JPS6334582B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a delta-type color picture tube in which three electron guns are arranged at three vertices of an equilateral triangle.

Generally, in a delta-type color picture tube, a delta-arranged three
A cup-shaped body made of non-magnetic metal is attached to the collective tip of the book electron gun, and three pairs of radial pole pieces made of magnetic metal are attached to this cup-shaped body. To explain this using a drawing, as shown in FIG _.
The cup-shaped body 4 attached to the tip of the cup is made of non-magnetic metal, and as shown in FIG. Pair of radial pole pieces 6,
6'; 7, 7'; 8, 8' are installed inside.

3 pairs of radial pole pieces 6, 6'; 7,
Each pair of 7'; 8, 8' is excited by three dynamic convergence excitation devices 9, 10, 11 provided outside the tube facing them.
This excitation is obtained by passing an excitation current whose magnitude changes depending on the deflection angle of the electron beam through each winding 12, 13, and 14, and the correction magnetic field generated between the radial pole pieces, that is, as shown in FIG. The correction magnetic field indicated by the dashed arrow gives a dynamic convergence effect to the electron beam passing through it, and the electron beam, whose trajectory is bent thereby, concentrates on an arbitrary point on the phosphor screen. Reference numeral 15 indicates a glass bulb, and reference numeral 16 indicates an insulating column for supporting an electrode.

By the way, in the case of a normal raster scanning method in a television receiver, etc., if a correction excitation current of a magnitude corresponding to each position of an electron beam on a fluorescent screen is determined in advance, the excitation devices 9, 10, 11
The temporal change in magnetic flux caused by is constant at each position. The eddy current shown by reference numeral 17 in FIG. 3 and the resulting magnetic field 18 are also constant, but in the random scanning method used in graphic display devices, the electron beam is directed to a certain point on the phosphor screen. Since the deflection speed when deflecting to one point is not constant, the eddy current generated by the magnetic flux passing through the cup-shaped body 4 and the radial pole pieces 6, 6'; 7, 7'; 8, 8' and the magnetic field generated by this eddy current is no longer constant. For this reason, it is necessary to change the correction excitation current when deflecting the electron beam to a certain point on the phosphor screen according to the deflection speed, and the configuration of the circuit that generates the correction excitation current becomes extremely complicated. .

The present invention has been made with the above points in mind,
In the color picture tube of the present invention, a large number of notches are provided in multiple stages on the fixed edge of the radial pole piece and on the side wall of the cup-shaped body that accommodates the same in order to suppress the generation of eddy current. This will be explained in detail together with the embodiment shown in .

As shown in FIG. 4, a cup-shaped body 19 made of non-magnetic metal such as stainless steel is attached to the collective tip of three electron guns arranged in a delta arrangement.
has three axially long rectangular openings 20 in its side wall, and its internal space is divided into three sections by a magnetic shield 21 made of magnetic metal and having a Y-shaped cross section. Three pairs of radial pole pieces 22 made of magnetic metal are inserted one pair into each opening 20,
22'; 23, 23'; 24, 24' are opposed to each other within the section in each pair as before, but the cup-shaped body 19
As shown in FIG. 5, there are a number of elongated cuts 25, 2 extending laterally from both left and right sides of the opening 20 in the side wall, that is, along the circumferential direction of the side wall.
5' in multiple stages.

three pairs of radial pole pieces 22, 22';
23, 23'; 24, 24' each fixed edge 26, 2
6', a large number of elongated cuts 27, 27' are formed in multiple stages as shown in FIG. On the outside,
They are welded by electric welding or the like so that the notch 27 overlaps with the notch 25, and the notch 27' overlaps with the notch 25'. In addition, each radial pole piece 22, 22'; 23,
23'; wing-like free edges 28, 28' of 24, 24'
Also, a large number of notches 29, 29' are formed in multiple stages. Cuts 25, 25'; 27, 27':
Each width of 29 and 29' can be set to about 0.5 mm. Moreover, these cuts may be slit-shaped.

In the color picture tube of the present invention configured as described above, the side wall of the cup-shaped body has a large number of notches extending in the circumferential direction from the opening of the side wall in multiple stages, and the radial pole piece has Since the fixed edge has a large number of notches that overlap with the notches, the eddy current path at the fixed edge, which tends to generate eddy current even when magnetically coupled to a dynamic convergence excitation device, is blocked by the notches. It turns out. Therefore, the magnetic field generated by this eddy current becomes weak, making it possible to accurately and easily apply an optimal correction magnetic field to the electron beam regardless of the deflection speed, especially in a set that uses a random scanning method. It has excellent practical effects.

[Brief explanation of the drawing]

Figure 1 is a side view of a conventional color picture tube showing the electron gun, Figure 2 is a cross-sectional view of the color picture tube, and Figure 3 is the eddy current generated in a pair of radial pole pieces of the color picture tube. FIG. 4 is a perspective view of the main parts of a color picture tube embodying the present invention, FIG. 5 is a side view of the cup-shaped body of the color picture tube, and FIG. 6 is a perspective view of the color picture tube according to the present invention. FIG. 3 is a perspective view of a radial pole piece of a tube. 1, 2, 3... Electron gun, 4, 19... Cup-shaped body, 6, 6'; 7, 7'; 8, 8'; 22, 22';
23, 23'; 24, 24'; Radial pole piece, 25, 25'; 27, 27'; 29, 29';
...notch.

Claims (1)

[Claims] 1 A cup-shaped body made of non-magnetic metal attached to the collective tip of three electron guns in a delta arrangement has three axially long openings on the side wall, and is excited by a dynamic convergence excitation device. Each pair of three pairs of radial pole pieces made of magnetic metal, each having a wing-shaped free edge protruding into the cup-shaped body through the corresponding one of the openings, and each pair is welded to the outer surface of the side wall. In a color picture tube having a fixed edge, the side wall has a plurality of notches extending in a circumferential direction from the opening in multiple stages, and the fixed edge has a plurality of notches overlapping the notches in multiple stages. A color picture tube characterized by having: