JPS6010541A - Production of cathode structure for electron tube - Google Patents

Abstract

PURPOSE:To eliminate an open circuit and perform reliable welding by fitting a conductive support body so that its top is positioned lower than two cathode sleeves, depressing a heater leg section from above with plate-like support pieces, and bringing the support pieces in contact with the top of the support body for laser welding. CONSTITUTION:A conductive support body 13 penetrates through a cylinder body 2 fixed to a cathode support cylinder 1 and is fitted with adhesive glass 4 so that its top is positioned lower than the lower end of a cathode sleeve 6. In addition, sleeves 6, 6 are fixed through the upper ends of support pieces 5, 5 fixed inside the support cylinder 1. A base metal body 7 coated with an electron emitting material is fixed to the enveloping top surface of the sleeve 6. A heater 8 is inserted in the sleeve 6, a heater leg section 8A is pushed down with a plate-like support piece 10, and the support piece 10 is brought into contact with the top of the support body 13. Under this condition, laser rays are illuminated from above the support piece 10 to weld the support piece 10 to the support body 13, then laser rays are illuminated to the contact section between the support piece 10 and leg section 8A from above the support piece 10, thus reliable welding can be performed with no open circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a cathode assembly for a cathode ray tube, and more particularly to an improvement in a method for manufacturing an anode assembly suitable for being disposed within a cathode ray tube.

[Technical background of the invention and its problems]

An example of a double-sided structure for an electron tube, such as a cathode S tube, is shown in FIGS. 1 to 3. A supporting tube (1) which is a cylindrical body with an elliptical cross section, two cylindrical bodies (2) fixed such that at least the L end touches the inner surface of the circular part of the supporting tube (1), and this cylindrical body. (2) Inside the support tube (3), which is fixed with an insulator (4) such as adhesive glass, is located inside the support tube (1) symmetrically to the support tube @. A pair of fixed support pieces (5), and two curved cylinder-shaped holes arranged perpendicularly and parallel to the support cylinder axis via one end of the support pieces (5). Sleeves (6), a base metal body (7) attached to the envelope top surface l/C of these sleeves (6) and coated with an electron radioactive substance (ΔI), and inserted into the cathode sleeve (6). Heater (8) made by winding nine coils of VC, the surface of which is covered with an insulating material except for the legs.
This is a cathode structure comprising jL. Figure 1 is a perspective view.
FIG. 2 is a top view, and FIG. 3 is a sectional view taken along line A-A in FIG.

In the shade structure formed in this way, the base metal body is projected so that the cathode beam gun 111 is centered approximately at the center in the length direction of the cathode beam IJ-P, that is, when the cathode beam VC is disposed. Due to the rounded structure, the VC is located approximately at the center of the heater. Therefore, when a voltage is applied to the heater, the temperature of the base metal body rises extremely quickly because the temperature rises from the longitudinal center of the heater, that is, the center of the cathode sleeve. Furthermore, since the heater and the base metal body are of a non-contact structure, even if the particles scattered from the heater are collected on the cathode sleeve, they are not attached to the base metal body, and excellent emission of heat and electrons can be obtained. As described above, in a cathode tube incorporating a cathode assembly having this structure, the image output characteristics are extremely fast and the interlocking performance is extremely good.

However, it has the following drawbacks. In other words, the diameter of the heater inserted into the sleeve is, for example, 20 to 30μ.
The wire rods are extremely thin and made of tungsten or rhenium tungsten, and since resistance welding is usually used when bonding them to the conductive support, the heater wires are also heated to high temperatures, causing them to become brittle and break. It also happens that they invite people. In addition, since the diameter of the heater wire is small, the shape of the bath contact electrode used for resistance welding is extremely important, but during mass production, the contact between the electrode, heater, and support is often poor due to wear of the electrode, resulting in poor contact during welding. Due to the discharge phenomenon, problems such as embrittlement and disconnection of the heater become more serious. Furthermore, when welding the heater to the conductive support,
It is extremely difficult to precisely position the legs of the heater at the top V'C of the isoelectric support. In this method, when an insulating material such as alumina is coated on the heater, sintering is performed, but the heater is deformed due to the difference in thermal expansion coefficient between the wire and the alumina, and as a result, the position of the heater legs is changed. The isoelectric support Vc is not aligned with accuracy.
This means that some parts cannot be welded. If the heaters cannot be arranged in the predetermined alignment f), the heat transfer to the base metal body will be delayed due to the misalignment, and the speed of operation will be impaired.

[Purpose of the invention]

The present invention takes these points into consideration, and it is possible to extremely easily and reliably attach the heater to the top of the conductive support by welding, thereby improving manufacturing yield and quality characteristics. The object of the present invention is to provide a method for manufacturing a cathode assembly for an electron tube.

[Summary of the invention]

In the manufacturing method of the present invention, a heater is inserted into a cathode sleeve attached via a support piece fixed to a cathode support tube, and the heater legs are attached to the top of a support member attached to the cathode support tube by melting. At this time, the top of the #electrode support is lower than the lower end of the anode sleeve iI'1. The legs of the heater are held down from above by plate-shaped supports, and the supports are brought into contact with the top of the conductive support, and a laser beam is irradiated from above the support. The supporter and the isoelectric supporter are welded together, and then a laser beam is irradiated from above the supporter to the outside of the area where the heater leg and the supporter are in contact to weld the heater leg and the supporter. This is a method for manufacturing a cathode assembly for an electron tube, characterized in that the cathode assembly is formed by connecting the legs to an isoelectric support.

[Embodiments of the invention]

Embodiments of the invention will be described below with reference to the drawings.

