JPS62140342A - Color picture tube device - Google Patents

Abstract

PURPOSE:To make the trilemma of a color picture tube to zero low-costly and without increasing the deflection power so as to obtaine good convergence characteristics by providing a pair of notches on the end portion of the electron gun side of the circular core of a deflection yoke of a color picture tube provided with an in-line type electron gun so as to be faced to each other symmetrically to the vertical plane including the tube axis. CONSTITUTION:The circular core 1 made of ferrite of a color picture tube provided with an in-line type electron gun is formed like a funnel as a whole and has a pair of rectangular notches 2a, 2b on the end portion of the electron gun side. This pair of notches 2a, 2b are faced to each other so as to be symmetrical to the vertical plane including the tube axis 0 and the vertical axis Y. The deflection yoke obtained by assembling conventionally the horizontal and the vertical deflection coil generating the horizontal deflection magnetic field of pincushion distribution and the vertical deflection magnetic field of barrel type distribution respectively on such a circular core is attached to the color picture tube, and a pair of correction coils for vertical coma aberration are attached to the electron gun side of the deflection yoke.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an in-line electron gun, a deflection yoke attached to the picture tube, and a vertical coma aberration correction coil provided on the electron gun side of the deflection yoke. The present invention relates to a color picture tube device consisting of the following.

2. Description of the Related Art In general, a deflection yoke attached to a color picture tube equipped with an in-line electron gun is formed to generate a horizontal deflection magnetic field with a pincushion-like distribution and a vertical deflection magnetic field with a barrel-like distribution. For this reason, a so-called self-convergence configuration is possible, and a complicated convergence circuit is not required. However, when distorted horizontal and vertical deflection magnetic fields are applied to the electron beam, the electrons at the center are distorted as shown in Figure 5. Misconvergence (coma aberration) occurs in which the green raster G produced by the beam does not match the red and blue rasters R and B produced by the electron beams on both sides.

As a countermeasure to this problem, as disclosed in Japanese Patent Publication No. 55-7658, etc., a plurality of small magnetic pieces called enhancer shunts are attached to the tip of an in-line electron gun, and the deflection magnetic field is directed toward the electron gun side. A method has been proposed to adjust the magnetic field distribution. However, it is not easy to accurately make a plurality of small magnetic pieces and attach the bracket to the tip of an electron gun with high precision, which tends to cause variations in the characteristics of the device.

Therefore, another correction method has been proposed in which the distribution of the deflection magnetic field on the electron gun side is locally distorted to the opposite polarity.

In this case, as shown in Fig. 6, a pair of magnetic pieces P, P2 are pasted on the left and right sides of the electron gun side of the horizontal deflection coil channel that generates a horizontal deflection magnetic field with a pincushion-like distribution, and the horizontal deflection magnetic field H is The electron gun side is locally distorted to have a barrel tendency as shown in the figure, so that the center electron beam g becomes Fg, and both side electron beams r and b become Fr.
, Fb (F r = F b <
F g ), horizontal deflection coma aberration can be eliminated. Further, as shown in FIG. 7, a pair of vertical coma aberration correction coils S1 are provided on the electron gun side of the vertical deflection coils that generate vertical deflection magnetic fields with a barrel-like distribution. When Sz is provided and a vertical deflection current is passed through it to locally generate a magnetic field V with a pincushion-like distribution, three electron beams g and r are generated.

The forces of Fg, Fr, and Fb act on b, respectively (Fr-
Fb<Fg), vertical coma aberration can also be eliminated. In addition, each coil Sj, Ss has a U-shaped core U.
and a winding C wound around both legs.

Problems to be Solved by the Invention However, it is necessary to attach the above-mentioned vertical coma aberration correction coil to a small color picture tube with a screen diagonal length of about 14 inches, and to generate a pincushion distributed magnetic field to the extent that coma aberration is eliminated. If it is strengthened, the amount of overhang of the vertical deflection magnetic field toward the electron gun side becomes excessive, and cross-convergence due to a positive trilemma occurs. Note that if the amount of horizontal and vertical deflection magnetic fields that extend toward the electron gun is appropriate, the trilemma (cross convergence) can be reduced to zero, and the smaller the picture tube is, the more electrons in the vertical deflection magnetic field will be It is necessary to make the amount of overhang toward the gun side smaller than the overhang of the horizontal deflection magnetic field toward the electron gun side.

Therefore, it is conceivable to reduce the distance between the legs of the U-shaped core U and reduce the number of turns of the winding C to reduce only the magnetic flux density without changing the degree of pincushion distribution distortion. Even if we do this, a positive trilemma remains. Furthermore, if the annular core of the deflection yoke is biased toward the phosphor screen side or if the annular core is shortened on the electron gun side, the power required for horizontal and vertical deflection increases.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a color picture tube device that is easy to manufacture, does not require an increase in deflection power, and can reduce the trilemma to zero.

