JPH04322040A - Color picture tube - Google Patents

Abstract

PURPOSE:To easily fix a magnetic body to an electrode of an electron gun in a predetermined direction by constituting a given electrode of a plurality of divided electrodes arranged adjacent to each other in the tube axial direction, and interposing the magnetic body between the divided electrodes. CONSTITUTION:A fifth grid of an electron gun 20 comprises four cupshaped divided electrodes G51-G54 adjacent to each other in the tube axial direction, where a gap 25 is formed between the electrodes G52, G53. An annular magnetic body 24 is inserted into the gap 25, and it is held at both ends of the horizontally elliptical electrodes G52, G53 in the horizontal direction. Accordingly, the magnetic body 24 can be precisely arranged with ease within a plane perpendicular to the traveling direction of electron beams 22G, 22B, 22R. Stationary convergence and color purity of the three electron beams 22G, 22B, 22R can be accurately adjusted without changing a magnetic characteristic of the magnetic body 24. Consequently, the magnetic body 24 can be easily arranged on the plane perpendicular to the traveling direction of the electron beams in the case where it is fixed to the electrode of the electron gun 20.

Description

[Detailed description of the invention]

[Object of the invention]

0002

[Industrial Application Field] This invention relates to color picture tubes, and in particular, by attaching a magnetic material to an electron gun and magnetizing this magnetic material from outside the neck, quiet convergence and color purity on a phosphor screen can be achieved. Related to color picture tubes for adjusting etc.

0003

2. Description of the Related Art Generally, a color picture tube has an envelope consisting of a panel 1 and a funnel 2 integrally joined to the panel 1, as shown in FIG. 6(a). 3 emitted from an electron gun 4 located at
Electron beams 5B, 5G, and 5R are deflected by a magnetic field generated by a deflection yoke 6 mounted on the outside of the funnel 2, and formed on the inner surface of the panel 1 through a shadow mask 7 arranged inside the panel 1. By horizontally and vertically scanning the phosphor screen 8, a color image is displayed on the phosphor screen 8.

In order to improve the quality of the color image drawn on the phosphor screen 8, three electron beams 5B, 5G, and 5R emitted from the electron gun 4 are concentrated at one point on the phosphor screen 8 ( static convergence) and 3
It is necessary for the electron beams 5B, 5G, and 5R to properly land on the three-color phosphor layers constituting the phosphor screen 8 so that a predetermined color purity can be obtained. However, in the actually manufactured color picture tube, due to assembly errors of the electron gun 4 and the assembly error of the color picture tube itself, the three electron beams 5B, 5G, and 5R are concentrated, and the three electron beams 5B, 5B, and 5R are not focused on the three color phosphor layers. The landing of 5G and 5R will be shifted, and the screen quality will deteriorate.

[0005] Therefore, a magnet is attached to an ordinary color picture tube in order to correct its static convergence and landing deviation. In the color picture tube shown in FIG. 6(a), the magnet 9 is attached to the outside of the neck 3. Normally, this magnet 9 has two poles and four poles along the periphery of the annular magnetic body.
It consists of three sets of permanent magnets, one set of two magnets forming a pole and six poles, and by rotating each set of magnets and appropriately shifting the two sets of magnetic poles in the circumferential direction, It is used to adjust convergence and color purity.

However, adjusting the static convergence and color purity using three sets of permanent magnets (one set of two magnets) not only requires skill and a considerable amount of time, but also requires experience. Because of this, it is difficult to make accurate and sufficient adjustments.

[0007] To compensate for this problem caused by external magnets, Japanese Patent Laid-Open Nos. 52-117512 and 1982-1
No. 8235, US Pat. No. 4,162,470, and US Pat. No. 4,138,628, etc.,
As shown in FIG. 6(b), 1
Attach more than one magnetizable annular magnetic body 11, and polarize and magnetize the annular magnetic body 11 from the outside of the neck 3 into 2 poles, 4 poles, 6 poles, 12 poles, etc. to improve static convergence and color purity. There is a color picture tube to adjust.

Conventional methods for attaching the magnetic material 11 of this color picture tube include a method in which a metal piece 13 is welded to the outer peripheral surface of the electrode 12, as shown in FIG. 7(a);
There is also a method of welding the magnetic material 11 directly to the outer circumferential surface of the electrode 12, as shown at point (14) in FIG.

By the way, regarding the installation of the magnetic material 11, (a) In order to adjust the static convergence and color purity more accurately, it is necessary to install the magnetic material perpendicularly to the tube axis (Z-axis) (progressing direction of the electron beam). (b) When the magnetic material attached to the electrode approaches the inner surface of the neck, spark discharge occurs between the magnetic material and the inner surface of the neck when the color picture tube is operated, and the color picture tube is driven. This may destroy the circuit or, due to the spark discharge, change the magnetization properties of the magnetic material that is magnetized to optimally correct static convergence and color purity, resulting in insufficient adjustment of static convergence and color purity. Therefore, it is necessary to install it as far away from the inner surface of the neck as possible.

