JP2006302664A - Discharge lamp and lamp system equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp having external electrodes, hardly degrading appearance and capable of improving light emission efficiency. <P>SOLUTION: In this external electrode type fluorescent lamp 10 including a glass vessel 12 formed of a glass material containing an alkaline constituent (potassium), and the external electrodes 16 and 18 arranged in the peripheries on both end sides of the glass vessel 12, a plurality of granular substances 20 formed of a transition metal (iron) are respectively embedded in parts of the inside surface of the glass vessel 12 corresponding to the external electrodes 16 and 18 to expose partial parts thereof. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a discharge lamp and a lamp system including the discharge lamp, and more particularly to a discharge lamp having an external electrode disposed on the outer surface of a glass container.

One of the discharge lamps having an external electrode is an external electrode type fluorescent lamp (EEFL). As with the cold cathode fluorescent lamp, the external electrode fluorescent lamp is suitable for reducing the diameter as compared with the hot cathode fluorescent lamp. For this reason, it is suitably used as a light source of a backlight unit that is required to be thin (downsized).
However, the external electrode fluorescent lamp has lower luminous efficiency than the hot cathode fluorescent lamp. For this reason, improvement of luminous efficiency is one of the main problems imposed on the external electrode type fluorescent lamp.

As one of the measures for improving the luminous efficiency, it is conceivable to increase the secondary electron emission coefficient of the inner part of the glass container corresponding to the arrangement position of the external electrode.
For this reason, in Patent Document 1, an easily electron-emitting substance layer having a thickness of 0.1 to 20 μm made of magnesium oxide or the like, which is a substance having a secondary electron emission coefficient larger than that of the glass container material, corresponds to the external electrode. An external electrode type fluorescent lamp formed on the inner surface of a glass container is disclosed. This facilitates the emission of secondary electrons, so that the voltage applied to the external electrode can be lowered, thereby improving the light emission efficiency.

It is known that when an alkali metal is adsorbed on a transition metal, the work function is lowered. Therefore, although Patent Document 2 does not refer to an external electrode fluorescent lamp, as a configuration of an electron emission portion having a reduced work function, a metal and an alkali metal supply material (glass) in contact with the metal are used. An electron emission portion is disclosed.
For example, Patent Document 2 discloses an example in which the electron emission unit is applied to a cold cathode fluorescent lamp. In this cold-cathode fluorescent lamp, an electron emission portion is composed of a bottomed cylindrical metal body (internal electrode) facing the discharge space and an alkali metal supply substance (glass) disposed in the cylinder of the metal body. Yes.
Japanese Patent Laid-Open No. 11-354079 JP 2004-247171 A (FIGS. 3 and 7)

However, in Patent Document 1, accelerated ions strike a thin electron-emitting material layer having a thickness of 0.1 to 20 μm at the time of discharge. There is a risk of peeling. If the peeled-off electron-emitting material layer moves to the phosphor film formation region, the appearance quality may be impaired.
The electron emission portion described in Patent Document 2 includes an electrode facing the discharge space as a constituent element. For this reason, it is difficult to immediately apply the technique described in Patent Document 2 to the external electrode fluorescent lamp.

The above problem is common to external electrode type discharge lamps that do not have a phosphor layer.
In view of the above-described problems, an object of the present invention is to provide a discharge lamp and a lamp unit including the discharge lamp, in which appearance quality due to the above-described causes is hardly impaired and the light emission efficiency can be improved.

In order to achieve the above object, a discharge lamp according to the present invention has a glass container made of a glass material containing an alkali component, and an external electrode disposed on the outer surface of the glass container, and corresponds to the external electrode. Each of the plurality of granular materials having at least a surface made of a transition metal is embedded on the inner surface of the glass container so that a part thereof is exposed.
In order to achieve the above object, a discharge lamp according to the present invention has a glass container and an external electrode disposed on the outer surface of the glass container, and is disposed on the inner surface of the glass container corresponding to the external electrode. In addition, each of a plurality of granular materials having at least a surface made of a transition metal is embedded in a glass member made of a glass material containing an alkali component so that a part thereof is exposed.

