JP2938838B2 - Discharge lamp electrode and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a discharge lamp electrode used for various discharge lamps such as a backlight of a liquid crystal display device, a bulb-type fluorescent lamp, a reading light source such as a facsimile and a scanner, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, liquid crystal displays which can be reduced in weight with low power consumption are rapidly spreading. Along with this,
2. Description of the Related Art Small fluorescent lamps are being actively developed as light sources for liquid crystal displays. Similarly, a bulb-shaped fluorescent lamp is
It is becoming popular because it consumes less power and has a longer life than incandescent bulbs.

In general, fluorescent lamps can be classified into hot cathode lamps utilizing arc discharge due to thermionic emission and cold cathode lamps utilizing glow discharge utilizing secondary electron emission.

[0004] Hot cathode lamps have a smaller cathode drop voltage and higher luminous efficiency with respect to electric power than cold cathode lamps. Further, due to thermionic emission, a large current density can be obtained, and higher brightness can be achieved as compared with a cold cathode. Therefore, it is suitable for a light source that requires a large amount of luminous flux, such as a backlight for a large-screen liquid crystal display, a bulb-shaped fluorescent lamp, and a reading light source such as a facsimile or a scanner.

[0005] As an electrode for a conventional hot cathode lamp, an electrode obtained by coating a part of a transition metal and an alkaline earth metal containing barium on a tungsten coil (JP-A-59-75553).
Is known.

[0006] However, with the thinning of the liquid crystal display device, there is an increasing demand for a fluorescent lamp as a light source that emits a large amount of light in a thin tube. Similarly, bulb-shaped fluorescent lamps,
As for the facsimile and the scanner, there is a strong demand for a fluorescent lamp as a light source that emits a large amount of luminous flux through a thin tube with the downsizing. In a conventional hot cathode lamp, a preheating circuit for starting thermionic emission is required, so that it is difficult to make the tube as thin as a cold cathode lamp.

The present inventors have proposed an electrode material that solves these problems in Japanese Patent Application Laid-Open No. 2-186550, and further described an electrode material, an electrode material manufacturing method and an electrode in Japanese Patent Application Laid-Open No. 4-43546. JP-A-6-267404, JP-A-7-296768, and JP-A-9-296.
No. 129177.

In JP-A-7-142031 and JP-A-7-142032, a conductor cap made of a material having high electric conductivity such as a metal or a semiconductor ceramic is used as a method for holding an electrode. A method was proposed. Japanese Patent Application Laid-Open No. 7-262963 proposed a conductor pipe made of a material having high electric conductivity such as metal and semiconductor ceramic, and a method of winding a lead wire around an electrode.

FIG. 4A and FIG.
It is sectional drawing which shows one tube end part of the discharge lamp described in No. 2031. 4A and 4B, reference numeral 1 denotes a glass bulb of a fluorescent lamp, 2 denotes an electrode container having conductivity, 3 denotes an aggregate-type electron-emitting material filled in the electrode container 2, and 4 denotes an electrode container. , A bottomed cylindrical metal cap 5 fitted to the bottom of the lead 5 is a lead wire, and the lead wire 5 is electrically and mechanically connected to the metal cap 4. A mercury gas as a discharge gas and an argon gas for promoting ionization of the mercury gas are sealed in the bulb 1.
Then, the ultraviolet light emitted by the mercury gas is applied to a fluorescent substance applied to the tube wall of the bulb 1 to convert the ultraviolet light into visible light.

The electrode container 2 is made of a semiconductor porcelain having a high melting point or a good sputtering property, for example, Ba-Z.
It is composed of r-Ta oxide-based semiconductor porcelain,
An anti-sputtering layer made of an a-based nitride or carbide is formed and has conductivity. The electron emission material 3 is formed of a granular, massive, or porous semiconductor porcelain filled in the electrode container 2.

In the example of FIG. 4B, a hole 2a is provided on the bottom surface of the electrode container 2, a metal 6 is buried in the hole 2a, and a lead wire 5 is electrically connected to the metal 6. .

