JPH09147761A - Electron gun for color picture tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the accuracy of assembly by forming at least one of focusing electrodes into a focusing correcting electrode which forms axially asymmetrical electron lenses on each side, and providing an electrode-position regulating hole in the middle of the focusing correcting electrode. SOLUTION: This electron gun comprises a control electrode 11, an accelerating electrode 12, first to fourth focusing electrodes 13a to 13d, a final accelerating electrode 14, and cathodes 18a, b, c. A position where two rectangular holes overlap is displaced by moving either the electrode 13b or 13b toward the short sides of the rectangular holes. The electrode 13c can be positioned accurately while preventing its deformation by regulating a middle thick-walled electrode member. The use of the electrode member formed by the thick-walled plate member ensures regulation of the position using a position regulating pin, enhancing the accuracy of assembling the electron gun. A color picture tube excellent in picture characteristics can thus be obtained.

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 having an in-line structure in which a plurality of cathodes are arranged in a straight line.

[0002]

2. Description of the Related Art FIG. 8 shows an example of a sectional structure of a conventional electron gun. The electron gun of the conventional example shown in this figure displays an image with good resolution over the entire area of the phosphor screen surface, and in order to prevent the occurrence of moire,
4 focusing electrodes, and the third focusing electrode has a vertically long and a horizontally long length for forming a non-axisymmetric electron lens between the second, third and third to fourth focusing electrodes, respectively. An electron beam passage hole is provided. Such conventional electron guns for color picture tubes are disclosed in JP-A-3-93135 and JP-A-3-95835.

[0003]

As described above, since the electron beam passage hole of the third focusing electrode has a non-axisymmetric shape, it is sufficiently regulated by the position regulating pin which is usually used when assembling the electron gun. I can't. That is, if it is attempted to regulate the vertically long and horizontally long beam passage holes with a common pin, there arises a problem that there is a margin in the horizontal direction and the vertical direction in each portion. When the electrode position cannot be sufficiently regulated as described above, undesired distortion occurs in the electron lens caused by the potential difference between the electrodes facing each other.

It is also possible to use another position regulating means or the like for regulating the position of the third focusing electrode.
As a result, the manufacturing process of the electron gun becomes complicated, and as a result, the manufacturing cost of the electron gun increases.

Therefore, the present invention can improve the assembly accuracy of the electron gun and realize a color picture tube excellent in image characteristics even in the case of the conventional position regulating method using the position regulating pin. The purpose is to provide an electron gun.

[0006]

To achieve the above object, an electron gun for a color picture tube according to the present invention comprises three cathodes, a control electrode, an accelerating electrode, one or a plurality of focusing electrodes, and a final accelerating electrode arranged in-line. Electrodes are sequentially arranged in the tube axis direction, and the feature thereof is that at least one of the focusing electrodes is a focusing correction electrode which forms a non-axisymmetric electron lens on both sides, and The point is that there is a hole for controlling the position of the electrode in the middle part.

Preferably, the focusing correction electrode is formed by combining at least three electrode members, which are an intermediate electrode member and both outer electrode members arranged so as to sandwich the intermediate electrode member, and the intermediate electrode member is used for position regulation. A hole is provided. Further, it is preferable that the intermediate electrode member is a plate member having a thickness larger than that of the electrode members on both outer sides. It is also preferable that at least one of the holes for forming the non-axisymmetric electron lens on both sides of the focusing correction electrode is a rectangular hole. More preferably, a wall surface provided upright in the pipe axis direction from the peripheral portion of the hole is provided. For example, the wall surface can be provided by bending. The shape of the position regulating hole may be circular or non-circular. Further, the intermediate electrode member of the focusing correction electrode may be a thick plate made by bonding two plate members together.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a cross section of an electron gun according to an embodiment of the present invention. This electron gun has a control electrode 1
1, the accelerating electrode 12, the first to fourth focusing electrodes 13a to 13d, the final accelerating electrode 14, and the cathodes 18a, 18b, 18c, and four focusing electrodes. The third focusing electrode 1 shown in FIG.
3c shows a side appearance. Of the three electrode members that form the third focusing electrode 13c, the intermediate electrode member 22 is a plate member that is thicker than the other outer electrode members 21 and 23. The material is stainless steel or FeNi.

FIG. 3 shows the positional relationship between the holes formed in the outer electrode member 21 and the holes formed in the opposing second focusing electrode 13b as viewed from the outer electrode member 21 side. As can be seen from this figure, the position of the overlapping portion of the two rectangular holes is displaced by moving either the second focusing electrode 13b or the third focusing electrode 13c in the short side direction of the rectangular hole. The third focusing electrode 13c of the present embodiment can be accurately aligned while preventing deformation by regulating the intermediate thick electrode member 22. Since the intermediate electrode member 22 made of the thick plate member is used, the position can be surely regulated by the position regulating pin, so that the assembly accuracy of the electron gun is also improved.