The glass material contains at least potassium as the alkali component. Furthermore, it is preferable that the glass material contains sodium as the alkali component.
The transition metal may be iron and / or nickel.
Alternatively, a part of the plurality of granular materials may be made of iron, and the remaining number may be made of nickel.

Further, the plurality of granular materials are distributed substantially uniformly in the inner surface direction of the glass container.
In order to achieve the above object, a lamp system according to the present invention comprises the above-described discharge lamp as a light source.

  According to the discharge lamp of the present invention, an alkali component (metal) supplied from a glass container made of a glass material containing an alkali component is adsorbed on the surface of a granular material made of a transition metal, and the work function of the adsorption surface becomes small. . That is, as the alkali metal is adsorbed on the root surface of the embedded granular material, the work function is reduced. As a result, electron emission from this portion is facilitated, and the luminous efficiency is improved.

And since a part of granular material is embed | buried under the inner surface part of a glass container, even if it receives the impact of ion at the time of lighting discharge, it will hardly detach | leave from a glass container.
Furthermore, since the glass container, which is an essential component for a discharge lamp having an external electrode, serves as an alkali metal supply material to the granular material, it is not necessary to provide a separate alkali metal supply material.

  Moreover, according to the discharge lamp according to the present invention, the alkali component (metal) supplied from the glass member made of a glass material containing an alkali component is adsorbed on the surface of the granular material made of a transition metal, and the work function of the adsorption surface is Get smaller. As a result, the same effect as the above discharge lamp can be obtained. In addition, since a glass member which is an alkali metal supply substance is provided separately from the glass container, the luminous efficiency can be improved even in a discharge lamp in which the glass container does not contain a sufficient amount of alkali components. Is possible.

  According to the lamp system of the present invention, since the discharge lamp is provided, the luminous efficiency is improved for the same reason as described above.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1A is a partially cutaway longitudinal sectional view showing a schematic configuration of an external electrode type fluorescent lamp 10 which is a kind of low-pressure discharge lamp, and FIG. 1B is a portion A in FIG. FIG. In all the drawings including FIGS. 1A and 1B, the scales between components are not unified.

  The external electrode type fluorescent lamp 10 according to Embodiment 1 includes a tubular glass container 12 in which both ends of a glass tube made of lead glass are hermetically sealed. The lead glass used as the glass material of the glass container 12 contains a lot of alkali components. In this example, about 4% by weight of potassium and about 8% by weight of sodium are contained in terms of oxide. The total length L of the glass container 12 is 420 mm, the inner diameter D is 7 mm, and the thickness T is 0.7 mm.

A phosphor film 14 is formed on the inner peripheral surface of the glass container 12. The phosphor film 14 is formed in the tube axis (center axis) direction of the glass container 12 and in the middle excluding a predetermined range of both end portions. The phosphor film 14 includes three kinds of rare earth phosphors of red (R), green (G), and blue (B), and emits white light as a whole.
In addition, a mixed gas containing neon and argon and saturated mercury vapor are enclosed in the glass container 12 as a discharge substance (discharge gas) (both not shown). The mixed gas is sealed at a pressure of 8 kPa, and the mixing ratio of neon and argon is 9: 1 in volume ratio.

