JPH06162957A - Electron gun - Google Patents

Abstract

PURPOSE:To easily provide a cathode-ray tube having high accuracy of focusing performance by applying two conductive ribbons for electrically connecting many divided sections of an electrode in the electron gun of the cathode-ray tube, and laying the ribbons diagonally. CONSTITUTION:In assembling a cathode-ray tube having an electron gun of in-line 3-beam type, a conductive ribbon 4a for connecting electrically the electrodes 13b and 13c of a G3 electrode having transmission holes 13R, 13G and 13B for in-line three beams is welded to the lower outer wall of the electrode 13b at the side of the hole 13R and another conductive ribbon 4b is welded to the upper side wall of the electrode 13b at the side of the hole 13B, so that both ribbons 4a and 4b are diagonal with each other, among a plurality of G1 grid electrodes 11 to G4 grid electrodes 14 in an electron gun body. According to this construction, axial deformation due to welding heat takes place only in a symmetrical direction, and the inclination of the electrodes 13b and 13c is lessened. Also, the deterioration of interval parallelism between the G4 grid electrodes 14 and G3 grid electrodes 13 is alleviated, thereby enabling an electron gun having high accuracy to be easily manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the assembly accuracy of an electron gun for a cathode ray tube for a color television or a display monitor.

[0002]

2. Description of the Related Art In an electron gun for a cathode ray tube for a color television, a drawing press part and a plate-like punching press part, which are generally made of non-magnetic stainless steel, are accurately arranged. Figure 4
Fig. 1 shows the electrode configuration of a typical electron gun. The electron gun body 1 is composed of a shield cup 15 to which a G ₁ electrode 11, a G ₂ electrode 12, a G ₃ electrode 13, a G ₄ electrode 14 and a contactor 16 are attached, and is connected and held to a stem 2 to which a voltage is applied from the outside. (Specific connection diagram is omitted).

Generally, a medium-high voltage is applied to the G ₃ electrode 13, the total length of the focus voltage is long, and the G ₃ electrode is divided in order to enhance the velocity modulation effect.
It is composed of many electrodes. In the example of FIG. 4, the G ₃ electrode 13
Is composed of a G ₃ A electrode 13a, a G ₃ B electrode 13b, a G ₃ C electrode 13c, and a G ₃ D electrode 13d. Of these, the G ₃ A electrode 13a, the G ₃ B electrode 13b, and the G ₃ C electrode 13
The c and G ₃ D electrodes 13d are assembled and welded in advance by using the flange portions of the electrodes in the previous step. After that, the G ₁ electrode 11,
G ₂ electrode 12, pre-assembled G ₃ electrodes 13a, 13
b: 13c, and 13d and G ₄ electrode 14 assembled by a glass bead. This is done by heating the bead glass 3 to a high temperature of about 1200 ° C. Then G ₃ electrode 1
3a, 13b: 13c, 13d are connected to each other by the conductive ribbon 4 to connect the G ₃ B electrode 13b and the G ₃ C electrode 13c. The specific front view is shown in FIG. G ₃ B electrode 1
3b has three holes 13R, 1 for passing in-line 3 beams.
3G and 13B are arranged, and one end of the conductive ribbon 4 is G ₃ B.
One place is welded to the side wall of the electrode 13b on the hole 13B side,
The other end of the conducting ribbon 4 is welded to the G ₃ electrode 13c to conduct electricity. Then, the focus voltage is applied to G ₃
The electrode 13a is connected to the lead wire of the stem 2 via the G ₃ connector 5. Therefore, the focus voltage is G
G ₃ electrodes 13a, 13b, 13 via the ₃ connector 5
It is applied to all of c and 13d.

[0004]

As described above, in the conventional electron gun, the conduction between the G ₃ electrodes is carried out through one conduction ribbon 4, so that gas is emitted from the electrodes in the exhaust process during the manufacture of the cathode ray tube. When the electrode is heated to a high temperature for emission, the electrode thermally expands. At that time, the gap parallelism of the gap d between the G ₃ electrode 13d and the G ₄ electrode 14 forming the main lens of the electron gun body 1 is deteriorated. Therefore, the electron lens formed by the interval d is tilted and asymmetrical, and the converged state of the electron beam is asymmetrical and the halo is biased to deteriorate the focusing performance.

The present invention has been made to solve the above-described deterioration in parallelism of the main lens electrode spacing.

