JPH047060B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a color television receiver.
The convergence correction circuit can be omitted,
The present invention also relates to a color picture tube structure having an in-line electron gun that can reduce the amount of pin distortion correction.

Technical Background and Problems of the Invention In a color picture tube having an in-line array of electron guns, as shown in FIG. This has the advantage of reducing color shift between beams and simplifying the convergence correction circuit.

However, as mentioned above, since a nonuniform magnetic field is used, there is a drawback that the deflection sensitivity for the center beam 4 is worse than the deflection sensitivity for the side beams 3 and 5. A pattern is obtained. In FIG. 2, b is a rectangular pattern formed by side beams 3 and 5;
7 is a rectangular pattern formed by the central beam 4.
This phenomenon is called "coma aberration". In order to correct this, conventionally magnetic field control elements 8, 9, 10 and 11 as shown in FIG.
It is provided immediately after 3 and 14.

In FIG. 3, magnetic field control elements 8 and 9 work to weaken the horizontal and vertical deflection magnetic fields near the side beam emission holes 12 and 14 and strengthen the vertical deflection magnetic field near the central beam emission hole 13.

Further, the magnetic field control elements 10 and 11 act to strengthen the horizontal deflection magnetic field near the central beam emission hole 13.

As a result, the deflection sensitivity for the side beams 3 and 5 is worse than the deflection sensitivity for the center beam 4, and the deterioration in the deflection sensitivity of the center beam 4 due to the non-uniform deflection magnetic field is compensated for, and the coma aberration is not reflected on the screen. You will get a pattern that does not exist.

In addition, if the type of deflection yoke and magnetic field distribution are varied in an attempt to omit the convergence correction circuit or to reduce the amount of pincushion distortion correction, it is possible to achieve the above goals by using a deflection yoke and an in-line array electron gun. The pattern of comatic aberration for a combination of color picture tubes is not necessarily a pattern as shown in FIG. 2, but may be a pattern as shown in FIG. 4a or b.

In Fig. 4, 6a and 6b are both side beams 3,
5 is a rectangular pattern, and 7a and 7b are rectangular patterns by the central beam 4.

When correcting comatic aberration as shown in FIG. 4a, magnetic field control elements 15 to 15 as shown in FIG.
22 may be provided immediately after the electron beam emitting holes 12, 13 and 14 of the electron gun. In the figure, portions 19, 20, 2 of magnetic field control elements 15 and 16
1 and 22 act to weaken the vertical deflection magnetic field near the side beam emission holes 12 and 14 and strengthen the vertical deflection magnetic field near the central beam emission hole 13.

Further, the magnetic field control elements 17 and 18 act to strengthen the horizontal deflection magnetic field near both side beam emission holes 12 and 14 and weaken the horizontal deflection magnetic field near the central beam emission hole 13.

As a result, the vertical deflection sensitivity for the center beam 4 becomes higher than the vertical deflection sensitivity for both side beams 3 and 5, and the horizontal deflection sensitivity for the center beam 4 becomes lower than the horizontal deflection sensitivity for both side beams 3 and 5. By correcting coma aberration as shown in FIG. 4a, a pattern free of coma aberration can be obtained on the screen.

However, when the amount of correction of the left and right coma aberrations is extremely large as shown in FIG. 4b, the left and right coma aberrations cannot be completely corrected by the magnetic field control element shown in FIG. The first reason for this is that the shielding effect of the horizontal deflection magnetic field on the center beam 4 in the magnetic field control elements 15 and 16 and 17 and 18 is poor. Second, the magnetic field control element portions 19, 20,
The problem is that the focusing effect of the magnetic flux of the horizontal deflection magnetic field on the side beams 3 and 5 of 21 and 22 is poor. Therefore, another magnetic field control element is required to correct the coma aberration of the pattern shown in FIG. 4b.

OBJECTS OF THE INVENTION It is an object of the present invention to eliminate the drawbacks of the prior art described above, and to provide a combination of a color picture tube and a deflection yoke with different deflection sensitivities for both side beams and for the center beam. An object of the present invention is to provide a color picture tube with a deflection magnetic field control element that eliminates differences in deflection sensitivity.

