JPS6074229A - Method of manufacturing impregnated type cathode - Google Patents

Abstract

PURPOSE:To enable to excellently maintain electron emission characteristic and insulation resistance between cathode heasters by fixing a cathode pellet to an upper side of a metal plate by means of welding after airtightly fixing the metal plate to an upper end of cathode supporting cylindrical body by means of soldering material with good soldering flow. CONSTITUTION:A metal plate 7 is airtightly fixed to the upper end of a cathode supporting cylindrical body 2 by means of a soldering material 6 with good soldering flow, without making gaps. Next, a cathode pellet 1 is mounted on the upper side of the metal plate 7 and its periphery is fixed to the metal plate by means of electric welding. And thereafter, the heater 4 is inserted into the cathod supporting cylindrical body 2 to fix, or to separately fix the heater 4 and to supporting cylindrical body 2 so as to permit the heater 4 to position in side the supporting cylindrical body 2 and a impregnated type cathode is formed. Whereby, electron emission characteristic and insulation resistance between cathod heaters can excellently be maintained without allowing the flow of the soldering material into the cathode pellet.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing an impregnated cathode, and particularly to a method for manufacturing an impregnated cathode that has high insulation resistance between cathode heaters and is useful for use in cathode ray tubes and the like.

[Conventional technology]

The structure of a conventional indirectly heated impregnated cathode is as shown in Figs. It is configured. That is, in Fig. 1, I is an impregnated cathode pellet,
A porous tungsten substrate is melted and impregnated with an electron emitting substance at high temperature in hydrogen gas. 2 is a cathode support cylinder;
3 is low interest, 4. In the heater wire, an insulator 5 made of alumina or the like is sprayed or electrodeposited on the surface of the heater wire. The waxing ratio 3 of this impregnated cathode was published in Utility Model Application No. 49-5287.
As described in the conventional example No. 3, the cathode
-] and the cathode support cylinder 2, the cathode pel
/It also serves the purpose of preventing the evaporation of electron radioactive substances from the back side of throat 1 to the heat shield side. However, this low profit 3
Since this method uses wax that has relatively poor wax flow to prevent it from penetrating into the fine pores of the cathode pellet 3, bin poles are formed in the wax material, which prevents the evaporation and diffusion of electron radioactive substances to the back surface of the cathode pellet 1. It is not possible to sufficiently achieve IL protection.

Therefore, it is disclosed in Utility Model Application No. 49-5287:3. , l: 5K, the configuration shown in Figure 2 is considered. That is, in Figure 2, 6 is the second layer of platinum brazing material etc. 4
In g, after the conventional first layer of wax 3 is deposited, it is deposited again using a high frequency electric furnace or the like to fill the pinholes in the first layer of wax 3 (-7).

[However, even with this configuration, since wax A is used on the back side of the cathode pellet, even though the wax flow is poor, the wax IN flows into the fine pores of the cathode pellet, reducing the amount of electron radioactive material impregnated. Even if you use a material with a good flow of wax to remove the wax in the second layer, it is not possible to completely convert the pinball into wax (7 cathode pens). During the step of impregnating the Vl cathode pellet 1 with the electron radioactive material after deposition, the back surface of the Vl cathode pellet 1, that is, the exposed surface of the deposited wax, is contaminated and it is difficult to remove it;
There are disadvantages such as when the cathode support cylinder 2 is mixed with the cathode support cylinder 2, the electron radioactive substance wraps around the heater side and adversely affects the operation.

Furthermore, as shown in FIG. 3, a one-filter structure in which the cathode pellets 1 and the cathode support cylinder 2 are fixed via a metal plate 7 has been considered. This is done for the purpose of completely preventing pinholes in the waxing.
Because it is carried out with -J double series (balls with less impregnation of electron radioactive substances), ■-1: At the time of 1 digit, the electron emitting crop %h is absorbed into the heater ill.・The disadvantage is (・'', 4' years left). Juda Jiganaki/18
-9950 Jul.'15-: Sun 543-: As disclosed in the official gazette (・C1 negative pellet and cathode section), a metal plate is inserted between the cylinder body by welding or horn/metal. It is also considered that the cathode part 1 + i node rest, t
: and these small cathode parts (, 'l thickness is also thin < +
'R'; i9 fi, 'j There are cracks, cow!
, Nikah / Me is natural /, ``The gap is j・, a) / Second, the cathode has a high f! Shiita IFI!l
1. [Problem to be solved by the invention] As mentioned above, in an impregnated cathode used in a case such as a cathode ray tube that requires high insulation resistance between the cathode heaters, the electron radioactive substance wraps around the heater side. Many attempts have been made to prevent this from occurring, but it has been difficult to obtain a device that maintains electron radiation characteristics for a long time and maintains good insulation resistance for over 1,000 hours. There was a drawback.