External electrodes 16 and 18 are disposed on both ends of the outer periphery of the glass container 12. The external electrodes 16 and 18 are configured by winding an aluminum foil having a thickness of 0.05 mm and a width W = 20 mm in close contact with the outer surface over the entire circumference of the glass container 12.
On the inner peripheral surface portion of the glass container 12 corresponding to the external electrodes 16, 18, a plurality of granular materials 20 made of transition metal are arranged substantially uniformly. In this example, iron (Fe) is used as the transition metal. The maximum particle size of the granular material 20 is 0.15 mm. That is, the granular material 20 is in the form of a fine powder in a state where a large number of granular materials 20 are gathered. The plurality of granular materials 20 are dispersed at a density of about 150 particles / cm ² . The dispersion density is the number of granular materials 20 per unit area on the inner peripheral surface of the glass container 12. As shown in FIG. 1B, each granular material 20 is embedded in the glass container 20 so that a part thereof is exposed.

  In the external electrode fluorescent lamp 10 having the above configuration, when a high frequency voltage is applied to the external electrodes 16 and 18 by an inverter, a discharge phenomenon occurs in an airtight sealed space (discharge space) in the glass container 12. Ultraviolet rays are emitted, and the ultraviolet rays are converted into visible light by the phosphor film 14 and emitted outside the glass container 12. As the inverter, for example, an inverter having a maximum applied voltage of 2.5 kV and an operating frequency of 50 kHz can be used.

The discharge is a dielectric barrier discharge. The dielectric barrier discharge is a discharge in which the discharge space is surrounded by a dielectric (glass container 12) and the electrode is not directly exposed to plasma. Here, as described in the background section, the luminous efficiency of the lamp can be improved by reducing the work function of the inner part of the glass container corresponding to the external electrode.
In this example, in order to reduce the work function of the inner part of the glass container 12 corresponding to the external electrodes 16 and 18, as described above, the granular material 20 made of iron (hereinafter also referred to as “iron particle 20”) is glass. The inner surface of the container 12 was embedded. As described above, the glass container 12 (lead glass) in which the iron particles 20 are embedded contains potassium and sodium which are alkali components. Therefore, these alkali metals are adsorbed on the surface of the iron particles 20 in the portion embedded in the glass container 12 (the portion in contact with the lead glass). In particular, the alkali metal is adsorbed on the root surface of the buried iron particle 20 (the surface of the boundary portion between the surface of the iron particle 20 and the surface of the glass container 12 facing the discharge space). And the emission of electrons from the root surface (hereinafter referred to as “alkali metal adsorption surface”) is facilitated. As a result, even if the voltage applied to the external electrode is lowered, the conventional external electrode fluorescent lamp (thing which is not particularly provided on the inner surface of the glass container corresponding to the external electrode, hereinafter “conventional external electrode type” Tube surface brightness equivalent to that of a “fluorescent lamp” is obtained (that is, luminous efficiency [lm / W] is improved). Although no detailed data is shown, according to the external electrode fluorescent lamp 10 according to the embodiment, the luminous efficiency is about 1.8 times that of the conventional external electrode fluorescent lamp having the same specifications. Has been obtained.

  The inventor of the present application turned on the external electrode type fluorescent lamp 10 and observed the spectrum of the emitted light, and at least recognized the emission line spectrum of sodium. This is presumed to be because alkali components (potassium, sodium) are released into the discharge space by the impact of electrons colliding with the alkali metal adsorption surface. That is, the alkali metal on the alkali metal adsorption surface is diffused. However, the external electrode fluorescent lamp 10 can continue to be lit stably without lowering the luminous efficiency. This is because when alkali metal on the alkali metal adsorption surface is diffused, potassium ions and sodium ions move to the alkali metal adsorption surface whose concentration has been reduced by the diffusion due to thermal diffusion in the glass container 12 (lead glass). (Concentration diffusion). Further, in the external electrode fluorescent lamp 10, the glass container 12 portion in which the iron particles 20 are embedded repeats the dielectric polarization while inverting the polarity at a very short period by the application of the high frequency voltage. This is also because the movement of potassium ions and sodium ions in the glass container 12 (lead glass) is smooth, and the potassium ions and sodium ions are stably supplied to the alkali metal adsorption surface. it is conceivable that.

Moreover, the alkali component in the glass container 12 (lead glass) can be utilized effectively by densely arranging the plurality of iron particles 20 (dispersion density of about 150 particles / cm ² ). Although it can be said that the alkali component can move in the glass container 12 in the form of ions as described above, it is considered that the range (movement distance) has a limit. Therefore, when the iron particles 20 are sparsely arranged, the probability that an alkali component existing in a portion far from the iron particles 20 is utilized (adsorbed on the surface of the iron particles 20) is reduced. On the other hand, in this example, since the iron particles 20 are densely arranged, the alkali components in the glass container 12 can be used without leaving as much as possible. In other words, the more the iron particles 20 are arranged, the longer the life of the external electrode fluorescent lamp 10 can be extended.

  Further, in the external electrode type fluorescent lamp 10, the occurrence of pinhole leak that tends to occur in the glass container in the conventional lamp is suppressed. Electrons and ions are accelerated by the difference (sheath voltage) between the potential of the positive column (plasma) and the potential of the solid wall (the inner peripheral surface of the glass container 12 corresponding to the external electrodes 16, 18). Pinhole leak occurs due to hitting the surface. As described above, in the external electrode type fluorescent lamp 10, the work function of the inner part of the glass container 12 corresponding to the external electrodes 16 and 18 becomes small due to the presence of the iron particles 20, so that the sheath voltage decreases. As a result, the collision energy of ions with the inner peripheral surface of the glass container 12 is reduced, and the occurrence of the pinhole leak is suppressed.

  Next, a method for manufacturing the external electrode fluorescent lamp 10 having the above-described configuration will be described. The manufacturing method of the external electrode fluorescent lamp 10 is the same as the conventional general manufacturing method of the external electrode fluorescent lamp except that a step of embedding the iron particles 20 on the inner surface of the glass tube is added. Therefore, only the embedding process of the iron particles 20 will be described, and the description of the remaining processes will be omitted.

First, as shown in FIG. 2A, a carbon heater 32 is inserted from one end of a glass tube 30 in which the phosphor film 14 is formed and both ends are unsealed, and a region where the iron particles 20 are to be embedded. The inner surface of the glass tube 30 corresponding to the above is radiantly heated and softened.
Next, as shown in FIG. 2 (b), an iron grain supply cylinder 36 with a mesh-shaped cap 34 covered at the tip is inserted into the glass tube 30 from the one end side. In addition, the cap 34 has a bottomed cylindrical shape as a whole, and only its side wall has a mesh shape. Then, after a predetermined amount of iron particles 20 is charged into the iron particle supply cylinder 36, argon gas is fed into the iron particle supply cylinder 36, and the iron particles 20 are blown out vigorously from the mesh of the cap 34 (inside the glass tube 30). Spray on the surface). Then, the iron particles 20 are driven into the softened glass tube 30 surface and buried. Here, the amount of implantation can be adjusted by implantation conditions (argon gas pressure, mesh roughness, etc.). Appropriate driving conditions can be determined by experiment.

When the softened glass tube 30 is cooled and solidified, the iron particles 20 are firmly fixed to the inner peripheral surface of the glass tube 30.
Moreover, the process of embedding the iron particles 20 on the inner surface of the glass tube can be performed as follows, for example, in addition to the above.
A thickener such as nitrocellulose is mixed with a butyl acetate solvent to produce a slurry. A predetermined amount of iron particles 20 is mixed in this slurry. The slurry in which the iron particles 20 are mixed is thinly applied to the inner surface of the glass tube 30 corresponding to the planned embedding region of the iron particles 20 and dried. Thereby, the iron particles 20 are temporarily fixed. Then, in a state where argon gas is circulated in the glass tube 30, a carbon rod is inserted into the glass tube 30, and the carbon rod is induction heated by a coil disposed outside the glass tube 30. Due to the heat generated by the carbon rod, the inner surface portion of the glass tube 30 is melted and the iron particles 20 sink. When a part of the iron particles 20 sinks, the heating is stopped and the inner surface portion of the glass tube 30 is solidified. Thereby, a part of the iron particles 20 can be embedded in the inner surface of the glass tube 30.

