JPH06349421A - Color cathode-ray tube display device - Google Patents

Abstract

PURPOSE:To improve the focus characteristic. CONSTITUTION:A deflecting yoke 1, a horizontal auxiliary deflecting yoke 2 for correcting the miss-convergence in the horizontal direction and a correcting yoke 3 for correcting the beam spot shape are fitted out of a neck part of a cathode-ray tube C in this order from a side close to a funnel. The deflecting yoke 1, in which a vertical deflecting coil generates the barrel-like magnetic field and a horizontal deflecting coil generates the magnetic field having the nearly even distribution, generates the miss-convergence in the horizontal direction in the periphery of a faceplate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube display device having an in-line type electron gun.

[0002]

2. Description of the Related Art In a color cathode ray tube display device, an electron beam emitted from an electron gun is deflected by a deflection yoke to scan the entire screen. A conventional color cathode ray tube display device employs a self-convergence type deflection yoke in order to correct misconvergence that occurs during scanning. FIG. 9 is an explanatory diagram showing a horizontal magnetic field by the self-convergence method from the screen side, and FIG.
It is explanatory drawing which similarly shows the perpendicular magnetic field by a self-convergence system from the screen side. As shown in FIG. 9, the horizontal deflection magnetic field (Hg) generated by the horizontal deflection coil is distorted in a pincushion shape, and the vertical deflection magnetic field (Vg) generated by the vertical deflection coil is distorted in a barrel shape as shown in FIG. A deflection yoke is used to reduce the amount of misconvergence on the screen to approximately zero.

However, in such a self-convergence system, the quadrupole magnetic field component generated by this non-uniform magnetic field causes astigmatism in the deflected electron beam. Therefore, the electron beam undergoes a focusing action, that is, deflection aberration (distortion) in the vertical direction, and the deflected beam spot becomes overfocused in the vertical direction. FIG. 11 shows the beam spot shape obtained in the upper right quarter portion of the screen in this state. As shown in FIG. 11, the spot shape S causes a halo (overfocusing) elongated in the vertical direction around the screen F, and the vertical focus characteristics of the electron beams R, G, and B are deteriorated.

Therefore, there is a method in which the vertical or horizontal deflection magnetic field is made substantially uniform to reduce the deterioration of the focus characteristics due to the distortion of the deflection magnetic field, and the misconvergence due to the uniform deflection magnetic field is corrected by providing another auxiliary deflection yoke. Proposed.

[0005]

However, even if the deflection magnetic field is made substantially uniform to reduce the deterioration of the focus characteristics as described above, the beam spot shape in the peripheral portion of the screen is still elliptical. This is because, as shown in Fig. 12, the focusing fire surface 12 of the beam spot, which has the best focus characteristics in the periphery of the screen, is inside the screen 11, and the focus characteristics are not uniform in the center of the screen and the periphery of the screen. There was a problem that was. The present invention has been made in view of the above circumstances, and a color cathode-ray tube display having excellent focus characteristics by correcting the beam spot shape of a deflection yoke having a substantially uniform horizontal deflection magnetic field with a correction yoke. The purpose is to provide a device.

[0006]

A color cathode ray tube display device according to the present invention is characterized by comprising a correction yoke for forming a magnetic field for correcting the horizontal diameter of a beam spot by a deflection yoke.

[0007]

In the present invention, the focusing yoke of the electron beam is moved by forming a magnetic field in the correction yoke such that the electron beam receives different forces on one side and the other side in the horizontal direction. Thus, the beam spot shape by the deflection yoke having a substantially uniform horizontal deflection magnetic field is corrected.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. FIG. 1 is a side view showing a main part of a color cathode ray tube display device according to the present invention. In the figure, C is a known cathode ray tube having an electron gun (not shown) inside,
At the neck of the cathode ray tube C, a deflection yoke 1, a horizontal auxiliary deflection yoke 2 for correcting horizontal misconvergence, and a correction yoke 3 for correcting the beam spot shape.
Is fitted and mounted from the funnel side in this order.

In the deflection yoke 1, a vertical deflection coil generates a barrel-shaped magnetic field, a saddle winding type horizontal deflection coil generates a magnetic field having a substantially uniform distribution, and three electron beams R, G, and
The two outer electron beams R and B out of B generate horizontal misconvergence around the screen.

