JPH0429184B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a metal vapor discharge lamp, particularly a light-emitting lamp that uses a ceramic envelope and seals both ends of the lamp with ceramic closures that support electrodes. The present invention relates to a metal vapor discharge lamp having a tube.

Prior Art Conventionally, in high-pressure sodium lamps, a ceramic tube made of translucent alumina has been used as the envelope of the arc tube. The ends of this ceramic tube are generally hermetically sealed by brazing using a ceramic closure body with an electrical introduction member attached to the center. Further, as the electricity introduction member, niobium, which has a coefficient of thermal expansion that closely matches that of alumina, is used. Recently, similar to high-pressure sodium lamps, metal halide lamps have been attempted in which a ceramic tube is used instead of the conventional quartz tube as the envelope of the arc tube. However, in this metal halide lamp, niobium cannot be used as an end electricity introduction material unlike a high-pressure sodium lamp because of the reaction with the metal halide that is the filling material of the arc tube. Therefore, for example,
As described in Publication No. 71695, tungsten has the functions of both an electricity introducing body and a closing body.
It has been proposed to use alumina cermet. As another method, for example, JP-A-59-
As described in Japanese Patent No. 35353, it has been proposed to use an end sealing component in which a thick conductive metal film is provided within the closure.

Problems to be Solved by the Invention High-pressure sodium lamps use niobium as an electricity introduction material, but since niobium is expensive, it has been a major factor in increasing lamp costs. Furthermore, variations in manufacturing or use or differences in conditions tend to cause differences in airtightness between the niobium and the closing body, and this is not necessarily a sufficient sealing method from the standpoint of lamp life. In addition, known cermet or conductive metal thick film methods have been attempted as end sealing parts and end sealing methods for arc tubes filled with conventional metal halides, but There were many problems, such as variations in quality. In particular, in the conventional conductive metal thick film method, the conductive part and the ceramic part are made separately by laminating ceramic and conductive metal thick film, and after being combined with each other, they are fired and integrated. , and this conductive metal thick film has a shape that is disposed at right angles to the plane of the closure body. In these methods and shapes, in order to flow a predetermined current value, complex shapes such as multi-layered conductive metal thick films or cylindrical shapes are used. Heat during lighting or variations in heat generation due to non-uniform resistance of the conductive parts can easily cause thermal distortion, and peeling between the ceramic sheet and the conductive metal thick film can easily cause leaks, cracks, or the electrical conductor can fall off. However, there were problems with quality, reliability, and cost.

Means for Solving the Problems The present invention provides a metal vapor discharge lamp having an arc tube in which both ends of a translucent ceramic tube are sealed with ceramic closures that support electrodes. A ceramic molded product is used in which a conductive metal thick film is integrally sintered between multiple ceramic sheets, and this molded product is in the form of a plate with its flat surface made of ceramic sheets, and the conductive material between the ceramic sheets is By forming a thick metal film parallel to the plane of the ceramic sheet, a low-cost and highly reliable metal vapor discharge lamp is provided.

Embodiments The present invention will now be described in detail with reference to illustrated embodiments.

FIG. 1 is a sectional view showing an embodiment of the arc tube of a 250 watt metal halide lamp according to the present invention;
FIG. 2 shows an enlarged view of one end of the arc tube of FIG. 1, which is normally housed within an outer tube (not shown). In Figures 1 and 2, the tube is made of translucent alumina ceramic tube with an inner diameter of 16 mm and a length of 55 mm.
At both ends of the arc tube bulb 1, there are obturators (hereinafter referred to as conductive disks) with a thickness of approximately 2.5 mm and an outer diameter of approximately 10 mm.
2 and 2' are hermetically sealed with glass brazing material 3 and 3'. A recess is provided in the center of the plane of the conductive disks 2, 2' facing the inside of the arc tube.
In the recesses, electricity introduction bodies 4, 4' which are also electrode supports are placed.
After a molybdenum pipe with an outer diameter of 1 mm is hammered in, it is fixed with glass brazing materials 5 and 5'. Further, tungsten electrodes 6, 6' are welded to the molybdenum pipes 4, 4'. In addition, mercury and, for example, sodium iodide, are contained in the arc tube bulb 1.
A metal halide such as thallium iodide and argon gas (not shown) are sealed as a starting rare gas. As the electricity introduction bodies 4, 4', rod-shaped materials such as tungsten, rhenium, etc., alone or alloys in addition to molybdenum may be used. A method of attaching directly to the disk is also possible.

