JPH02155149A - Color cathode-ray tube - Google Patents

Abstract

PURPOSE:To increase the size accuracy of an electrode and to improve the astigmatism property by providing a cup-form outer electrode, and a cup-form inner electrode a little smaller than the outer electrode, whose flange at the peripheral edge has a specific interval to the peripheral edge of the outer electrode when it is set inside the outer electrode to take a specific relative position to the outer electrode. CONSTITUTION:An outer electrode 11 is a cup-form electrode which has a common aperture 21 to pass three electron beams at the top surface, while an inner electrode 12 has three independent apertures 22 through which three electron beams pass respectively at the top surface, and an inner electrode flange 13 which is buried in an insulator support when an electron lens is assembled by using the electrodes so as to hold the electrodes, at the peripheral edge. The inner electrode 12 is inserted inside the outer electrode 11 with its top, fixed at the position to secure a specific dimension accurately, and welded at welding points 14 to be fixed. In this case, the length of the outer electrode 11 is set not to contact its peripheral edge to the flange 13 of the inner electrode 12. As a result, the size accuracy of the depth of the independent apertures is increased, and the astigmatism property can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color cathode ray tube, and more particularly to a color cathode ray tube having an in-line electron gun.

[Conventional technology]

In order to improve focus characteristics in an in-line color cathode ray tube, it is necessary to increase the diameter of the main focus lens of the electron gun to reduce spherical aberration.

As a way to achieve this, for example, Figures 3 and 4 (a
There is a method in which two sets of electrodes as shown in ) and (b) are arranged on the low voltage side and high voltage side and are opposed to each other, and used as a main focus lens. This electrode has a common aperture 41 through which the three electron beams pass, and three independent apertures behind the common aperture 41, through which the three electron beams individually pass, on opposite surfaces forming the main focus lens. It has 42.

By using this electrode for the main focus lens, a large aperture lens with reduced spherical aberration can be formed. However, if such a non-rotationally symmetric main focus lens is used, astigmatism will occur, but the shape of the common aperture 41 and the dimensions of the independent aperture depth 44 are changed on the low voltage side and the high voltage side. By doing so, this astigmatism can be removed.

Such electrodes are generally manufactured by integral molding using press processing, as shown in FIG.

[Problem to be solved by the invention]

Manufacture of the electrode by the conventional breath integral molding described above is difficult because the shape of the electrode is complicated, and therefore the manufacturing cost is high. In addition, the common aperture size 43, the independent aperture depth 44, etc. require precision on the order of several microns in order to eliminate astigmatism as described above. There is a problem in that it is extremely difficult to achieve this by integrally molding the bracelet.

Therefore, as an improved second method, the method shown in Figs.
A manufacturing method as shown in Figures (a) and (b) was considered.

That is, this electrode with a complicated opening shape is divided into two parts: an external electrode 5 which has only a common opening 61 at the top of the cup-shaped electrode, and an internal electrode 52 which has only an independent opening 62. The electrode 52 is completely housed inside the external electrode 51 and welded at a welding point 53 on the side surface.

By dividing the electrode into two, the shape of each electrode becomes very simple and easy to process. - On the other hand, if a non-pressure welding method such as laser welding is adopted as a welding method, accurate positioning of the external electrode 51 and the internal electrode 52 can be relatively easily achieved. Further, the internal electrode 52 is connected to the external electrode 51
By welding with other electrodes at the external electrode flange portion 54 of the external electrode 51, it can be handled in exactly the same way as an integrally molded part of the breather, and the appearance is almost the same. There is no difference.

However, in the second method described above, FIG. 7(a).

As shown in (b), as long as the cup-shaped electrode is formed by press working, the peripheral edge 71 of the internal electrode 52 spreads outward by a very small amount, and this causes the internal electrode 52 to become closer to the outer electrode 5.
1, the peripheral edge 71 of the internal electrode 52
There is a problem in that this hits the external electrode 51, leading to a decrease in the accuracy of the independent opening depth 64 during picture electrode welding, and worsening the above-mentioned astigmatism characteristics.

