occur | produce, attachment is possible, and it can align a position on the basis of one side.

(Embodiment 1)
<Overview>
In the first embodiment of the present invention, in the dielectric barrier discharge lamp, the external electrode is formed of a metal cap, and this is bonded to the outer peripheral surface of the tube end portion of the glass tube with an adhesive material including a glass frit having a relatively low melting point. As a result, the external electrode is not easily scratched or peeled off, corona discharge is unlikely to occur, and the life is inferior to that of other parts.

<Configuration>
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.
The high-frequency electronic ballast 13 is a lighting circuit that lights all 16 dielectric barrier discharge lamps 100.
FIG. 2A 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. 2 (a), the dielectric barrier discharge lamp 100 according to the first embodiment of the present invention is a fluorescent lamp having an outer electrode on the outer periphery of the end of a tubular glass bulb. A body 102, mercury 103, buffer rare gas 104, metal cap 105, metal cap 106, and adhesive material 107 are provided.
The glass tube 101 is a discharge envelope and is made of a borosilicate glass member. In this embodiment, the glass tube 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. 2B is a diagram showing the appearance of the metal cap 105.
The appearance of the metal cap 106 is the same as that of the metal cap 105.
The phosphor 102 is a fluorescent material for wavelength conversion applied to the inner surface of the tube. In this embodiment, Y ₂ O ₃ : Eu, LaPO ₄ : Ce, Tb, and BaMg _{2 that} emit red, green, and blue light. A rare earth phosphor mixed with Al ₁₆ O ₂₇ : Eu, Mn phosphor was used.

Mercury 103 is enclosed in a tube in the same manner as a conventional fluorescent lamp, and the amount of the mercury 103 is about 2.5 mg.
The buffer rare gas 104 is enclosed in a tube together with mercury 103 as in the conventional fluorescent lamp, and is composed of a neon / argon mixed gas having a composition (Ne + Ar 5%), and the enclosure pressure is about 8 kPa.

  The metal cap 105 and the metal cap 106 are metal members made of a so-called cap-shaped Fe-Ni-Co member having a shape in which a hemispherical dome is put on one circular side of a cylinder, and is a glass tube Since the end of the discharge space side in the tube axis direction is chamfered so as not to have an acute angle portion as shown in FIG. It does not have an acute angle portion within a range where peripheral corona discharge can occur.

The metal cap 105 and the metal cap 106 do not have a fixed shape, such as a metal foil or a metal tape, but change shape when force is applied from the outside, and plasticity that retains the shape as it is when force is applied. Unlike the above member, it is a non-plastic metal member that has a fixed shape and does not easily change its shape even when a force is applied from the outside.
In this embodiment, the metal cap 105 and the metal cap 106 have an overall length of 23.0 mm, an outer diameter of the cylindrical portion of 4.5 mm, an inner diameter of 4.1 mm, and a wall thickness of 0.2 mm, and are like metal foil or metal tape. Since it is not necessary to have plasticity, it can be set thick so that scratches and peeling do not easily occur.

In general, it is known that corona discharge starts to occur when the electric field strength in the outward normal direction on the metal surface exceeds 3 × 10 ⁴ V / cm. In this embodiment, corona discharge occurs. It is sufficient to assume a range to be obtained of 0.5 mm.
Here, since the outer diameter of the glass tube 101 is 4.0 mm and the inner diameter of the metal caps 105 and 106 is 4.1 mm, the average gap between the glass tube 101 and the metal caps 105 and 106 is 0.05 mm.

The adhesive material 107 includes a glass frit having a relatively low melting point (transition point 308 ° C., softening point 348 ° C.), a gap between one end of the glass tube 101 and the metal cap 105, and the other tube of the glass tube 101. The gap between the end and the metal cap 106 is filled and heated to bond them. Details of the procedure of the bonding step will be described later.
In this embodiment, the adhesive material 107 is an amorphous PbO.B ₂ O ₃ system glass frit powder having a transition point of 308 ° C. and a softening point of 348 ° C., and this is a bead-like shape having a diameter of 0.10 mm. What mixed glass and the binder which volatilizes by baking was diluted with diluents, such as toluene and xylene, and this mixing member was shape | molded and used for the column shape of 4.0 mm in diameter and 4.0 mm in height. Here, the reason why the bead-shaped glass having a uniform size is mixed is to keep the gap between the glass tube and the metal cap relatively uniform throughout. For example, CBBP, CBB, and CBP made of CaO, BaO, B ₂ O ₃ , and P ₂ O ₅ may be used as the glass frit.

