JPH04129125A - Indirect heated cathode for cathode-ray tube and its manufacture - Google Patents

Abstract

PURPOSE:To lessen temperature difference between a heater and a cathode part so as to improve heat efficiency and lessen heater consumption power and make supporting structure stable and further enable to be manufactured simply, by connecting plural cathode supporting materials to depressions formed at an intermediate part of a metal cylindrical pipe. CONSTITUTION:A metal cylindrical pipe 1 has depressions 2 being formed by squeezing about its center part inward and protrusions 3 being formed on its inside. To these depression 2 parts the tips of cathode supporting materials 9, 9 being made of metal wire are connected and extending downward radially. There are three or four supporting materials 9, 9, and because their connected points are in the middle of the pipe 1, the thermal conductivity between a cathode part 5 and a heater 8 is not affected at all by the supporting materials 9, 9. Thereby the temperature difference between the heater and the cathode part is lessened, when the heater is heated, and the cathode part is heated, and heat efficiency is improved and consumption power of the heater is lessened and at the same time stable supporting structure is made, and further manufacture is possible to be made simple.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an indirectly heated cathode ray cathode member used in a cathode ray tube such as a television picture tube, an oscilloscope observation tube, or an image pickup tube.

[Prior Art] Conventionally, as this type of indirectly heated cathode for cathode ray tubes, there is one disclosed in Japanese Patent Application Laid-Open No. 61-288339. The indirectly heated cathode for cathode ray tubes disclosed in this publication includes a heater, a cylindrical pipe made of a high melting point metal with one end closed and containing the heater, and a metal pipe attached to the outer surface of the closed end wall of the pipe. It includes a cup and an electron emitting cathode section built into the cup. In addition, the intersecting parts of the two supporting metal wires are inserted between the bottom of the metal cup and one end of the metal cylindrical pipe, and in this state, the cup and the metal cylindrical vibe are joined. There is.

``Problems to be Solved by the Invention'' As mentioned above, the conventional cathode consists of a metal cup welded to the outer surface of the closed end wall of a metal cylindrical pipe with a built-in heater and one end closed. It has a structure in which a radioactive cathode part is built in.Therefore, the closed end wall of the metal cylindrical pipe and the bottom surface of the cup are interposed between the heating heater and the electron radioactive cathode part, and the electron radioactive cathode part is Heating occurs via these two metal plates.

For this reason, radiant heat from the heater radiates from the metal vibrator or cup, increasing radiant heat loss, creating a large temperature difference between the heater and the cathode, decreasing thermal efficiency, and increasing power consumption of the heater. There were problems such as.

Furthermore, the cup and the metal cylindrical vibrator are joined together via a metal wire, which has the disadvantage of significantly lowering efficiency.

In addition, in order to cross two metal wires, it is necessary to use substantially four wires.
The structure is such that the cathode part is supported by a book, and its position is easily moved, so it is difficult to say that it is a stable structure.

Therefore, the present invention first divides the inner space into upper and lower parts by drawing the middle part of the metal vibrator.
We proposed an indirectly heated cathode for cathode ray tubes, which has a cathode section above and a heater below. With this cathode structure, it is possible to reduce the temperature difference between the heater and the cathode portion, improve thermal efficiency, and reduce heater power consumption. Note that the support mechanism is not considered here.

Therefore, a technical object of the present invention is to provide an indirectly heated cathode for a cathode ray tube having the above-described structure and having a stable support structure.

Furthermore, another technical object of the present invention is to provide a method for manufacturing an indirectly heated cathode for a cathode ray tube that can be easily manufactured.

[Means for Solving the Problems] In order to solve the above-mentioned problems of the conventional technology, the present invention provides a high melting point material having a circumferential depression formed by squeezing and pressing in the middle part. This indirectly heated cathode for a cathode ray tube is equipped with a metal vibrator, and is characterized in that a plurality of cathode supports are connected to the recess.

The present invention provides the indirectly heated cathode for a cathode ray tube, characterized in that at least one of the plurality of cathode supporting materials is joined to the recess.

The present invention also provides the indirectly heated cathode for a cathode ray tube, comprising:
The indirectly heated cathode for a cathode ray tube is characterized in that substantially three cathode supporting members extend from the recess.

Furthermore, the present invention is characterized in that a plurality of cathode supports are connected to the recesses of the indirectly heated cathode body, which is equipped with a refractory metal vibrator having a circumferential recess formed by drawing in the middle part. This is a method for manufacturing an indirectly heated cathode for a cathode ray tube.