FIG. 2 is a cross-sectional view of the color cathode ray tube display device taken along line II-II of FIG. 1, and FIG. 3 is a schematic view showing a coil winding of the horizontal auxiliary deflection yoke 2. Reference numeral 4 in the drawing denotes a core, and the core 4 is composed of a ring portion 4a and eight core portions 41 to 48 extending in the radial direction from the ring portion 4a to the vicinity of the cathode ray tube C. Here, the vertical direction in FIG. 2 is assumed to be the vertical direction when actually installed.

Above the passage of the electron beam R, a plane having a width sufficient for this electron beam diameter, horizontal to the passage of the electron beam R, and a plane having a 1/4 arc cross section are provided. Becomes
The length of the electron beam in the passage direction is substantially the same as that of the core 4, and a magnetic body 51R is provided so that the horizontal surface faces the passage of the electron beam R and the arc-shaped surface is close to the cathode ray tube C. Has been. A magnetic material 52 is provided below the passage of the electron beam R.
R is a magnetic body 51L above the passage of the electron beam B,
Magnetic bodies 52L are similarly provided on the upper side of the passage of the electron beam B, respectively. And the core part 42 on the upper right of the cathode ray tube C
And coils 42a and 44a are wound around the lower right core portion 44, and the coils 46a and 44a are wound around the lower left core portion 46 and the upper left core portion 48, respectively.
Each 48a is wound.

As shown in FIG. 3, the windings of the coils 42a and 44a are connected to each other so that currents can flow simultaneously. In addition, the windings of the coils 46a and 48a are connected to each other so that currents can flow simultaneously. And coil 42a,
The current can be separately supplied to the coil 44a and the coils 46a and 48a. When an electric current is applied to the coils 42a and 44a, the magnetic lines of force pass from the coil 44a through the magnetic body 52R and the magnetic body 51R to the coil 42a.
A magnetic field H _C1 is formed which is directed towards. As a result, the electron beam R receives a force D _H1 to the right and is deflected in this direction.
Similarly, as shown in FIG.
When an electric current is applied to a and 48a, the lines of magnetic force are transferred from the coil 48a
A magnetic field H _C2 is formed toward the coil 46a via the 51L and the magnetic body 52L. This causes the electron beam B to have a force D to the left.
_It receives _H2 and is deflected in this direction.

FIG. 4 is a sectional view of the color cathode ray tube display device taken along line IV-IV in FIG. 1, and FIG. 5 is a correction yoke 3
It is a schematic diagram which shows the winding of the coil. A core 4 having the same shape as that shown in FIG. 2 is also used for the correction yoke 3. Upper right core portion 42, lower right core portion 44, lower left core portion of the cathode ray tube C
46, coils 42b, 44b, 46b, 48b are wound around the upper left core portion 48, respectively. As shown in FIG. 5, the windings of the coils 42b and 44b are connected to each other so that currents flow simultaneously. Further, the windings of the coils 46b and 48b are connected to each other so that currents can flow simultaneously. And coil 42
The b, 44b and the coils 46b, 48b can separately flow current.

[0014] In the case of the right deflection, the coil 42b, when an electric current is applied to the 44b, because although upward magnetic field M _C directed from the coil 44b to the coil 42b is formed, the magnetic field M _C is a pincushion, electronic The beam R receives a force D _B in the right direction, which is larger on the right side than on the left side. As a result, the electron beam R
The horizontal diameter on the screen can be shortened. When a current is applied to the coils 46b and 48b, the coils 46b to 48b
An upward magnetic field (not shown) is formed toward the electron beam B, so that the electron beam B is subjected to a rightward force (not shown) larger on the left side than on the right side. As a result, the horizontal diameter of the electron beam B on the screen can be shortened. At this time, the currents flowing through the coils 42b and 44b and the currents flowing through the coils 46b and 48b are made different from each other to form a magnetic field according to the deflection amount.

In the case of left deflection, an electric current in the opposite direction to that described above is applied to the coils 42b, 44b, 46b, 48b to form a downward magnetic field, and a required leftward force is applied to each electron beam. give. In addition, the magnetic fields generated by the coils 42b and 44b and the coils 46b and 4b
By reversing the direction of the magnetic field by 8b, each electron beam R,
The beam spot shapes of G and B can be balanced.

The deflection yoke 1 is configured such that a horizontal deflection coil generates a substantially uniform magnetic field in the horizontal direction and a vertical deflection coil generates a barrel-shaped magnetic field in the vertical direction. Therefore, in the misconvergence pattern when the deflection yoke 1 is used, the vertical misconvergence is almost corrected, but the horizontal misconvergence is not corrected at all.