  Further, the adhesive material 107 may contain 15 to 100% by weight of low-melting glass after firing, does not contain a conductive substance such as silver, and has a dielectric constant comparable to that of the glass tube 101. Also good. In this case, since the adhesive material 107 is integrated with the glass tube 101 by a melting process to become one dielectric, the dielectric material is formed by integrating the adhesive material 107 and the glass tube 101 and the metal caps 105 and 106. The external electrodes are in close contact with each other and corona discharge does not occur.

  Further, the adhesive material 107 may include a conductive substance such as silver, aluminum, and copper after firing, and the dielectric constant may be equal to or higher than that of the glass tube 101. In this case, since the metal caps 105 and 106 and the adhesive material 107 are electrically coupled and integrated to form an external electrode, the metal caps 105 and 106 and the adhesive material 107 are respectively integrated. The formed external electrode and the dielectric made of the glass tube 101 are in close contact with each other, so that corona discharge does not occur.

As shown in an enlarged manner in FIG. 2, it is preferable that the space between the discharge space side end in the tube axis direction of the glass tube of each metal cap and the glass tube is filled with the adhesive material 107 because the electrode area becomes stable. .
<Operation>
FIG. 3 is a diagram showing the procedure of the bonding process between the glass tube and the metal cap.

The procedure of the bonding process between the glass tube and the metal cap will be described below with reference to FIG.
(1) The disc-shaped adhesive material as described above is inserted into the inner bottom of the metal cap 105, and attached to one end of the glass tube 101 (step S1).
(2) A spring-type assembly jig that presses the metal cap 105 attached to one end of the glass tube 101 toward the center of the glass tube 101 is attached (step S2).

(3) With the assembly jig mounted, the metal cap 105 side is faced down and passed through a tunnel-type heating furnace (step S3).
(4) After returning to normal temperature, each of the adhesive materials formed in a disk shape as described above is inserted into the inner bottom of the metal cap 106, and attached to the other tube end of the glass tube 101 (step S4). ).

(5) A spring-type assembly jig, which presses the metal cap 106 attached to the other end of the glass tube 101 toward the center of the glass tube 101, is attached (step S5).
(6) With the assembly jig mounted, the metal cap 106 side is faced down and passed through a tunnel-type heating furnace (step S6).
In the present embodiment, the heating furnace is set at a processing temperature of 450 ° C. and a processing time of about 10 minutes.

At a processing temperature of 450 ° C, the glass tube and metal cap do not melt, and the glass frit melts and penetrates the entire gap between the glass tube and metal cap by capillarity, eliminating the air gap and generating corona discharge. It becomes difficult to do.
In addition, if the glass tube and the metal cap are simply bonded, a processing time of about 1.5 minutes is sufficient, but here the processing time is about 10 minutes, and the state where the glass frit is melted is lengthened. The gap is filled without leaving a void, and bubbles due to the diluting liquid that has volatilized are made difficult to remain.

In addition, the temperature setting of the heating furnace is set to two stages of a first temperature lower than the melting temperature of the glass frit for volatilizing the binder and a second temperature for melting the glass frit. Before the frit is melted, the generation of bubbles in the adhesive material can be suppressed by sufficiently volatilizing the diluting liquid at the first temperature.
For example, in the case where the diluent is toluene and has a viscosity of 1020 cp, drying for 10 minutes at the first temperature (120 ° C.) and baking for 4 minutes at the second temperature (620 ° C.) can suppress the generation of bubbles in the adhesive material. it can.

<Test 1>
FIG. 4 is a diagram showing the results of a high-temperature and high-humidity test 1 performed to verify the durability of each of a conventional resin-based conductive pressure-sensitive adhesive and an adhesive material including low-melting glass.
In the high-temperature and high-humidity test 1, a conductive paste for electrode formation using a special fine polymer as a binder material and an adhesive material having a low melting point glass content of 10% are uniformly applied to a glass tube and fired. Ten pieces, 20 pieces in total, were allowed to stand for 500 hours at an ambient temperature of 60 ° C. and a humidity of 90%, and the presence or absence of peeling was verified.

