JP3045736B2 - Color picture tube equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube provided with a top unit for dynamic convergence at the tip of an in-line type electron gun, and a horizontal picture tube attached to the color picture tube. A deflection yoke for generating a vertical deflection magnetic field, and a pair of U-shaped cores provided opposite to each other on an outer peripheral surface of a neck portion of the color picture tube and wound with an exciting coil; The present invention relates to a color picture tube device.

2. Description of the Related Art Generally, in driving a color picture tube equipped with an in-line type electron gun, a horizontal deflection magnetic field is provided in a pincushion shape and a vertical deflection magnetic field is provided in order to achieve a so-called self-convergence configuration which does not require a dynamic convergence circuit. Each is distorted in a barrel shape.

However, such non-uniform horizontal and vertical deflection magnetic fields
Since deflection distortion is given to the electron beam passing through the same magnetic field,
The cross-sectional shape of the electron beam, and thus the beam spot, is distorted non-circularly, making it impossible to obtain good resolution especially at the periphery of the screen.

Therefore, in a color picture tube device for industrial equipment that requires particularly high resolution, a deflection yoke that generates almost uniform horizontal and vertical deflection magnetic fields is installed even though it is a color picture tube with an in-line type electron gun. The configuration is such that misconvergence caused thereby is corrected by dynamic convergence means.

In this case, since the horizontal and vertical deflection magnetic fields provided by the deflection yoke are substantially uniform, the vertical red line R and blue line B appearing on the screen are curved in opposite directions due to misconvergence as shown in FIG. And a mismatch occurs.
The dynamic convergence means for correcting this is, as shown in FIGS. 5 and 6, a dynamic convergence top unit 2 provided at the tip of the in-line type electron gun 1.
A magnetic field for correction is applied to a pair of magnetic pieces 3, 4, 5, 6 from a pair of U-shaped cores 7, 8 provided outside the tube. A pair of cores 7 and 8 are provided opposite to each other on the outer peripheral surface of the neck portion of the color picture tube, and the exciting coils 9 and 9 respectively wound therearound are provided.
The parabolic wave current for correction flows in 10 in synchronization with the horizontal deflection or the vertical deflection, so that it is contradictory between the pair of magnetic pieces 3 and 4 of the top unit 2 and between the pair of magnetic pieces 5 and 6. Correction magnetic fields 11 and 12 are generated in the directions, respectively, and the above-described misconvergence is dynamically corrected.

The electron beam path 13 at the center is horizontally sandwiched by a pair of magnetic shield plates 14 and 15 formed of strip-shaped magnetic material pieces, and the electron beam paths 16 and 17 on both sides are formed by a pair of magnetic material. The inner edges 3a, 4a of the pieces 3, 4 and the inner edges 5a, 6a of the pair of magnetic pieces 5, 6 are vertically sandwiched, respectively. Each outer edge 3b, 4b of the pair of magnetic pieces 34 is bent outward to face the protruding end faces of both legs of the U-shaped core 7, and the pair of magnetic pieces 5, 6 Each outer edge 5
Also, b and 6b are bent outward and face the protruding end surfaces of both legs of the U-shaped core 8. Reference numeral 18 denotes a bottomed cylindrical unit case made of a nonmagnetic metal.

Problems to be Solved by the Invention In the conventional color picture tube device configured as described above,
Although the intended purpose can be achieved almost completely, a considerable amount of leakage magnetic field is generated when the magnetic field is supplied from the U-shaped core to the magnetic piece, which is disadvantageous not only in terms of efficiency but also this leakage magnetic field Electron beam on both sides as shown
Since the astigmatism is given to B and R, there is a problem that the beam spot is distorted non-circularly. Further, there is another problem that the beam spot of the center electron beam G is distorted by astigmatism as shown in FIG. 8 due to the leakage magnetic field before and after the pair of magnetic shield plates 14 and 15 in the tube axis direction.

Means for Solving the Problems According to the present invention, the length of the outer end edge of the magnetic piece in the tube axis direction is U
The thickness of the core is greater than the thickness of the U-shaped core, the length of the inner edge in the tube axis direction is smaller than the length of the outer edge in the tube axis direction, and the length of the magnetic shield plate in the tube axis direction is the inner end. Make it larger than the length of the edge in the tube axis direction.