FIG. 3 is an enlarged sectional view of the conductive disk 2 used in the embodiment of the present invention shown in FIGS. 1 and 2. FIG.
The conductive disk 2 is a disk-shaped molded product made of ceramic sheets 7, 8 and a thick conductive metal film 9 made of metal such as tungsten or tungsten-molybdenum and having a thickness of about 0.005 to 0.5 mm. Further, the conductive disk 2 has a shape in which the planar portion thereof is made of a ceramic sheet, and a conductive metal thick film 9 is provided in parallel between them. The ceramic sheets 7 and 8 are provided between the ceramic sheets 7 and 8 so as to be perpendicular to each other. Further, a recess 10 is provided on one of the planes of the conductive disk 2, and the conductive metal thick film 9 is exposed at the bottom of the recess 10. In other words, approximately 1 mm in the center of the ceramic sheet 7.
It is shaped like a hole with a diameter of . As previously explained with reference to FIGS. 1 and 2, the electricity introducing body 4 is hammered into the recess 10 and fixed with the glass brazing material 5, so that the tungsten electrode 6,
An electric circuit of the electricity introducing body 4 and the conductive metal thick film 9 is formed. Further, connection of this electric circuit to an external circuit is performed by brazing an external lead wire (not shown) wound around the outer periphery of the conductive disk 7 and the conductive metal thick film 9 with a metal solder. It will be done. In this way, by using a ceramic sheet as the flat surface of the plate-shaped conductive disk 2 and providing a thick conductive metal film in parallel between them, the current capacity of the conductive part can be increased. This can make it difficult for leaks and cracks to occur due to thermal strain in the conductive metal thick film.

4, 5, 6, and 7 are enlarged sectional views showing other embodiments of the conductive disk used in the metal vapor discharge lamp according to the present invention.

In the embodiment shown in FIG. 4, a conductive metal layer is formed between the ceramic sheets 11 and 12 as in the embodiment shown in FIG. In addition to the film 13, conductive metal thick films 15 and 16 are also applied to the outer circumferential surface and the inner surface of the recess 14, respectively. a recess 14 on one plane of the conductive disk;
In other words, the conductive metal thick film 15 on the inner surface of the hole in the center of the ceramic sheet 11 is
It is electrically connected to the conductive metal thick film 13 between 1 and 12, and the connection to the electrical introduction body is made by driving a molybdenum pipe or the like into the recess 14. By this method, it is possible to make the electrical bonding between the conductive metal thick film and a metal such as tungsten or molybdenum whose thermal expansion is significantly different from that of ceramics more reliable. Further, the joint can be reliably fixed by glass soldering or metal soldering. A conductive metal thick film 16 is also applied to the outer circumferential surface of the conductive disk, and electrical connection can be established simply by winding an external lead wire around the outer circumference. In this way, external leads, conductive metal thick film 1
6, 13, 15, the electric circuit of the electricity introducing body can be easily formed.

In the embodiment shown in FIG. 5, in order to further increase the current capacity of the conductive disk, ceramic sheets 17,
A conductive metal thick film 20 between 18 and between 18 and 19,
21, and conductive metal thick films 23 and 21 are provided on the outer peripheral surface and inside the recess 22, respectively.
24. In this case, the conductive metal thick films 23 and 24 are the conductive metal thick films 20 and 21.
are provided so as to be electrically connected to each of them.

In the embodiment shown in FIG.
Holes are provided in holes 7 and 28, and this recess 25 is used for the electricity introducing body as an electrode support.
Reference numeral 6 is for an electrical introduction body for attaching external lead wires. Also, ceramic sheets 27, 28
A conductive metal thick film 29 is provided in between so as not to protrude from the outer peripheral edge of the conductive disk. This is effective in further increasing the adhesion and airtightness between the ceramic sheets by providing a joint between the ceramic sheets 27 and 28. Further, a conductive metal thick film 30 is applied to the recess 25 and a conductive metal thick film 31 is applied to the recess 26, respectively, and the conductive metal thick films 30 and 31 are electrically connected to the conductive metal thick film 29. ing.

