JPH077637B2 - Method for assembling a cathode ray tube electron gun - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method of assembling an electron gun having a small outer diameter, which is suitable for a cathode ray tube having a narrow neck tube diameter.

[Background of the Invention]

As is well known, a cathode ray tube electron gun has a cylindrical electrode having a cylindrical shape or a cross section in which a part of a circle is removed along a chord,
The electrodes are formed by stacking and fixing a plurality of them in the axial direction of the cylinder, and lead wires for voltage supply are connected to these electrodes, respectively.

Conventionally, as shown in FIG. 1, the voltage supply lead wire 3 resists the welding member 2 (for example, a short wire bent into an L shape) which is attached to the side surface of the electrode 1 in advance for lead wire welding. It was fixed by welding. But,
In such a method, a force often acting in the direction shown by the arrow in FIG. 1 is left in the welding operation.
As a result, after the welding operation, such a force may act on the electrodes 1 to shift the distance between the adjacent electrodes from a predetermined value or to shift the center of the electrode array.

Further, in recent years, a cathode ray tube having a narrow diameter of a neck tube portion of a valve into which an electron gun is inserted has come to be used, and a margin is reduced between an outer side of the electron gun and an inner wall of the neck tube. Since it becomes difficult to attach the welding member 2 as described above in advance, there are cases where the voltage supply lead wire 3 is directly welded to the electrode 1 itself. Also, in many cases, the force that acts to shift the electrode position after the welding work is often left, and the gap between the adjacent electrodes is shifted from the desired value, or the position of the hole of the electrode is shifted from the desired position. Occasionally, things often happened.

[Object of the Invention]

An object of the present invention is to weld a voltage supply lead wire directly to an electrode, to insert into a thin neck tube, to have a small outer diameter, and to apply a force that displaces the electrode position after performing welding work. It is an object of the present invention to provide a method of assembling a cathode ray tube electron gun that does not remain.

[Outline of Invention]

To achieve the above object, in the present invention, a lead wire for supplying a voltage to an electron gun electrode is provided with a portion parallel to the axial direction of the electron gun, and a portion extending substantially orthogonal to this direction along the electrode wall. And the end portion of the lead wire is directly resistance-welded to the side surface of the electrode.

This is because the voltage supply lead wire is bent in the middle to provide a portion parallel to the axial direction of the electron gun and a portion that is substantially orthogonal to this direction and extends along the outer wall of the electrode. There is a considerable margin in length, and the L-shaped bent portion is easy to bend, so after the welding work, the force to pull or bend the lead wire remains at the welding point. However, the force is absorbed by the deformation of the voltage supply lead wire, and the distance between the electrodes is not changed or the electrode hole position is displaced.

Conventionally, when welding a welding member (2 in FIG. 1) to the side surface of an electrode, a wire rod having a circular cross section may be welded as it is.
Unless the members to be welded are pressed against each other with a large force, a good welded state cannot be obtained, so that the members are often pressed with an excessive force. When the welding member 2 dedicated to welding is previously welded to the side surface of the electrode 1 as shown in FIG. 1, one electrode of the welding machine is put inside the electrode 1 and welded. Therefore, even if the crimping force at the time of welding is considerably increased, there is not much problem. But the electron gun electrode
When welding the voltage supply leads directly to the outside of the electrode wall of the electron gun after fixing and arranging them on the glass insulating support rod, put the electrode of the welding machine inside the wall of the electrode of the electron gun. Since such a thing cannot be done, when the member to be welded is pressure-bonded with a large force, the electrode of the electron gun is often deformed. As a measure against such a problem, if the end portion of the voltage supply wire is crushed in advance to form a planar portion, it becomes possible to perform welding with a comparatively small crimping force. It is possible to make the effective area of the electrode of the welding machine to flow the welding current for heating and melting the welded part to the welded member relatively large, and even if the crimping force is relatively small, the welding current of a sufficiently large value can be obtained. Because it can be washed. Similarly, if a sufficiently large welding current is to be applied to the welded portion with a relatively small crimping force, the surface condition of the member to be welded must be clean (no oxide having a large electric resistance is attached). As is well known, in order to prevent oxides from being generated in the welded portion even when heated to a high temperature, the atmosphere in the welded portion may be an inert gas. for that purpose,
For example, a nitrogen stream may be blown onto the welding area.

