JP2008146841A - Electrode mount, discharge lamp, backlight unit, and liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode mount capable of mounting an electrode main body on an inner face of a glass bulb in high accuracy even with narrow wires, to provide a discharge lamp, to provide a backlight unit, and to provide a liquid crystal display. <P>SOLUTION: In the discharge lamp 100 with a phosphor layer 110 formed on an inner wall of the glass bulb 101, with rare gas or rare gas and mercury sealed inside the glass bulb 101, lead wires 106 airtightly sealed onto either end of the glass bulb 101, and an electrode 102 connected to each of the terminal of the lead wires 106 inside the glass bulb 101, the electrode 102 is fitted with its bottom face at a rear end in contact with a space side end face of the glass bulb 101, with its tip end part and an outer periphery face protruded and exposed into the space of the glass bulb 101. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrode mount, a discharge lamp, and a backlight unit using the discharge lamp as a light source.

A discharge lamp (cold cathode fluorescent lamp) used in a backlight unit of a liquid crystal display device (hereinafter referred to as LCD) is becoming longer and thinner with the increase in size and thickness of the LCD. This discharge lamp includes a cylindrical glass bulb and cold cathode electrodes sealed at both ends of the glass bulb. The electrode has, for example, a bottomed cylindrical electrode body and a lead wire attached to the bottom thereof, and a part of the lead wire is sealed to the end of the glass bulb via glass beads. At this time, there is a gap between the electrode-bottomed portion and the glass bead end face facing it (Patent Document 1).
JP 2004-253141 A

  2. Description of the Related Art In recent years, discharge lamps have become thinner as liquid crystal display devices become thinner, and in accordance with this, miniaturization of electrodes (main bodies) is progressing. That is, the bottomed cylindrical electrode body has a minute gap with respect to the inner surface of the glass bulb to maximize the electrode outer diameter in order to extend the life.

  As the discharge lamp is made thinner, if the lead wire is thick, the dimensional change due to thermal expansion is large, and the sealing margin in the radial direction of the glass beads is also small, and cracking of the sealed portion due to thermal expansion occurs. If the wire diameter of the lead wire is reduced in order to suppress the cracking, the bottomed cylindrical electrode body is inclined with respect to the tube axis and cannot be held by the lead wire, and the tip of the electrode body is placed on the inner surface of the thin glass bulb. There is a problem that the glass bulb inner surface may melt due to contact and the electrode heat concentrates on the contact portion during lighting.

  In view of the above problems, the present invention provides an electrode mount, a discharge lamp, a backlight unit using the lamp, and a liquid crystal display device, which can attach an electrode body to a glass bulb inner surface with high accuracy even with a thin lead wire. The purpose is to provide.

  The electrode mount according to claim 1 of the present invention includes an electrode having a flat surface on the outer peripheral surface, a lead wire connected to the electrode flat surface, and a glass bead or a glass stem holding the lead wire, A flat surface is provided in contact with an end surface of the glass bead or the glass stem.

  The electrode mount according to claim 2 of the present invention is characterized in that the electrode has a bottomed cylindrical shape, a rod shape, or a conical shape.

  The electrode mount according to claim 3 of the present invention is characterized in that the bottomed cylindrical or rod-like electrode is formed in a tapered shape whose diameter is smaller on the electrode rear end side than the electrode front end portion.

  In the electrode mount according to claim 4 of the present invention, the electrode has a lead wire connected to the center of the electrode plane, and the electrode plane is the extension when viewed from the outside of the lead wire. The glass beads or the glass stem are in contact with the end faces of the glass beads in a state of surrounding the lead wires.

  In the electrode mount according to claim 5 of the present invention, at least two lead wires connected to the electrode plane are held on the glass beads or the glass stem, and an air supply / exhaust pipe is provided between the two lead wires. It is characterized by being arranged in.

  In the electrode mount according to claim 6 of the present invention, the outer peripheral edge of the electrode plane is not in contact with the end surface of the glass bead or the glass stem when viewed from the outside of the lead wire. Features.

  In the electrode mount according to claim 7 of the present invention, the plane of the electrode is in surface contact with the end face of the glass bead or the glass stem.

  In the electrode mount according to claim 8 of the present invention, any one of the electrode and the glass bead or the glass stem is located between the plane of the electrode and the end face of the glass bead or the glass stem so as to surround the center of the electrode. Protruding portions are provided on either side, and the electrode is held by the glass beads or the glass stem through the protruding portions.

  In the electrode mount according to claim 9 of the present invention, in the connection portion where the electrode plane and the lead wire are connected, the concave portion in which the connection portion is accommodated is any of the electrode plane and the glass beads or the glass stem. One of them is provided.

  In the electrode mount according to claim 10 of the present invention, in the longitudinal direction position of the lead wire, the connection position of the connection portion is substantially the same position as the position where the electrode plane and the end face of the glass bead or glass stem are in contact with each other. It is characterized by being provided in.

  In the electrode mount according to claim 11 of the present invention, the linear expansion coefficient with respect to the lead wire is characterized in that the glass bead or the glass stem is substantially the same material and is the same material or different material from the electrode. .

  The electrode mount according to claim 12 of the present invention is characterized in that the electrode is formed of nickel, molybdenum, niobium, tantalum, titanium, tungsten, or an alloy material thereof.

  The electrode mount according to claim 13 of the present invention is characterized in that at least a part of the lead wire is made of a sealing wire.

  In a discharge lamp according to a fourteenth aspect of the present invention, in the discharge lamp having a pair of electrodes at both ends of the glass bulb, at least one of the pair of electrodes is the electrode mount according to any one of the first to thirteenth aspects. It is sealed at the end of the through hole of the glass bulb.

  In the discharge lamp according to claim 15 of the present invention, a phosphor layer is formed on the inner wall of the glass bulb, rare gas or rare gas and mercury are enclosed inside the glass bulb, and leads are provided at both ends of the glass bulb. In a discharge lamp in which a wire is hermetically sealed and an electrode is connected to each of the end portions of the lead wire on the inner side of the glass bulb, the electrode has a front end portion and an outer peripheral surface at the space of the glass bulb. A discharge lamp characterized in that a flat surface on the rear end side of the electrode is provided in contact with a space side end surface of the glass bulb in a state of protruding and exposed inside.

  The discharge lamp according to claim 16 of the present invention is characterized in that the electrode has a bottomed cylindrical shape, a rod shape, or a conical shape.

  The discharge lamp according to claim 17 of the present invention is characterized in that the bottomed cylindrical or rod-like electrode is formed in a tapered shape whose diameter is smaller on the electrode rear end side than the electrode front end portion.

In the discharge lamp according to claim 18 of the present invention, the minimum distance (d ₁ ) between the inner peripheral surface of the glass bulb and the outer peripheral surface of the cylindrical electrode is in the range of 0 <d ₁ ≦ 0.2 [mm]. It is characterized by regulation.

  In the discharge lamp according to claim 19 of the present invention, the electrode has the lead wire connected to the center portion of the electrode bottom surface, and the electrode bottom surface is viewed from the outside of the lead wire. The lead wire is in contact with the inner end face of the glass bulb in a state of surrounding the lead wire.

  In the discharge lamp according to claim 20 of the present invention, at least one of the sealing portions of the glass bulb has at least two lead wires connected to the bottom surface of the electrode, and air supply / exhaust between the two lead wires. A tube is arranged.

  The discharge lamp according to claim 21 of the present invention is characterized in that the electrode is formed of nickel, molybdenum, niobium, tantalum, titanium, tungsten or an alloy material thereof.

  The discharge lamp according to claim 22 of the present invention is characterized in that at least a part of the lead wire is made of a sealing wire.

  The discharge lamp according to claim 23 of the present invention is characterized in that the lead wire is a sealing alloy containing Fe, Ni, and Co, and the glass bulb is made of borosilicate glass.

  The discharge lamp according to claim 24 of the present invention is characterized in that the borosilicate glass is doped with an ultraviolet absorber.

  In the discharge lamp according to claim 25 of the present invention, the ultraviolet absorber is composed of any one or a combination of titanium oxide and cerium oxide.

  In the discharge lamp according to claim 26 of the present invention, the lead wire is made of molybdenum or tungsten, and the glass bulb is made of hard glass.

  In the discharge lamp according to claim 27 of the present invention, the lead wire is a dumet wire, and the glass bulb is made of soft glass.

  A discharge lamp according to claim 28 of the present invention is provided with a power supply terminal that is provided outside both ends of the glass bulb and is joined to a lead wire of the electrode, and the power supply terminal is joined to the lead wire. The portion other than the portion is a thin film formed on the outer surface of the glass bulb.

  In a discharge lamp according to a twenty-ninth aspect of the present invention, the thin film has a thickness of 5 to 120 [μm].

  In a discharge lamp according to a thirty-third aspect of the present invention, the lead wire is joined to the power supply terminal at a protruding portion that protrudes from an outer surface of the glass bulb toward a tube axis direction of the glass bulb. The length of the portion in the tube axis direction is 1 [mm] or less.

  In a discharge lamp according to a thirty-first aspect of the present invention, at least the joint portion of the power supply terminal is formed of solder.

  The backlight unit according to claim 32 of the present invention is characterized in that the discharge lamp according to any one of claims 14 to 31 is mounted as a light source.

  In a liquid crystal display device according to a thirty-third aspect of the present invention, the backlight unit is mounted.

  According to the electrode mount configuration of the first aspect of the present invention, since the electrode plane side is provided in contact with the end surface side, the electrode can be attached to the glass bead or the glass stem with high precision even with a thin lead wire. . In addition, the electrode can absorb the dimensional change in the radial direction due to thermal expansion on the discharge space side, and the thin lead wire can reduce the dimensional change in the radial direction due to thermal expansion. Can be prevented. Further, when a thin lead wire is used, the sealing margin in the radial direction of the glass beads or the glass stem can be increased, and further, cracking of the sealing portion due to thermal expansion can be suppressed.

With the electrode mount configuration according to claim 2 of the present invention, the discharge area is reduced particularly when the inner diameter (D ₁ ) of the glass bulb is as thin as 1 to 8 [mm] by making the shape of the electrode into a bottomed cylindrical shape. This increases the life of the electrode.