SUMMARY OF THE INVENTION An object of the present invention is to provide a color cathode ray tube with high dimensional accuracy of the independent aperture depth and good astigmatism characteristics.

[Means to solve the problem]

The color cathode ray tube of the present invention includes a cup-shaped external electrode having a common opening, and a peripheral end portion when placed in a predetermined positional relationship with respect to the external electrode that is fitted into the external electrode. The provided flange portion has three independent openings that are spaced apart from the peripheral edge of the external electrode and arranged in a straight line.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a partially cutaway perspective view of an embodiment of a grid electrode of a color cathode ray tube according to the present invention, and FIG. 2(a).

(b) is a vertical cross-sectional view and a cross-sectional view of the grid electrode of FIG. 1;

As shown in FIGS. 1 and 2 (a) and (b), the external chamber f! 11 is a cup-shaped electrode having a common opening 21 on its top surface through which three electron beams pass;
has three independent apertures 22 on its top surface through which the three electron beams pass, and a peripheral edge that is embedded in an insulating column to hold the electrodes when assembling an electron lens using this electrode. It has an internal electrode flange portion 13 for

The top of the internal electrode 12 is inserted into the external electrode 11, fixed at a position where a predetermined dimension can be accurately obtained, and welded and fixed at a welding point 14. At this time, the length of the external electrode 11 is set so that the peripheral edge of the external electrode 11 does not touch the internal electrode flange portion 13.

〔Effect of the invention〕

As explained above, the present invention includes a cup-shaped external electrode,
The flange portion is slightly smaller than the external electrode, and is fitted into the external electrode, and when arranged in a predetermined positional relationship with respect to the external electrode, the flange portion provided at the peripheral edge portion forms the peripheral edge of the external electrode. A cup-shaped internal electrode having three independent openings arranged in a straight line and having a constant distance from the end thereof, and the cup-shaped internal electrode is fitted into the cup-shaped external electrode. , Arrange them so that their positional relationship is in the prescribed relationship, and weld them at their respective side walls.

By fixing the electrode and realizing a predetermined electrode shape, it is possible to simplify the manufacturing method, improve the dimensional accuracy of the electrode, and improve astigmatism characteristics.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of an embodiment of a grid electrode of a color cathode ray tube according to the present invention, and FIG. 2(a). (b) is a vertical cross-sectional view and a cross-sectional view of the grid electrode in Fig. 1, Fig. 3 is a partially cutaway perspective view of an example of the grid electrode of a conventional color cathode ray tube, and Figs. ＞ is a vertical cross-sectional view and a cross-sectional view of the grid electrode in FIG. 3, FIG. 5 is a partially cutaway perspective view of another example of the grid electrode of a conventional color cathode ray tube, and FIG.
), (b) are longitudinal and transverse cross-sectional views of the grid electrode in Fig. 5, and Fig. 7 (a) and (b) are longitudinal and transverse cross-sectional views of the internal electrode in Fig. 5 after forming by press working. It is a front view. 11... External electrode, 12... Internal electrode, 13...
Internal electrode flange portion, 14... Welding point, 21... Common opening, 22... Independent opening, 41... Common opening, 42... Independent opening, 43... Common opening Dimensions, 44...Independent opening depth, 51...External electrode, 5
2... Internal electrode, 53... Welding point, 54... External electrode flange portion, 61... Common opening, 62... Independent opening, 63... Common opening dimension, 64... ...Independent opening depth, 71...Peripheral edge. Agent Patent Attorney Oto Uchihara (α) 4 troubles (Tanitsu (α), fl (5?)

Claims (1)

[Claims] A cup-shaped external electrode having a common opening, and a flange portion provided at a peripheral edge of the external electrode when arranged in a predetermined positional relationship with respect to the external electrode that fits into the external electrode. having a certain distance from the peripheral edge of the electrode, and
a cup-shaped internal electrode having three independent openings arranged in a straight line, the cup-shaped internal electrode is fitted into the cup-shaped external electrode, and the external electrode and the internal electrode are connected to each other; 1. A color cathode ray tube, characterized in that it has grid electrodes which are arranged such that their positions are in a predetermined positional relationship, and which are welded and fixed to their respective side walls.