0010

[Problem to be Solved by the Invention] As mentioned above, in order to adjust the static convergence and color purity of a color picture tube,
Attach one or more magnetizable annular magnetic bodies to the outer circumferential surface of the electron gun electrode, and adjust the annular magnetic bodies by polarizing them from outside the neck into 2 poles, 4 poles, 6 poles, 12 poles, etc. There is a color picture tube. The magnetic material can be attached by welding a metal piece to the outer circumferential surface of the electrode, or by welding the magnetic material directly to the outer circumferential surface of the electrode.
Whichever method is used for mounting, it is necessary to place the magnetic material on a plane perpendicular to the tube axis and to mount it as far away from the inner surface of the neck as possible to prevent spark discharge.

However, in the method of attaching the metal pieces by welding, it is difficult to accurately arrange the magnetic material on a plane perpendicular to the tube axis, and in addition, it is difficult to weld the metal pieces to the electrodes.
Because the metal pieces come close to the inner surface of the neck, spark discharge is likely to occur. Furthermore, there are other problems such as the need for a metal piece to attach the magnetic material. On the other hand, with the method of directly welding the magnetic material to the outer circumferential surface of the electrode, it is difficult to place the magnetic material accurately on a plane perpendicular to the tube axis, and depending on the shape of the magnetic material, many spot welds are required. There are problems such as affecting the magnetization characteristics of the magnet. Furthermore, no matter which method is used for attachment, since the magnetic body is located on the outer circumferential surface of the electrode, it can easily approach the inner surface of the neck. Particularly when the outer diameter of the electrode is larger than the inner diameter of the neck, it becomes impossible to arrange the magnetic body.

The present invention was made to solve the above problems, and when attaching a magnetic material to the electrode of an electron gun, it is easy to attach the magnetic material to the tube axis, that is, on a plane perpendicular to the traveling direction of the electron beam. It is an object of the present invention to configure a color picture tube such that it can be arranged and located away from the inner surface of the neck.

[Configuration of the invention]

[0014]

[Means for Solving the Problems] An electron gun consisting of a cathode and a plurality of electrodes arranged successively adjacent to the cathode is arranged in the neck, and at least one magnetizable electrode is arranged in a predetermined electrode of the electron gun. A ring-shaped magnetic body is attached,
In a color picture tube that corrects the trajectory of an electron beam emitted from the electron gun by magnetizing the magnetic material, the predetermined electrode is composed of a plurality of divided electrodes located adjacent to each other in the tube axis direction, A magnetic material was inserted between the divided electrodes.

[0015]

[Operation] As mentioned above, if the electrode for attaching the magnetic material is composed of multiple divided electrodes located adjacent to each other in the tube axis direction, and the magnetic material is inserted between the divided electrodes, the magnetic material can be easily inserted into the tube. It can be placed on a plane perpendicular to the axis, and can be fixed between the divided electrodes with a minimum number of welding points so as not to affect the magnetization characteristics. Furthermore, it becomes possible to arrange the magnetic body away from the inner surface of the neck, and on the other hand, it becomes possible to bring it closer to the trajectory of the electron beam, thereby making it possible to correct the trajectory of the electron beam with high precision using a smaller magnetic field.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments with reference to the drawings.

FIG. 1 shows a color picture tube which is one embodiment of the present invention. This color picture tube has an envelope consisting of a panel 1 and a funnel 2 integrally joined to the panel 1, and a shadow mask 7 disposed inside the panel 1 in which a large number of electron beam passage holes are formed. A phosphor screen 8 consisting of three color phosphor layers emitting blue, green, and red light is formed on the inner surface of the panel 1 opposite to the phosphor screen 8 . Further, an electron gun 20 is disposed within the neck 3 of the funnel 2. In addition,
6 is a deflection yoke attached to the outside of the funnel 2.

The electron gun 20 has a center beam 22G and a pair of side beams 22B passing on the same horizontal plane.
, 22R arranged in a row, 3 electron beams 22G
, 22B, 22R, and has three cathodes K arranged in a row as shown in Figure 2.
(only one heater is shown in the drawing), three heaters H for heating each cathode K, and a tube shaft (
The first to sixth grids G1 to G6 arranged at predetermined intervals in the direction of the phosphor screen along the Z-axis and the convergence grid attached to the sixth grid G6.
Consists of cup C. The first to third grid G1~
G3 consists of plate electrodes each having an oval shape long in the horizontal direction, and the fourth to sixth grids G4 to G6 each consist of cylindrical electrodes having an oval shape long in the horizontal direction. , three electron beam passing holes are formed in a row in the horizontal direction, corresponding to the three cathodes K.