In the present invention, the high melting point metal refers to a metal or alloy having a high melting point, including molybdenum, tantalum, and the like. In the present invention, the cathode support material refers to a metal wire, a metal tape, a long thin metal plate, etc. for supporting the indirectly heated cathode body for a cathode ray tube.

[Function] In the present invention, by connecting a plurality of cathode supporting materials to the recess formed along the circumferential surface of the intermediate portion of the molybdenum vibe, the indirectly heated cathode body for a cathode ray tube can be easily and stably supported. can do.

[Example] Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a sectional view for explaining the structure of an indirectly heated cathode for a cathode ray tube according to a first embodiment of the present invention. In Figure 1, the material is molybdenum, the total length is 5°75mm, and the thickness is 35mm.
A metal cylindrical pipe 1 with a diameter of less than μm has a depression 2 formed by squeezing the approximately central part inward at a position of 0.4 to 0.7 mm from the upper end, and a protrusion 3 formed inward corresponding to the depression 2. have In addition, a metal disc 4 with a thickness of 5 to 50 μm is inserted from the upper end of the space created as a result of the metal cylindrical vibrator 1 and is seated on the protrusion 3. It is joined to the protrusion 3. This results in
The internal window i of the metal cylindrical vibe 1 has two spaces 10 above and below.
a and 10b 2 Subsequently, a cathode part 5 made of a cathode impregnated with a porous sintered tungsten body is inserted into this space part 10a, and the metal disk 4 and the cathode part 5J are connected to the metal cylindrical vibe 1. The door is attached by welding the outer periphery of the door.

As the cathode part 5, an impregnated cathode in which tungsten-based sintered □ is impregnated with a Ba-based emitter material is used.The surface of the cathode part 5 is coated with an osminium film 7 to facilitate electron emission. As the heat-absorbing film 5, a sintered film containing high-melting point metal powder, such as tungsten powder, with an average particle size of 5 μm or less, as disclosed in the prior art, is used. , a heating heater 8 is accommodated in the lower space.

In this case, the metal disk 4 may be fixed to the metal cylindrical vibe 1 by welding the metal disk 4 to the metal cylindrical vibe 1. Further, the lower end 1a of the illustrated metal cylindrical vibrator 1 has a diameter enlarged by expansion processing. A heat absorbing film 6 is formed on the inner peripheral surface of the lower space 10b of the metal cylindrical vibe 1.

Furthermore, a cathode support material 9 made of metal wire is placed in the 2 portions of the depression.
The tips of 9 are joined and extend radially downward. There are three or four cathode supporting materials 9.9, and since the connecting position of the cathode supporting materials 9.9 is in the middle of the metal cylindrical vibe 1, these cathode supporting materials 9.9 connect the cathode portion This does not affect the thermal conductivity between the heating element 5 and the heating heater 8 in any way.

This indirectly heated cathode for a cathode ray tube is manufactured as follows.

43% Ru was added to the metal cylindrical vibrator 1 shown in FIG.
A powdered brazing filler metal made of -Mo is applied to a metal disk, inserted and seated, and brazed at 1750'C in a vacuum or in a hydrogen atmosphere.

11 in FIG. 1 indicates a brazing material used for joining.

Furthermore, when the cathode part 5 is inserted and electric welding is performed from the periphery, a heat absorbing film 6 and a heating heater 8 are inserted into the inner peripheral surface of the space 10b of the pipe 1 other than the cathode part 5, and the first An indirectly heated cathode for a cathode ray tube as shown in the figure is obtained.

FIG. 2 is a sectional view showing an indirectly heated cathode for a cathode ray tube according to a second embodiment of the present invention.

The indirectly heated cathode according to the second embodiment is different from the first embodiment.
In addition to being drawn at the open end 1b of the metal cylindrical vibrator 1, the cathode supports 9' and 9 are joined in different directions.

That is, the cathode supporting members 9'', 9- made of metal wires have their tips welded to the depressions 2 and extend downward, are bent near their lower ends, and extend upward and radially.

The structure other than that described above is the same as that of the first embodiment, so the explanation will be omitted.

In FIGS. 1 and 2, an osminium film 7 is provided on the surface of the cathode portion 5 to facilitate electron emission.