As shown in FIG. 4, 10 out of 10 fine polymer-bonded pastes were peeled off, and the glass-bonded adhesive material had 0 peels out of 10.
From the above results, the paste of fine polymer cannot clear the high-temperature and high-humidity test and is inappropriate in the durability of peeling, whereas the adhesive material of glass adhesion can clear the high-temperature and high-humidity test, It is suitable for durability.

<Test 2>
FIG. 5 is a diagram showing the results of the high-temperature and high-humidity test 2 performed to verify the appropriate value of the content of the low-melting glass in the adhesive material 107 after firing.
In the high-temperature and high-humidity test 2, an adhesive material having a low-melting-point glass content of 1 to 20% by weight, uniformly applied to a glass tube and baked, 100 pieces each, a total of 2000 pieces, were measured at an ambient temperature. After leaving at 60 ° C. and a humidity of 90% for 500 hours, insertion into and removal from the electrode socket were repeated 20 times to verify the presence or absence of peeling.

As shown in FIG. 5, the number of peels is zero for the low melting point glass content of 15 to 20% by weight, and the whole number is peeled for the low melting point glass content of 1 to 2% by weight. It can be seen that as the glass content decreases, the rate of occurrence of peeling increases.
From the above results, it can be said that the adhesive material 107 desirably contains 15% by weight or more of low-melting glass after firing.

<Summary>
As described above, according to the first embodiment of the present invention, since the outer electrode is made of a metal member, scratches and peeling are unlikely to occur, and the gap between the glass tube and the metal member is filled with the adhesive material. In addition, since the adhesive material is low melting glass, the durability is not inferior to the glass tube, and the results of the high-temperature and high-humidity test are also good, so it is estimated that it has a life that is comparable to the life of other parts it can.
(Embodiment 2)
<Overview>
The second embodiment of the present invention suppresses the generation of corona discharge by improving the shape of the external electrode in the dielectric barrier discharge lamp of the first embodiment.

<Configuration>
FIG. 6A is a diagram showing an outline of the dielectric barrier discharge lamp 200 according to the second embodiment of the present invention.
As shown in FIG. 6A, the dielectric barrier discharge lamp 200 according to the second embodiment of the present invention is a fluorescent lamp having an outer electrode on the outer periphery of the end of a tubular glass bulb. A body 102, mercury 103, buffer rare gas 104, metal cap 201, metal cap 202, and adhesive material 107 are provided.

FIG. 6B is a diagram illustrating an appearance of the metal cap 201.
The appearance of the metal cap 202 is the same as that of the metal cap 201.
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.
The metal cap 201 and the metal cap 202 have a shape in which the discharge space side end portions of the metal cap 105 and the metal cap 106 in the first embodiment are expanded outward from the cylindrical main portion. In the present embodiment, the range in which corona discharge can occur is assumed to be 0.5 mm as in the first embodiment. Therefore, the inner diameter of the end of the discharge side end is φ5.1 mm, and the dimensions of the other portions are metal. The cap 105 and the metal cap 106 are the same.

In addition, as shown in an enlarged manner in FIG. 6, it is preferable that the space between the discharge space side end in the tube axis direction of the glass tube of each metal cap and the glass tube is filled with the adhesive material 107 because the electrode area becomes stable. .
<Summary>
As described above, according to the second embodiment of the present invention, the discharge space side end of the metal cap is widened outward from the outer periphery of the glass tube, and its tip is widened outward from the cylindrical main portion. In addition, since there is no sharp portion within the range where corona discharge can occur, the occurrence of corona discharge at the end portion on the discharge space side can be reliably suppressed.

Note that the shape of the metal cap is not limited to the first and second embodiments, and may be any thickness and shape that does not easily cause scratches or peeling. For example, the protrusion of the adhesive material In order to remove bubbles, holes may be made in the bottom and side surfaces, slits may be made in the side surfaces, a net shape may be used, or a cylindrical shape may be used.
(Embodiment 3)
<Overview>
Therefore, Embodiment 3 of the present invention is an improvement when the dielectric barrier discharge lamp is attached to the electrode socket, and the hardness of the metal cap is made higher than the hardness of the electrode socket so that scratches and peeling are less likely to occur. Further, since a high voltage is applied to the dielectric barrier discharge lamp, the metal cap has a barring for preventing it from coming off so that it does not fall off easily.