  With the electrode mount configuration according to claim 3 of the present invention, the bottomed cylindrical or rod-like electrode is formed in a tapered shape whose diameter is smaller on the electrode rear end side than the electrode front end portion. When glass beads or glass stems are sealed to the portion, contact between the outer peripheral surface of the tapered electrode having a small diameter and the inner peripheral surface of the glass bulb can be prevented. As a result, the crack of the sealing part can be suppressed.

  According to the electrode mount structure of claim 4 of the present invention, when viewed from the outside of the lead wire, the electrode plane is in contact with the end face of the glass bead or the glass stem in a state of surrounding the lead wire. The lead wire can attach the electrode to the glass bead or the glass stem with high accuracy and stubbornly.

According to the electrode mount configuration of claim 5 of the present invention, at least two lead wires connected to the electrode plane are held on the glass beads or the glass stem, and the air supply / exhaust pipe is disposed between the two lead wires. Therefore, even when the inner diameter (D ₁ ) of the glass bulb is larger than 8 [mm], the electrode can be attached to the glass bead or the glass stem with high accuracy and stubbornly with a thin lead wire.

  According to the electrode mount configuration of claim 6 of the present invention, the outer peripheral edge of the electrode plane is not in contact with the end surface of the glass bead or the glass stem when viewed from the outside of the lead wire. Even if the outer peripheral edge portion of the electrode plane changes due to thermal expansion, it can smoothly expand and contract in the radial direction of the electrode without being caught by the end face of the glass bead or the glass stem. As a result, it is possible to suppress breakage of the glass beads or the glass stem caused by the expansion and contraction of the electrodes in the radial direction.

  According to the electrode mount configuration of claim 7 of the present invention, since the plane of the electrode is in surface contact with the end face of the glass bead or the glass stem, the electrode and the lead wire and the glass bead or the electrode and the lead wire and the glass stem are Even if the linear expansion coefficients are different, the electrode can expand and contract in the radial direction and the axial direction. As a result, it is possible to suppress the breakage of the glass beads or the glass stem, which is caused by the expansion and contraction in the axial direction of the electrode, the lead wire and the glass stem, or the electrode, the lead wire and the glass stem.

  With the electrode mount configuration according to the eighth aspect of the present invention, since the electrode is held on the glass bead or the glass stem via the convex portion, the electrode can smoothly expand and contract in the radial direction due to thermal expansion. . As a result, it is possible to suppress breakage of the glass beads or the glass stem caused by the expansion and contraction of the electrodes in the radial direction.

  According to the electrode mount configuration of claim 9 of the present invention, the connection portion where the electrode plane and the lead wire are connected is provided with a recess in which the connection portion is accommodated in one of the electrode plane and the glass bead or the glass stem. Therefore, even if the connecting portion is thermally expanded, the recess can absorb the thermal expansion. As a result, deformation of the electrode and breakage of the glass beads or the glass stem can be prevented.

  According to the electrode mount configuration of claim 10 of the present invention, in the longitudinal position of the lead wire, the connection position of the connection portion is substantially the same as the position where the electrode plane and the end face of the glass bead or glass stem contact each other. By providing at the position, even if the linear expansion coefficient of the electrode and the lead wire or the glass bead or the glass stem is different, the electrode and the lead wire or the glass bead or the glass stem expands and contracts based on the connection position of the connecting portion. As a result, the electrode can be attached to the glass bead or the glass stem with high accuracy and stubbornly.

  According to the electrode mount structure of claim 11 of the present invention, regarding the linear expansion coefficient with respect to the lead wire, even if the glass beads or the glass stem are substantially the same material and the same material or different material as the electrode, the glass beads Alternatively, the electrode expands and contracts with reference to the electrode plane in contact with the glass stem. As a result, even if it is the said different material, the crack of the glass bead or the glass stem resulting from an electrode linear expansion coefficient can be prevented.

  According to the electrode mount structure of the twelfth aspect of the present invention, if nickel is used as the electrode, the cost can be reduced, and if molybdenum, niobium, tantalum, titanium, tungsten or an alloy material thereof is used, the life can be extended.

  According to the electrode mount configuration of the thirteenth aspect of the present invention, since at least a part of the lead wire is composed of the sealing wire, the airtightness with the glass beads or the glass stem can be maintained.

  According to the discharge lamp configuration of the fourteenth aspect of the present invention, since the electrode mount according to any one of the first to thirteenth aspects is sealed to the end portion of the through hole of the glass bulb, the end of the through hole of the glass bulb The electrode mount can be attached to the part with high accuracy. Also, when sealing the electrode mount to the glass bulb, the electrode can absorb the dimensional change in the radial direction due to thermal expansion on the discharge space side, and the thin lead wire can reduce the dimensional change in the radial direction due to thermal expansion, The crack of the sealing part resulting from thermal expansion can be prevented. Moreover, since it is a thin lead wire, it is possible to increase the sealing margin in the radial direction of the glass beads or the glass stem, and to further suppress the cracking of the sealing portion due to thermal expansion. Further, since the electrode plane side is provided in contact with the end face side, the effective light emission length is increased by the gap relative to the conventional discharge lamp having a gap between the electrode plane and the glass bead end face facing the electrode plane. can do. In addition, since there is no gap between the bottom of the electrode and the glass bead end face facing it, it is difficult for the discharge to transfer to the lead wire of the electrode mount during lighting, and the lead wire sputtering can be suppressed to suppress the mercury consumption rate. Thus, the life of the lamp can be extended.

According to the discharge lamp configuration of the fifteenth aspect of the present invention, various shapes such as a bottomed cylindrical shape, a rod shape or a conical shape can be used as the electrode. Particularly electrode, using the bottomed cylindrical, to concentrate discharge to the cylindrical inner surface, a glass bulb outside diameter of the bottomed cylindrical portion inner diameter of the glass bulb (D ₁₎ is in a slender and 1~6mm It can be enlarged to the vicinity of the inner diameter. As a result, the discharge area on the inner surface of the bottomed cylindrical part is increased, and the life of the electrode can be extended and discharge on the outer peripheral surface of the bottomed cylindrical part can be prevented. Can be suppressed.

According to the discharge lamp configuration of claim 16 of the present invention, since the bottom surface of the electrode is provided in contact with the inner end face side of the glass bulb sealed, the electrode can be held with high precision with a thin lead wire, In addition, the effective light emission length can be increased by the gap relative to the conventional discharge lamp having a gap between the electrode bottomed portion and the sealed inner end face of the glass bulb facing it. Moreover, since it is a bottomed cylindrical electrode, especially when the glass bulb has an inner diameter (D ₁ ) as thin as 1 to 8 [mm], the discharge area is increased, and the life of the electrode can be extended. Furthermore, since there is no gap between the electrode bottomed portion and the glass bead end face facing it, the discharge during lighting is less likely to shift to the lead wire, and the lead wire sputtering can be suppressed to suppress the mercury consumption rate. Furthermore, the lamp life can be extended.

  According to the discharge lamp configuration of the seventeenth aspect of the present invention, the bottomed cylindrical, rod-shaped, or conical electrode is formed in a tapered shape whose diameter is smaller on the electrode rear end side than the electrode front end portion. When the end portion is sealed, contact between the outer peripheral edge on the electrode plane side and the inner surface of the glass bulb on the glass bulb end portion side can be prevented.

According to the discharge lamp configuration of claim 18 of the present invention, the minimum distance (d ₁ ) between the inner peripheral surface of the glass bulb and the outer peripheral surface of the cylindrical electrode is regulated in the range of 0 <d ₁ ≦ 0.2 [mm]. Therefore, it becomes difficult for the discharge during lighting to shift to the outside of the cylindrical electrode, the excessive sputtering can be suppressed, the mercury consumption rate can be suppressed, and the life of the lamp can be extended.

  According to the discharge lamp configuration of the nineteenth aspect of the present invention, when viewed from the outside of the lead wire, the electrode bottom surface is in contact with the inner end surface of the glass bulb so as to surround the lead wire. Thus, the electrode can be stubbornly attached to the inner end face of the glass bulb with high accuracy.

According to the discharge lamp configuration of claim 20 of the present invention, at least one of the sealing portions of the glass bulb has at least two lead wires connected to the bottom surface of the electrode and a supply / exhaust pipe between the two lead wires. Since it is arranged, the electrode can be attached to the sealing portion of the glass bulb with high precision and stubbornly with a thin lead wire even when the inner diameter (D ₁ ) of the glass bulb is larger than 8 mm. .

  According to the discharge lamp configuration of claim 21 of the present invention, if nickel is used as an electrode, the cost can be reduced, and if molybdenum, niobium, tantalum, titanium, tungsten or an alloy material thereof is used, sputtering is suppressed and the consumption rate of mercury is suppressed. And can have a long service life.

  According to the discharge lamp configuration of the twenty-second aspect of the present invention, since at least a part of the lead wire is composed of the sealing wire, the hermeticity in the sealing portion of the glass bulb can be maintained.

  According to the discharge lamp configuration of claim 23 of the present invention, the lead wire is a sealing alloy containing Fe, Ni and Co, and the glass bulb is made of borosilicate glass. Airtightness can be maintained.

  According to the discharge lamp configuration of the twenty-fourth aspect of the present invention, since the ultraviolet absorber is doped, the ultraviolet rays can be shielded. As a result, it is possible to suppress deterioration and discoloration of the resin-made diffusion plate and reflecting plate due to ultraviolet rays, and consequently to suppress a reduction in surface luminance of the backlight unit.

  In the discharge lamp configuration according to claim 25 of the present invention, the ultraviolet absorber is made of any one or a combination of titanium oxide and cerium oxide, and in particular, 313 [nm] ultraviolet rays are sufficiently shielded. In particular, it is possible to suppress deterioration and discoloration of the diffusion plate or reflector made of PC resin, and consequently to suppress a decrease in surface luminance of the backlight unit.

  According to the discharge lamp configuration of claim 26 of the present invention, since the lead wire is made of molybdenum or tungsten and the glass bulb is made of hard glass, the hermeticity in the sealing portion of the glass bulb can be maintained.