Means for Solving the Problems The present invention provides a color picture tube including an in-line electron gun in which three beam emission ports are arranged in a horizontal plane including the tube axis, and a color picture tube that is attached to the color picture tube. a deflection yoke that generates a horizontal deflection magnetic field with a pincushion-like distribution and a vertical deflection magnetic field with a barrel-like distribution, and a pair of vertical coma aberrations arranged so as to face each other across the horizontal plane on the electron gun side of the deflection yoke. In a color picture tube device comprising a correction coil, a pair of notches are provided at the electron gun side end of the annular core of the deflection yoke, and the pair of notches define a vertical plane including the tube axis. They are formed so as to face each other through.

Effect: With this structure, not only is the electron gun side of the vertical deflection magnetic field distorted in a pincushion-like manner by the vertical coma aberration correction coil, but also the end of the annular core on the electron gun side is distorted in a pincushion-like manner. By appropriately reducing the amount of winding of the vertical coma aberration correction coil, it is possible to reduce the amount of protrusion of the vertical deflection magnetic field toward the electron gun side.

Embodiment According to the present invention, a ferrite annular core 1- as shown in FIGS. 1 and 2, for example, is used. This core 1 is for a toroidal type or zaddle type vertical deflection coil, and is shaped as a funnel as a whole.
A pair of notches 2a, 2 are provided at the end on the electron gun side, which is the small diameter end.
It has b. However, the pair of notches 2a and 2b are U-shaped and face each other across a vertical plane that includes the tube axis O and the vertical axis Y.

An in-line electron gun is enclosed in a deflection yoke obtained by conventionally combining horizontal and vertical deflection coils that generate a horizontal deflection magnetic field with a pincushion-like distribution and a vertical deflection magnetic field with a barrel-like distribution in such an annular core. attached to a color picture tube. A pair of conventional vertical coma aberration correction coils as shown in FIG. 7 are mounted on the electron gun side of the deflection yoke.

In the color picture tube device configured in this manner, not only the vertical deflection magnetic field on the electron gun side is distorted in a pincushion tendency due to the magnetic field generated by the coma aberration correction coil, but also a pair of notches 2a provided in the annular core are distorted. , 2b, the tendency shown by the solid line arrow in Fig. 2 is shown by the broken line arrow in Fig. 2.
This figure shows the degree of magnetic field distortion when the notches 2a and 2b are not provided, and the barrel tendency is stronger than that shown by the solid arrow. Since the notches 2a and 2b are provided in this way, the number of turns of the coma aberration correction coil can be reduced compared to the conventional one, and the amount of overhang of the vertical deflection magnetic field toward the electron gun side can be shortened or shortened. , the positive trilemma can be reduced,
Good convergence characteristics can be obtained.

As a result of experiments, it has been found that it is sufficient that the width a of the notch formed in the annular core 1 is one-third or less of the outer diameter of the small diameter portion.

Since the outer diameter of the small diameter portion of the annular core of the deflection yoke attached to the 14-inch color picture tube is about 7 cm, the radius a can be set to about 2 cm. When the width a of the cutout is set to 2 cm and the axial length C is set to 7 mm, the number of turns of the coma aberration correction coil can be reduced by 17% compared to the one without such a cutout, and the trilemma can be reduced to almost zero. I was able to do it.

The cutout does not have to be U-shaped, but may be V-shaped or U-shaped as shown in FIGS. 3 and 4.

Effects of the Invention As described above, according to the present invention, by simply providing a notch in the annular core of the deflection yoke, the amount of overhang of the horizontal and vertical deflection magnetic fields toward the electron gun side can be adjusted. The trilemma caused by this can be brought to zero at a very low cost and without increasing the deflection power, and good convergence characteristics can be obtained.

[Brief explanation of drawings]

FIG. 1 is a side view of the annular core of the deflection yoke of a color picture tube device embodying the present invention, and FIG. 2 is a rear view of the same core.
3 and 4 are side views of annular cores according to other embodiments of the present invention, FIG. 5 is a front view showing rasters on a phosphor screen to explain misconvergence, and FIG. 6 is a front view of a conventional annular core. FIG. 7 is a cross-sectional view showing the relationship between the horizontal deflection coil and the magnetic piece of the deflection yoke, and FIG. 7 is a view showing the vertical coma aberration correction coil and the distribution of the magnetic field generated thereby. 1... Annular core, 2a, 2b... Notch, SI
, S2... Vertical coma aberration correction coil. Name of agent: Patent attorney Toshio Nakao One idiot Figure 1
Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A color picture tube is constructed by enclosing an in-line type electron gun in which three beam emission ports are arranged in a horizontal plane including the tube axis, and a horizontal deflection magnetic field with a pincushion-like distribution and a barrel-like shape are attached to the color picture tube. a deflection yoke that generates a distributed vertical deflection magnetic field; and a pair of vertical coma aberration correction coils arranged on the electron gun side of the deflection yoke so as to face each other across the horizontal plane; A color picture tube device characterized in that the core has a pair of notches at an end on the electron gun side that face each other across a vertical plane that includes the tube axis.