In the embodiment shown in FIG. 7, two recesses 32 and 33 are provided in the lower plane of the conductive disk, and two layers 34 and 35 are formed of conductive metal thick films. The current capacity is increased. Further, the external lead wires 36 and 37 are simultaneously fired and fixed with metal powders 38 and 39 of tungsten or the like interposed therebetween during firing during the manufacturing process of the conductive disk.

Next, a basic method for manufacturing a conductive disk according to the present invention will be outlined. Punch holes for the recesses are made in a flexible flat ceramic green sheet before sintering, print a thick conductive metal film with an arbitrary pattern on top of it, and punch holes for the recesses at appropriate locations on top of it. The occluding body and the conductor are stacked on top of another ceramic green sheet provided with a conductive disk, punched out into a predetermined shape that will become the conductive disk, and coated with a conductive metal solution on other necessary parts, followed by firing. A conductive disk with both functions is completed. Therefore, this method allows a large number of conductive disks to be manufactured at the same time without going through complicated steps, and is excellent in terms of manufacturing method and bondability between ceramic and conductive metal thick film. In addition, it is possible to easily set the number of layers of conductive metal thick film or the number of electrical inductors to be installed, and the printed pattern of conductive metal thick film allows, for example, to connect two or more electrical circuits into one. It can also be easily provided on a conductive disk.

Effects of the Invention As detailed above, the metal vapor discharge lamp according to the present invention is easy to manufacture, mass-produced, and can be used as a material because the closing body (conductive disk) has a simple plate-like shape. It is inexpensive and can be manufactured at low cost. In addition, since the closure body (conductive disk) is plate-shaped, the molded body is less likely to deform during firing.
Therefore, the joining surface with the arc tube bulb can be made uniform, and since the arc tube bulb and the closing body (conductive disk) are bonded with the same ceramic material such as alumina, there is no difference in expansion rate. It has great utility value, such as being able to eliminate poor airtightness, and in particular has made it possible to put metal halide lamps using ceramic envelopes into practical use.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the metal halide lamp arc tube according to the present invention, FIG. 2 is an enlarged view of one end of the arc tube in FIG. 1, and FIG. 3 is the same as shown in FIGS. FIGS. 4, 5, and 6 are enlarged cross-sectional views of the closure body (conductive disk) used in the embodiments of the present invention.
7 and 7 are enlarged sectional views showing other embodiments of the closure body (conductive disk) used in the metal vapor discharge lamp according to the present invention. 1... Arc tube bulb, 2, 2'... Closure body (conductive disk), 4, 4'... Electric introduction body, 6, 6'
... Electrode, 7, 8 ... Ceramic sheet, 9 ...
Conductive metal thick film, 10... recess.

Claims (1)

[Scope of Claims] 1. A metal vapor discharge lamp having an arc tube in which both ends of a translucent ceramic tube are sealed with ceramic closing bodies that support electrodes, wherein the closing bodies are made of a plurality of ceramic sheets. It consists of a ceramic molded product with a conductive metal thick film integrally sintered between the ceramic sheets, and this molded product is plate-shaped, and its flat surface is made of a ceramic sheet, and furthermore, the conductive metal thick film between the ceramic sheets is made of a ceramic sheet. A metal vapor discharge lamp characterized by being installed parallel to a plane. 2. The ceramic molded product has a recess in its flat surface for attaching an electrical introduction member, and the conductive metal thick film between the ceramic sheets is exposed at the bottom of the recess. A metal vapor discharge lamp according to scope 1. 3. The ceramic molded product has a recess on its flat surface for attaching an electricity introducing body, and a conductive metal thick film is provided on the inner surface of the recess, and the conductive metal thick film on the inner surface of the recess is made of a ceramic sheet. The metal vapor discharge lamp according to claim 1, wherein the metal vapor discharge lamp is electrically connected to a conductive metal thick film between the metal vapor discharge lamps. 4. A patent characterized in that the ceramic molded article has a conductive metal thick film on its outer peripheral surface, and the conductive metal thick film is electrically connected to the conductive metal thick film between the ceramic sheets. A metal vapor discharge lamp according to claim 2 or 3.