  According to the discharge lamp configuration of the twenty-seventh aspect of the present invention, since the lead wire is a dumet wire and the glass bulb is made of soft glass, airtightness in the sealing portion of the glass bulb can be maintained. In particular, the copper that constitutes the jumet wire absorbs mercury and becomes ineffective mercury, which tends to be consumed, but there is no gap between the electrode bottom and the glass bead end face facing it, so it suppresses mercury adsorption on the jumet wire. Reduce the consumption rate of mercury.

  According to the discharge lamp configuration of claim 28 of the present invention, the power supply terminal joined to the lead wire of the electrode is formed as a thin film on the outer surface of the glass bulb. For this reason, the power supply terminal has a small outer surface area, and has a smaller heat dissipation effect than a conventional power supply terminal. Accordingly, the temperature of the lead wire is difficult to decrease, and mercury vapor is unlikely to collect around the lead wire, so that the phenomenon that the lamp luminance is lowered due to insufficient mercury vapor in the discharge path is less likely to occur.

  According to the discharge lamp configuration of the twenty-ninth aspect of the present invention, since the thickness of the thin film is 5 [μm] or more, sufficient lamp luminance can be obtained. That is, if the thickness of the thin film is less than 5 [μm], the thin film is easily peeled off from the glass bulb and cannot be used in actual use. On the other hand, if the thickness of the thin film increases and the area of the outer surface of the power supply terminal becomes too large, the heat dissipation effect of the power supply terminal becomes too large and the lead wire temperature decreases, so the cold cathode described in the background art In fluorescent lamps, mercury vapor may adhere to the periphery of the lead wire, but in this configuration, mercury vapor adheres to the lead wire because the lead wire is hidden by contacting the flat surface of the electrode and the space side end surface of the glass bulb. Can be suppressed. Therefore, there is a degree of freedom with respect to the thickness of the thin film, and even when the thickness of the thin film becomes too thick, the phenomenon that the mercury vapor in the discharge path is insufficient and the lamp brightness of the cold cathode fluorescent lamp decreases is unlikely to occur.

  In the discharge lamp configuration according to claim 30 of the present invention, when the length of the protruding portion of the lead wire in the tube axis direction is 1 [mm] or less, the discharge lamp of the general size described in the background art above The protruding portion does not protrude too much when viewed from the entire lamp. Therefore, there is little possibility that the protruding portion will collide and be bent, or the lead wire sealing portion may be damaged by the stress when the protruding portion is bent.

  According to the discharge lamp configuration of the thirty-first aspect of the present invention, when at least the joint portion of the power supply terminal is formed of solder, the power supply terminal can be formed by a known dipping method or the like. In particular, when the entire power supply terminal is formed of solder, it is easy to form the power supply terminal by the dipping method. Therefore, the discharge lamp can be manufactured more easily and at a lower cost than a conventional power supply terminal that requires assembly of components. In addition, since the solder generally has lower thermal conductivity than the iron / nickel alloy used for the cap-shaped power supply terminal, the heat radiation action of the power supply terminal can be further reduced. For this reason, the lamp brightness is less likely to decrease.

  With the configuration of the backlight unit according to the thirty-second aspect of the present invention, since the discharge lamp is mounted as a light source, the lamp unit has a sufficient lamp brightness while having a long life. Further, since the discharge lamp can increase the effective light emission length with respect to the entire length of the lamp, the unit can be miniaturized.

  With the configuration of the liquid crystal display device according to the thirty-third aspect of the present invention, since the discharge lamp is mounted, the lamp has a sufficient lamp brightness while having a long life. Further, since the discharge lamp can increase the effective light emission length with respect to the entire length of the lamp, the liquid crystal display device can be miniaturized.

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

  A liquid crystal display device 10 illustrated 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 of the liquid crystal television in Embodiment 1 of the present invention includes a color filter substrate, a liquid crystal, a TFT substrate, a drive module, etc. (not shown), and forms a color image based on an image signal from the outside. .

  FIG. 2 is a perspective view showing the backlight unit 12, and is a view showing the internal structure by cutting out a part of the front panel 21.

  The backlight unit 12, for example, covers a plurality of discharge lamps 100 (hereinafter referred to as “lamp 100”), a housing 13 having openings and housing these lamps 100, and covers the openings of the housing 13. A front panel 21 and a lighting device 50 (see FIGS. 3 and 4) for lighting a plurality of lamps 100 are provided.

  The housing 13 is, for example, a polyethylene terephthalate (PET) resin material, and a reflective surface is formed by depositing a metal such as aluminum on the inner surface 14 thereof.

  The lamp 100 has a straight tube shape, and, for example, 16 lamps 100 having power supply terminals 104 and 105 at both ends thereof are arranged in the casing 13 in a direct manner. The detailed configuration of the lamp 100 will be described later.

  As shown in FIGS. 3 and 4, the lighting device 50 includes a pair of U-shaped lamp holders 15 and 16 disposed on the inner surface on the housing 13 side at positions corresponding to the mounting positions of the lamps 100. For example, it is composed of a lighting control circuit 60 (see FIG. 4) that is attached to the outside of the housing 13 and that lights each lamp 100 connected to the lamp holders 15 and 16.

  The lamp holders 15 and 16 are electrically conductive and are formed by bending a plate material such as stainless steel or phosphor bronze. Each lamp holder 15 (16) includes sandwiching plates 15a and 15b (16a and 16b) and a connecting piece 15c (16c) that couples the sandwiching plates 15a and 15b (16a and 16b) at the lower edge. The sandwiching plates 15a and 15b and the sandwiching plates 16a and 16b are provided with recesses that match the outer shapes of the power supply terminals 104 and 105 of the lamp 100, and by inserting the power supply terminals 104 and 105 of the lamp 100 into the recesses. The lamps 100 are held by the lamp holders 15 and 16 by the leaf spring action of the clamping plates 15a and 15b and the clamping plates 16a and 16b, and the lamp holders 15 and 16 and the power feeding terminals 104 and 105 are electrically connected. Connected. Note that the width D of the holding portions of the lamp holders 15 and 16 is held within the region of the power supply terminals 104 and 105 provided outside the both ends of the lamp 100 in order to suppress the occurrence of corona discharge when the lamp is lit. The dimensions are designed to be possible.

  Electric power is supplied to each lamp 100 provided in the backlight unit 12 from the lighting control circuit 60 shown in FIG.

  Here, the lamp holders 15 and 16 hold each of the plurality of lamps 100 substantially in parallel at a predetermined interval, and one power supply terminal 104 (in FIG. 4) in the two adjacent lamps 100. The lamp holders 15 holding the power supply terminals 104) such as the lamps La1 and La2 and the lamps La7 and La8 are connected to each other. As a result, for example, a pseudo bent tube (U-shaped tube) can be formed by the two straight tubular lamps La1 and La2. According to this configuration, it is possible to form a pseudo-bent portion (U-shaped tube) that can reduce the number of inverters in half, and in addition to a lamp having a conventional bent portion, the lamp length direction (right and left in the housing) The brightness unevenness on both sides can be reduced, the sealing part of the lamp 100 can be prevented from being damaged, and the lamp 100 can be attached and detached with one touch.

  In addition, since a plurality of straight tubular lamps 100 having electrodes (such as “hollow electrode 102” described below) at both ends are arranged at predetermined intervals in the vertical direction, for example, Since the electrodes do not concentrate on one side, it is possible to prevent a temperature difference between the left and right sides of the housing 13 and, as a result, suppress uneven brightness of the backlight unit 12 due to the influence of the mercury vapor pressure of the lamp. be able to.

  Further, an insulating plate 17 made of polycarbonate that insulates the lamp holders 15, 16 and the housing 13 is disposed between the lamp holders 15, 16 and the housing 13. In the above embodiment, for example, the lamp holder 15 to which the power supply terminals 104 of the lamps La1 and La2 or the power supply terminals 104 of the lamps La7 and La8 are connected is one of the U-shaped lamp holders 15. One is welded to the metal substrate 15d. The lamp holder 15 is composed of a plurality of parts in which each of the U-shaped lamp holders 15 is welded to the metal substrate 15d so as to correspond to each lamp, but is not limited thereto. Alternatively, a single-component structure in which the holding plates 15a and 15b are cut and raised from a single plate by a known method may be used.

  4 shows an example of the lighting control circuit 60 provided in the lighting device 50. FIG. 4A shows the lighting control circuit 60, and FIG. 4B shows each of the lighting control circuits 60 connected to the lighting control circuit 60. It is a figure which shows the connection relation of the lamp | ramp 100. FIG.

  For example, as shown in (a), the lighting control circuit 60 includes a DC power supply (VDC), switch elements Q1 and Q2 connected to the DC power supply (VDC), capacitors C2 and C3, and switch elements Q1 and Q2. Supply gate signals for alternately turning on and off the step-up transformers T1 and T2 (or step-up transformers T7 and T8) and the switch elements Q1 and Q2 connected between the connection point and the connection point between the capacitor C2 and the capacitor C3. The inverter control IC is configured.

  On the secondary side of the transformer, as shown in (b), a series resonant circuit is formed by the transformer secondary side leakage inductance, the transformer output, the parasitic capacitance generated in the inner surface 14 of the housing 13 and the lamp, and the lighting The control circuit 60 supplies a sine wave current having a phase difference of approximately 180 degrees to two adjacent lamps La1 and La2.

  In addition, as shown in FIG. 4B, the plurality of lamps 100 are connected by connecting the lamp holders 15 holding one power supply terminal 104 of the two adjacent lamps La1 and La2 to each other. Not only the form which forms a tube (U-shaped tube), but as shown in FIG. 4C, the power supply terminals 104 of one of the two lamps 100 adjacent to each other or the power supply terminals 105 of the other are provided. Discharge lamps 100 that are connected and are arranged (for example, two adjacent lamps La1 and La2, two adjacent lamps La2 and La3, two adjacent lamps La3 and La4, and adjacent ones). Two matching lamps La9 and La10, two adjacent lamps La10 and La11, two adjacent lamps La11 and La12, and so on. One of the feeding terminals 104 of the two adjacent lamps La1 and La2 in the two lamps La1 and La2, the two adjacent lamps La2 and La3, and the two adjacent lamps La3 and La4). Lamp holder 15, so as to connect the other of the power supply terminals 105 of the next two adjacent lamps La2 and La3 and one of the next power supply terminals 104 of the two adjacent lamps La3 and La4, 16 may be arranged in a zigzag pattern. According to this configuration, the number of lighting control circuits can be further reduced, and harness processing can be performed simply by arranging the lamp holders 15 and 16 in a staggered manner, that is, the lighting control circuits for the lamp holders 15 and 16. Since it is not necessary to perform wiring processing from the harness, harness processing can be reduced.