In particular, the fifth grid G5 of this electron gun 20 has four cup-shaped divided electrodes G5 adjacent to each other in the tube axis direction.
1 to G54, and its divided electrodes G52 and G
53 means that there is a gap 2 between them as shown in Figure 3.
5 is provided, and an annular magnetic body 24 shown in FIG. 4 is inserted into the gap 25. That is, a horizontally long oval-shaped divided electrode G52
, G53, the magnetic body 24 is divided into electrodes G5
2. It is formed into an annular shape with an outer diameter approximately equal to the horizontal major axis of G53, and is held between the horizontal ends of both split electrodes G52 and G53, and in order to ensure the fixation by this holding, the minimum Split electrode at welding point G52, G5
It is welded to 3. The inner diameter of this magnetic body 24 is such that when it is placed between the divided electrodes G52 and G53 as described above, it does not block the electron beam passing through the inside of these divided electrodes G52 and G53.

Note that this magnetic material 24 is attached in advance when assembling the electron gun, and after the electron gun is sealed in the neck and evacuated to produce a color picture tube, the magnetic material 24 is attached.
A magnetizing device is disposed outside the neck corresponding to No. 4, and magnetic poles necessary for convergence shift and color purity correction are formed.

By the way, if the predetermined electrode on which the magnetic material 24 is to be arranged is composed of a plurality of divided electrodes adjacent to each other in the tube axis direction as described above, and the magnetic material 24 is inserted between the divided electrodes, the electron beam Since the magnetic body 24 can be accurately and easily arranged in a plane perpendicular to the traveling direction of the magnetic bodies 22G, 22B, and 22R, and the magnetic body 24 can be securely fixed with a minimum number of welding points, the magnetization of the magnetic body 24 can be reduced. 3 electron beams 22G, 22B, 22R without changing the characteristics
It is possible to accurately correct static convergence and color purity. In addition, compared to the conventional arrangement of magnetic materials, it is possible to position them closer to the electron beams 22G, 22B, 22R, so static convergence and color purity can be adjusted with less magnetic field, and they can be placed farther away from the inner surface of the neck. By locating the color picture tube in the opposite direction, sparks are less likely to occur during operation of the color picture tube.

In the above embodiment, the magnetic material 24 was formed in an annular shape, but as shown in FIG. It may be formed in other shapes that do not block the area. Further, the magnetic body does not necessarily have to have a circular cross section, and may have another shape such as a plate shape.

Furthermore, in the above embodiment, a case has been described in which one magnetic body is inserted between the divided electrodes, but a plurality of magnetic bodies may be inserted between the divided electrodes. Further, it can be fixed not only between divided electrodes but also between adjacent electrodes having a potential difference.

Furthermore, although the above embodiments have been described with reference to the case where static convergence and color purity are adjusted, the present invention is applicable not only to static convergence and color purity adjustment, but also to correction of aberrations caused by axis deviation of electron beams. In short, it can be used to correct the orbit of the electron beam.

[0025]

Effects of the Invention: A color picture tube in which at least one magnetizable annular magnetic body is attached to a predetermined electrode of an electron gun, and the magnetic body is magnetized to correct the trajectory of an electron beam emitted from the electron gun. In this case, if the above-mentioned predetermined electrode is composed of a plurality of divided electrodes located adjacent to each other in the tube axis direction, and a magnetic material is inserted between the divided electrodes, the magnetic material can be easily aligned orthogonally to the traveling direction of the electron beam. It can be placed on a flat surface, fixed between divided electrodes with a minimum number of welding points so as not to affect magnetization characteristics, and can accurately correct static convergence, color purity, etc. In addition, by placing the magnetic material closer to the electron beam trajectory, it is possible to correct the electron beam trajectory with less magnetic field, and by placing the magnetic material away from the inner surface of the neck, sparks can be reduced when the color picture tube operates. This can be made less likely to occur.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a color picture tube that is an embodiment of the present invention.

FIG. 2 is a diagram showing the configuration of an electron gun to which the magnetic material is attached.

FIG. 3 is a perspective view illustrating a divided electrode to which a magnetic material of the electron gun is attached.

FIG. 4 is a perspective view of a magnetic body attached to the divided electrodes.

FIG. 5 is a perspective view of magnetic bodies having different shapes.

FIG. 6 is a diagram showing the configuration of a conventional color picture tube;
Figure 6 (a) is a block diagram of a color picture tube with magnets installed outside the neck to adjust static convergence and color purity;
) is a configuration diagram of a color picture tube in which a magnetic material is placed inside the neck.

FIGS. 7(a) and 7(b) are diagrams showing a method of attaching the magnetic body.

[Explanation of symbols]

2...Funnel 3...Neck 8...phosphor screen 20...electron gun 24...Magnetic material H...Heater G1...1st grid G2...Second grid G3…3rd grid G4…4th grid G5...5th grid G6…6th grid G51 ~ G54...Divided electrode K...Cathode

Claims (1)

[Claims] 1. An electron gun consisting of a cathode and a plurality of electrodes arranged sequentially adjacent to the cathode is disposed in the neck, and at least one electrode is connected to a predetermined electrode of the electron gun.
In a color picture tube, a magnetizable annular magnetic body is attached, and the magnetic body is magnetized to correct the trajectory of the electron beam emitted from the electron gun. 1. A color picture tube comprising a plurality of divided electrodes located at the same distance, and the above-mentioned magnetic material being interposed between the divided electrodes.