As shown in FIGS. 4 to 6, cylinders (2) are fixed to the inner surface of the circular part of the cathode support cylinder (1), which is a cylinder with an oval cross section. It is penetrated and fixed with adhesive crow (4), and the top is the cathode sleeve (described later).
S-electrode support (I: 9
is fixed. Moreover, a pair of supports (5) are fixed inside the cathode support cylinder (1) at symmetrical positions with respect to the support cylinder uAr, and a pair of supports (5) are fixed at right angles to the support cylinder axis through the upper end of the supports (5). and two cylindrical bodies arranged in parallel and having a circular cross section.
A base metal body (7) is fixed to the envelope top surface of this cathode sleeve (6) with its center aligned with the support cylinder l1ilII. A radioactive substance is applied and deposited.A heater (8) is inserted into each of the cathode sleeves (6).The surfaces of these heaters (8) are coated with alumina except for the legs of the cathode. Both the inner and outer surfaces of the sleeve (6) are subjected to a vortex treatment in a hydrogen furnace with added moisture to form a blackened coating layer.

After inserting the heater (8) into the cathode sleeve (6) and positioning it in a predetermined position, push down the heater leg (8A) using the plate-like support [0] as shown in FIG. At the same time, the supporter (10) is brought into contact with the top of the isoelectric supporter (131). In this state, a laser beam is irradiated from above the supporter (10) in the direction of the arrow in the figure, and the supporter (io) and the like are irradiated. Fix the electric support (I3) by welding.Then, attach the heater leg (8A).
) and the supporter (10) are in contact with each other.
o) Weld and fix the heater leg (8A) and supporter (10) by irradiating the laser beam from above in the direction of the arrow shown in the figure.

The leg at the other end of the heater is filled in the same way.

When welding the heater legs in this way, the heater legs are oriented upward by the spring force and are in contact with the lower surface of the supporter, so when welding is performed by laser irradiation, the supporter is slightly acidified. The material melts and wraps around the heater legs, creating a beautiful bathing experience.

When forming the cathode structure in this way, the welding of the heater leg to the conductive support does not change;
Furthermore, this can be done extremely easily and reliably without causing any positional deviation. It goes without saying that the shape of the supporter holding down the heater leg may be modified in various ways other than those described above.

〔Effect of the invention〕

When the heating element is formed by the method of the present invention, the position of the heater leg may change due to deformation caused by the alumina coating treatment of the heater or deformation of the heater leg during handling of the heater. Since the supports are sufficiently large compared to the heater and heater legs, problems that occur in the past when the heater legs are melted onto the isoelectric support do not occur, and they can be fixed by welding very easily and reliably. come. In addition, the top of the electrostatic support is located at a lower position than the lower end of the cathode sleeve,
In addition, since the support is large, the support can always touch the top of the guide support while holding down the heater legs, and the heater legs are always in contact with the support with a constant force due to the spring action. For light irradiation.

Welding and fixing can be performed reliably. Furthermore, when welding the heater legs, only the base material of the supporter is melted to wrap around and fix the heater legs, so unlike conventional methods, the heater wire does not become JIls, and the heater's 1+Jr wire does not occur. do not have. Furthermore, since laser beam welding can be performed without contact, alumina can be applied up to the vicinity of the bath contact point of the heater leg, and the area of the heater leg that is not coated with alumina can be almost completely eliminated. For this reason, it is possible to prevent the preliminary heating of the heater legs that occurs when voltage is applied, and since the temperature rises from the center of the heater, the interlocking is better maintained. The method of the present invention has a high work efficiency, no heater breakage occurs, and improves both yield and quality characteristics, making the method of the present invention an extremely useful method in terms of engineering. Needless to say, when the cathode structure formed by the method of the present invention is disposed in an anode ray tube, even better interlocking properties can be obtained.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional cathode structure, Fig. 2 is a top view of Fig. 1, Fig. 3 is a sectional view taken along line A-A in Fig. 2, and Fig. 4 is a cross-sectional view of the main body. Perspective view of one embodiment of the invention, fifth
The figure is a top view of Fig. 4, Fig. 6 is a cross-sectional view of Fig. 5 taken along line A-A Vζ, and Fig. 7 shows a state in which the heater legs of the present invention are welded to the support body. FIG. DESCRIPTION OF SYMBOLS 1...Cathode support tube, 2...Cylinder, 13...Isoelectric support, 5...Support piece, 6...Cathode sleeve 1, 8...
Heater, 8A...Heater leg, 10...Supporter. Agent Patent Attorney Mr. Inoue Figure 1 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] A cylindrical body is formed, and a cylindrical body having a conductive support fixed therein is fixed to the inner surface of the inner circular part of the cylindrical body, and a top portion is made to protrude from the cylindrical body on the inner surface of the cylindrical body symmetrically with respect to the axis of the cylindrical body. A cathode support cylinder to which a pair of support pieces were fixed and tightly attached, and a base metal body arranged perpendicularly and parallel to the axis of the support cylinder and whose surface was coated with an electron radioactive substance were attached to its envelope top surface Vc. For an electron tube comprising two cylindrical cathode sleeves and a heater inserted into each sleeve, the surface of which is covered with an insulator except for the legs 1115, and the legs are fixed to the top of the conductive support. In forming the cathode structure, the cathode sleeves are each fixed to the supporting pieces, and the conductive support fixed inside the cylinder is fixed so that its top is at a position lower than the do end of the sleeve, The heater leg is pressed from above with a temporary support, and the support is brought into contact with the top of the 1111 rod electric prong holder, and then a p laser beam is irradiated from above the support to convert the support into a conductive support. A method for producing a cathode structure for an electron tube, which comprises welding the heater leg and the support by irradiating a laser source from above the support to the outside of the contact area of the support and the heater leg. .