  Returning to FIG. 2, the opening of the housing 13 is sealed with a translucent front panel 21 formed by laminating a diffusion plate 18 made of polycarbonate resin, a diffusion sheet 19, and a lens sheet 20 made of acrylic resin.

  The diffusing plate 18 and the diffusing sheet 19 in the front panel 21 scatter and diffuse the light emitted from the lamp 100, and the lens sheet 20 aligns the light in the normal direction of the sheet 20, Thus, the light emitted from the lamp 100 is configured to irradiate the front uniformly over the entire surface (light emitting surface) of the front panel 21.

  The lamp 100 is operated at a lighting frequency of 40 to 120 kHz and a lamp current of 3.5 to 8.5 [mA].

  FIG. 5 is a partially broken perspective view showing the cold cathode discharge lamp 100 according to the embodiment of the present invention, and FIG. 6 is an enlarged sectional view showing one end portion of the cold cathode discharge lamp 100.

As shown in FIG. 5, the lamp 100 is used as a light source of the backlight unit 12, and includes a glass bulb 101 and hollow electrodes sealed at both ends (ends of through holes) of the glass bulb 101. The electrode mount 103 which has 102, and the electric power feeding terminals 104 and 105 provided in the outer side of the both ends of the glass bulb 101 are provided. A phosphor layer 110 is formed on the inner surface of the glass bulb 101. The phosphor layer 110 includes, for example, a blue phosphor activated with europium-activated barium magnesium aluminate [BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ] (abbreviation: BAM-B), and a green phosphor co-activated with cerium / terbium. Rare earth phosphor comprising lanthanum phosphate [LaPO ₄ : Ce ³⁺ , Tb ³⁺ ] (abbreviation: LAP) and red phosphor comprising europium activated yttrium oxide [Y ₂ O ₃ : Eu ³⁺ ] (abbreviation: YOX) It is formed with. Further, for example, about 1200 μg of mercury and about 8 kPa (20 ° C.) neon / argon mixed gas (Ne 95% + Ar 5%) are sealed as the inside of the glass bulb 101.

  In addition, the structure of mercury and a noble gas is not limited to the said structure. For example, a neon / krypton mixed gas (Ne 95% + Kr 5%) may be enclosed as a rare gas. When a neon / krypton mixed gas is used as the rare gas, the lamp startability is improved and the lamp 100 can be lit at a low voltage.

  The glass bulb 101 is obtained by processing a hard glass tube made of borosilicate glass, and borosilicate glass is doped with titanium oxide as an ultraviolet absorber. The ultraviolet absorber is not limited to titanium oxide, and may be composed of any one or a combination of titanium oxide, cerium oxide, zinc oxide, and iron oxide. The glass bulb 101 includes a tubular glass bulb main body 108, and a sealing portion 109 formed using a pair of broken glass beads 107 (see FIG. 6) located on both sides of the glass bulb main body 108 in the longitudinal direction. It consists of The glass bulb body 108 has an annular cross section, and has a total length of 730 [mm], an outer diameter of 4 [mm], an inner diameter of 3 [mm], and a wall thickness of 0.5 [mm]. A lead wire 106 of the hollow electrode 102 is hermetically sealed to the sealing portion 109 with a width S of the glass bulb 101 in the tube axis A direction being 2 [mm] or more.

The electrode mount 103 includes an electrode having a substantially flat surface 102a on the outer peripheral surface, for example, a hollow electrode 102 having a bottom surface having a cylindrical shape, a lead wire 106 connected to a central portion of the electrode flat surface 102a (bottom surface), and the lead And a glass bead 107 holding the wire 106, and when viewed from the outside of the lead wire 106, the electrode flat surface 102 a is provided in contact with the end face side of the glass bead 107 so as to surround the lead wire 106. ing. In this embodiment, since the electrode plane 102 a is in surface contact with the end face of the glass bead 107, the hollow electrode 102 can be attached to the glass bead 107 with high accuracy even if the lead wire 106 is thin, for example. In addition, since there is no gap between the bottom surface of the hollow electrode 102 and the end face of the glass bead 107 facing it, a conventional discharge lamp having a gap between the hollow electrode and the sealed inner end face of the glass bulb facing it. On the other hand, the effective light emission length can be increased by the gap, and the discharge during lighting is less likely to transfer to the lead wire 106, and the sputtering of the lead wire 106 can be suppressed to reduce the mercury consumption rate. Thus, the life of the lamp can be extended. In addition, since the shape of the bottomed cylindrical electrode is used, the discharge area is increased particularly when the glass bulb has a thin inner diameter (D ₁ ) of 1 to 8 [mm], and the life of the electrode can be extended. Further, since the hollow electrode 102 can absorb the dimensional change in the radial direction due to thermal expansion on the discharge space side, and the thin lead wire 106 can reduce the dimensional change in the radial direction due to thermal expansion, the sealed portion caused by the thermal expansion Can be prevented. Furthermore, when the thin lead wire 106 is used, the sealing margin in the radial direction of the glass bead 107 can be increased, and cracking of the sealing portion due to thermal expansion can be further suppressed.

  Further, at the position in the longitudinal direction of the lead wire 106, the connection position of the connection portion where the electrode plane 102a and the lead wire 106 are connected is provided at substantially the same position as the position where the electrode plane 102a and the glass bead 107 are in contact. ing. With this configuration, even if the linear expansion coefficients of the hollow electrode 102 and the lead wire 106 or the glass bead 107 are different, the hollow electrode 102 can be firmly attached to the glass bead 107 with high accuracy.

  Further, when viewed from the outside of the lead wire 106, the outer peripheral edge C of the electrode plane 102a has a bent R shape and is not in contact with the end face of the glass bead 107. In addition, the structure which makes the outer peripheral edge part C of the electrode plane 102a and the end surface of the glass bead 107 non-contact is not limited to the bent R shape, but is a chamfered instead of the bent R shape, or the electrode plane 102a. For example, the glass beads 107 may be curved so that the outer peripheral edge is separated from the glass beads 107. With this configuration, even if the outer peripheral edge C of the electrode flat surface 102a changes due to thermal expansion, the hollow electrode 102 can be smoothly expanded and contracted without being caught by the end face of the glass bead 107. As a result, it is possible to suppress the breakage of the glass beads caused by the expansion and contraction of the hollow electrode 102 in the radial direction.

The hollow electrode 102 is formed of a nickel (Ni) material in a bottomed cylindrical shape. Bottomed cylindrical portion has an overall length _{L 1} is 5.2 [mm], outer diameter _{P 1} is 2.7 [mm], the inner diameter _{P 2} is 2.3 [mm], the thickness t is 0.2 [mm ]. The hollow electrode 102 has a tip portion (open end) and an outer peripheral surface protruding into the space of the glass bulb 101 and exposed, that is, the axis of the bottomed cylindrical portion and the tube axis of the glass bulb 101 substantially coincide. The minimum distance between the outer peripheral surface of the bottomed tubular portion and the inner surface of the glass bulb 101 (the “minimum distance d ₁ ” described below) is the entire outer periphery of the bottomed tubular portion. The electrode flat surface 102a on the rear end side of the electrode is provided in contact with the inner end face of the glass bulb 101 (the end face on the space side of the glass bulb).

Specifically minimum distance _{d 1} is 0.15 [mm]. Preferably, the minimum distance d ₁ between the inner peripheral surface of the glass bulb 101 and the outer peripheral surface of the cylindrical electrode is in the range of 0 <d ₁ ≦ 0.2 [mm]. That is, when the minimum distance d ₁ is within the narrow range, discharge does not enter the interval, and discharge mainly occurs inside the hollow electrode 102. As a result, the discharge during lighting does not easily move to the outer peripheral surface side of the hollow electrode 102, and the sputtered material deposited on the inner peripheral surface of the glass bulb 101 facing the outer peripheral surface of the cylindrical electrode is suppressed. Can be suppressed, and the life of the lamp can be extended. In addition, by making the shape of the electrode into a bottomed cylinder, the discharge area is increased particularly when the inner diameter (D ₁ ) of the glass bulb is 1 [mm] to 8 [mm] and the life of the electrode is extended. Can be planned.

  The lead wire 106 is a connection between an internal lead wire 106a made of tungsten (W) or molybdenum (Mo) and an external lead wire 106b made of nickel, to which solder or the like easily adheres. In the lead wire 106, the joint surface between the internal lead wire 106 a and the external lead wire 106 b is substantially flush with the outer surface of the glass bulb 101. That is, the internal lead wire 106 a is located inside the outer surface of the glass bulb 101, and the external lead wire 106 b is located outside the outer surface of the glass bulb 101.

The internal lead wire 106a has a substantially circular cross section, a total length of 2 [mm], and a wire diameter of 0.4 [mm]. The internal lead wire 106 a is sealed to the sealing portion 109 of the glass bulb 101 on the external lead wire 106 b side, and the end opposite to the external lead wire 106 b side is approximately at the center of the outer surface of the bottom surface 102 a of the hollow electrode 102. Joined by welding or the like. The internal lead wire 106a is the wire diameter is not limited to 0.4 [mm], intended narrow bore glass bulb _{(D 1)} is a 1 [mm] ~8 [mm] , wire diameter 0.1 A thin lead wire of [mm] to 0.8 [mm] is suitable. That is, when the wire diameter is 0.1 [mm] or less, the welding strength with the bottom surface 102a of the hollow electrode 102 decreases, and when the wire diameter is 0.8 [mm] or more, depending on the inner diameter (D ₁ ) of the glass bulb, There is a problem that the sealing part 109 is damaged.