[Means for solving problems]

In view of this situation, the present invention has developed an impregnated cathode that does not allow electron radioactive substances to enter the heater side at all, and maintains good insulation resistance between the cathode heaters (fc) even after approximately 10,000 hours of operation. Specifically, first, a metal plate is airtightly fixed to the upper end of the cathode support cylinder by waxing with good wax flow, and then cathode pellets are placed on one side of the vaginal metal plate. It is manufactured by fixing it by welding.

[For production]

Since the impregnated cathode manufactured according to the present invention is manufactured by the method described above, there is no risk of electron radioactive substances getting into the cathode cylinder where the heater is placed, and the cathode pellets are fixed by welding. There is no fear that the wax will penetrate into the fine pores of the cathode pellet and reduce the amount of electron radioactive material. 1jfK #n
l"I' and operate.

〔Example〕

FIG. 4 shows a cross-sectional view of an impregnated cathode according to the present invention.
One part of iJ is shown. This impregnated type manufacturing hand oil Ll', ,
Attach the metal plate 7 to the two ends of the cathode support cylinder 2 (26) so that no gaps are formed.
It sticks to 1q1. This soldering hole 6 is placed separately, and -C is also placed (F2.
・) On the lower surface of the S plate 7, it is possible to apply the metal that will become the wax 2 in advance by sawing or by vapor deposition), and then apply the cathode pereno l-1 to the upper surface of the metal plate 7. Place it on the table and secure it around it with electricity and @connection. Thereafter, the heater 4 is inserted into the cathode support cylinder 2 and fixed, or the heater soil is placed inside the cathode support cylinder 2 by fixing the heater 4 and the cathode support cylinder 2 separately. Form an impregnated cathode.

In the above-described embodiment, the metal plate 7 is formed into a flat metal plate, but it goes without saying that the same applies to a flat metal plate as shown in FIG.

〔Effect of the invention〕

As explained above, the impregnated cathode (
Well, since the wax filler flows into the cathode pellet and there is no U, the brazing material does not seep into the cathode pellet, and the electron radioactive material is sufficiently impregnated. Since contamination inside the body can be completely prevented, electron emission characteristics and insulation resistance between the cathode heaters can be maintained well even during long-term use.

Figure 5 shows the insulation resistance between the cathode heaters of the impregnated type cathode manufactured according to the present invention and the impregnated cathode manufactured by the present invention (in the case of Figure 1), as well as changes over time, and the area ■
is an impregnated cathode according to the present invention.

Region '11 is the characteristic range of the conventional impregnated cathode.

As is clear from FIG. 5, the product according to the present invention has excellent initial characteristics and changes over time.

As a result of the above, it is possible to use a θ-containing cathode even in fields where the high supply edge resistance is y·4, such as in fluorown tubes. High current of '1, ↑, 1' degree, which is a characteristic of impregnated cathode.

The advantage of long life is -1 “Speech ITl” /7
゜

[Brief explanation of drawings]

No. 11￥1c to No. 3: Fig. 01, Inoe came to the field 7 (
11 is a cross-sectional view showing the I'i7; and part of the cathode. Fig. 2'U5) Compare the aging deterioration J1 of the insulation single resistor between the cathode heaters with the one according to the present invention (area 1) and the conventional example, and 1'a) also ()) (area 11, ). It is a diagram shown as 1, ' 71 L1'i
, Yin (Sebe v) F + 2 ・−IX 几f”j'
-yL 4"'+' 1 cylinder. 4- Heater, 6 Row 4A', 7 Metal plate.

Claims (1)

[Claims] A method for producing an impregnated cathode in which an impregnated cathode pellet is fixed to the upper end of a cathode support cylinder via a metal plate, wherein the metal plate is airtightly fixed to the upper end of the cathode support cylinder by row cutting. A method for manufacturing an impregnated cathode, which comprises fixing the impregnated cathode pellets to the upper surface 11411 of a gold plate by welding.