[0006]

According to the electron gun of the present invention, when electrically conducting a multi-divided electrode with a conducting ribbon, the conducting ribbon is provided with two conducting ribbons in a diagonal direction of an electrode having an in-line three-beam electrode hole. It is to be provided in some places.

[0007]

In the present invention, the conductive ribbon has the in-line 3
Since the two electrodes are attached to the diagonal outer wall of the electrode having the beam electrode holes, thermal deformation of the electrodes occurs symmetrically during the heating process in which the electrodes are heated, so that the G ₃ electrode is prevented from tilting. It

[0008]

FIG. 1 shows an embodiment of the present invention. The electron gun of the present invention is provided with two conductive ribbons that electrically connect the G ₃ electrodes 13b and 13c. The details are shown in Figure 2.
Shown in. The G ₃ B electrode 13b has in-line 3 beam passage holes 13R, 13G, 13B as in the conventional case, but one conducting ribbon 4a is formed on the lower outer wall of the G ₃ electrode 13b on the side of the hole 13R, and the other conducting ribbon 4b is G. _{3 The} electrode 13b is welded to the upper outer wall of the hole 13B side. That is, as shown in FIG. 2, the two conductive ribbons 4a and 4b are arranged diagonally. Conductive ribbon 4a on the G ₃ C electrode 13c,
The position of the other end of 4b is also the same position facing the G ₃ B electrode 13, and welded electrical conduction is performed. The welding of the conductive ribbons 4a and 4b is carried out after bead assembly of the electrodes with the bead glass 3 as in the conventional case.

During the manufacturing process of the color cathode ray tube, particularly in the exhausting step, the color cathode ray tube is heated at a high frequency of 500 to 600 ° C. in order to accelerate the gas emission from the electrode of the electron gun. Therefore, each of the multi-divided G ₃ electrodes thermally expands in the axial direction of the electron gun. The displacement is 0.1m
The order is m. At that time, the G ₃ electrodes 13b and 13c thermally expand each other to deform the electrode supporting portions of the respective electrodes (the vicinity of the flange that is in contact with the glass beads 3) and fix the electrode supporting portions held by the bead glass 3 to the fixing points. Bend as
Even if the electrodes are cooled after completion of high-frequency heating, a gap remains between these electrodes. However, in the present invention, the G ₃ B electrode 13b and the G ₃ C electrode 1
Since two ribbons are welded diagonally to 3c, the axial deformation is symmetrical and the electrode inclination of the electrodes 13c and 13b is reduced. Therefore, G ₄ electrode 14 and G ₃ electrode 1
The deterioration of the parallelism of the distance d with respect to 3 is reduced. In addition,
As shown in FIG. 2, it is not limited to providing two conducting ribbons in one diagonal direction, and two conducting ribbons may be provided in another diagonal direction. In any case, a plurality of conductive ribbons may be arranged and welded so that the deformation due to thermal expansion is symmetrical.

[0010]

As described above, according to the present invention, since at least two conductive ribbons for conducting the multi-divided electrodes are provided in at least one diagonal direction, the electron gun is heated to a high temperature during the cathode ray tube manufacturing process. However, the electrode inclination is small,
It is possible to obtain a high-precision electron gun with a small change in the electrode spacing, and it is possible to prevent deterioration of the focus performance.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of an electron gun according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a welding arrangement of conductive ribbons, which is a main part of the present invention.

FIG. 3 is a sectional view showing a welding arrangement of conductive ribbons of a conventional electron gun.

FIG. 4 is a side view showing a schematic configuration of a conventional electron gun.

[Explanation of symbols]

1 Electron Gun Main Body 2 Stem 3 Bead Glass 4a Conducting Ribbon 4b Conducting Ribbon 11 G ₁ Electrode 12 G ₂ Electrode 13 G ₃ Electrode 13a G ₃ A Electrode 13b G ₃ B Electrode 13c G ₃ C Electrode 13d G ₃ D Electrode 14 G ₄ Electrode 15 Shield cup 16 Contactor

Claims (2)

[Claims] 1. An electrode constituting an electron gun for a cathode ray tube,
An electron gun characterized in that a multi-divided electrode conducted by a conducting ribbon is arranged and welded with a plurality of conducting ribbons arranged on the multi-divided electrode so that deformation due to thermal expansion is symmetrical. 2. Among electrodes constituting an in-line three-beam type electron gun, welding is conducted at two places on a diagonal electrode side wall of an electrode hole surface having a multi-divided in-line three-beam hole by conducting ribbons. An electron gun characterized by.