  The external lead wire 106 b is a protruding portion that protrudes from the outer surface of the glass bulb 101 toward the tube axis A direction, and is joined to the power supply terminal 104. The external lead wire 106b has a total length of 1 [mm], and the axial center of the external lead wire 106b and the tube axis A of the glass bulb 101 substantially coincide with each other. The length is 1 [mm]. The external lead wire 106b has a substantially circular cross section and a wire diameter of, for example, 0.3 [mm], which is thinner than the internal lead wire 106a.

  The length of the external lead wire 106b in the tube axis A direction is preferably 1 [mm] or less. That is, if the length of the external lead wire 106b in the direction of the tube axis A is 1 [mm] or less, the external lead wire 106b does not protrude too much when viewed from the entire discharge lamp 100. For example, the lamp 100 is attached to the backlight unit 12. At this time, the external lead wire 106b is unlikely to be bent when it hits the backlight unit 12, or the sealing portion 109 is hardly damaged by the stress applied to the external lead wire 106b when it hits.

  The power supply terminal 104 is provided at both ends of the glass bulb 101 so as to cover both ends. The power supply terminal 104 is made of solder, and has a joint portion 111 joined to the external lead wire 106b and a thickness other than the joint portion 111 of 5 [μm] to 120 [μm] and a thin film length. The thin film portion 112 has a thickness of 2 [mm] to 19 [mm].

  The joint portion 111 is a portion where the power supply terminal 104 is electrically connected to the lead wire 106 and has a substantially conical shape in appearance. According to this configuration, the external lead wire 106b is completely covered with the power supply terminal 104, and the end portion of the discharge lamp 100 is smoothly rounded, so that the end portion of the discharge lamp 100 hits the backlight unit 12. However, there is little possibility that the external lead wire 106b is bent or the sealing portion 109 is damaged due to stress applied to the external lead wire 106b.

  The thin film portion 112 is a predetermined region on the sealing portion 109 side on the outer surface of the glass bulb main body 108 and the glass bulb main body 108 side on the outer surface of the sealing portion 109 in consideration of heat dissipation of the power supply terminal 104. The predetermined region and film thickness are appropriately set.

  The power supply terminal 104 can be formed by a known dipping method (for example, JP 2004-146351 A). A method for forming the power supply terminal 104 by the dipping method will be briefly described. For example, the sealing portion 109 of the glass bulb 101 to which the hollow electrode 102 is sealed is immersed in the molten solder in the melting tank. When the sealing portion 109 is immersed in the molten solder, ultrasonic waves may be applied. In such a dipping method, since the power supply terminal 104 can be formed easily and inexpensively, the discharge lamp 100 can be manufactured at low cost.

  Note that the power supply terminal 104 may be formed by a method other than the dipping method. For example, you may form by methods, such as vapor deposition and plating.

  Further, the configuration of the power supply terminal 104 is not limited to the above configuration, and for example, a configuration as shown in Modifications 1 and 2 can be considered. Note that the discharge lamps according to the first and second modifications basically have the same configuration as that of the discharge lamp 100 of the present embodiment except that the configuration of the power supply terminal and the electrode is different. Therefore, common parts are denoted by the same reference numerals as in the present embodiment, description thereof is omitted, and only different parts are described.

  FIG. 7 is an enlarged cross-sectional view showing one end of the discharge lamp according to the first modification. The power supply terminal 204 of the discharge lamp 200 shown in FIG. 7 includes a joining portion 211 and a thin film portion 212. The joint portion 211 is a thin film that covers the entire outer surface of the lead wire 206 made of, for example, tungsten (W) (only the internal lead wire of the first embodiment). The film thickness is 10 [μm], which is the same as that of the thin film portion 212. Thus, by using the entire power supply terminal 204 as a thin film, the amount of solder used can be reduced, and the discharge lamp 200 can be manufactured at a lower cost.

  FIG. 8 is an enlarged cross-sectional view showing one end portion of the discharge lamp according to the second modification, and FIG. 9 is a perspective view showing a thin film member constituting the power supply terminal. The power supply terminal 304 of the discharge lamp 300 shown in FIG. 8 includes a solder joint portion 314 and a thin film member 312 made of, for example, an iron / nickel alloy having a similar thermal expansion coefficient. In this way, the entire power supply terminal 304 does not necessarily have to be made of the same material.

  As shown in FIG. 9, the thin film member 312 is a cylindrical body having a wall thickness of 120 [μm] formed in a substantially C-shaped cross section, and is fitted on the end of the glass bulb 101. The inner diameter of the thin film member 312 is slightly smaller than the outer diameter of the glass bulb 101, and the thin film member 312 is provided with a slit 313. Therefore, the inner surface of the thin film member 312 is designed to be in close contact with the outer surface of the glass bulb 101 even if a slight dimensional error occurs between the inner diameter of the thin film member 312 and the outer diameter of the glass bulb 101. Note that the thin film member 312 is not limited to a cylindrical body having a substantially C-shaped cross section, and may be formed by providing a slit in a cylindrical body having a cross section of a polygon such as a substantially triangular shape or a substantially square shape, or an elliptical shape. Moreover, the case where a slit is not provided is also considered.

The total length of the external lead wire 106b is 2 [mm], the length L ₁ of the inside fit portion of the thin film member 312 is an internal lead wire 106a side of which is a 1 [mm], the remaining thin film member the length L ₂ of the portion which projects outwardly from 312 is 1 [mm]. The joint portion 314 covers a thick region 316 joined to a portion of the external lead wire 106b that is housed inside the thin film member 312 and a portion of the external lead wire 106b that protrudes outward from the thin film member 312. And a thin region 315.

When the power supply terminal 304 is configured as described above, the external lead wire 106b is fixed in the thick region 316 of the thin film member 312, so that the portion of the external lead wire 106b that protrudes outward from the thin film member 312 is bumped. However, stress is not easily applied to the sealing portion 109 of the glass bulb 101, and the sealing portion 109 is not easily damaged. However, since it is better not easily collide if external lead wire 106b are possible, it is preferred length L ₂ of the portion protruding from the thin film member 312 of the external lead wire 106b to the outside is 1 [mm] or less. The protruding portion of the external lead wire 106b is, for example, a portion indicated by L2 in the case of the external lead wire 106b according to Modification ₂ .

  In the first embodiment, the glass mount 107 is used as the holding means for the lead wire 106 in the electrode mount 103, but the same effect can be obtained by using a glass stem instead of the glass bead 107.

  However, when the lamp 100 is made thin, it is desirable to use glass beads 107 as means for holding the lead wire 106. Generally, the inner diameter of the glass bulb main body 108 is 1.0 [mm] to 8.0 [mm]. mm] and a thickness of 0.2 [mm] to 0.7 [mm]. When the lamp 100 is made thick, it is desirable to use a glass stem used for a general fluorescent lamp or the like as a means for holding the lead wire 106. Generally, the inner diameter of the glass bulb body 108 is 8.0 [mm]. ] To 32.5 mm and the thickness is preferably 0.5 [mm] to 1.0 [mm].

  Further, the internal lead wire 106a is formed of a tungsten material, but is not limited thereto, and is a sealing alloy containing Fe, Ni, and Co, that is, a sealing wire material having substantially the same thermal expansion coefficient as that of borosilicate glass. Can be considered.

  The external lead wire 106b is made of nickel material, but is not limited to this. For example, it is made of Ni alloy such as Fe—Ni alloy, Cu—Ni alloy, etc. Can be considered.

  Furthermore, the structure of the both ends of a discharge lamp is not limited to the said structure. The configuration will be described below.

(Embodiment 2)
FIG. 10 is a partial cross-sectional view and a partial perspective view showing a cold cathode discharge lamp 400 according to Embodiment 2 of the present invention. The discharge lamp according to the second embodiment basically has the same configuration as the discharge lamps 100, 200, and 300 of the first embodiment except that the configuration of the sealing portion 109 and the lead wire 106 is different. Therefore, common parts are denoted by the same reference numerals as those in the first embodiment, description thereof is omitted, and only different parts are described.

  As shown in FIG. 10, the lamp 400 does not have the glass beads and the glass stem described above, and has a cylindrical glass bulb 101 having a crushing portion 401 whose both ends are crushed, and at least one crushing portion 401. The two lead wires 406 connected to the bottom surface of the hollow electrode 102 and the air supply / exhaust pipe 407 are disposed between the two lead wires. In addition, for example, one end of the air supply / exhaust tube 407 protrudes from the crushing portion 401 toward the discharge space in the tube axis direction of the glass bulb 101, and comes into surface contact with the central portion of the bottom surface of the hollow electrode 102. 102 is supported.

  The power supply terminals 404 and 405 are provided outside the both end portions of the glass bulb 101, and are joined at the projecting portions of the two lead wires 406 projecting from the outer surface of the glass bulb 101 toward the tube axis direction of the glass bulb 101. Has been.

  In this embodiment, in the other crushing portion 401, two lead wires 406 connected to the bottom surface of the hollow electrode 102 and a glass tube 408 (or a glass rod 408) are arranged between the two lead wires. Has been. Further, the glass tube 408 (or the glass rod 408) has, for example, one end portion protruding from the crushing portion 401 toward the discharge space in the tube axis direction of the glass bulb 101 and facing the center portion of the bottom surface of the hollow electrode 102. It contacts and supports the hollow electrode 102.

  The power supply terminals 404 and 405 are provided outside the both end portions of the glass bulb 101, and are joined at the projecting portions of the two lead wires 406 projecting from the outer surface of the glass bulb 101 toward the tube axis direction of the glass bulb 101. Has been. The length of the protruding portion of the lead wire 406 in the tube axis direction is 0.5 [mm] to 1 [mm].

  The crushing portion 401 is not limited to the configuration in which the two lead wires and the air supply / exhaust pipe are provided. For example, the glass bead or the glass stem may be provided with the two lead wires and the air supply / exhaust pipe.

  In addition, the material of the above-described components is made of soft glass in which the glass bulb 101, the air supply / exhaust pipe 407 and the glass pipe 408 (or the glass rod 408) are made of soda lime glass or lead-free glass, and the two lead wires 406 are dumet. The hollow electrode 102 is made of a nickel (Ni) material. That is, the components of the glass bulb 101, the supply / exhaust tube 407, the glass tube 408 (or the glass rod 408), and the lead wire 406 are equal in thermal expansion coefficient, and the components and the hollow electrode 102 are different.