In addition, the external electrode fluorescent lamp 10 finally manufactured becomes unstable discharge at the beginning of lighting immediately after manufacture, but after aging lighting for ten and several minutes, the discharge may be stabilized thereafter. It has been confirmed.
As described above, according to the external electrode fluorescent lamp 10 according to the present embodiment, the iron particles 20 are embedded in the inner peripheral surface of the glass container 12, thereby emitting light more than the conventional external electrode fluorescent lamp. Efficiency can be improved.

Moreover, since the iron particles 20 are firmly embedded (fixed) in the inner peripheral surface of the glass container 12, they are almost detached from the inner peripheral surface of the glass container 12 even when struck by ions during lighting discharge. There is nothing to do.
(Embodiment 2)
FIG. 3A shows a schematic configuration of the external electrode fluorescent lamp 50 according to the second embodiment.

  The external electrode fluorescent lamp 50 differs from the external electrode fluorescent lamp 10 (FIG. 1) according to Embodiment 1 mainly in the shape of the end portion of the glass container. Accordingly, the following description will focus on these different portions, and the components substantially the same as those of the external electrode fluorescent lamp 10 according to the first embodiment are denoted by the same reference numerals as those in FIG. The detailed description is omitted.

The external electrode fluorescent lamp 50 has a glass container 52 in which both ends of a glass tube made of hard glass are hermetically sealed.
At both ends of the glass container 52 having a tubular shape, concave portions 54 recessed in a cylindrical shape are formed on the inner side in the tube axis direction. External electrodes 56 and 58 are formed on the inner wall of the recess 54 (the outer surface of the glass container 52). The external electrodes 56 and 58 are formed by firing a conductive paste applied to the outer surface of the glass container 54.

Further, glass members 60 and 62 made of lead glass (the same material used for the glass container 12 of the first embodiment) are attached to the outer wall of the recess 54 (the inner surface of the glass container 52). That is, the glass members 60 and 62 contain about 4 wt% potassium and about 8 wt% sodium in terms of oxide.
And in the glass members 60 and 62, the granular material (iron particle) 20 is embed | buried so that the one part may be exposed to discharge space.

At both ends of the glass container 52, lead wires 64 and 66 are provided supported by external electrodes 56 and 58.
In addition, the sealing part of the both ends of the external electrode type fluorescent lamp 50 can be formed as follows. As shown in FIG. 3B, a bottomed cylindrical member 70 with a flange (flare) 68 is formed. The cylindrical member 70 is made of hard glass. A slurry containing iron particles 20 and fine powder of lead glass is applied to the outer wall of the cylindrical member 70 in a film form, dried, and then heated to soften the lead glass. When the lead glass is solidified, this becomes the glass member 60 (62). Then, the outer periphery of the flange (flare) 68 of the cylindrical member 70 is combined with the end of the straight tubular hard glass tube (having the phosphor film 14 formed on the inner surface), and then heated and melted. Are joined together (sealing by the same method as so-called flare sealing in a hot cathode fluorescent lamp).

  In the external electrode fluorescent lamp 50 having the above configuration, when high frequency power is supplied through the lead wires 64 and 66, a discharge phenomenon occurs in the hermetic sealed space (discharge space) in the glass container 52, and ultraviolet rays are emitted. The ultraviolet rays are converted into visible light by the phosphor film 14 and emitted outside the glass container 52. At this time, the effect brought about by the iron particles 20 embedded in the glass members 60 and 62 is the same as the effect brought about by the iron particles 20 embedded in the inner surface of the glass container 12 in the first embodiment.