FIGS. 3(a) and 3(b) are diagrams showing a first example of a support structure for an indirectly heated cathode for a cathode ray tube according to an embodiment of the present invention.

In the figure, the center circle 2a shows the cross section of the depression 2. As shown in FIG. 3(a), the tip 32g of the metal wire 32 having the same length is joined to the center part of the circular arc portion 31a of the metal wire 31, which has a length of 2/3 of the circumference of the circle 2a. and forms a cathode support material 3o.

As shown in FIG. 3(b), the arc portion of the cathode support material 30 is wound around the circle 2a, and the bent portions 31a, 3 of the cathode support material are wrapped around the circle 2a.
1b, each branch 31c, 31d,
32, the extending directions thereof form an angle of 120# with respect to the center of the circle 2a indicating the depression.

Since such a cathode support material 3o supports the cathode body at three points, it is supported more stably than one that supports it at four points.

FIGS. 4(a) and 4(b) are diagrams showing a second example of a support structure for an indirectly heated cathode for a cathode ray tube according to an embodiment of the present invention.

In the figure, the circle 2a in the center indicates the cross section of the 2 portions of the depressions, as described above.

As shown in Figure 4(a), one of the circumferences forming the cross section
Cathode supports 41 and 42 made of metal wires having circular arcs 41a and 42g equal to the length of /4 at the center are arranged facing each other across the circle 2a as shown in FIG. 6(b). 2a, the circular arc portions 41 and 42 are brought into contact with each other.
The parts indicated by 47, 48° and 49 are brazed to form a four-point support.

In the above example, a high melting point metal wire such as a molybdenum wire or a tungsten wire was used as the cathode support material.
It is also possible to use a long thin metal plate or metal tape made of the same material.

Further, the cathode support structure shown in FIGS. 3 and 4 can be applied to any of the indirectly heated cathodes shown in FIGS. 1 and 2.

[Effects of the Invention] As described above, in the present invention, in an indirectly heated cathode for a cathode ray tube that forms a metal vibrator in which a cathode portion is provided above and a heating heater is arranged below, the heater is heated. Therefore, it is possible to provide an indirectly heated cathode for a cathode ray tube that reduces the temperature difference between the heater and the cathode when heating the cathode, improves thermal efficiency, and reduces power consumption of the heater.

Further, according to the present invention, it is possible to provide an indirectly heated cathode for a cathode ray tube that has a stable support structure by connecting a cathode support material to the recess.

Further, according to the present invention, a method for manufacturing an indirectly heated cathode for a cathode ray tube, in which it is easy to manufacture an indirectly heated cathode body for a cathode ray tube, and the cathode support structure can be easily manufactured by connecting a cathode support material. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an indirectly heated cathode for a cathode ray tube according to a first embodiment of the present invention, and FIG. 2 is a sectional view showing an indirectly heated cathode for a cathode ray tube according to a second embodiment of the invention. 3(a) and (b) are diagrams showing a first example of the support structure of an indirectly heated cathode for a cathode ray tube according to an embodiment of the present invention, and FIG. 4 is a diagram (a) and (b).
) is the second indirectly heated cathode for a cathode ray tube according to an embodiment of the present invention.
FIG. 2 is a diagram showing an example of a sentence structure. In the figure, 1...metal cylindrical vibe, 2...dent, 3 protrusion, 10a, 10b...space, 4...metal circle 5
. . . Cathode part, 6 . ...metal wire,
442...Cathode support material. Holding board, Holding 1゜Fig. 4

Claims (1)

[Claims] 1. In an indirectly heated cathode for a cathode ray tube, the cathode is equipped with a pipe made of a high melting point metal and has a circumferential depression formed by drawing in the middle, comprising: a plurality of cathode supporting materials in the depression; An indirectly heated cathode for a cathode ray tube characterized by being connected. 2. In the indirectly heated cathode for a cathode ray tube according to the first claim,
An indirectly heated cathode for a cathode ray tube, wherein at least one of the plurality of cathode supporting materials is joined to the recess. 3. In the indirectly heated cathode for a cathode ray tube according to the second claim,
An indirectly heated cathode for a cathode ray tube, characterized in that substantially three cathode supporting members extend from the recess. 4. For a cathode ray tube, characterized in that a plurality of cathode supports are connected to the recesses of an indirectly heated cathode body, which is equipped with a refractory metal pipe having a circumferential recess formed by drawing in the middle part. Method for manufacturing an indirectly heated cathode.