(Embodiment 3)
11 (a), 11 (b), and 11 (c) are partial sectional views showing a cold cathode discharge lamp according to Embodiment 3 of the present invention. The discharge lamp according to the third embodiment is basically the same as the discharge lamps 100, 200, and 300 of the first embodiment except that there is no power supply terminal and the configuration of the sealing portion 109 and the electrode is different. It has the composition of. Therefore, common parts are denoted by the same reference numerals as those in the first embodiment, description thereof is omitted, and only different parts are described.

As shown in FIG. 11A, the lamp 500 does not have power supply terminals at both ends, and the end portion of the lead wire 106 is welded to the bottom center portion (electrode plane) 102a of the hollow electrode 102. Is. In addition, in the connection portion 102d where the electrode plane 102 and the lead wire 106 are connected, a recess (a depression larger than the connection portion 102d) in which the connection portion 102d is accommodated is formed in either the hollow electrode 102 or the glass bead 107. For example, the glass bead 107 is provided with a recess 107d in which the connecting portion 102d is accommodated. The hollow electrode 102 is a nickel (Ni) material, the total length _{L 1} is 5.2 [mm], outer diameter _{P 1} is 2.7 [mm], the inner diameter _{P 2} is 2.3 [mm], the thickness t is formed to 0.2 [mm]. The lead wire 106 is made of tungsten (W) and has a total length of 8 [mm] and a wire diameter of 0.8 [mm].

As shown in FIG. 11B, the lamp 600 does not have power supply terminals at both ends, and is formed using a pair of columnar glass beads 107a located on both sides in the longitudinal direction of the glass bulb main body 108. And the sealing part 109 made. A convex portion is formed on one of the hollow electrode 602 and the glass bead 107a so as to surround the center (axial core) of the hollow electrode 602 between the bottom surface 602a of the hollow electrode 602 and the end surface 107b of the glass bead 107a. For example, a cylindrical convex portion 602b integrally formed on the bottom surface of the hollow electrode 602 is provided, and the hollow electrode 602 is held by the glass beads 107a via the convex portion 602b. Further, the end portion of the lead wire 106 is welded to the center portion (electrode plane) 602 a of the bottom surface of the hollow electrode 602. The hollow electrode 602 is made of a nickel (Ni) material, has an overall length L ₁ of 6.2 [mm], an outer diameter P ₁ of 2.7 [mm], an inner diameter P ₂ of 2.3 [mm], and a convex portion. H is formed to 1.0 [mm] and the wall thickness t is 0.2 [mm]. The internal lead wire 106 is made of tungsten (W) and has a total length of 8 [mm] and a wire diameter of 0.8 [mm]. With this configuration, the contact area between the bottom surface 602a of the hollow electrode 602 and the end surface 107b of the glass bead 107a is reduced, and even if the outer peripheral edge C of the hollow electrode 602 changes due to thermal expansion, the contact area between the end surface of the glass bead 107a is reduced. The hollow electrode 602 can expand and contract smoothly.

  Note that the convex portion 602b is not limited to the cylindrical shape, and may have, for example, three or more convex placement portions having a uniform height at a predetermined angle and position with respect to the electrode center line. In this configuration, the contact area can be further reduced.

As shown in FIG. 11C, the lamp 700 does not have power supply terminals at both ends, and is formed by using a pair of cylindrical glass beads 107a located on both sides in the longitudinal direction of the glass bulb main body 108. And the sealing part 109 made. Further, the hollow electrode 702 is formed in a tapered shape so that the electrode flat surface portion 702b on the electrode bottom surface side is smaller in diameter than the opening 702a on the electrode front end side. Specifically, hollow electrode 702 is a nickel (Ni) material, the total length _{L 2} is 5.2 [mm], the thickness t is 0.2 [mm], the outer diameter P3 openings 2.7 mm], and the outer diameter P4 of the electrode plane portion is 2.1 [mm]. The end of the lead wire 106 is welded to the bottom center of the hollow electrode 702. With this configuration, when the glass beads 107 are sealed to the end portion of the glass bulb 101, the contact between the outer peripheral surface of the tapered hollow electrode 702 having a small diameter and the inner peripheral surface of the glass bulb 101 is prevented. Can do. As a result, the crack of the sealing part can be suppressed.

  In addition, although it demonstrated concretely based on the said Embodiment 1, its modification, Embodiment 2, and Embodiment 3, the discharge lamp which concerns on this invention is not limited to said Embodiment.

  Although the discharge lamp has been described as having a straight tube shape, the present invention is not limited thereto, and a “U” -shaped, “U” -shaped or “L” -shaped bent tube may be used. Further, although the cross section has been described as a circular one, the present invention is not limited to this, and is a flat discharge lamp such as an effective light emitting section excluding the electrode sections at both ends, which has an elliptical or elongated circular shape. Also good.

The material of the glass bulb 101 is borosilicate glass, but is not limited thereto, and lead glass, lead-free glass, soda glass, or the like may be used. In this case, the dark startability can be improved. That is, the glass as described above contains a large amount of alkali metal oxide typified by sodium oxide (Na ₂ O). For example, in the case of sodium oxide, the sodium (Na) component elutes on the inner surface of the glass bulb over time. To do. Since sodium has a low electronegativity, it is considered that sodium eluted particularly at the inner end of the glass bulb where no protective film is formed contributes to the improvement of the dark startability.

  For example, when the alkali metal oxide is sodium oxide, the content is preferably 5 [mol%] or more and 20 [mol%] or less. If it is less than 5 [mol%], the probability that the dark start time will exceed 1 second increases (in other words, if it is 5 [mol%] or more, the probability that the dark start time will be within 1 second increases), 20 If the amount exceeds [mol%], the glass bulb will be whitened due to long-term use, resulting in a decrease in brightness, and the strength of the glass bulb may be reduced.

  And when natural environment protection is considered, it is preferable to use lead-free glass. However, lead-free glass may contain lead as an impurity in the manufacturing process. Therefore, glass containing lead at an impurity level of 0.1% or less is also defined as lead-free glass.

  Next, the additive to the material of the glass bulb 101, for example, borosilicate glass lead glass, lead-free glass, soda glass, etc. is as follows.

By adjusting the thermal expansion coefficient of the glass, the sealing strength with a sealing member such as a lead wire of a cold cathode fluorescent lamp can be increased. For example, when the sealing member is made of tungsten (W), it is preferably set to 36 × 10 ⁻⁷ [K ⁻¹ ] to 45 × 10 ⁻⁷ [K ⁻¹ ]. In this case, the thermal expansion coefficient of glass can be made into said range by making the sum total of the alkali metal component and alkaline-earth metal component in glass into 4 [mol%]-10 [mol%].

When the sealing member is made of Kovar or Molybdenum (Mo), it is preferably 45 × 10 ⁻⁷ [K ⁻¹ ] to 56 × 10 ⁻⁷ [K ⁻¹ ]. In this case, the thermal expansion coefficient of glass can be made into said range by making the sum total of the alkali metal component and alkaline-earth metal component in glass into 7 [mol%]-14 [mol%].

When the sealing member is a dumet wire, it is preferably in the vicinity of 94 × 10 ⁻⁷ [K ⁻¹ ]. In this case, the thermal expansion coefficient of glass can be made into said range by making the sum total of the alkali-metal component and alkaline-earth metal component in glass into 20 [mol%]-30 [mol%].

It is possible to absorb ultraviolet rays of 254 [nm] or 313 [nm] by doping glass with a predetermined amount of transition metal oxide depending on its type (ultraviolet absorber). Specifically, for example, in the case of titanium oxide (TiO ₂ ), the composition ratio of 0.05 [mol%] or more is doped to absorb ultraviolet rays of 254 [nm], and the composition ratio is 2 [mol%] or more. Thus, it is possible to absorb ultraviolet rays of 313 [nm]. However, when titanium oxide is doped more than the composition ratio of 5.0 [mol%], the glass is devitrified, so the composition ratio is 0.05 [mol%] or more and 5.0 [mol%] or less. It is preferable to dope in the range.

In the case of cerium oxide (CeO ₂ ), ultraviolet rays of 254 [nm] can be absorbed by doping at a composition ratio of 0.05 [mol%] or more. However, when cerium oxide is doped more than 0.5 [mol%], the glass is colored, so cerium oxide has a composition ratio of 0.05 [mol%] to 0.5 [mol%]. It is preferable to dope in the following range. In addition, since coloring of glass by cerium oxide can be suppressed by doping tin oxide (SnO) in addition to cerium oxide, cerium oxide can be doped to a composition ratio of 5.0 [mol%] or less. . In this case, if cerium oxide is doped with a composition ratio of 0.5 [mol%] or more, ultraviolet rays of 313 [nm] can be absorbed. However, even in this case, when the composition ratio of cerium oxide is more than 5.0 [mol%], the glass is devitrified.

In the case of zinc oxide (ZnO), 254 [nm] ultraviolet rays can be absorbed by doping at a composition ratio of 2.0 [mol%] or more. However, when zinc oxide is doped more than 10 [mol%], the thermal expansion coefficient of the glass becomes large, and when the sealing member is made of tungsten (W), the thermal expansion coefficient of the sealing member (about 44 × 10 ⁻⁷ [K ⁻¹ ]) and the glass have a coefficient of thermal expansion that makes sealing difficult, so that zinc oxide is contained in the range of 2.0 [mol%] to 10 [mol%]. It is preferable to dope. However, when the sealing member is made of Koval or molybdenum (Mo), the thermal expansion coefficient (about 51 × 10 ⁻⁷ [K ⁻¹ ]) of the sealing member is larger than that of tungsten. Therefore, zinc oxide can be doped to a composition ratio of 14 [mol%] or less. Further, when zinc oxide is doped more than 20 [mol%], the glass may be devitrified, so that zinc oxide is in the range of 2.0 [mol%] to 20 [mol%]. It is preferable to dope.