[0012]

The problem to be solved by the invention is as shown in FIG.
What fixed the metal cap 4 to the bottom of the electrode container 2
In view of the strength of the metal cap 4, it is necessary to set its thickness t to about 0.1 mm or more. For example, when the outer diameter d1 of the valve 1 is 3 mm and the inner diameter d2 is 2 mm, the inner wall of the valve 1 and the metal cap Assuming that a gap g between the electrode container 2 and the electrode container 4 is about 0.25 mm, the outer diameter d3 of the electrode container 2 is (2 mm−
0.1 mm × 2−0.25 mm × 2) = 1.3 mm, and when the thickness of the electrode container 2 is set to 0.3 mm, the inner diameter d4 of the electrode container 2 is reduced to 0.7 mm. For this reason, the opening area of the electrode container 2, that is, the filling area of the electron-emitting material 3 was reduced, and the life of the lighting time was not sufficient. Conversely, in order to obtain the same diameter as the electrode container 2, the diameter of the bulb 1 must be increased, and the thickness of the fluorescent lamp increases.

Further, since the thickness of the bottom 4a of the metal cap 4 is also set to the thickness t, the effective light emission length (the effective light emission) by the thickness t when the length of the bulb 1 is fixed. (The length is substantially proportional to the distance between the electron-emitting materials 3 at both ends of the bulb 1). In other words, the length of the fluorescent lamp is increased.

On the other hand, as shown in FIG. 4B, a hole 2a is provided in the bottom surface of the electrode container 2 and a metal 6 is embedded therein.
When the thickness s is set to, for example, about 1 mm in consideration of the fixing strength of the metal 6, the effective emission length is reduced by a total of 2 mm at both ends.

In view of the above problems, the present invention provides a discharge lamp electrode having a configuration that can reduce the thickness and length of a discharge lamp, increase the effective light emission length, and extend the life. It is an object of the present invention to provide a manufacturing method thereof.

[0016]

[0017]

[0018]

According to the present invention , there is provided an electrode for a discharge lamp in which a through hole is provided at the bottom of a ceramic bottomed cylindrical electrode container having at least a surface having conductivity, and a lead wire is provided in the through hole. It is fitted and fixed by sintering shrinkage of ceramics, and the electrode container accommodates a filler having an aggregate type structure made of an electron emitting material (Claim 1 ).

[0019] In a first aspect of the invention, the increase in effective emission length, reduction of the valve diameter on is possible, the lead wire is firmly coupled to the electrode vessel.

According to the first aspect of the present invention, as the electrode container,
When using ceramics, preferably the electrode container
If the surface is fired in a reducing atmosphere
Or made of ceramics with conductivity throughout
(Claim 2) .

[0021]

Further, the electrode for a discharge lamp of the present invention is a bottomed cylinder.
The Jo electrode container constituted by a ceramic, a metal layer is formed on the bottom surface of the electrode container, the lead wire on the metal layer of the electrode bottom poppy brazing, from the electron-emitting material in the electrode container
A filler having an aggregate type structure is accommodated (claim 3 ).

According to the third aspect of the invention, the lead wire can be firmly brazed to the ceramic electrode.

The electrode for a discharge lamp of the present invention is a mercury getter.
Characterized by being welded ter the lead (claim
4) .

Further, in the discharge lamp electrode of the present invention, preferably, the electron emission material contains a first component comprising a compound containing at least one of Ba, Sr and Ca, and Zr and / or Ti. and a second component comprising a compound, characterized by comprising the material and a third component comprising a compound containing Ta and / or Nb (claim 5).

Further, in the present invention, the electron emission material may be such that the molar ratio of the first component, the second component, and the third component is X, Y, and Z, respectively, where 0.8 ≦ X / (Y + Z) ≦ 2 in the range represented by 2.0, and the second component is characterized by the 0.05 ≦ Y ≦ 0.6 third component is 0.4 ≦ Z ≦ 0.95 (claim 6).

Further, the discharge lamp electrode of the present invention, the surface of the electron emission material, wherein the sputtering preventing layer of carbide and / or nitride of Ta or Nb is formed (claim 7 ).

In the inventions of claims 5 to 7 , of the electron-emitting materials, the first component is mainly an electron-emitting material having a low work function, and the second component is to increase the melting point and lower the electric resistance of the electron-emitting material. The third component is a sputter-prevention layer formed on the surface of the electron-emitting material. By having the electron emission material composition, electron emission, high melting point,
An electron-emitting material having good electrical characteristics with low electric resistance and prevented from being consumed by sputtering can be obtained, and the life of the discharge lamp can be extended. Then, the use of the electron-emitting material having such a composition, the coupling structure of the lead wire and the electrode container as claimed in claim 1-4, namely prolonging the life due to the increase of the electron-emitting material containing portion of the electrode container (inner diameter) And a long-life fluorescent lamp can be provided.