<Configuration>
FIG. 7A is a diagram showing an outline of a dielectric barrier discharge lamp 300 according to Embodiment 3 of the present invention.
As shown in FIG. 7 (a), a dielectric barrier discharge lamp 300 according to the third embodiment of the present invention is a fluorescent lamp having an outer electrode on the outer periphery of the end of a tubular glass bulb. A body 102, mercury 103, buffer rare gas 104, metal cap 310, metal cap 320, and adhesive material 107 are provided.

FIG. 7B is a diagram showing the appearance of the metal cap 310 and the metal cap 320.
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.
FIG. 8 is a diagram showing an outline of the socket base 400 in the third embodiment of the present invention.
As shown in FIG. 8, the socket base 400 is a device that holds and lights the dielectric barrier discharge lamp 300, and includes an electrode socket 410 and an electrode socket 420.

The metal cap 310 has a shape in which the metal cap 105 according to the first embodiment is provided with a convex portion 311 and a convex portion 312 having a barb for preventing slipping, and is made of a metal having a hardness higher than that of the electrode socket 410. .
Similarly, the metal cap 320 has a shape in which the metal cap 106 according to the first embodiment is provided with a convex portion 321 and a convex portion 322 having a barb for preventing removal, and is formed of a metal having a hardness higher than that of the electrode socket 420. ing.

Here, the convex portions 311, 312, 321, and 322 have the same size.
The electrode socket 410 is electrically connected to the metal cap 310 and holds the dielectric barrier discharge lamp 300. The electrode socket 410 locks the barb of the convex portion 311 and fits the convex portion 311. It includes a recess 412 that locks the barb 312 and fits with the protrusion 312, and is made of a metal having a lower hardness than the metal cap 310. Here, the concave portion 411 is positioned in the longitudinal direction of the fluorescent lamp and fits the convex portion 311, and the concave portion 412 is positioned in the longitudinal direction of the fluorescent lamp and fits the convex portion 312. .

  The electrode socket 420 is electrically connected to the metal cap 320 and holds the dielectric barrier discharge lamp 300. The electrode socket 420 locks the barb of the convex portion 321 and fits the convex portion 321, and the convex portion. It includes a concave portion 422 that locks the barb 322 and fits with the convex portion 322, and is made of a metal having a hardness lower than that of the metal cap 320. Here, the concave portion 421 is sized to fit with the convex portion 321 leaving a gap in the longitudinal direction of the fluorescent lamp, and the concave portion 422 is sized to fit with the convex portion 322 leaving a gap in the longitudinal direction of the fluorescent lamp. It is.

Here, for example, the metal cap 310 and the metal cap 320 are made of stainless steel, and the electrode socket 410 and the electrode socket 420 are made of a copper alloy such as phosphor bronze, aluminum, or the like.
<Summary>
As described above, according to the third embodiment of the present invention, the metal cap is made of a metal having a hardness higher than that of the electrode socket.

Further, since the convex portion and the concave portion are fitted and locked by barbing, it is possible to prevent the fluorescent lamp from falling off.
In addition, since there is play in one of the recesses, attachment is possible even if there is a variation in the distance between the metal cap 310 and the metal cap 320 or the distance between the electrode socket 410 and the electrode socket 420. The position can be adjusted based on the side.

  The second embodiment and the third embodiment may be combined.

  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 be scratched or peeled off, hardly generates corona discharge, and has a life comparable to that of other portions. Can contribute to extending the service life of the product, and its industrial utility value is extremely high.

It is a figure which shows the outline | summary of the liquid crystal television in Embodiment 1 of this invention. FIG. 2A is a diagram showing an outline of the dielectric barrier discharge lamp 100 according to Embodiment 1 of the present invention.

FIG. 2B is a diagram showing the appearance of the metal cap 105.
It is a figure which shows the procedure of the adhesion process of a glass tube and a metal cap. It is a figure which shows the result of the high-temperature, high-humidity test 1 performed in order to verify durability of each adhesive material containing the conventional resin-type conductive adhesive and low melting glass. It is a figure which shows the result of the high temperature, high humidity test 2 performed in order to verify the appropriate value of content of the low melting glass in the adhesive material 107 after baking. FIG. 6A is a diagram showing an outline of the dielectric barrier discharge lamp 200 according to the second embodiment of the present invention.