Further, according to the second embodiment, even when a glass material that does not contain a sufficient amount of an alkali component is adopted as the glass material of the glass container (by providing a glass member that is an alkali metal supply substance separately). There is an advantage that the luminous efficiency can be improved.
(Embodiment 3)
Next, an example in which the external electrode fluorescent lamp according to the above embodiment is used in a backlight unit shown as an example of a lamp system will be described. Either the external electrode fluorescent lamp 10 or the external electrode fluorescent lamp 50 described above may be used as the light source. Here, an example using the external electrode fluorescent lamp 10 according to the first embodiment is used. Show.

FIG. 4 is a perspective view showing a schematic configuration of a direct-type backlight unit 80 according to the third embodiment. FIG. 4 is a view in which a translucent plate 86 described later is broken. The backlight unit 80 is arranged and used on the back surface of an LCD (liquid crystal display) panel (not shown), and constitutes an LCD device.
The backlight unit 80 includes an envelope 88 including a rectangular reflecting plate 82, a side plate 84 surrounding the reflecting plate 82, and a translucent plate 86 provided in parallel with the reflecting plate 82. The reflecting plate 82 and the side plate 84 are both reflecting films (not shown) in which silver or the like is vapor-deposited on one main surface (the inner surface when assembled as the envelope 88) of a plate material made of PET (polyethylene terephthalate) resin. Is formed.

The light transmissive plate 86 is formed by laminating a light diffusing plate 90, a light diffusing sheet 91, and a lens sheet 92 in order from the reflecting plate 82 side.
A plurality (16 in this example) of external electrode type fluorescent lamps 10 are accommodated in the envelope 88 at regular intervals in the short side direction in parallel with the long side of the reflecting plate 82. The external electrode fluorescent lamps 10 are electrically connected in parallel by a wiring member (not shown).

FIG. 5 is a block diagram showing the backlight unit 80 including an inverter 94 which is a power supply circuit unit for lighting the 16 external electrode fluorescent lamps 10.
The inverter 94 converts 50/60 Hz AC power from the commercial power source 96 into high frequency power (for example, 50 kHz as described above) and supplies the external electrode fluorescent lamp 10 with power.

As described above, the present invention has been described based on the embodiment. However, the present invention is not limited to the above-described form, and for example, the following form is also possible.
(1) In the first and second embodiments, iron (Fe) is used as the transition metal constituting the granular material. However, the present invention is not limited thereto, and for example, nickel (Ni) may be used. It has been confirmed that even if the granular material is made of nickel, the luminous efficiency close to the above case where the granular material is made of iron can be obtained.

Alternatively, both iron and nickel may be used. That is, iron particles and nickel particles may be blended at a ratio of 5 to 5, for example. The mixing ratio of iron particles and nickel particles is not limited to 5 to 5, but is arbitrary.
Furthermore, one granular material may be composed of both iron and nickel. Such a granular material can be obtained as follows, for example. The surface of the nickel-coated iron wire is appropriately shaved with a sandpaper or the like to expose the iron surface randomly. The wire obtained by coexisting the nickel surface and the iron surface thus obtained is cut into a predetermined length to obtain a granular material. Alternatively, the nickel-coated iron wire may be simply cut into a predetermined length. This is because the cut surface is an iron surface and the remaining surface is a nickel surface.