According to the method of manufacturing an electrode for a discharge lamp of the present invention, a metal layer is formed on the bottom surface of a ceramic bottomed cylindrical electrode container containing an aggregate-type filling made of an electron-emitting material. The lead wire is brazed in a neutral or non-oxidizing atmosphere (claim 8 ).

Further, in the method of manufacturing an electrode for a discharge lamp according to the present invention, a metal layer is formed on a bottom surface of a ceramic bottomed cylindrical electrode container containing an aggregate-type filling made of an electron-emitting material. 700 ° C ~
It is characterized by brazing at 1000 ° C.
9 ).

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Overall Configuration of Fluorescent Lamp) FIG.
1A is a partial cross-sectional side view of one end of a fluorescent lamp showing an embodiment of a discharge lamp electrode according to the present invention, and FIG. 1B is an EE cross-sectional view thereof. In FIG. 1, reference numeral 1 denotes a fluorescent lamp bulb formed of elongated glass, and a fluorescent substance is applied to an inner surface thereof. A rare gas is sealed inside the bulb 1 and hermetically sealed at both ends, and the inside constitutes a discharge space 7.

Lead wires 5 made of a conductor are fixed to both ends of the bulb 1. Also, the conductive electrode container 8 in the bulb 1
On the bottom surface, a solder 9 such as a silver solder
Are connected mechanically and electrically.

The electrode container 8 has an opening on the side of the discharge space 7, and the opening is filled with an aggregate-type structure filling as the electron-emitting material 10. Discharge space 7
Contains at least one of argon (Ar) gas, neon (Ne) gas, krypton (Kr) gas, and xenon (Xe) gas from 1330 Pa to 22,000 Pa (10 To
(rr to 170 Torr), and discharge is started by applying a potential difference between both electrodes through the lead wire 5.

Reference numeral 11 denotes a mercury getter joined to the lead wire 5. The mercury getter is not always required to be provided, and may be of a type that supplies mercury during the sealing process. The details of each part are described below. (Electrode container 8) The electrode container 8 of the present invention has a bottomed cylindrical shape. The material of these electrode containers 8 is preferably formed of ceramics having a conductive surface or a conductive material coated thereon. Here, the reason for setting the high melting point of 1400 ° C. or higher is that when the electrode emitting material 10 and the electrode container 8 which are the aggregate type structure filler having the composition described later are simultaneously fired, the firing is performed at a temperature of about 1400 ° C. or higher. It is necessary to prevent dissolution of the electrode container 8 in that case.

If the electrode container 8 is preferably made of a material close to the electron-emitting material 10, the electrode container 8 and the electron-emitting material 10 are firmly adhered to each other, have a small difference in thermal expansion, and are resistant to heat cycles. It is preferable in that it becomes. For example, the electrode container 8 or the electron emission material 10
A first component containing a compound containing at least one of Ba, Sr and Ca, and Zr and / or Ti
A ceramic material containing a second component composed of a compound containing and a third component composed of a compound containing Ta and / or Nb is used. (Electron Emitting Material 10) Electron Emitting Material 10 in the Present Invention
May be any effective electron-emitting material. As an example, preferably, one utilizing the earlier application by the present inventors (JP-A-9-12977) can be used. This is because Ba, S used for the electrode container 8 are also used.
An electron including a first component composed of a compound containing at least one of r and Ca, a second component composed of a compound containing Zr and / or Ti, and a third component composed of a compound containing Ta and / or Nb. The emission material is granulated into granules, stored in the electrode container 8 and fired to obtain the electron emission material 10 as a filler having an aggregate structure. Also,
On the surface of the electron-emitting material 10 as a filler, a sputtering prevention layer made of a carbide and / or nitride of Ta or Nb is formed.

Of the above components, the first component is mainly an electron-emitting material having a low work function. The second component is a component for increasing the melting point and lowering the electrical resistance of the electron-emitting material, and the third component is for supplying carbides and / or nitrides that serve as a sputtering prevention layer formed on the surface of the electron-emitting material. Source.