Example of Invention

 The present invention will be described in more detail with reference to the drawings.

FIG. 2 (a) is a view of the vicinity of the welding portion of the voltage supply lead wire 3a and the electrode 1 according to the present invention as seen from the axial direction of the electron gun,
FIG. 2B is a side view of the welded portion between the lead wire 3a and the outer wall surface of the electrode 1. In this way, the voltage supply lead wire 3a is bent into an L-shape, has a sufficient length, and is easy to bend.
When welding, even if the welding location (marked with ×) varies a little,
The force that causes the change in the position of the electrode 1 does not remain. All are absorbed by the deformation of the lead wire.

Further, when carrying out the present invention, the array assembly of the electron gun electrode 1 has already been completed, and the electrode of the welding machine cannot be pressed against the inner wall surface of the electrode of the electron gun. As shown in FIG. 3, the welder electrode must be brought into contact with the outer side of the electron gun electrode 1 on the opposite side of the welding portion of the lead wire 3a. The area of the end of the electrode receiving rod 5 of the welding machine which is brought into contact with the outer wall surface of the electron gun electrode on the side opposite to the welding point is made large so that the same area as the side surface area of the electron gun electrode can be secured. However, it is preferable because the pressing force can be lowered. Further, as described above, it is preferable to blow an inert gas, for example, a nitrogen gas stream 6 onto the welding spot in order to prevent oxidation of the welding spot. In FIG. 3, reference numeral 4 designates one of the electrodes forming a pair with the electrode receiving rod 5 of the welding machine.

In addition, FIG. 4 is a diagram showing the relationship between the welding pressure (kg / cm ² ) for crimping the member to be welded and the degree of deformation during welding. In carrying out the present invention, the welding pressure is 1 kg / Good results (no electrode deformation) were obtained with a cm ^{2 level} . If the cross section of the end of the lead wire is left circular, good results cannot be obtained unless the welding pressure is approximately 4 kg / cm ² .

When the present invention is applied to the welding of the lead wire for connecting the third grid and the fifth grid, and the lead wire for supplying the third grid and the voltage supply of the thin neck cathode ray tube electron gun, the electrode displacement can be suppressed, so that the halo defect occurs. It has been reduced to half of the conventional one.

〔The invention's effect〕

As described above, according to the present invention, it is possible to assemble a small-diameter electron gun having a high electrode position accuracy and a high-quality image, with the conventional equipment.

[Brief description of drawings]

FIG. 1 is a diagram showing a conventional welding method of an electrode and a lead wire, and FIG.
Figures (a) and (b) are views of the vicinity of the welded portion of the electrode and the lead wire according to the embodiment of the present invention, Figure 3 is an explanatory view of the situation when the present invention is carried out, and Figure 4 is welding during resistance welding. It is a figure which shows the relationship between the pressing force and the deformation degree of an electrode. 1 ... Electron gun electrode, 3a ... Lead wire according to the present invention, 4, 5 ...
Welder electrode, 6 ... Nitrogen flow.

Claims (2)

[Claims] 1. A method of assembling a cathode ray tube electron gun, wherein a plurality of cylindrical electron gun electrodes having a cylindrical shape or a cross section in which a part of a circle is removed along a chord are arranged and fixed in a stacked manner in the axial direction of the cylinder. At, the lead wires for voltage supply to these electron gun electrodes are
The lead wire is formed of a portion parallel to the axial direction of the electron gun, and a portion that is substantially orthogonal to the axial direction and extends along the first outer wall surface of the electron gun electrode. First
The end portion of the portion extending along the outer wall surface of the electrode is crushed to form a flat surface, the first outer wall surface of the electron gun electrode and the flat surface of the lead wire are brought into contact with each other, and the flat surface of the lead wire is One welder electrode is brought into contact with the second outer wall surface of the electron gun electrode located on the opposite side of the first outer wall surface of the electron gun electrode, and the second welder electrode is brought into contact with the second outer wall surface of the electron gun electrode. A method for assembling a cathode ray tube electron gun, wherein a flat surface is directly resistance-welded to the first outer wall surface of the electron gun electrode. 2. A flat surface is formed by crushing the ends of the lead wire,
The method for assembling a cathode ray tube electron gun according to claim 1, wherein an inert gas flow is blown to the welding site.