JPS61259440A - Inline-type electron gun electrode structure - Google Patents

Abstract

PURPOSE:To improve resolution characteristics of main electron lenses to avoid their convergence change with the passage of time, by making main electron lens openings of an inline electron gun with united electrodes not to be in excess of eccentric distance, and enlarging their effective apertures. CONSTITUTION:Plural electron beam-transmission openings 23R, 23G, and 23B are unitedly formed on an identical electrode blocked surface 25 of an inline-type electron gun structure, to form a blocked cylindrical electrode 2 which serves as a main electron lens composite electrode. The electrode 2 is equipped with elliptical openings 21R, 21G, and 21B, which have short diameter DS approximating to an eccentric distance S between openings, without being in excess of it, and long diameter DL perpendicular to the opening, in the direction of arrangement in which the openings are formed inline on the blocked surface 25. In succession to them, recessed parts comprising spheroid conical surfaces 22R, 22G, and 22B are formed on the blocked surface 25, and cylindrical side part 26 is formed in succession to the blocked surface 25, so that the effective apertures of transmission openings 23R, 23G, and 23B are enlarged to improve resolution characteristics of main electron lens.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in the main electron lens constituent electrode of an electron gun for an in-line color picture tube.

[Conventional technology]

The resolution characteristics of electron guns for picture tubes are mainly limited by the spherical aberration of the electron lens, and in order to obtain high resolution characteristics, it is necessary to reduce the spherical aberration of the electron lens by increasing the diameter of the electrodes that make up the main electron lens. . The electrode aperture of the main electron lens is limited to the inner diameter of the glass neck of the picture tube in which the electron gun is installed, and three apertures are arranged in a straight line through which three electron beams emitted from the same plane pass. In a type electron gun, the diameter of the main electron lens electrode is at most 14 or less, which is the inner diameter of the glass neck, and it is important to approach this maximum diameter in designing the electron gun electrode structure.

FIGS. 4 and 5 each show an example of the main electron beam forming electrode 1 of an in-line electron gun, which is formed from an integrated electrode in which three conventionally used apertures are drilled in the same electrode. FIG. That is, the electrode structure 1 has central and both outer electron beam transmission apertures 11R, IIG, and I
IB is drilled in the closed surface 15 with a diameter Do while maintaining the eccentric distance S, which is the distance between the openings, and continues to the closed surface 15 with the part side 1
6 is a closed cylindrical body formed therein. Opening hole 11R111G
, IIB is surrounded by a protruding edge 14 that protrudes into the inside of the closed cylinder.
The electrode closing surfaces of this pair are opposed to each other to prevent mutual influence between adjacent holes of the electrostatic electron lens formed in each opening, and to strengthen the closing surface 15. In particular, in order to eliminate the mutual influence of the electron lens, the higher the height of the protruding edge 14 is, the more desirable it is, and usually it is required to be at least 1/3 of the aperture diameter, but as the aperture diameter increases, the height of the protruding edge 14 increases. It becomes difficult to increase the height.

On the other hand, simply increasing the aperture diameter DO increases the eccentric pressure @S and requires increasing the neck diameter of the picture tube that seals the electron gun. As is well known, an increase in the eccentricity degrades the convergence characteristic of concentrating the two electron beams over the entire area of the fluorescent surface, and an increase in the neck diameter increases the required deflection power of the picture tube, both of which are undesirable. .

Therefore, the aperture 11R, IIG of the main electron lens.

The opening diameter Do of the opening 11B is limited by the eccentric distance S and the width do of the U-shaped narrow gap 17 sandwiched between the opening protruding edges 14.

[Problem that the invention seeks to solve]

Recently, color picture tubes using in-line electron guns have become popular, and the demand for improving the resolution of electron guns, especially when used as high-resolution displays, is increasing. However, as mentioned above, the integrated electrode 1 commonly used as the main electron lens of an in-line type electron gun
In this case, when forming three independent protruding edges 14 around each opening 11R, IIG, and IIB, it is impossible to reduce the width do of the narrow gap 17 to below the predetermined level due to the necessity of machining the parts. This is the aperture diameter Do required for high resolution.
The biggest constraint on increasing the size was due to the electrode structure. Normally, when the electrode forming base material plate thickness is 0.2 to 0.4 -, do is 0.9 to 1.2 w regardless of the opening diameter DO.
About m is required.

The present invention has been made in view of the above-mentioned drawbacks, and it is possible to improve the effective The present invention provides an in-line electron gun electrode structure that can improve the resolution characteristics of a main electron lens by increasing the aperture diameter.

[Means for solving problems]

The present invention provides an in-line electron gun electrode assembly equipped with a closed cylindrical electrode in which three electron beam transmitting apertures are integrally formed on the same electrode closed surface, in which the electrode structure is eccentric in the direction of the aperture arrangement on the closed surface. It has an elliptical shape with a short axis that is close to the distance S without exceeding it, and a long axis in the direction of the arrangement of the holes, and the closed surface that is continuous with this becomes a spheroid-shaped conical surface that includes the ellipse. It is characterized in that it is recessed as shown in FIG. By configuring the electrode in this way, it is possible to avoid exceeding the eccentric distance S, and
It is possible to form an electron lens with a large effective diameter without being limited by the width of the narrow gap between adjacent openings, and to obtain an in-line electron gun electrode structure that can improve the resolution characteristics of the main electron lens.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

1 and 2 are closed cylindrical body electrodes which are main electron lens constituent electrodes based on one embodiment of the present invention. FIG. 2 is a perspective view and a side sectional view. Closed tube electrode? is an elliptical shape having a short axis Ds that is close to but not exceeding the eccentric distance S between the holes in the direction of the hole arrangement arranged inline on the closed surface 25, and a long axis DL in the direction perpendicular to the direction of the hole arrangement. Opening holes 21R, 21G,
21B, the closed surface 25 is continuously concave to become conical surfaces 22R, 22G, and 22B made of a spheroid including an ellipse, and a protruding edge is formed near the bottom surface thereof with an eccentric distance S. Complete circular hole 23R, 23 with diameter DO with 24
G, 23B are drilled. Further, a side portion 26 is formed continuously from the closed surface 25 as in the conventional case.