SUMMARY OF THE INVENTION The present invention provides a color picture tube having an in-line array of electron guns, in which a magnetic field control element including a part extending in the direction of a vertical deflection magnetic field and a part extending in the direction of a horizontal deflection magnetic field is provided near the electron beam emission hole of the electron gun. In addition, in the part extending in the direction of the horizontal deflection magnetic field, the interval between the parts facing each other with the central beam emission hole in between is as follows.
The portions facing each other at the upper and lower ends are made smaller than the portions facing each other at the center, thereby making the shielding effect of the horizontal deflection magnetic field in the vicinity of the central beam emission hole more effective.

Embodiment of the Invention FIG. 6 is a front view showing an embodiment of a color picture tube with a deflection magnetic field control element according to the present invention.

In FIG. 6, reference numerals 12 and 14 indicate both side beam emission holes of the electron gun, and 13 indicates a central beam emission hole. Further, 23 and 24 are deflection magnetic field control elements applied to the present invention, and 25 to 30 indicate respective parts of the magnetic field control element. With such a configuration, much of the magnetic flux of the horizontal deflection magnetic field near the central beam emission hole 13 is converged by the portions 25 and 26 of the magnetic field control elements 23 and 24, so that the deflection of the prior art shown in FIG. Magnetic field control elements 15 and 16
The strength of the horizontal deflection magnetic field near the central beam emission hole 13 is considerably sparser than that of the horizontal deflection magnetic field. Therefore, the magnetic field control elements 23 and 2 according to the invention shown in FIG.
4 functions to further weaken the horizontal deflection sensitivity of the central beam 4 compared to the prior art magnetic field control elements 15 and 16 shown in FIG. 5, and even coma aberration as shown in FIG. 4b can be easily corrected. I can do it. An example of the relationship between the deflection magnetic field control element and the horizontal deflection magnetic field strength _BH in this case is shown in FIG. In FIG. 7, 31, 32 and 33 on the horizontal axis indicate each beam emission hole 12,
13 and 14, 34 indicates the horizontal deflection magnetic field strength near the beam emission hole produced by the conventional deflection magnetic field control element shown in FIG. 5, and 35 indicates the horizontal deflection magnetic field intensity produced by the deflection magnetic field control element applied to the present invention. It shows.

Effects of the Invention The conventional coma aberration correction deflection magnetic field control element shown in FIG. 5 could only correct the coma aberration in the pattern shown in FIG.
It is possible to correct even a pattern in which left and right coma aberration is extremely large, as shown in FIG. Therefore, it has a great effect on reducing the cost and improving the reliability of color television receivers.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a deflection magnetic field of a color picture tube having an in-line array of electron guns, and FIG. 2 is a schematic diagram showing a conventional coma aberration pattern when no deflection magnetic field control element for coma aberration correction is used. Fig. 3 is a schematic diagram showing a coma aberration correction deflection magnetic field control element when correcting a conventional coma aberration pattern, Fig. 4a
and b are schematic diagrams showing patterns of coma aberration that tend to appear when a deflection magnetic field control element for coma aberration correction is not used; FIG. 5 is a schematic diagram showing a conventional deflection magnetic field control element for coma aberration correction; The figure is a schematic diagram showing one embodiment of the deflection magnetic field control element applied to the present invention, and FIG. 7 is a characteristic diagram showing the horizontal deflection magnetic field strength in FIGS. 5 and 6. 3, 5...Side beam, 4...Central beam, 1
2, 14... Side beam emission hole, 13... Central beam emission hole, 8-11, 15-30... Deflection magnetic field control element.

Claims (1)

[Claims] 1. In a color picture tube having an electron gun in which a deflection magnetic field control element made of two magnetic materials is provided near the electron beam emission hole of an in-line array electron gun, the side parallel to the vertical deflection magnetic field of the deflection magnetic field control element is Sides located near the upper and lower ends of both side beam emission holes of the electron gun and parallel to the horizontal deflection magnetic field of the deflection magnetic field control element are arranged at the left and right ends of the central beam emission hole of the electron gun, respectively, and the horizontal A color picture tube characterized in that the distance between opposing parts across a central beam emission hole on sides parallel to the deflection magnetic field is smaller at the upper and lower ends than at the center.