JPH0145693B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cathode support structure suitable for use in an electron gun of a color cathode ray tube.

Generally, a cathode ray tube electron gun is equipped with a cathode that is heated to emit electrons. The cathode is housed within a cylindrical cathode fitting, which is further secured within the envelope. and,
The cathode portion of the electron gun is assembled by fixing this envelope to an electrode support made of beet glass. Since three sets of such cathode sections are used in a color cathode ray tube, the overall shape of the cathode device becomes large, and there is a problem in that it requires many man-hours for assembly. For this reason,
A cathode support structure has been considered in which a common enclosure is used and three cathode mounting portions are provided within the enclosure.

FIG. 1 is a partially sectional front view of such a conventional cathode support structure, and FIG. 2 is a plan view. In the figure, 1 is an envelope formed into a rectangular square tube shape, 2 is a cylindrical cathode mounting part in which three cathodes are arranged in line inside the envelope 1, and 3 is a cylindrical cathode mounting part arranged inside the envelope 1. This is crystallized glass for insulating and holding the cathode mounting portion 2. These constitute an in-line cathode support structure. Although not shown, a heater and a cathode are housed in the cathode mounting part 2, and
The envelope 1 is adapted to be fixed to an electrode support. Although it is possible to use ceramic to insulate and support the cathode mounting portion 2, crystallized glass is generally used because it is inexpensive and easy to manufacture.

When manufacturing such a cathode support structure, a firing jig is used to position the envelope 1 and the cathode mounting portion 2.

FIG. 3 is a front sectional view of a state in which the device is manufactured using a jig. In the figure, both a lower mold 4 and an upper mold 5 are made of carbon, and the lower mold 4 has a recess 4a for inserting the envelope 1 and a recess 4a provided on the bottom surface for fitting the cathode mounting part 2. 3 protrusions 4
b are respectively formed, and the upper mold 5 has a cathode mounting portion 2.
A recess 5a into which is inserted is formed. Lower mold 4
After attaching the envelope 1 and the cathode mounting part 2 to the mold, fill it with pre-combusted crystallized glass powder or pellets, and insert the upper mold 5 into the recess 5a of the cathode mounting part 2.
The powder or pellets are inserted into the lower die 4 and pressed with appropriate pressure so that the powder or pellets are sufficiently packed. In this state, it is heated to about 850°C and fired.

However, in such a manufacturing process,
If the pressure is not strong, the crystallized glass 3 may not be sufficiently spread to the corners of the envelope 1, or
If the pressure is too strong, there is a problem that the crystallized glass 3 protrudes along the walls of the envelope 1 and the cathode mounting portion 2, resulting in defective products and a decrease in yield. Furthermore, residual stress is generated in the crystallized glass 3 due to the difference in thermal expansion coefficient between the crystallized glass 3, the envelope 1, and the cathode mounting part 2, but the shape of the crystallized glass 3 is different from the cathode mounting part 2. Since the structure is asymmetrical, the distribution of residual stress in the crystallized glass 3 becomes non-uniform, and cracks tend to occur in the crystallized glass 3, resulting in a deterioration in quality and reliability.

The present invention has been made to eliminate such conventional drawbacks, and its purpose is to provide crystallized glass symmetrically around the cathode mounting portion, thereby improving productivity, quality, and reliability. An object of the present invention is to provide an improved cathode support structure for a color cathode ray tube electron gun.

In order to achieve such an objective, the present invention
A plurality of cylindrical bodies whose axial directions are parallel to each other are provided in the envelope, and cathode mounting portions are arranged approximately concentrically within the cylindrical bodies,
The structure is such that crystallized glass is filled between the cylindrical body and the cathode mounting portion.

Hereinafter, the present invention will be explained in detail based on examples.

