JPH0737520A - In-line type electron gun - Google Patents

Abstract

PURPOSE:To eliminate deformation or position displacement at the time of electrode assembling of a lens electric field generation plate assembled into the respective cylindrical bodies of a focusing electrode and a positive electrode, and at the time of electric gun assembling. CONSTITUTION:Elliptic openings 5 and 6 having a long shaft in a horizontal direction are provided on an end surface-where the respective cylindrical bodies 2 and 4 of a focusing electrode 1 and a positive electrode 3 are faced each other. Elliptic lens electric field generation plates 7 and 8 inserted in the respective cylindrical bodies 2 and 4 respectively in only a small region 12 set in small projections 9 and 10 protruded in a width direction from the respective sides of two long sides of the generation plates 7 and 8 and in the respective sides of two short sides.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun for a color picture tube, and more particularly to an in-line type electron gun in which three electron beam emitting ports are arranged inline.

[0002]

2. Description of the Related Art The resolution of a color picture tube depends on the focus characteristic of a three-electron beam emitted from an electron gun. The focus characteristic depends on the spherical aberration of a main lens electric field generated between a focusing electrode and an anode. Greatly affected. Therefore, the aperture of the main lens electric field is made as large as possible to reduce the influence of spherical aberration.

When the diameters of the three electron beam passage holes arranged in-line in each of the focusing electrode and the anode are increased,
The diameter of the main lens electric field generated between both electrodes is increased, and spherical aberration is reduced. However, if the electron beam passage hole is enlarged, the eccentric distance is also increased, so that the diameter of the electron gun is increased. As the diameter of the electron gun increases, the neck portion of the glass bulb that houses the electron gun also increases in diameter, and the deflection sensitivity of the deflection yoke attached to this neck portion decreases.

Therefore, an oblong opening having a major axis in the horizontal direction is provided on the opposed end faces of the cylindrical body forming the outer shells of the focusing electrode and the anode, while three electron beam passage holes are arranged inline. The oval lens electric field generation plate is provided in the cylindrical body. According to this structure, a main lens electric field having a diameter larger than that of the electron beam passage hole can be generated between the focusing electrode and the anode without increasing the eccentric distance.

[0005]

However, during the electrode assembly process of incorporating the lens electric field generating plate into the cylindrical body forming the outer shells of the focusing electrode and the anode, stress deformation is likely to occur in the lens electric field generating plate. was there. In order to prevent this, it is conceivable to reduce the degree of fitting between the lens electric field generation plate and the cylindrical body and provide a gap between them, but if this structure is adopted, it is difficult to assemble the electrode with high precision. No
During the electron gun assembly process of embedding and fixing the respective supporting portions of the focusing electrode and the anode together with the supporting portions of the other electrodes in the pair of glass rods, the lens electric field generating plate is likely to be displaced or deformed.

In the process of assembling the electron gun, the supporting portions of a large number of electrodes constituting the electron gun are embedded and fixed in a pair of glass rods as described above. Since a pair of position regulating pins as an assembling jig are inserted into both sides of the individual electron beam passage holes, the above-mentioned air gap exists between the lens electric field generation plate and the cylindrical body. Then, the lens electric field generation plate is displaced or deformed due to the stress when the pin is inserted or removed.

Therefore, an object of the present invention is to allow the lens electric field generating plate to be accurately incorporated into the cylindrical body forming the outer shells of the focusing electrode and the anode without deformation, and furthermore, to support the focusing electrode and the anode. Another object of the present invention is to provide an in-line type electron gun that is free from the risk of positional displacement or deformation of the lens electric field generating plate even in the electron gun assembling step of embedding it in a pair of glass rods together with other electrode supporting portions.

[0008]

According to the present invention, in order to achieve the above-mentioned object, a cylindrical body forming each outer shell of a focusing electrode and an anode adjacent to the focusing electrode is horizontally arranged on end faces facing each other. It has an oval opening for placing the major axis, a built-in elliptical lens electric field generation plate along this opening, and three electron beam passage holes in which the lens electric field generation plate is arranged inline in the horizontal direction. In the electron gun described above, the lens electric field generation plate has small projections protruding in the width direction from the two long sides and abutting against the inner surface of the tubular body, and small areas set on the two short sides. An in-line type electron gun is provided, which is welded to the cylindrical body only.

