JPS6065434A - In-line type electron gun electrode body structure - Google Patents

Abstract

PURPOSE:To reduce spherical aberration and improve resolution in a closed cylindrical electrode in which independent apertures are perforated coaxially on a second closed surface by providing a recessed groove that is connected to overlapping type apertures at the cylinder side in the aperture alignment direction. CONSTITUTION:A closed cylindrical electrode 2 forms a second closed surface 13 that is receded only for a specified distance from a first closed surface by tapering the first closed surface with the diameter D1 exceeding the eccentric length S so that the center and both outside apertures 12R-12B can mutually be overlapped. Independent apertures 13R-13B with the smaller diameter D2 than the above diameter are perforated on the closed surface 13 coaxially with electron gun axes 20R-20B. In addition, a groove 22 that reaches the second closed surface 13 is formed with the same with l as the in-line alignment direction of a connection section 21 inserted between the center and both outside apertures, between the cylinder side 15 of the in-line alignment direction of the apertures 12R-12B and both outside apertures 12R and 12B.

Description

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

The resolution of an electron gun is mainly limited by the spherical aberration of the static electron lens, which is composed of a pi-bontency lens lens, a uni-botency roof φ-cass type, and other multi-stage focusing types. It is necessary to increase the aperture of the electrodes that make up the electron lens and reduce the spherical aberration of the C1 electron lens.The aperture of the main electron lens electrode is limited to the inner diameter of the glass neck of the color picture tube, and three electron guns are arranged in a row. In an in-line color picture tube, the diameter of the main electron lens is at most 1/3 or less of the inner diameter of the glass neck, and in designing the electron gun structure, it is important to approach this maximum diameter as usual.

On the other hand, in order to increase the main electron lens power and i-aperture sound, it is necessary to increase the distance between the apertures. convergence characteristics.

Therefore, the eccentricity Mf of the in-line electron gun! ', As a method for reducing spherical aberration by increasing the aperture of the main electron lens constituent electrode without changing S and the glass neck aperture, a closed cylindrical electrode J shown in Figs. 1 and 2 was proposed. ing. FIG. 1 is a plan view of the closed cylindrical body electrode 1, and FIG. 2 is a side sectional view thereof.The closed surface 11 has a central diameter Dl larger than the eccentric distance S.

and inner and outer 9111 electron beam transmission apertures 12G, 12
几.

12B is opened, and the openings 121 on both sides of the central opening 12G are opened.
t, , 12B are connected to each other by 1 tatami, and the openings form a bundle 2 closed surface 13 inside the electrode which is set back from the closed surface 11 by a distance IH, and MIJ markings are written on this surface. Hole 1
2) Completely circular holes 13R, 130, 13B with a diameter D2 smaller than the eccentric distance S are drilled coaxially with L and 120.12B. 13 holes opened in history, 130.1:3B
A protruding edge 14 having a height b2 (f) is formed from the second closing surface 13, and curves each opening independently.

In FIGS. 3 and 4, an electrode assembly l' having the same structure as this electrode assembly l is arranged facing each other on the same axis 101'L, IOG, and IOB, and the voltage related to the electrode assembly 1 is raised to the pole assembly l'. When a low voltage at a constant ratio of voltage is applied, the three electron gun shafts 10f4, 100. lo) Main electrons in the cross section including J (horizontal plane to the phosphor screen of the color picture tube) and the cross section including the central electron gun axis 10G perpendicular to this (plane perpendicular to the phosphor screen of the color picture tube) The electrostatic field that forms the lens electric field is shown, and the equipotential lines that are the intersections of the equipotential surfaces and these cross sections are shown by line groups 18 and 19, respectively. As is clear from the figure, the superimposed apertures with apertures DI larger than the eccentric distance S and the independent apertures with the aperture D2 that are coaxial with the superimposed apertures result in significantly more spherical aberration than in the case of the apertures with the aperture D2. This results in an electron lens with reduced .

However, since the distance d2 between the center and the opposing parts of the inner and outer opening gap 160 in the horizontal cross section shown in FIG.
A group of equipotential lines 18 are formed between opposing parts of the gap 16 on both sides 11C6 of
The density of the inner and outer openings is 12R.

12B is rougher than the opposing portions on the side 15 side. On the other hand, as is clear from Fig. 4, in the vertical plane, the electron gun axis 1
A group of equipotential lines 19 that are axially symmetrical with respect to 0G are obtained, and although not shown, a group of equipotential lines that are axially symmetrical are also obtained in a vertical cross section that includes both outer electron gun axes 10R210B. Because the equipotential line group 18 in the horizontal plane is rougher in the central aperture opposing part than in the inner and outer aperture opposing parts, the electron lens formed in the central aperture 10G opposing part in the horizontal plane The lens strength becomes weaker than that in the vertical plane. Furthermore, in the horizontal plane, the intensity of the central electron lens is weaker than the intensity of the electron lenses on both outer sides.

Therefore, in the electron lens using the lever electrode structure 1, the focusing conditions do not match between the center and the inner and outer electron lenses, and due to the difference in lens strength in the horizontal plane and the vertical plane, the electron beam spot for fluorescence enhancement becomes horizontally elongated and vertically There was a drawback that directional resolution was impaired.