FIG. 4 is a partially sectional front view of an embodiment of a cathode support structure for a color cathode ray tube electron gun according to the present invention, and FIG. 5 is a plan view. In the figure, 6 is Fe-Ni
An envelope made of alloy and formed into a rectangular cylindrical shape,
6a is bent inwardly into the envelope 6 in an in-line shape 3
The cylindrical body parts 7, which are integrally formed side by side, are made of Kovar and are cathode mounting parts formed in a cylindrical shape having an outer diameter smaller than the inner diameter of the cylindrical body part 6a. The cylindrical body portions 6a are formed so that their axes are parallel to each other, and the cathode mounting portions 7 are arranged substantially concentrically within the cylindrical body portions 6a. and,
The annular space between the cylindrical body portion 6a and the cathode mounting portion 7 is filled with crystallized glass 8 for insulating and holding the cathode mounting portion 7. Note that when manufacturing this cathode support structure, a lower mold and an upper mold similar to those shown in FIG. The cathode mounting part 7 is positioned inside the cylindrical body part 6a by the convex part of the lower mold and mounted almost concentrically, and then the cylindrical body part 6a is attached.
The annular space between the mold and the cathode mounting part 7 is filled with pre-fired crystallized glass powder or pellets, and then the upper mold is assembled with the lower mold and the powder or pellets are pressed under appropriate pressure so that the powder or pellets are sufficiently packed. push. Then, in this state, firing is performed at a high temperature of about 850°C.

According to such a cathode support structure, the crystallized glass 8 is formed in an annular shape and is completely symmetrical with respect to the outer periphery of the cathode mounting portion 7, so that the crystallized glass 8 is The distribution of residual stress generated in the process becomes uniform, eliminating the occurrence of cracks. In addition, since the shape of the crystallized glass 8 is simpler and the amount thereof is smaller than before, less pressure is applied to the mold during manufacturing, and the cylindrical body portion 6
There is almost no crystallized glass protruding along the walls of the cathode mounting portion 7 and the wall of the cathode mounting portion 7. In addition, crystallized glass 8
A small amount also has the effect of minimizing deterioration of the performance of the color cathode ray tube due to harmful gases generated from the crystallized glass 8. moreover,
In an in-line type cathode support structure, the middle cathode mounting part is sandwiched between the cathode mounting parts at both ends, so in a conventional cathode support structure, the center part becomes relatively hotter than the two end parts, causing mutual expansion displacement. In the cathode support structure of the present invention, the crystallized glass 8 is divided for each cathode mounting portion 7, so that the different distortions may occur in the crystallized glass, which may cause cracks. A crystallized glass 8 of the material can be formed. Therefore, it is possible to use materials with different thermal expansion coefficients for the cathode mounting portions 7 corresponding to the crystallized glass 8, thereby making it possible to equalize the displacements of the three cathode mounting portions 7 due to expansion. can.

6 to 8 are partially sectional front views of other embodiments, respectively.

In the embodiment shown in FIG. 6, a cylindrical body portion 16a formed integrally with the envelope 16 is bent toward the outside of the envelope 16. Although the height is greater than that of the embodiment shown in FIG. 4, manufacturing is easier.

In the embodiment shown in FIG. 7, the envelope 26 is formed by drilling three holes in a flat plate, into which a separately manufactured cylindrical body 26a is inserted and welded. Although the welding process is added, the press mold is simpler, and the envelope 26
Cheap materials can be used.

The embodiment shown in FIG. 8 has the same structure as the embodiment shown in FIG. 7, in which the end of the cylindrical body 36a is welded to the envelope 36.

As described above, the cathode support structure according to the present invention has the excellent effects of reducing component costs and manufacturing man-hours of a color cathode ray tube electron gun, improving manufacturing yield, and improving quality and reliability. .

[Brief explanation of drawings]

Fig. 1 is a partially sectional front view of a conventional cathode support structure, Fig. 2 is a plan view thereof, Fig. 3 is a front sectional view of the manufactured state, and Fig. 4 is a cathode support of a color cathode electron gun according to the present invention. FIG. 5 is a partially sectional front view of one embodiment of the structure, FIG. 5 is a plan view thereof, and FIGS. 6 to 8 are partially sectional front views of other embodiments. 6... Envelope, 6a... Cylindrical body part, 7... Cathode mounting part, 8... Crystallized glass.

Claims (1)

[Claims] 1. An envelope having three cylindrical bodies whose axes are parallel to each other and arranged in-line at equal intervals;
A cylindrical cathode mounting portion having an outer diameter smaller than the inner diameter of the cylindrical body and arranged approximately concentrically within each cylinder; A cathode support structure for an in-line color cathode ray tube electron gun, which is equipped with a ring-shaped crystallized glass.