Assuming that the molar ratios of the first, second and third components are X, Y and Z, respectively, 0.8 ≦ X / (Y
+ Z) ≦ 2.0, the second component is 0.05 ≦ Y ≦ 0.6,
The third component is preferably in a range of 0.4 ≦ Z ≦ 0.95.

As described in the above-mentioned Japanese Patent Application Laid-Open No. 9-12977, when the first component is less than the lower limit of the above-mentioned range, the amount of the electron-emitting material becomes insufficient, resulting in early lighting failure. On the other hand, when the amount exceeds the upper limit of the above range, evaporation and scattering of the electron-emitting material become remarkable during the discharge, the blackening of the lamp tube wall becomes severe, and the luminance is lowered, which is not preferable in practical use.

When the amount of the compound containing Zr and / or Ti as the second component is less than the lower limit of the above range, the melting point of the electron-emitting material is lowered, and during the reduction firing, the electron-emitting material 1
0 cannot maintain the state of the aggregate-type structured packing, and the discharge becomes unstable. On the other hand, if it is more than the upper limit of the above range, the resistance of the electron-emitting material becomes high, and the discharge becomes unstable.

The third component Ta and / or Nb
When the amount of the compound containing is less than the lower limit of the above range, it is difficult to form a carbide or a nitride serving as a sputtering prevention layer on the surface of the electron emission material 10 by firing in a reducing atmosphere. On the other hand, if it is more than the upper limit of the above range, evaporation and scattering of the electron-emitting material become severe due to firing in a reducing atmosphere, which is a problem in production.

The anti-sputtering layer formed on the surface of the electron-emitting material 10 may be made of either carbide or nitride, Ta-Nb-C, Ta-NC, Ta-Nb-N-.
A solid solution such as C may be used.

Japanese Unexamined Patent Publication No. Hei 6-333534 discloses that an electrode for a high-pressure discharge lamp containing a carbide such as HfC has an effect of preventing blackening of a tube wall. The carbides and / or nitrides on the surface of the electron emission material 10 of the discharge lamp electrode are also resistant to ion sputtering and excellent in thermal shock, so that the blackening of the lamp tube wall during continuous lighting is small.

The shape of the electron-emitting material 10 is not limited to a spherical shape, but may be an irregular mass. The filling of the electrode container 8 has an aggregate-type structure, so that the aggregate-type structure can be selectively filled. There is heat in the object part. As a result, an arc spot can be reliably formed as described in JP-A-7-296768. (Mercury Getter) The mercury getter 11 is made of a powder of Ti ₃ Hg and a powder of Zr—Al alloy. The mercury getter 11 seals the tube end of the bulb 1, heats a Zr-Al alloy as a getter material of the material by a high-frequency induction heating device to adsorb unnecessary residual gas, and then forms a mercury alloy Ti. ₃ H
It evaporates mercury vapor from g. (Method of Manufacturing Discharge Lamp Electrode) FIG. 2 is a process chart showing an example of a method of manufacturing a fluorescent lamp according to the present invention. In the steps shown in FIG. 2, the discharge electrodes are manufactured in the steps (a) to (e). The entire manufacturing process can be performed in substantially the same manner as a general ceramics manufacturing method. In the weighing step (a), each raw material is weighed so as to have a predetermined ratio as described above. Each raw material here is usually BaCO ₃ ,
SrCO ₃ , CaCO ₃ , ZrO ₂ , TiO ₂ , Ta ₂ O ₅ ,
Although Nb ₂ O _{5 and the} like are used, oxides, carbonates, oxalates, and the like other than those mentioned here may be used. In the mixing step (b), the raw materials of the components weighed in the weighing step (a) are mixed to obtain a powder. As a mixing method, a method such as a ball mill method, a friction mill method, and a coprecipitation method is used, and thereafter, drying is performed by a dehydration heating drying method or a freeze drying method. In the calcining step (c), the raw material powder mixed in the mixing step (b) is calcined. The calcining temperature is set at about 800 ° C to 1300 ° C,
A compound of an electron emission material is obtained. This calcination may be performed in a powder state or in a state where the powder is formed. In the pulverizing step (d), the compound obtained in the calcining step (c) is pulverized. This fine pulverization is performed by a ball mill method, air current pulverization, or the like. In the granulation step (e), granules of an appropriate size are obtained from the fine particles obtained in the pulverization step in step (d). The powder obtained by the fine pulverization is converted to polyvinyl alcohol (PV
A), granulation is performed using an aqueous solution containing an organic binder such as polyethylene glycol (PEG) and polyethylene oxide (PEO) to obtain a granular raw material powder of an electron emission material. At this time, granulation is performed using a spray drying method, an extrusion granulation method, a tumbling granulation method, or a mortar or pestle, but the granulation method is not limited to these methods. In the forming step (f), a formed body of the electrode container 8 is obtained from the granular electron emission material powder selected in the granulating step (e). At this time, as shown in FIG. 3 (A) or (B), the lead wire 5 is connected to the bottom of the electrode container 8.
May be formed at the same time. (G)
In the filling step, the electrode element 8 is obtained by filling the electrode container 8 with the granular electron-emitting material 10 obtained in the granulation step of step (e). At this time, the raw material powder of the granular electron emission material is filled without applying pressure.