FIG. 6B is a diagram illustrating an appearance of the metal cap 201.
FIG. 7A is a diagram showing an outline of a dielectric barrier discharge lamp 300 according to Embodiment 3 of the present invention. FIG. 7B is a view showing the appearance of the metal cap 301. It is a figure which shows the outline | summary of the socket stand 400 in Embodiment 3 of this invention. It is a figure which shows the outline | summary of the conventional typical dielectric barrier discharge lamp 90. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Liquid crystal television 11 Liquid crystal screen unit 12 Backlight unit 13 High frequency electronic ballast 100 Dielectric barrier discharge lamp 101 Glass tube 102 Phosphor 103 Mercury 104 Buffer rare gas 105 Metal cap 106 Metal cap 107 Adhesive material 200 Dielectric barrier discharge lamp 201 Metal Cap 202 Metal Cap 300 Dielectric Barrier Discharge Lamp 310 Metal Cap 311 Convex 312 Convex 320 Metal Cap 321 Convex 322 Convex 400 Socket Base 410 Electrode Socket 411 Concave 412 Concave 420 Electrode Socket 421 Concave 422 Concave

Claims (15)

A fluorescent lamp comprising an external electrode on the outer periphery of the end of a tubular glass bulb,
The external electrode has a metal member on the outer shell,
A fluorescent lamp, wherein a gap between the glass bulb and the metal member is filled with an adhesive material including low-melting glass. The fluorescent lamp according to claim 1, wherein the adhesive material contains 15% by weight or more of the low-melting glass. The low melting point glass contained in the adhesive material has a lower melting point than the glass bulb,
The dielectric constant of the adhesive material is comparable to the dielectric constant of the glass bulb,
The fluorescent lamp according to claim 2, wherein the adhesive material is integrated with the glass bulb by a melting process. The fluorescent lamp according to claim 1, wherein a dielectric constant of the adhesive material is equal to or higher than a dielectric constant of the glass bulb. The fluorescent lamp according to claim 4, wherein the adhesive material includes a conductive substance. The fluorescent lamp according to claim 5, wherein the metal member and the adhesive material are electrically coupled and integrated to form the external electrode. The fluorescent lamp according to claim 1, wherein the metal member is a cap-shaped metal cap and is fitted in the glass bulb. The metal cap is
8. The fluorescent lamp according to claim 7, wherein there is no acute angle portion within a range where corona discharge around the outer periphery of the glass bulb can occur. The discharge space side end in the tube axis direction of the metal cap is
The fluorescent lamp according to claim 8, wherein the fluorescent lamp is widened outward from the outer periphery of the glass bulb and has a tip outside the range. A fluorescent lamp unit for holding and lighting a fluorescent lamp,
The fluorescent lamp according to any one of claims 1 to 9,
A fluorescent lamp unit comprising: an electrode socket electrically connected to the external electrode and holding the fluorescent lamp. The fluorescent lamp unit according to claim 10, wherein the hardness of the metal member is higher than the hardness of the electrode socket. The metal member includes a convex portion having a barb for preventing slipping,
The fluorescent lamp unit according to claim 10, wherein the electrode socket includes a concave portion that locks the barb and fits into the convex portion. There are two external electrodes at both ends of the fluorescent lamp,
There are two electrode sockets for two external electrodes,
The two convex portions have the same size,
One of the concave portions is positioned in the longitudinal direction of the fluorescent lamp and fits with the convex portion, and the other has a size that fits with the convex portion leaving a gap in the longitudinal direction of the fluorescent lamp. The fluorescent lamp unit according to claim 12. It is a direct type backlight unit used for LCD TVs,
A plurality of fluorescent lamps according to any one of claims 1 to 9,
A backlight unit comprising: one high-frequency electronic ballast that turns on all of the plurality of fluorescent lamps. A liquid crystal television with a direct backlight unit,
The backlight unit is
A plurality of fluorescent lamps according to any one of claims 1 to 9,
A liquid crystal television, comprising: one high-frequency electronic ballast that turns on all of the plurality of fluorescent lamps.

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