In the case of iron oxide (Fe ₂ O ₃ ), ultraviolet rays of 254 [nm] can be absorbed by doping at a composition ratio of 0.01 [mol%] or more. However, when iron oxide is doped more than the composition ratio of 2.0 [mol%], the glass is colored, so the iron oxide is contained in the composition ratio of 0.01 [mol%] to 2.0 [mol%]. It is preferable to dope in the following range.

  The infrared transmittance coefficient indicating the water content in the glass is preferably adjusted to be in the range of 0.3 to 1.2, particularly 0.4 to 0.8. If the infrared transmittance coefficient is 1.2 or less, it is easy to obtain a low dielectric loss tangent applicable to a high voltage application lamp such as a long cold cathode fluorescent lamp, and if it is 0.8 or less, the dielectric loss tangent is sufficient. It becomes small and becomes applicable to a high voltage application lamp.

  The infrared transmittance coefficient (X) can be expressed by the following formula.

[Formula 1] X = (log (a / b)) / t
a: Transmittance [%] of a minimum point in the vicinity of 3840 [cm ⁻¹ ]
b: Transmittance [%] of a minimum point in the vicinity of 3560 [cm ⁻¹ ].
t: Thickness of glass The hollow electrode 102 has been described with a nickel material. However, the invention is not limited to this. For example, a transition metal of group IV to VI with little sputtering of the electrode, for example, niobium (Nb), tantalum (Ta), molybdenum (Mo), titanium (Ti), tungsten (W) or an alloy material thereof is preferable. The shape of the electrode is not limited to a bottomed cylindrical shape, and may be a rod shape or a conical shape. Furthermore, in order to further improve the dark starting characteristics, a coating made of a starting assisting metal such as a compound such as cesium, Li, K, Rb is opposed to the inner surface of the glass bulb in order to reduce scattering of the starting assisting metal. It is preferable to provide on the outer peripheral surface of the hollow electrode.

  The power supply terminals 104, 204, 304, and 404 have been described using solder as a material to be formed. However, the present invention is not limited thereto, and any material having at least conductivity may be used. In general, solder is suitable as a material for a power supply terminal because of its good conductivity and low price. In particular, a solder mainly composed of tin (Sn), tin-indium (In) alloy, tin-bismuth (Bi) alloy, or the like may form the power supply terminals 104, 204, 304, and 404 having high mechanical strength. Since it is possible, it is more preferable. A solder obtained by adding at least one of antimony (Sb), zinc (Zn), aluminum (Al), gold (Au), iron (Fe), platinum (Pt) and palladium (Pd) to glass is used. Therefore, it is possible to form the power supply terminals 104, 204, 304, 404 that are difficult to peel off from the glass bulb 101, which is more preferable. In addition, lead-free solder is preferable because it can produce a discharge lamp in consideration of the environment.

  If the material forming the power supply terminals 104, 204, and 304 is familiar with tungsten, the external lead wire 106b may be made of tungsten. That is, it can be considered that the entire lead wire 106 is formed of tungsten. By doing so, the disconnection failure of the lead wires 106 and 206 can be reduced, and the cost of components can be reduced.

  In addition, the power supply terminal is not limited to the configuration of the solder material described above. For example, the main body layer mainly composed of silver or copper formed on the outer surface of the glass bulb and the main layer laminated on the outside thereof is a coating made of solder. The thing of the structure which consists of layers may be sufficient. In this case, the maximum thickness of the power supply terminal is 5 [μm] to 120 [μm], and the thickness of the edge portion of the power supply terminal is made thinner toward the edge.

  According to this configuration, the main body layer of the power supply terminal is not easily exposed to the atmosphere, and silver sulfide and copper oxidation are unlikely to occur, so that the conductivity is unlikely to decrease. As a result, it is possible to improve the connectivity between the power supply terminal and the lead wire of the electrode, and it is possible to prevent the power supply terminal from being scratched or cracked when the discharge lamp is mounted on the lamp holder. Compared with the one having an angular edge, the corona discharge generated between the edge of the power supply terminal and the outer surface of the glass bulb can be prevented, and the generation of ozone can be suppressed.

  The phosphor layer 110 has been described using BAM-B for the blue phosphor, LAP for the green phosphor and YOX for the red phosphor, but the present invention is not limited to this, and the following phosphors may be used depending on the purpose. .

(1) UV absorption For example, in recent years, with the increase in size of liquid crystal color televisions, polycarbonate having good dimensional stability has been used for the diffusion plate that closes the opening of the backlight unit. This polycarbonate is easily deteriorated by ultraviolet rays having a wavelength of 313 [nm] emitted from mercury. In such a case, a phosphor that absorbs ultraviolet light having a wavelength of 313 [nm] may be used. The following phosphors absorb 313 [nm] ultraviolet rays.

(A) Blue Europium / manganese co-activated barium aluminate / strontium / magnesium [Ba _1-xy Sr _x Eu _y Mg _1-z Mn _z Al ₁₀ O ₁₇ ] or [Ba _1-xy Sr _x Eu _y Mg _{2− z} Mn _z Al ₁₆ O ₂₇ ]
Here, x, y, and z are preferably numbers satisfying the conditions of 0 ≦ x ≦ 0.4, 0.07 ≦ y ≦ 0.25, and 0 ≦ z <0.1, respectively.

Examples of such phosphors include europium activated barium magnesium aluminate [BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ], [BaMgAl ₁₀ O ₁₇ : Eu ²⁺ ] (abbreviation: BAM-B), Europium activated barium aluminate / strontium / magnesium [(Ba, Sr) Mg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ], [(Ba, Sr) MgAl ₁₀ O ₁₇ : Eu ²⁺ ] (abbreviation: SBAM-B) Etc.

(B) Green • Manganese inactive magnesium gallate [MgGa ₂ O ₄ : Mn ²⁺ ] (abbreviation: MGM)
Manganese activated cerium aluminate, magnesium, zinc [Ce (Mg, Zn) Al ₁₁ O ₁₉ : Mn ²⁺ ] (abbreviation: CMZ)
· Active aluminate, cerium-magnesium with terbium ^{_{[CeMgAl 11 O 19: Tb 3+}} ] ( abbreviation: CAT)
• Europium • Manganese co-activated barium aluminate • Strontium • Magnesium [Ba _{1 -xy} Sr _x Eu _y Mg _{1 -z} Mn _z Al ₁₀ O ₁₇ ] or [Ba _{1 -xy} Sr _x Eu _y Mg _{2 -z} Mn _z Al ₁₆ O ₂₇ ]
Here, x, y and z are numbers satisfying the conditions of 0 ≦ x ≦ 0.4, 0.07 ≦ y ≦ 0.25, and 0.1 ≦ z ≦ 0.6, respectively, and z is 0.4 It is preferable that ≦ x ≦ 0.5.

Examples of such phosphors include europium / manganese co-activated barium aluminate / magnesium [BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ , Mn ²⁺ ], [BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ^{2]. +} ] (Abbreviation: BAM-G), europium / manganese co-activated barium aluminate / strontium / magnesium [(Ba, Sr) Mg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ , Mn ²⁺ ], [(Ba, Sr) MgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ ] (abbreviation: SBAM-G).

(C) Red • Europium activated phosphorus • Yttrium vanadate [Y (P, V) O ₄ : Eu ³⁺ ] (abbreviation: YPV)
Europium activated yttrium vanadate [YVO ₄ : Eu ³⁺ ] (abbreviation: YVO)
・ Europium-activated yttrium oxysulfide [Y ₂ O ₂ S: Eu ³⁺ ] (abbreviation: YOS)
Manganese-activated magnesium fluoride germanate [3.5MgO.0.5MgF ₂ .GeO ₂ : Mn ⁴⁺ ] (abbreviation: MFG)
Dysprosium-activated yttrium vanadate [YVO ₄ : Dy ³⁺ ] (red and green two-component phosphor, abbreviation: YDS)
In addition, you may mix and use the fluorescent substance of a different compound with respect to one type of luminescent color. For example, only BAM-B (absorbs 313 nm) in blue, LAP (does not absorb 313 nm) and BAM-G (absorbs 313 nm) in green, YOX (does not absorb 313 nm) and YVO in red. A phosphor (absorbing 313 nm) may be used. In such a case, as described above, the phosphor that absorbs the wavelength 313 (nm) is adjusted so that the total weight composition ratio is larger than 50%, so that the ultraviolet ray almost leaks out of the glass tube. Can be prevented. Therefore, when the phosphor layer 110 contains a phosphor that absorbs ultraviolet rays of 313 [nm], deterioration due to ultraviolet rays such as a diffusion plate made of polycarbonate (PC) that closes the opening of the backlight unit is suppressed, The characteristics as a backlight unit can be maintained for a long time.

  Here, “absorbing ultraviolet light of 313 [nm]” means an excitation wavelength spectrum near 254 [nm] (excitation wavelength spectrum means excitation light emission while changing the wavelength of the phosphor, It is defined that the intensity of the excitation wavelength spectrum of 313 [nm] is 80 [%] or more when the intensity of 100) is 100 (%). That is, the phosphor that absorbs ultraviolet rays of 313 [nm] is a phosphor that can absorb ultraviolet rays of 313 [nm] and convert it into visible light.

(2) High color reproduction In a liquid crystal display device typified by a liquid crystal color TV, discharge used as a light source of a backlight unit of the liquid crystal display device in accordance with the recent high color reproduction performed as part of the improvement in image quality. There is a demand for an increase in the reproducible chromaticity range of the lamp.

  In response to such a request, for example, by using the following phosphor, the chromaticity range can be expanded as compared with the case of using the phosphor in the embodiment. Specifically, in the CIE 1931 chromaticity diagram, the chromaticity coordinate value of the phosphor for high color reproduction includes a triangle formed by connecting the chromaticity coordinate values of the three phosphors used in the embodiment. Located at the coordinates that expand the reproduction range.

(A) Blue • Europium-activated strontium chloroapatite [Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ ] (abbreviation: SCA), chromaticity coordinates: x = 0.151, y = 0.065
In addition to the above, europium-activated strontium, calcium, barium, chloroapatite [(Sr, Ca, Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ ] (abbreviation: SBCA) can also be used, and the wavelength 313 [nm] SBAM-B, which can absorb ultraviolet rays, can also be used for high color reproduction.