FIG. 6 shows the beam spot shape of the electron beam R (or B) when the deflection yoke 1 is used.
It can be seen that the beam spot shape is better than when the self-convergence deflection yoke shown in FIG. 11 is used. Then, in this state, a pincushion-shaped correction magnetic field is applied by the correction yoke 3 shown in FIG. FIG. 7 is a schematic diagram showing the locus of the electron beam, the solid line shows the locus of the electron beam when no current is flowing through the correction yoke 3, and the alternate long and short dash line shows the time when current is flowing through the correction yoke 3. The trajectory of the electron beam is shown. The irradiation area when reaching the screen is the beam spot S.

When no current is applied to the correction yoke 3, the focusing fire surface 12 of the beam spot, which has the best focusing characteristics, is inside the screen (horizontal direction) 11 of the cathode ray tube, but the current is applied to the correction yoke 3. , The electron beam receives different forces in the left-right direction and spreads and the focusing point moves to the screen side, so that the beam spot S can be made small on the peripheral screen 11 as well. As a result, the focus characteristic becomes the best on the screen, and the uniform focus characteristic is obtained over the entire screen. By passing a current adjusted according to the deflection position of the electron beam to the correction yoke 3, it is possible to correct the beam spot shape over the entire screen.

FIG. 8 is a graph showing the relationship between the current flowing through the correction yoke 3 and the horizontal diameter of the beam spot on the screen. The measurement was performed at the center horizontal line edge and the diagonal line edge of the screen as shown in the upper part of the graph. In the graph, the measurement result at the end of the central horizontal line is indicated by x, and the measurement result at the end of the diagonal line is indicated by ●. It can be seen from FIG. 8 that the horizontal diameter is deflected by the current flowing through the correction yoke 3. 0.8 to 0.9 at both ends of the center horizontal line and diagonal ends
When the current of (A) is passed, the horizontal diameter of the beam spot becomes 20-25.
% Improved. By adjusting the current to flow according to the position on the screen as described above, excellent focus characteristics can be obtained over the entire screen.

Further, in this embodiment, the horizontal misconvergence caused by the deflection yoke 1 is corrected by the magnetic field formed by the horizontal auxiliary deflection yoke 2 shown in FIG. 2, so that the convergence characteristic is also good.

[0021]

As described above, in the color cathode ray tube display device according to the present invention, the beam spot shape of the deflection yoke having a substantially uniform horizontal deflection magnetic field is corrected by the correction yoke to focus the electron beam. Since the surface can be moved to the screen side and focused on the screen, the present invention has excellent effects such as improvement of focus characteristics.

[Brief description of drawings]

FIG. 1 is a side view showing a main part of a color cathode ray tube display device according to the present invention.

2 is a sectional view of the color cathode ray tube display device taken along line II-II of FIG.

FIG. 3 is a schematic diagram showing a coil winding of the horizontal auxiliary deflection yoke shown in FIG.

4 is a cross-sectional view of the color cathode ray tube display device taken along line IV-IV in FIG.

5 is a schematic diagram showing a coil winding of the correction yoke shown in FIG. 1. FIG.

6 is a schematic diagram showing a beam spot shape by the deflection yoke shown in FIG.

FIG. 7 is a schematic diagram showing a trajectory of an electron beam in the device of the present invention.

FIG. 8 is a graph showing a relationship between a horizontal diameter of a beam spot and a correction current.

FIG. 9 is an explanatory diagram showing a horizontal magnetic field by the self-convergence method.

FIG. 10 is an explanatory diagram showing a vertical magnetic field by a self-convergence method.

FIG. 11 is a schematic diagram showing a beam spot shape when a self-convergence method is used.

FIG. 12 is a schematic diagram showing a trajectory of an electron beam in a conventional device.

[Explanation of symbols]

 1 deflection yoke 2 horizontal auxiliary deflection yoke 3 correction yoke 4 core C cathode ray tube

Claims (1)

[Claims] 1. An in-line type electron gun that emits three electron beams, a vertical deflection coil that generates a barrel-shaped vertical deflection magnetic field for deflecting the trajectory of the electron beam, and a substantially uniform horizontal deflection magnetic field. A horizontal deflection coil, and a deflection yoke that is set so that a horizontal concentration error of the two outer electron beams of the three electron beams is formed in the periphery of the screen; In a color cathode ray tube display device including a horizontal auxiliary deflection yoke that generates a magnetic field that corrects a concentration error, a correction yoke that forms a magnetic field for correcting the horizontal diameter of a beam spot by the deflection yoke is provided. Color cathode ray tube display device.