JPH023256B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of sealing a neck portion and a stem of a cathode ray tube.

The cut-down method shown in FIGS. 1a and 1b is used to seal the neck and stem of a conventional cathode ray tube. That is, a plurality of stem pins 3 to which an electron gun structure 4 is connected are connected to a circular glass base 2.
A stem 1 is installed through the base 2 in a circular shape, and an exhaust thin pipe 5 extending downward is connected to the center of the base 2.
is inserted into a glass neck 6 having a flared part 7 whose end is expanded outward, and the vicinity of the base 2 of the stem 1 is heated by a burner 8 or the like to remove the excess flared part 7 at the end of the neck, that is, the cullet 9. It is cut and welded and sealed. The feature of this type of cut-down method is that the thickness of the neck can be made thinner when cutting down the cut-down 9. In particular, the larger the difference between the inner diameter of the neck 6 and the outer diameter of the stem base 2, the larger the amount of reduction. It was advantageous in sealing. However, the larger the inner diameter of the exhaust thin tube 5 is, the more preferable it is from the point of view of exhaust efficiency, and the larger the diameter of the circular implantation of the base 2 of the stem pin 3, the wider the distance between the stem pins, which is preferable from the point of view of electrical leakage and pressure resistance. In this cut-down method, increasing the diameter of the exhaust capillary tube or the stem pin circle is susceptible to the effects of heat welding, easily causing glass deformation or oxidation, and cannot be expanded beyond a certain limit.

That is, in this method, the glass neck 6 is heated and softened to narrow it down to the side end of the stem base 2, and from there, the side end of the stem base 2 is also indirectly softened to complete welding, so the heating capacity is increased. This is because it becomes quite large. Also unnecessary karets 9
This is also disadvantageous in terms of material efficiency due to loss of parts and efficiency in storing and transporting the valve. On the other hand, as shown in FIG. 2, the base 2 of the stem 1 is formed slightly larger than that in FIG.
A method has also been considered in which the end face 9 of the neck 6 is brought into contact with the outer circumferential surface of the upper side part and heated and welded with a burner 8. However, the glass thickness of the neck 6 of the cathode ray tube is more than 2 mm thick to prevent X-ray leakage, and in this state, heat does not enter in the thickness direction of the neck, resulting in insufficient welding. Moreover, in order to avoid this, it is not preferable to provide a slight gap between the neck end face and the base face to allow sufficient heat to enter in the thickness direction, as this tends to cause oxidation of the stem pin 3 and the electrode structure 4.

The present invention has been made in view of the above points, and an object of the present invention is to provide a sealing method that enlarges the exhaust capillary tube and stem pin circle and improves material efficiency when sealing the neck and stem of a cathode ray tube by welding. do.

The present invention will be described in detail below with reference to Examples. FIG. 3 is a schematic diagram showing an embodiment of the present invention, and parts common to those in FIG. 1 are designated by the same numbers. In the stem 1, a plurality of stem pins 3 to which an electron gun structure 4 is connected are implanted in a circular glass base 2, and an exhaust thin tube 5 extending downward is connected to the center of the base 2. . The outer diameter of the base 2 of the stem 1 is formed to substantially match the outer diameter of the glass neck 6. That is, the outer diameter of the base is larger than that of the conventional base. While the diameter line of the upper outer peripheral surface of the stem base 2 is substantially perpendicular to the tube axis, the cutting line of the end surface of the neck 6 is formed to have a tapered part 10 with an edge on the inner diameter side. and is non-parallel to the direction perpendicular to the tube axis. Such a stem 1 is arranged by inserting the electron gun assembly 4 into the neck 6 so that the upper outer circumferential surface of the base 2 and the edge portion 10 of the neck 6 properly correspond and abut. Next, while inert gas is introduced through the exhaust thin tube 5, heat welding is carried out using a burner 8 disposed at the side end of the base 2 or at an oblique position above the electron gun side of the side end. At this time, the angle between the end surface of the net and the upper outer peripheral surface of the base on the electron gun side is non-parallel.
Since the edge portion on the inner diameter side of the neck is in contact with the outer peripheral surface of the base, the flame of the burner does not directly enter the inside of the neck, so that oxidation of the internal electron gun structure and stem pin can be prevented. In addition, since the neck end face and the outer circumferential face of the base are simultaneously heated by the burner 8, the heating efficiency for welding and sealing is high and the heating time is short, making it possible to increase the diameter of the exhaust capillary tube and stem pin circle. It has the following advantages. Furthermore, since there is no cullet that is unnecessary during conventional sealing, there is no loss of material and it is economical, and it is also advantageous in terms of storage and transportation of the valve. In the sealing method shown in Figure 3, if the outer diameter of the welded seal part is insufficient due to the flame of the burner,
As shown in the figure, it is preferable to finish the welding with a molding element 11 after welding. If the angle between the neck end face and the outer circumferential surface of the stem base is less than 3 degrees, the heat by the burner will not be sufficiently applied to near the inner diameter of the neck, and if the angle is too large, chipping may occur between the time of forming the neck end face and the setting. Easily within 30 degrees is best, but between 5 degrees and
An angle of about 10 degrees was the most efficient. Also the third
In the embodiment shown in the figure, the neck end face is formed into a tapered shape to give it an angle, but a tapered portion 12 corresponding to the outer peripheral surface of the stem base may be provided as shown in FIG. It goes without saying that the shape shown in FIG. 5 may be combined, that is, the tapered portion may be provided on both the neck end face and the outer circumferential face of the stem base.

As described above, according to the cathode ray tube sealing method of the present invention, the exhaust thin tube and stem pin circle can be enlarged,
It can also improve material efficiency, work efficiency, storage and transportation efficiency, and its industrial value is great.

[Brief explanation of drawings]

1 and 2 are schematic diagrams for explaining a conventional sealing method, and FIGS. 3 to 5 are schematic diagrams for explaining an embodiment of the present invention. 1... Stem, 2... Base, 3... Stem pin, 4... Electron gun structure, 5... Exhaust tube, 6...
Netsuku, 7...flare section, 8...burner, 9...
...Cullet, 10, 12... Taper part, 11...
Molded child.

Claims (1)

[Scope of Claims] 1. In a cathode ray tube sealing method in which a neck portion at one end of a cathode ray tube glass bulb is welded to a glass stem having a plurality of stem pins connected to an electron gun structure, the outer diameter of the glass neck is and the outer diameter of the base of the glass stem are substantially the same, and the angle between the end face of the glass neck and the upper outer peripheral surface of the base of the glass stem on the electron gun side is in non-parallel contact so that the outer diameter sides are spaced apart. A method for sealing a cathode ray tube characterized by sealing by heat welding. 2. A method for sealing a cathode ray tube according to claim 1, characterized in that the angle formed by the abutting portion of the end surface of the glass neck and the upper outer peripheral surface of the base of the glass stem on the electron gun side is 3 degrees or more. . 3. Claim 1 or 3, characterized in that the end face of the glass neck and the upper outer circumferential surface of the base of the glass stem on the electron gun side are brought into contact with each other, heated and softened, and then pressurized with a molding tool to form the sealing part by welding. 2. The method for sealing a cathode ray tube according to item 2.