(B) Green BAM-G, chromaticity coordinates: x = 0.139, y = 0.574
CMZ, chromaticity coordinates: x = 0.164, y = 0.722
CAT, chromaticity coordinates: x = 0.267, y = 0.663
As described above, these can also absorb ultraviolet rays having a wavelength of 313 [nm], and in addition to the three phosphor particles described here, MGM can also be used for high color reproduction.

(C) Red • YOS, chromaticity coordinates: x = 0.651, y = 0.344
YPV, chromaticity coordinates: x = 0.658, y = 0.333
MFG, chromaticity coordinates: x = 0.711, y = 0.287
As described above, these can also absorb ultraviolet rays having a wavelength of 313 [nm], and besides the three phosphor particles described here, YVO and YDS can also be used for high color reproduction.

  In addition, the chromaticity coordinate values shown above are representative values measured only with each phosphor powder, and due to the measurement method (measurement principle), etc., the chromaticity coordinates indicated by each phosphor powder The value may be slightly different from the value listed above. For reference, the chromaticity coordinate values of the phosphor powders of the first embodiment are YOX (x = 0.644, y = 0.353), LAP (x = 0.351, y = 0.585). , BAM-B (x = 0.148, y = 0,056).

  Furthermore, the phosphor used for emitting each color of red, green, and blue is not limited to one type for each wavelength, and a plurality of types may be used in combination.

  Here, the case where a phosphor layer is formed using the above-described phosphor particles for high color reproduction will be described. In this evaluation, there are three evaluations in the case of using a phosphor for high color reproduction based on the area of the NTSC triangle (NTSC triangle) connecting the chromaticity coordinate values of the three primary colors of the NTSC standard in the CIE1931 chromaticity diagram. A triangular area ratio formed by connecting chromaticity coordinate values (hereinafter referred to as NTSC ratio) is used.

  For example, when BAM-B is used as blue, BAM-G as green, and YVO as red (Example 1), the NTSC ratio is 92 [%]. Also, SCA as blue, BAM-G as green, and YVO as red When used (Example 2), the NTSC ratio becomes 100 [%]. When SCA is used as blue, BAM-G as green, and YOX as red (Example 3), the NTSC ratio becomes 95 [%]. The luminance can be improved by 10 [%] compared to the second and second.

  The chromaticity coordinate values used for the evaluation here are measured in a state where a liquid crystal display device incorporating a lamp or the like is used.

  Furthermore, any of the above-described embodiments, modification examples, application examples, and the like may be combined.

  The discharge lamp according to the present invention has an effect that an electrode can be attached to a glass bead or a glass stem with high precision even if it is a thin lead wire. Using this lamp, a lighting device, a backlight unit, a lighting device, It is useful as a liquid crystal television and a liquid crystal display.

The perspective view which shows the outline | summary of the liquid crystal television in Embodiment 1 of this invention The perspective view which shows the backlight unit which concerns on Embodiment 1 of this invention. The perspective view which shows the lighting device which concerns on Embodiment 1 of this invention. An example of the lighting control circuit with which the lighting device which concerns on Embodiment 1 of this invention is provided is shown, (a) is a figure which shows a lighting control circuit, (b) shows the connection relation of each discharge lamp connected to the lighting control circuit. The figure to show, (c) is a figure which shows the other connection relation of each discharge lamp connected to the lighting control circuit The partially broken perspective view which shows the discharge lamp which concerns on Embodiment 1 of this invention Enlarged sectional view showing one end of the discharge lamp The expanded sectional view which shows the one end part of the discharge lamp which concerns on the modification 1 The expanded sectional view which shows the one end part of the discharge lamp which concerns on the modification 2 The perspective view which shows the thin film member which comprises an electric power feeding terminal The fragmentary sectional view and edge part perspective view which show the discharge lamp which concerns on Embodiment 2 of this invention (A) is sectional drawing which shows the discharge lamp concerning Embodiment 3 of this invention, (b) is sectional drawing which shows the discharge lamp concerning the application example 1, (c) is the discharge lamp concerning the application example 2. Cross section shown

Explanation of symbols

100, 200, 300, 400, 500, 600 Discharge lamp 101 Glass bulb 102, 602, 702 Hollow electrode 104, 105, 204, 304, 404, 405 Feed terminal 106 206, 406 Lead wire

Claims (33)

An electrode having a substantially flat surface on the outer peripheral surface, a lead wire connected to the electrode flat surface, and a glass bead or a glass stem holding the lead wire, wherein the electrode flat surface is an end surface of the glass bead or the glass stem. An electrode mount characterized by being provided in contact with the electrode. The electrode mount according to claim 1, wherein the electrode has a bottomed cylindrical shape, a rod shape, or a conical shape. 2. The electrode mount according to claim 1, wherein the bottomed cylindrical or rod-like electrode is formed in a taper shape having a smaller diameter on the electrode rear end side than the electrode front end portion. The electrode has a lead wire connected to a center portion of the electrode plane, and the glass bead or glass is in a state where the electrode plane surrounds the lead wire when viewed from the outside of the lead wire. The electrode mount according to claim 1, wherein the electrode mount is in contact with an end face of the stem. The glass bead or the glass stem holds at least two lead wires connected to the electrode plane, and an air supply / exhaust pipe is disposed between the two lead wires. The electrode mount according to any one of 1 to 3. The outer periphery of the electrode plane is not in contact with the end face of the glass bead or glass stem when viewed from the outside of the lead wire. Electrode mount. The electrode mount according to any one of claims 1 to 6, wherein a plane of the electrode is in surface contact with an end face of the glass bead or the glass stem. A convex portion is provided on one of the electrode and the glass bead or the glass stem so as to surround the electrode center between the plane of the electrode and the end surface of the glass bead or the glass stem. The electrode mount according to claim 1, wherein the electrode mount is held on the glass bead or the glass stem through a convex portion. 2. The connecting portion where the electrode plane and the lead wire are connected is provided with a recess for accommodating the connecting portion in either one of the electrode and the glass bead or the glass stem. 8. The electrode mount according to any one of 7 to 7. The connection position of the connection portion is provided at a position substantially the same as a position where the electrode plane and the end face of the glass bead or glass stem are in contact with each other at a position in the longitudinal direction of the lead wire. 10. The electrode mount according to any one of 9 above. 11. The electrode according to claim 1, wherein the glass beads or the glass stem are made of substantially the same material and have the same or different material as the electrode. mount. The electrode mount according to claim 1, wherein the electrode is formed of nickel, molybdenum, niobium, tantalum, titanium, tungsten, or an alloy material thereof. The electrode mount according to claim 1, wherein at least a part of the lead wire is made of a sealing wire. In a discharge lamp having a pair of electrodes at both ends of a glass bulb, at least one of the pair of electrodes is sealed with an electrode mount according to any one of claims 1 to 13 at an end of a through hole of the glass bulb. A discharge lamp characterized by that. A phosphor layer is formed on the inner wall of the glass bulb, rare gas or rare gas and mercury are sealed inside the glass bulb, and lead wires are hermetically sealed at both ends of the glass bulb. In the discharge lamp in which an electrode is connected to each of the end portions of the lead wire on the inner side, the electrode has a front end portion and an outer peripheral surface projecting into the space of the glass bulb and exposed to the rear of the electrode. A discharge lamp characterized in that an end-side plane is provided in contact with a space-side end surface of the glass bulb. The discharge lamp according to claim 15, wherein the electrode has a bottomed cylindrical shape, a rod shape, or a conical shape. The discharge lamp according to claim 16, wherein the electrode is formed in a tapered shape having a diameter smaller than that of the electrode front end portion. The minimum distance (d ₁ ) between the inner peripheral surface of the glass bulb and the outer peripheral surface of the electrode is regulated within a range of 0 <d ₁ ≦ 0.2 [mm]. The discharge lamp described in. The electrode has the lead wire connected to the central portion of the bottom surface of the electrode, and the electrode bottom surface surrounds the lead wire when viewed from the outside of the lead wire. The discharge lamp according to any one of claims 15 to 18, wherein the discharge lamp is in contact with the inner end face. At least one of the sealing parts of the glass bulb is characterized in that at least two lead wires connected to the bottom surface of the electrode and a supply / exhaust pipe are disposed between the two lead wires. Item 19. The discharge lamp according to any one of Items 15 to 18. 21. The discharge lamp according to claim 15, wherein the electrode is formed of nickel, molybdenum, niobium, tantalum, titanium, tungsten, or an alloy material thereof. The discharge lamp according to any one of claims 15 to 21, wherein at least a part of the lead wire is made of a sealing wire. The discharge lamp according to claim 15, wherein the lead wire is a sealing alloy containing Fe, Ni, and Co, and the glass bulb is made of borosilicate glass. The discharge lamp according to claim 23, wherein the borosilicate glass is doped with an ultraviolet absorber. The discharge lamp according to claim 24, wherein the ultraviolet absorber is made of one or a combination of titanium oxide and cerium oxide. The discharge lamp according to any one of claims 15 to 21, wherein the lead wire is made of molybdenum or tungsten, and the glass bulb is made of hard glass. The discharge lamp according to any one of claims 15 to 22, wherein the lead wire is a dumet wire, and the glass bulb is made of soft glass. Provided outside the both ends of the glass bulb, and provided with a power supply terminal joined to the lead wire of the electrode, the power supply terminal is on the outer surface of the glass bulb except for the joint portion with the lead wire The discharge lamp according to any one of claims 14 to 27, wherein the discharge lamp is a formed thin film. 29. The discharge lamp according to claim 28, wherein the thin film has a thickness of 5 to 120 [[mu] m]. The lead wire is joined to the power supply terminal at a protruding portion protruding from the outer surface of the glass bulb toward the tube axis direction of the glass bulb, and the length of the protruding portion in the tube axis direction is 1 [ The discharge lamp according to claim 28 or 29, wherein: 31. The discharge lamp according to claim 28, wherein at least the joining portion of the power supply terminal is formed of solder. A backlight unit comprising the discharge lamp according to any one of claims 14 to 31 as a light source. A liquid crystal display device, wherein the backlight unit according to claim 32 is mounted.

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