The outer electrode member 21 and the second electrode facing the outer electrode member 21.
The holes formed in the third focusing electrode side end surface 13b of the focusing electrode, or the third focusing electrode side end surface 13d of the outer electrode member 23 and the fourth focusing electrode facing the outer electrode member 23 are respectively shown in FIG.
Various shapes as shown in (d) can be combined. In the structure shown in FIGS. 4A and 4B, a rectangular or circular hole is provided with a wall surface that is bent and is erected in the axial direction in the peripheral portion. In the structure shown in FIGS. 4C and 4D, the hole of one of the electrodes is formed by one laterally long hole common to R, G, and B. Further, the holes formed in the intermediate electrode member 22 can have various shapes as shown in FIGS.

Further, as shown in FIGS. 6 (a) and 6 (b), the fourth focusing electrode 13d is also configured by combining two electrode members, so that the electrode member in the beading process of the electron gun assembling process. No need for welding.

Next, FIG. 7A shows a cross section of an electron gun according to another embodiment of the present invention. In this embodiment, the third focusing electrode 13c is configured by connecting four electrode members, and the intermediate electrode member in the above-described embodiment is thickened by bonding two plate members together. ing. In the case of the embodiment shown in FIG. 7B, the third focusing electrode 1 is also used.
3c is configured by connecting four electrode members, and the portion corresponding to the intermediate electrode member is also thickened by laminating the two electrode members.

Since the structure of the focusing electrode can be considered as appropriate, the present invention is not limited to the electron gun having the four focusing electrodes as in the above embodiment, and for example, a non-axisymmetric electron lens is provided on both sides of one focusing electrode. It can also be applied to those that form.

Further, the focusing correction electrode may be any one as long as it has a hole for position regulation in the intermediate portion, and is not limited to the three-body structure as described above. Further, the intermediate electrode member is not limited to the thick plate as described above, and may be, for example, a cup-shaped electrode similar to the both outer members. Also in the other embodiment shown in FIG. 7, all four electrodes may be cup-shaped electrodes.

[0015]

As described above, according to the present invention, with a simple structure using an intermediate member, the assembly accuracy can be significantly increased even by the position regulating method of the electron gun electrode by the conventionally used position regulating pin. A color picture tube which can be improved and has excellent image characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional configuration diagram of an electron gun according to an embodiment of the present invention.

FIG. 2 is a side view of a third focusing electrode forming the electron gun of FIG.

FIG. 3 is a view showing a hole overlapping relationship between a second focusing electrode and an outer electrode member of the third focusing electrode which form the electron gun of FIG.

FIG. 4 is a view exemplifying a hole shape formed in an outer electrode member of a third focusing electrode.

FIG. 5 is a view exemplifying a hole shape formed in an intermediate electrode member of a third focusing electrode.

FIG. 6 is a diagram showing an example in which the structure of a third focusing electrode is also applied to the fourth focusing electrode.

FIG. 7 is a cross-sectional configuration diagram of an electron gun according to another embodiment.

FIG. 8 is a sectional configuration diagram of a conventional electron gun.

[Explanation of symbols]

 11 Control Electrode 12 Accelerating Electrode 13a First Focusing Electrode 13b Second Focusing Electrode 13c Third Focusing Electrode 13d Fourth Focusing Electrode 14 Final Accelerating Electrode 18a, 18b, 18c Cathode 21,21 Outer Electrode Member 23 Intermediate Electrode Member

Claims (8)

[Claims] 1. An electron gun for a color picture tube in which three cathodes, a control electrode, an accelerating electrode, one or more focusing electrodes, and a final accelerating electrode, which are arranged in-line, are sequentially arranged in the tube axis direction. At least one of which is a focusing correction electrode which forms a non-axisymmetric electron lens on both sides, and which has a hole for regulating the position of the electrode in the intermediate portion of the focusing correction electrode. gun. 2. The focusing correction electrode is configured by combining at least three electrode members, which are an intermediate electrode member and both outer electrode members configured so as to sandwich the intermediate electrode member, and the intermediate electrode member has a position regulating hole. The electron gun for a color picture tube according to claim 1, further comprising: 3. The electron gun for a color picture tube according to claim 2, wherein the intermediate electrode member is a plate member thicker than the outer electrode members. 4. The color according to claim 1, wherein at least one of the holes for forming the non-axisymmetric electron lens on both sides of the focusing correction electrode is a rectangular hole. An electron gun for a picture tube. 5. The at least one of the holes for forming the non-axisymmetric electron lens on both sides of the focusing correction electrode has a wall surface standing in the tube axis direction from the peripheral portion of the hole. An electron gun for a color picture tube according to any one of claims 1 to 4. 6. The electron gun for a color picture tube according to claim 1, wherein a hole for restricting the position of the focusing correction electrode has a circular shape. 7. The hole shape for restricting the position of the focusing correction electrode has a non-circular shape, according to claim 1.
An electron gun for a color picture tube according to the item. 8. The electron gun for a color picture tube according to claim 3, wherein the intermediate electrode member of the focusing correction electrode is formed by bonding two plate members together. .