JPH0290442A - Manufacture of cathode-ray tube - Google Patents

Abstract

PURPOSE:To prevent deterioration of characteristics of a cathode-ray tube due to entrance of a small glass piece by making the wall thickness of the neck part of a funnel.neck composite member thin only at the stem sealing part and sealing the stem part of an electron gun at the part where the wall thickness in made thin. CONSTITUTION:A stem 2 is provided at the lower end 3 of a neck part 1 of a funnel.neck composite member so as to enable the sealing of the stem, and the centers of the neck part 1 and the stem 2 are caused to coincide with each other. The neck glass wall thickness 7 is caused to be 1/2 of the stem wall thickness 8 so that, when sealing is carried out by a gas burner, the melted neck glass can easily be brought in contact with the stem 2 and the strength of the welded formation is sufficient for subsequent working. The stem 2 is inserted to the lower end 3 of the neck and positioning is effected and the sealing part is melted by the gas burner 9. Then, the melted neck glass 1 is welded by the ejecting force of the gas burner 9 so that the neck part 1 and the stem 2 are melted and fixed sufficiently to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a cathode ray tube, and more particularly to a method for inserting and sealing an electron gun into a cathode ray tube.

[Conventional technology]

Conventionally, an electron gun is inserted into the neck of a cathode ray tube, and a gas burner is used to heat weld the glass of the neck of the cathode ray tube (hereinafter referred to as the neck) and the stem glass of the electron gun (hereinafter referred to as the stem) using gas and oxygen. Melting and sealing is performed using a mixed flame. FIG. 3 schematically shows the working procedure in this sealing process. First, as shown in Figure 3 (a), the neck part 1
The stem 11 is inserted into the neck sealing section 0 to the sealing position, and the neck sealing portion is melted by the gas burner 12. Next, as shown in FIG. 3(b), the molten part is pulled downward by the weight of the glass in the lower part, and the molten neck glass part 13 is stretched thin until it comes into contact with the stem 11. Weld to 11. Then Figure 3(c)
Cut the unnecessary part from the bottom end of the stem 11 into the burner 1 as shown in the figure.
Bake at 2. Further, the welded portion 14 between the stem 11 and the neck portion 10 is suitably melted and welded using the burner 12 to complete the process.

[Problem to be solved by the invention]

However, in the manufacture of cathode ray tubes, various methods have been tried to completely remove the unnecessary glass below the bottom end of the stem from the sealing device after the sealing operation is completed.
Currently, as the glass cools, microscopic fractures occur and it is difficult to remove the remaining glass pieces. These glass particles sometimes scatter to the surrounding area and enter the cathode ray tube, causing a significant deterioration of its characteristics. That is, if these glass particles enter the cathode ray tube, they may move within the tube during transportation or operation and may adhere to the electron gun electrode or shadow mask. For example, if it adheres to the electron gun electrode, it will cause discharge, deteriorating the withstand voltage characteristics or causing a short circuit between the electrodes. Moreover, if it adheres to the shadow mask, it will block the mask hole and block the path of the electron beam during operation, causing a so-called hole clogging phenomenon, impairing the image formed on the phosphor screen and degrading the screen quality. The disadvantage is that it is difficult to remove glass particles that adversely affect the characteristics of the cathode ray tube because the objects are so minute, and there is no effective method to prevent them from entering the cathode ray tube because the objects are so minute. was there.

An object of the present invention is to provide a manufacturing method that completely eliminates glass particles in the sealing process of the neck and stem, and prevents glass particles from entering the cathode ray tube and deteriorating the characteristics of the cathode ray tube.

[Means to solve the problem]

The present invention provides a method for manufacturing a cathode ray tube in which an electron gun is inserted into the neck of the cathode ray tube and sealed. It is designed to be as thin as possible without interfering with this, and to minimize the clearance between the inner wall of the neck and the outer wall of the stem, and to seal the thin neck part with the stem at the leading edge to prevent the generation of unnecessary glass and the scattering of small glass pieces.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a diagram showing the structure and positional relationship of a neck portion and a stem for explaining one embodiment of the present invention.

The stem 2 is arranged at the lower end 3 of the neck part 1 of the funnel neck composite so that the stem can be sealed, and the centers of the neck part 1 and the stem 2 are made to coincide with each other. Based on experience, the distance from the neck inner wall 5 to the stem outer wall 6 is 0.
3 to 0.5 mm is the optimum value when considering the clearance when inserting the electron gun and the weldability of the neck portion 1 and stem 2 during sealing. The neck glass thickness 7 is desirably 1/2 of the stem thickness 8 because the molten neck glass easily contacts the stem 2 during sealing with a gas burner, and the shape when welded is sufficient for processing strength. .

FIG. 2 is a diagram explaining the sealing procedure of the present invention. first,
As shown in FIG. 2(a), the stem 2 is inserted and positioned up to the lower end 3 of the neck, and the sealing portion is melted by a gas burner 9. Next, as shown in FIG. 2(b), the neck glass 1 melted by the jetting force of the gas burner 9 is adhered to the stem 2. Then, as shown in FIG. 2(C), the glued neck portion 1 and stem 2 are sufficiently melted and welded to complete the process.

As described above, the method of the present invention makes it possible to seal the neck portion and stem without generating unnecessary glass.

〔Effect of the invention〕

As explained above, the present invention makes it possible to eliminate unnecessary glass generated when inserting and sealing an electron gun into a cathode ray tube neck by using culletless sealing.
It is possible to prevent the generation and intrusion of glass particles that deteriorate the characteristics of cathode ray tubes, which has a great effect on improving the yield and quality of cathode ray tubes.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the structure and positional relationship of the neck portion and stem for explaining one embodiment of the present invention, Fig. 2(a),
(b) and (c) are diagrams showing the sealing process according to the present invention;
Figures (a), (b), and (c) are diagrams showing a conventional sealing process. 1.10...Neck part, 2,11...Stem, 3.
... Lower end of neck, 5 ... Neck inner wall, 6 ... Stem outer wall, 7 ... Neck glass wall thickness, 8 ... Stem wall thickness, 9°12 ... Gas burner, 13 ... Melting neck Glass part, 14...welded part. =7

Claims (1)

[Claims] In a method for manufacturing a cathode ray tube in which an electron gun is inserted into and sealed in the neck of the cathode ray tube, the thickness of the neck of the funnel-neck composite is made thinner only at the stem sealing portion, and the thickness is made different from that of the other neck portions; A method for manufacturing a cathode ray tube, characterized in that the thinned part is sealed with the stem of an electron gun.