With this configuration, not only can the magnetic field be efficiently supplied from the U-shaped core to the magnetic piece, but also the cross-sectional shape of the electron beam and thus the beam spot can be distorted into a non-circular shape due to astigmatism due to the leakage magnetic field. Is reduced, and the resolution can be further improved.

Next, the present invention will be described with reference to embodiments shown in the drawings.

The configuration shown in FIGS. 1 to 3 is different from the conventional configuration described above in that the tubes of the outer edges 3b, 4b, 5b, and 6b of the two pairs of magnetic pieces 3, 4, 5, and 6 are provided. The axial length is the U-shaped core 7,8
The thickness of each inner edge 3a, 4a, 5a, 6a in the tube axis direction is smaller than the length of each outer edge 3b, 4b, 5b, 6b in the tube axis direction. And the length of each magnetic shield plate 14, 15 in the tube axis direction is larger than the length of each inner edge 3a, 4a, 5a, 6a in the tube axis direction, and other configurations remain unchanged. .

When the thickness of each core 7, 8 is 5 mm, each outer edge 3b, 4b, 5b, 6
The length of b in the axial direction and the length of each of the magnetic shield plates 14 and 15 in the axial direction can be set to 10 mm, and the lengths of the inner edges 3a, 4a, 5a and 6a in the axial direction can be set to 6 mm. However, the tube axial length of each outer edge 3b, 4b, 5b, 6b is more than 1.1 times the thickness of each core 7, 8 and the tube axial length of each inner edge 3a, 4a, 5a, 6a. And, if the tube axial length of each magnetic shield plate 14, 15 is set to be 1.1 times or more the tube axial length of each inner edge 3a, 4a, 5a, 6a, respectively, the original purpose is achieved. be able to.

With this configuration, not only is the magnetic field supplied from the U-shaped cores 7, 8 to the two pairs of magnetic pieces 3, 4, 5, 6 efficiently, but also the leakage magnetic field generated during the supply process and the magnetic shield plate And the magnetic field leaking over the beam spot is reduced, and the distortion of the beam spot shape due to the astigmatism as described above can be reduced.

As described above, according to the present invention, it is possible to reduce the occurrence of astigmatism due to the leakage magnetic field when applying the dynamic convergence means, and to display a high quality image over the entire phosphor screen surface. be able to.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a main part of a color picture tube apparatus embodying the present invention, FIG. 2 is a side view of the main part, FIG. FIG. 4 is a pattern diagram for explaining misconvergence generated on a screen by using a deflection yoke for generating substantially uniform horizontal and vertical magnetic fields, FIG. 5 is a side view of a part of a conventional color picture tube device, and FIG. The figure is the front view,
7 and 8 are diagrams for explaining the relationship between astigmatism due to a leakage magnetic field and the beam spot shape. 1 ... Electron gun, 2 ... Top unit for dynamic convergence, 3,4,5,6 ... Magnetic piece, 7,8 ... U-shaped core, 14,15 ... Magnetic shield plate.

Continuation of the front page (72) Inventor Noboru Tominaga 1006 Kazuma Kadoma, Kazuma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-61-54785 (JP, A) JP-A-50-133827 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01J 29/54 H01J 29/50

Claims (1)

(57) [Claims] A color picture tube having a deflection yoke for generating substantially uniform horizontal and vertical deflection magnetic fields is provided with a top unit for dynamic convergence at the tip of an in-line type electron gun, and a neck of the color picture tube is provided. A pair of U-shaped cores provided opposite to each other on the outer peripheral surface of the unit are respectively wound with exciting coils, and the top unit horizontally sandwiches the center electron beam path.
A pair of magnetic shield plates, and two pairs of magnetic material pieces vertically sandwiching each of the electron beam paths on both sides by inner edges, and the outer edges of each pair of the magnetic material pieces are U-shaped. In the color picture tube device which is bent outward to face the protruding end faces of both legs of the core, the length of the outer end edge of the magnetic material piece in the tube axis direction is made larger than the thickness of the core. The length of the inner edge in the tube axis direction is smaller than the length of the outer edge in the tube axis direction, and the length of the magnetic shield plate in the tube axis direction is larger than the length of the inner edge in the tube axis direction. A color picture tube device characterized by the following.