At this time, if the through hole 8a is provided in the bottom 3 of the electrode container 8 in the forming step (f), the through hole 8a
(In the example of FIG. 3A, the lead wire 5 is fitted without penetrating the through hole 8a, and in the example of FIG. 3B, the lead wire 5 penetrates the through hole 8a. After that, the electrode container 8 is filled with the granular electron emitting material 10 obtained in the granulation step of the step (e). Also in this case, similarly, the raw material powder of the granular electron emission material 10 is filled without pressing.

When firing is performed after pressure molding as in the case of a sintered electrode, a sufficient heat storage effect for emitting thermoelectrons cannot be obtained, and a preheating circuit is used at the start of discharge. On the other hand, by filling the raw material powder of the granular electron-emitting material into the electrode container 8 with an appropriate gap without pressurizing, the arc discharge can be started immediately without using a preheating circuit. In the firing step (h), the electrode element obtained in the filling step (g) is fired to obtain a sintered body (discharge lamp electrode). The main component of the sintered body includes a first component made of a compound containing at least one of Ba, Sr, and Ca, a second component made of a compound containing Zr and / or Ti, and Ta and / or Nb. And a material including a third component. Granular electron emitting material 1
The firing temperature of the electrode element filled with the raw material powder of 0 is 140
0-2000 ° C is preferred. This firing temperature is 1400 ° C
If it is less than 3, a sputtering prevention layer made of Ta or Nb carbide and / or nitride is not formed on the surface of the electrode container 8. If the temperature exceeds 2000 ° C., an aggregate structure cannot be realized.

Regarding the firing atmosphere, for example, when a carbide is mainly formed on the surface of the electrode container 8, the firing is performed by flowing an inert gas such as argon or nitrogen containing benzene or carbon monoxide. Alternatively, the electrode container 8 may be buried in carbon powder and fired by flowing an inert gas or a nitrogen gas. Further, when the carbon source is previously contained in the material and is allowed to remain, such as when the binder removal is insufficient, the carbon source is not particularly necessary in the firing atmosphere. When a nitride is mainly formed on the surface of the electrode container 8, firing is performed by flowing a nitrogen gas containing a reducing gas such as hydrogen or carbon monoxide.

As described above, by firing in a reducing atmosphere, a sputtering prevention layer made of a carbide and / or nitride of Ta or Nb is formed on the surface of the electron-emitting material 10. In the lead wire bonding step (i), the bottom surface is cleaned and activated to facilitate brazing of the lead wire 5 to the bottom surface of the electrode container 8 made of ceramics obtained in the firing step (h). For example, a metal layer such as Mo—Mn is formed by metallization, or Au, Ag, Cu,
A metal layer such as Ni or Sn is formed by plating, vapor deposition, or sputtering, and a solder 9 such as nickel brazing or silver brazing is applied to the metal layer.
7 in a neutral or non-oxidizing atmosphere
The lead wire 5 is joined by baking at a temperature of 00 to 1000 ° C.

As shown in FIGS. 3A and 3B, when the through hole 8a is provided at the bottom of the electrode container 8, when the lead wire 5 is fitted into the through hole 8a and fired, The step of brazing the lead wire 5 can be omitted. If the lead wire 5 is fitted into the through hole 8a and fired simultaneously with the electron-emitting material 10, the lead wire 5 is firmly connected to the electrode container 8 by shrinkage in the firing and cooling step of the electrode container 8.

[0049]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the electrode manufacturing process described with reference to FIG. 2, according to steps (a) to (e), BaCO ₃ , SrC
O ₃ , CaCO ₃ , ZrO ₂ , TiO ₂ , Ta ₂ O ₅ , Nb ₂
A raw material powder of an unfired granular electron emission material is prepared using O ₅ or the like as a starting material.

Starting from BaCO ₃ , ZrO ₂ and Ta ₂ O ₅ , 1.0 mol of BaCO ₃ , 0.2 mol of ZrO ₂ and 0.8 mol of Ta ₂ O ₅ were weighed. Thereafter, the mixture is wet-mixed for 20 hours by a ball mill method,
And dried at a molding pressure of about 10 MPa. This was calcined in the air at 800 to 1300 ° C. for about 2 hours. The resulting powder is ball milled to 20
After crushing for about an hour and drying with a dryer at 80 to 130 ° C., an aqueous solution containing polyvinyl alcohol is added, and a mortar,
Granulation was performed using a pestle.

Next, among the steps shown in the method for manufacturing the electrode for a discharge lamp described with reference to FIG. 2, the electrode container 8 using the unfired granular electron emitting material according to the steps (f) to (i). Then, the same raw material powder was filled to form an electrode element, thereby completing an electrode for a discharge lamp. In addition, the lead wire 5 spot-welded with a mercury dispenser material 11 also serving as a mercury getter in advance.
Was brazed to the bottom surface of the electrode container 8 with silver brazing.

As shown in FIGS. 1 (A) and 1 (B), the lead wire 5 is brazed to the bottom surface of the electrode container 8, or as shown in FIGS. 4A is configured to fit into the through hole 8a of the electrode container 8, as shown in FIG. 4A, the electrode container 8 has a thickness t of the metal cap 4 as in the case where the metal cap 4 is used. It is not necessary to reduce the outer diameter d3 of the electrode container 8. As described above, the outer diameter d1 and the inner diameter d2 of the bulb 1 are 3 mm and 2 mm, respectively. , 0.9 mm, the opening area of the electrode container 8 can be increased by about 60%, and the opening area of the electrode container 8 can be made large while having the same tube diameter of the valve 1. 8 while reducing the diameter of the valve 1 Can Kusuru. FIG.
As shown in (B), the effective light emission length can be increased by about 1 mm × 2 = 2 mm as compared with the case where the metal 6 is provided in the electrode container. Particularly when the bulb 1 has a short length, for example, a liquid crystal backlight (for example, having a length of about 32 mm) used in a view finder of a camcorder, there is a remarkable effect.

[0053]

According to the present invention, electrostatic the through hole provided in the bottom of the pole container bound fitted leads to (claim 1), the metal and fitting the metal cap electrode container Compared to a structure in which a lead wire is joined to a cap or a structure in which a metal is fitted into a through hole provided in the bottom of a metal cap and a lead wire is joined to the metal, the effective light emission length is increased, The sectional area of the accommodating portion of the electrode container accommodating the emission material can be increased, and the valve can be made thinner and shorter. In other words, it is possible to provide a discharge lamp having the same size and high luminance.

[0054] Further, by fastening and fixing to the through hole of the electrode container leads by deflating the through-holes of the electrode vessel by firing the cooling step of the electrode vessel, it is possible to firmly fix the lead wire, Katsuro The step of attaching is unnecessary.

According to the second aspect of the present invention, since the electrode container is made of ceramics and fired in a reducing atmosphere to have conductivity on the surface, the ceramics has an affinity for the electron-emitting material and a high mutual bonding strength. When is used for an electrode container, it is not necessary to impart conductivity to the electrode container by a special process, and the process can be simplified.

[0056] Moreover, as claimed in claim 3, the ceramic used as the electrode vessel, by brazing the leads to the metal layer by forming a metal layer on the bottom, firmly and easily brazed leads can do.