Further, it is not necessary for the granular material to be entirely made of a transition metal. That is, as apparent from the action and effect of the particulate matter described in the first embodiment, at least the surface thereof may be made of a transition metal. Therefore, for example, the base material made of a metal other than the transition metal may be a granular material such as nickel plating.
(2) In the first embodiment, the external electrode is made of an aluminum foil. However, the external electrode is not limited to this and may be made of another metal foil, for example, a copper foil. Alternatively, a metal foil film may be formed on the glass container surface by vapor deposition, or a conductive paste applied in a film shape may be baked, and this may be used as an external electrode.
(3) In Embodiment 1 described above, the present invention has been described based on an example in which the present invention is applied to a fluorescent lamp provided with external electrodes at both ends of a glass container. However, as shown in FIG. The present invention can also be applied to a fluorescent lamp (low pressure discharge lamp) 44 in which the electrode on one end side of the container 40 is the external electrode 18 and the electrode on the other end side is the internal electrode 42 installed in the glass container 40. In FIG. 6, components that are substantially the same as those of the external electrode fluorescent lamp 10 are given the same reference numerals, and descriptions thereof are omitted. The end of the glass container 40 on the side where the internal electrode 42 is disposed is sealed with a lead wire 46 portion and hermetically sealed. The internal electrode 42 is joined to the inner end of the lead wire 46 in the glass container 40. The lead wire 46 is made of a tungsten wire. The internal electrode 42 is a so-called hollow electrode having a bottomed cylindrical shape, and is obtained by processing a niobium rod.
(4) In the first and second embodiments, lead glass is used as the glass material that constitutes the glass container 12 and the glass members 60 and 62. However, the present invention is not limited to this. May be used. In short, it has been confirmed that the above-described predetermined effect can be obtained if the glass material contains at least potassium as an alkali component in the composition.
(5) In Embodiments 1 and 2 described above, the present invention has been described using an example in which the present invention is applied to a fluorescent lamp. However, the present invention is not limited to a fluorescent lamp and can also be applied to an ultraviolet lamp. That is, the phosphor film may be removed from the configuration of the external electrode fluorescent lamp according to the above-described embodiment (the phosphor film is not formed) and configured as an external electrode ultraviolet lamp. The ultraviolet lamp irradiates an irradiated object with ultraviolet rays and is used for sterilization of the irradiated object.

  The discharge lamp according to the present invention can be suitably used for, for example, a light source of a backlight unit in a liquid crystal display device or general illumination applications.

(A) is a partially cutaway longitudinal cross-sectional view of the external electrode fluorescent lamp according to Embodiment 1, and (b) is an enlarged view of a portion A in (a). It is a figure which shows a part of manufacturing process of the said external electrode type fluorescent lamp. (A) is a figure which shows schematic structure of the external electrode type | mold fluorescent lamp which concerns on Embodiment 2, (b) is sectional drawing of a bottomed cylindrical member with a ridge (flare). 6 is a perspective view showing a schematic configuration of a backlight unit according to Embodiment 3. FIG. It is a block diagram of the said backlight unit. It is a partially notched longitudinal cross-sectional view which shows the fluorescent lamp which concerns on a modification.

Explanation of symbols

10, 50 External electrode type fluorescent lamp 12, 40, 52 Glass container 16, 18, 56, 58 External electrode 20 Granules (iron particles)
44 Fluorescent lamp 80 Backlight unit

Claims (8)

A glass container made of a glass material containing an alkali component;
An external electrode disposed on the outer surface of the glass container,
A discharge lamp characterized in that a plurality of granular materials each having at least a surface made of a transition metal are embedded on the inner surface of a glass container corresponding to the external electrode so that a part of each is exposed. A glass container;
An external electrode disposed on the outer surface of the glass container,
A glass member made of a glass material containing an alkali component, disposed on the inner surface of the glass container corresponding to the external electrode, so that at least a part of each of the plurality of granular materials having a surface made of a transition metal is exposed. A discharge lamp characterized by being embedded.   The discharge lamp according to claim 1 or 2, wherein the glass material contains at least potassium as the alkali component.   The discharge lamp according to claim 3, wherein the glass material further contains sodium as the alkali component.   The discharge lamp according to claim 1, wherein the transition metal is iron and / or nickel.   5. The discharge lamp according to claim 1, wherein a part of the plurality of granular materials is made of iron, and the remaining number is made of nickel.   The discharge lamp according to any one of claims 1 to 6, wherein the plurality of granular materials are dispersed substantially uniformly in the inner surface direction of the glass container.   A lamp system comprising the discharge lamp according to claim 1 as a light source.

Images