[0009]

According to the present invention, the elliptical lens electric field generating plate contained in the cylindrical body forming the outer shells of the focusing electrode and the anode projects in the width direction from each of the two long sides of the cylindrical body. Since there is a small protrusion that comes into contact with the cylindrical body, the fitting portion of the lens electric field generation plate incorporated in the cylindrical body is only the small protrusion. Therefore, it is possible to eliminate the risk that the lens electric field generation plate is deformed by stress during electrode assembly while obtaining the positioning effect by fitting. Further, the lens electric field generation plate is welded to the tubular body by the small projection portion and the small regions set on each of the two short sides, and is immobile on the four sides, so that each of the focusing electrode and the anode is fixed. Even if the position regulating pin is inserted into the electron beam passage hole of the lens electric field generation plate during the electron gun assembly process in which the support portion is embedded and fixed in the glass rod together with the support portions of the other electrodes, the stress caused by this causes the lens The electric field generation plate will not be displaced or deformed.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

As shown in FIGS. 1 and 2, the focusing electrode 1
The tubular body 2 forming the outer shell of the anode 3 and the tubular body 4 forming the outer shell of the anode 3 respectively have oval openings 5 and 6 with their long axes extending horizontally in the end faces facing each other. . Each of the openings 5 and 6 is obtained by curling one end edge of each cylindrical body inward, and the elliptical lens electric field generating plates 7 and 8 are provided at the positions retracted from the curled portion in the openings 5 and 6, respectively. It is built along.

The lens electric field generating plate 7 has three electron beam passage holes 7a, 7b, 7 arranged inline in the horizontal direction.
As shown in FIG. 3, each of the two long sides has a plurality of small protrusions 9 protruding in the width direction and abutting on the inner surface of the tubular body 2. The lens electric field generation plate 8 also has three electron beam passage holes 8 arranged inline in the horizontal direction.
In addition to having a, 8b, and 8c, each of the two long sides has a plurality of small protrusions 10 protruding in the width direction and abutting on the inner surface of the tubular body 4.

In assembling the focusing electrode 1, after the lens electric field generating plate 7 is fitted in the tubular body 2, the small projection 9 is laser-welded to the inner surface of the tubular body 2. 11 indicates a welding point. The lens electric field generating plate 7 in the process of being incorporated in the tubular body 2 is abutted against the inner surface of the tubular body 2 mainly at the small projections 9 and fits therein, so that the entire structure is not deformed by stress.

When the laser welding at the welding point 11 is completed, next, the small regions 12 set on the two short sides of the lens electric field generating plate 7 are laser-welded to the inner surface of the tubular body 2. Small area 1
There is a small gap between the cylindrical body 2 and the cylindrical body 2, but when the laser beam 13 is irradiated toward this small gap as shown in FIG. 4, both materials are locally melted and the welding point 14 is formed. can get. As a result, the lens electric field generation plate 7 is welded on the four sides inside the tubular body 2 and is stably supported. The remaining outer circumference of the lens electric field generation plate 7 is not welded and becomes a free edge. Reference numeral 15 indicates an electrode supporting portion.

The anode 3 is also assembled in exactly the same manner as the focusing electrode 1, and therefore its explanation is omitted. The neck diameter is 29.
In the case of an electron gun used for a large 1 mmφ color picture tube, as an example, the plate thickness of the cylindrical bodies 2 and 4 is 0.3 mm, the major axis of the openings 5 and 6 is 18.5 mm, and the minor axis is 9. 0 mm
Can be The thickness of each of the lens electric field generation plates 7 and 8 is 0.6 mm, and the gap between the cylindrical body 2 (or 4) and the free end edge of the lens electric field generation plate 7 (or 8) is about 0.1.
It can be mm. Furthermore, opening 5 (or 6)
To the lens electric field generating plate 7 (or 8) is about 2.
It can be set to 4 mm.

The focusing electrode 1 and the anode 3 are assembled into an electron gun together with other electrodes as shown in FIG. Here, 16a, 16b and 16c are cathodes, 17 is a control electrode, 18 is an accelerating electrode, 19 is a prefocusing electrode, and 20 is a cup electrode having an anodic potential.

[0017]

As described above, according to the present invention, the lens electric field generating plate can be accurately incorporated into the cylindrical body forming the outer shells of the focusing electrode and the anode without deformation, and
Also in the assembly process of the electron gun, there is no danger of the lens electric field generating plate being displaced or deformed, so that it can be applied to an electron gun of a large-sized color picture tube to improve its quality and manufacturing yield.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of an in-line type electron gun according to an embodiment of the present invention.

FIG. 2 is a side sectional view of an in-line type electron gun according to an embodiment of the present invention.

FIG. 3 is a sectional view of a focusing electrode according to an embodiment of the present invention.

FIG. 4 is a perspective view of a focusing electrode according to an embodiment of the present invention.

[Explanation of symbols]

 1 Focusing electrode 2 Cylindrical body 3 Anode 4 Cylindrical body 5,6 Opening 7,8 Lens electric field generating plate 9,10 Small protrusion 11 Welding point 12 Small area 14 Welding point

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noboru Tominaga 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electronics Industrial Co., Ltd.

Claims (1)

[Claims] 1. A cylindrical body forming a focusing electrode and outer shells of an anode adjacent to the focusing electrode has oval openings having horizontal major axes in the end faces facing each other, and
Built-in elliptical lens electric field generation plate along this opening,
Lens electric field generators are arranged inline horizontally 3
In the electron gun having a plurality of electron beam passage holes, the lens electric field generation plate has small projections and two short sides protruding from each side of the two long sides in the width direction and contacting the inner surface of the tubular body. An in-line type electron gun, which is welded to the cylindrical body only in a small area set on each side of the.