Further, by adopting the electron-emitting material according to any one of claims 5 to 7 , the life of the electron-emitting material is prolonged, and the lead wire according to any one of claims 1 to 4 is connected to an electrode container. As a result, it is possible to provide a discharge lamp with a long life as well as a longer life due to an increase in the sectional area of the accommodating portion of the electron-emitting material.

[Brief description of the drawings]

FIG. 1A is a sectional view showing an end of a discharge lamp showing an embodiment of the present invention, and FIG. 1B is a sectional view taken along line EE of FIG. 1A.

FIG. 2 is a process chart showing an example of a method for manufacturing a discharge lamp of the present invention.

FIGS. 3A and 3B are cross-sectional views each showing an end portion of a discharge lamp showing another embodiment according to the present invention.

FIGS. 4A and 4B are cross-sectional views each showing an end of a conventional discharge lamp.

[Explanation of symbols]

1: bulb, 7: discharge space, 8: electrode container, 9: wax,
10: electron emission material, 11: mercury dispenser material

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Taku Harada 1-1-13 Nihonbashi, Chuo-ku, Tokyo Inside TDC Corporation (56) References JP-A-10-12189 (JP, A) JP-A-56-130068 (JP, A) JP-A-57-21059 (JP, A) JP-A-9-120794 (JP, A) JP-A-7-142031 (JP, A) JP-A-7-142032 (JP, A) JP-A-10-3878 (JP, A) JP-A-9-129177 (JP, A) JP-A-7-296768 (JP, A) JP-A-7-262963 (JP, A) JP-A-6-267404 (JP, A) JP-A-4-43546 (JP, A) JP-A-2-186550 (JP, A) JP-A-2-186527 (JP, A) JP-A-11-102611 ( JP, A) WO 97/48121 (WO, A1) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01J 61/067 H0 1J 9/02 H01J 61/06

Claims (9)

(57) [Claims] 1. A through-hole is provided at the bottom of a ceramic bottomed cylindrical electrode container having at least a surface having conductivity, a lead wire is fitted into the through-hole and fixed by sintering shrinkage of the ceramic, An electrode for a discharge lamp, wherein the electrode container contains a filling material having an aggregate type structure made of an electron emitting material. 2. A method according to claim 1, wherein the electrode vessel, the discharge lamp electrode, characterized in that the surface or the whole of the electrode vessel has conductivity by firing in a reducing atmosphere. 3. A cylindrical electrode container with a bottom is made of ceramics.
Configured, a metal layer is formed on the surface including the bottom surface of the electrode vessel, poppy brazing the lead wire on the metal layer of the bottom surface of the electrode vessel, aggregate type structure formed of an electron emitting material on the electrode container
An electrode for a discharge lamp, characterized in that the electrode for a discharge lamp contains a filling material . 4. The electrode for a discharge lamp according to claim 1, wherein a mercury getter is welded to the lead wire. 5. The compound according to claim 1, wherein the electron-emitting material is a first component comprising a compound containing at least one of Ba, Sr and Ca, and a compound containing Zr and / or Ti. An electrode for a discharge lamp, comprising a material containing a second component consisting of: and a third component consisting of a compound containing Ta and / or Nb. 6. The electron emission material according to claim 5 , wherein the molar ratio of the first component, the second component, and the third component is X ≦ Y / Z, respectively, and 0.8 ≦ X / (Y
+ Z) ≦ 2.0, wherein the second component is 0.05 ≦ Y ≦ 0.6 and the third component is 0.4 ≦ Z ≦ 0.95. Electrodes. 7. The discharge lamp according to claim 1, wherein a sputtering prevention layer of a carbide and / or a nitride of Ta or Nb is formed on a surface of the electron emission material. Electrodes. 8. A metal layer is formed on the bottom surface of a ceramic bottomed cylindrical electrode container containing an aggregate-type filling made of an electron-emitting material, and a lead is formed on the metal layer in a neutral or non-oxidizing atmosphere. A method for manufacturing an electrode for a discharge lamp, comprising brazing a wire. 9. A metal layer is formed on the bottom surface of a ceramic bottomed cylindrical electrode container containing a filler having an aggregate structure made of an electron emitting material, and a lead wire is formed on the metal layer at a temperature of 700 ° C. to 1000 ° C. A method for producing an electrode for a discharge lamp, characterized by brazing at a temperature of ° C.