Because the electrode is configured in this way, even if the holes 21R, 21G, and 21B are adjacent to each other with a diameter Ds that approaches the eccentric distance S between the holes without exceeding it in the hole arrangement direction, the conventional predetermined Since there is no U-shaped narrow gap sandwiched between tall protruding edges, there are no restrictions on the processing of opening formation. Therefore, the short diameters of the openings 21R, 121G, and 21B can be made closer to the eccentric distance S than before. Furthermore, since the complete circular holes 23R, 23G, and 23B with the protruding edge 24 smaller than the minor axis Ds are formed on the conical surface of the spheroid inside the electrode, the distance between adjacent circular holes is about the same as in the conventional case. , there are no restrictions on the processing of circular holes with protruding edges.

On the other hand, the opening 21R921 in the direction perpendicular to the opening arrangement direction.
Since the long axis DI of G and 21G was taken, it was possible to set DL to be greater than the eccentric distance S, and it was possible to form a hole with a larger diameter than before.

Here, as shown in FIG. 3, the two sets of closed cylindrical body electrodes 2
, 2' are opposed to each other to form an electron lens. Three holes 21 in the hole arrangement direction
Since the minor axes DS of R, 21G, and 21B are adjacent to each other and have a value closer to S than before, the electron lens formed between each opposing opening has a focusing effect in the minor axis direction rather than in the major axis direction. However, since the area around the aperture is a spheroidal conical surface, the change in depth of the concave portion from the closed surface to the bottom surface of the aperture is gentler in the long axis direction. In other words, the change in the distance between the two opposing closed surfaces is smaller in the major axis direction than in the minor axis direction between opposing openings, and the focusing effect of the formed lens is stronger in the major axis direction than in the minor axis direction. . As a result, the difference in strength of the focusing lens due to the elliptical aperture described above is canceled out, and furthermore, complete apertures 23R, 23G, and 23B with projecting edges 24 are bored at the bottom of the conical surface. The effects are additive, and it becomes possible to make the lens electric field formed between each aperture a rotationally symmetrical shape and to correct astigmatism.

Therefore, the electron lens formed between each hole has a conical surface in the shape of a spheroid, so it is almost the same as an electron lens formed by a large-diameter circular hole with an effective diameter DL larger than the eccentric distance S. An equivalent electron lens is formed, and resolution characteristics can be dramatically improved.

Furthermore, since the short axis Ds of the three openings is not greater than the eccentric distance S, the long axis of the closed cylindrical electrode in the direction of the aperture arrangement does not become much larger than that of conventional electrodes, and the long axis of the closed cylindrical electrode The convergence, which is affected by the inner wall of the neck to which it is sealed, does not deteriorate over time.

In the above description, the short axis and long axis of the three openings are the same, but the ellipticity may be changed between the center and both outer holes, or may take different values between the two opposing electrodes.

In addition, the electrode structure of this structure uses the main electron lens focusing system Capai potential focus type, uni potential focus type,
Needless to say, it can be applied to any method such as a focus type or a multi-stage focusing type.

〔Effect of the invention〕

As described above, according to the present invention, the main electron lens of an in-line electron gun equipped with an integrated electrode can be used without being subject to restrictions on electrode processing and without deteriorating the withstand voltage characteristics and convergence characteristics over time. By enlarging the effective diameter of the aperture without making the aperture larger than the eccentric distance, an in-line electron gun electrode structure that can dramatically improve the resolution characteristics of the main electron lens can be obtained very easily.

[Brief explanation of the drawing]

1 and 2 are a perspective view and a side sectional view of a closed cylindrical body electrode 2 which is a main electron lens constituent electrode according to an embodiment of the present invention, and FIG. 3 is a side sectional view of the two sets of closed cylindrical body electrodes. FIG. 4 is a sectional view of the main parts when an electron lens is formed by facing each other.
FIG. 5 shows the conventional one. 1.2... Electrode, IIR, IIG, IIB;
23R. 23G, 23B... Electron beam transmission aperture, 21
R, 21Q21B... elliptical opening, 22R
, 22G, 22B...Spheroidal conical surface, 14
,24...Protruding edge, 15°25...
Closed surface, 16, 26... part side part, 17...
...Gap area.

Claims (1)

[Claims] In an in-line electron gun electrode assembly equipped with a closed cylindrical electrode in which a plurality of electron beam transmission apertures are integrally formed on the same electrode closed surface, the closed surface is opened in the direction of the aperture arrangement on that surface. It has an elliptical shape with a short axis close to, but not exceeding, the eccentric distance between the hole centers, and a long axis in the direction perpendicular to the hole arrangement direction, and the inner end is continuous to form a circular hole. An in-line electron gun electrode structure characterized in that it is recessed to form an electron beam transmission aperture.