In order to eliminate the above-mentioned drawbacks, the present invention provides an in-line array superimposed aperture that has a diameter greater than the eccentric distance of the aperture and is formed in a closed-base cylindrical body electrically closed surface, and a hole that is set back a predetermined distance from the closed surface. An independent aperture smaller than the above-mentioned diameter is coaxially drilled in the second obstructed surface.
A concave groove communicating with the vertical apertures is installed on the cylinder 1111 side in the C1 aperture arrangement direction. This makes it possible to substantially equalize the lens strength in the horizontal plane, match the focusing conditions of the central and inner and outer electron lenses, and obtain an electron lens with reduced spherical aberration and significantly improved resolution.

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

FIG. 5 is a perspective view of an electrode structure 2 based on an embodiment of the present invention, and FIG. 6 is a perspective view of an electrode structure 2 having the same structure as this electrode structure.
' are placed facing each other on the same axis 201 (, 200, 20B), and when a high voltage is applied to the electrode assembly 2 and a low voltage at a predetermined ratio of the high voltage is applied to the electrode assembly 2', the three electron gun axes 2 (u
(, , 20G, 20B are shown in the cross section including the main electron lens electric field, and the equipotential lines which are the lines of intersection with this plane are shown as the line group 28. The same reference numerals are given to the same parts in the following explanation.As shown in FIG. and inner and outer openings 121
(, 12G, 12B are arranged in a superimposed shape to form a second closing surface 13 which is recessed by a predetermined distance from the first closing surface.
Coaxially with the holes L, 20(), and 20B, independent openings 13H, 13G, and 13B having a diameter Dtt smaller than the aforementioned diameter are closed. However, the opening hole is 12, 12G, 12
Side part 15 and inner and outer openings 12 in the inline arrangement direction of B
A groove 22 reaching the second closed surface 13 is formed between 1'4 and 12B with the same width l as the inline arrangement direction of the communicating portion 21 sandwiched between the center and the inner and outer apertures.

Due to the presence of the groove 22, as shown in FIG.
The distance between the facing portions of the 5th closed surface has the same value d2, and the density of the equipotential line group 28 in the gap between them is equal, and the central and inner and outer openings 13G.

13) The main electron lens electric fields of the opposing parts L and 13B are each axially symmetrical. Furthermore, three openings 12R and 12G.

A continuous groove is formed in the central part of the closed surface 11 in which 12B is perforated, and the curved surface concave toward the inside of the electrode is equally constrained in the direction perpendicular to the inline arrangement direction. Each electron gun axis zoa in horizontal section is formed
, 20(J, 20B) The curvature of the electron lens electric field formed on 20B is smaller than in the case of Fig. 3, and matches the curvature of the electron lens electric field formed on each electron gun axis in the vertical section. .

According to the embodiment of the present invention, the lens strengths of the electron lenses formed in the central and inner and outer aperture opposing parts in the horizontal plane are made equal to each other, and the lens strengths of the electron lenses formed in the central and inner and outer aperture opposing parts are made equal to each other, and It becomes possible to match the strength of the electron lens formed on the opposite side with the strength of each electron lens on the horizontal plane.

Accordingly, an electron lens that combines two electrode structures has the same focusing conditions at the center and the inner and outer electron lenses, and also has the same lens strength in the horizontal plane and in the vertical curve, and has high resolution in both the horizontal and vertical directions. However, the effect of increasing the diameter of the main electron lens due to the fold-shaped aperture can be fully utilized, spherical aberration is reduced, and resolution is significantly improved.

[Brief explanation of the drawing]

Figures 1 and 2 show a flat curved view and a side cross-section of a conventional closed cylindrical body electrode in which the diameter of the main electron lens electrode is increased without changing the vertical distance between the apertures of the in-line electronic lens. The curve diagrams in Figures 3 and 4 show the case where the pair of electrodes are opposed to each other and a high voltage and a low voltage at a predetermined voltage ratio are respectively applied.
The main electron lens electric field in a cross section including three electron gun axes and a cross section perpendicular to this cross section and including the central electron gun axis is shown in FIG. FIG. 6 shows a perspective view of the pair of electrodes facing each other,
The main electron lens electric field in a cross section including the three electron gun axes is shown when a high voltage and a low voltage at a predetermined voltage ratio are respectively applied. 10R, IOG, IOB, 20ft, 20G. zoU... Electron gun axis, 11... First closed surface, 121, 12G, 12B... Superimposed opening, 13R9130, 1313... Independent hole, 14... protruding edge, 15... section side, 16... gap, 18, 19° 28...
・Equipotential line group, 21...Communication part, 22...
··groove. 28 Figure 6 Section S

Claims (1)

[Claims] A second closed surface that is set back a predetermined distance from the closed surface of the closed cylindrical electrode is formed with overlapping aperture-like recesses having an aperture larger than the distance and arranged in-line, and independent holes smaller than the aperture are formed on the second closed surface. A concave groove communicating with the superimposed apertures was installed on the side of the C1 aperture arrangement direction in the closed cylindrical electrode, each of which had apertures perforated along the same axis. An in-line electron gun electrode structure characterized by the following.