JPH11213915A - Deflection yoke device for color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid collision of side beams among electron beams with an inner wall of a funnel part of a cathode-ray tube bulb when a frame error is corrected by a frame correcting coil, in regard to a deflection yoke device for a color cathode-ray tube. SOLUTION: A magnetic field generated from a frame correcting coil 10 disposed on a neck part of a deflection yoke is synchronized with vertical deflection, and, for example, when deflection is made toward the upper side of a screen, the frame correcting coil 10 is slid by a slide mechanism 13 and thereby positions of electron beams 2B, 2G, 2R are preliminarily deflected toward the lower side of the screen by the magnetic field generated from the frame correcting coil 10, and, when deflection is made toward the lower side of the screen, the electron beams are preliminarily deflected toward the upper side of the screen. A frame error is corrected by forming the shape of the magnetic field generated from the frame correcting coil 10 into a barrel magnetic field shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke device for a color cathode ray tube, and more particularly to a method of correcting a coma error by a coma correction coil, in which a side beam of an electron beam collides with a funnel inner wall of a cathode ray tube valve. The present invention relates to a deflection yoke device for a color cathode ray tube which can be avoided.

[0002]

2. Description of the Related Art In general, a color cathode ray tube apparatus comprises, as shown in FIG.
B, 2G, 2R are deflected by a magnetic field generated by a deflection yoke 4 mounted outside the funnel portion 3 of the cathode ray tube bulb, and a phosphor screen 7 formed on the inner surface of the panel 6 via a shadow mask 5. Image display is performed by performing horizontal and vertical scans to.

In such a cathode ray tube, in particular, the electron gun 1 is an in-line type electron gun assembly which emits three electron beams 2B, 2G, 2R in a line, and a horizontal deflection which generates a pincushion type horizontal deflection magnetic field. A self-convergence system in combination with a deflection yoke 4 including a coil and a vertical deflection coil for generating a barrel-type vertical deflection magnetic field has become widespread.

However, in the self-convergence method, so-called coma aberration occurs because the deflection sensitivity to the center beam 2G is relatively larger than the deflection sensitivity to the pair of side beams 2B and 2R. Generally, as shown in FIG. 5, the coma aberration is obtained by winding coils 9, 9 around a pair of U-shaped cores 8, 8, respectively, and connecting the coils 9, 9 in series to the vertical deflection coil 4a of the deflection yoke 4. The correction coils 10, 10 are arranged at the electron gun side end of the deflection yoke 4 (hereinafter, this assembly is referred to as a deflection yoke device), and a pincushion-type magnetic field is generated corresponding to the barrel-type deflection magnetic field of the vertical deflection coil 4a. Generate and correct.

FIG. 6 shows a state in which a pin-cushion-type magnetic field is generated by a conventional frame correction coil to correct a frame error. This figure shows the case where the cathode ray tube is deflected upward by the deflection yoke, and the direction of preliminary deflection by the coma correction coil is also upward. In the figure, 10 is a frame correction coil, G is a magnetic field generated from the frame correction coil 10, 2G is a center beam of an electron beam, and 2B and 2R side beams.

[0006]

When the coma correction coil 10 is arranged on the deflection yoke 4 to correct the coma error to zero in the vertical direction as described above, the electron gun 1 emits light when the screen is deflected upward. Electron beam 2B, 2
Before the G and 2R enter the deflection yoke 4, the frame correction coil 10
Is preliminarily deflected to the upper side of the screen. When the screen is deflected downward, the electron beams 2B and 2B emitted from the electron gun 1 are emitted.
Since the G and 2R are preliminarily deflected to the lower side of the screen by the coma correction coil 10 before entering the deflection yoke, there is a drawback that the side beam easily collides with the inner wall of the funnel portion 3 of the cathode ray tube bulb.

This is because the side beams 2B and 2R are originally located farther from the tube axis than the center beam 2G, and the gap between the funnel portion 4 and the side beams 2B and 2R is small, so that the side beams 2B and 2R easily collide with the inner wall of the funnel portion 3. It is. For this reason, like the conventional frame correction coil 10,
When the deflection is performed to the upper side of the screen by the correction coil 10 when deflecting to the upper side of the screen, there is a disadvantage that the side beams 2B and 2R further approach the funnel section 3 and easily collide with the inner wall of the funnel section 3.

In order to reduce the power consumption of the color cathode ray tube, it is preferable to set the position where the deflection of the electron beams 2B, 2G and 2R starts on the electron gun 1 side. On the first side, the deflected electron beams 2B, 2G, and 2R are closer to the inner wall of the funnel 4 and are likely to collide. Therefore, the electron beam 2
The fact that B, 2G, and 2R easily collide with the inner wall of the funnel portion 4 was a major problem in reducing the power consumption of the color cathode ray tube.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to prevent a side beam from colliding with an inner wall of a funnel while correcting a frame error by a frame correction coil. And

[0010]

A deflection yoke device according to the present invention synchronizes a magnetic field generated from a coma correction coil arranged at a neck portion of a deflection yoke with a vertical deflection, and raises the coma correction coil upward when deflecting the screen upward. To position the electron beam below the center of the coma correction coil.
The pre-deflection on the lower side of the screen is performed by the magnetic field generated by the coma correction coil. Also, when the screen is deflected on the lower side, the coma correction coil is slid downward to position the electron beam above the center of the coma correction coil. Is formed by preliminarily deflecting the upper side of the screen by the magnetic field generated from.
Further, a configuration is adopted in which a frame error is corrected by setting the shape of the magnetic field generated from the frame correction coil to a barrel magnetic field shape.

According to the above structure, the electron beam is preliminarily deflected to the lower side of the screen by the magnetic field generated from the correction coil disposed at the neck of the deflection yoke when the upper side of the screen is deflected.
In addition, since the electron beam is preliminarily deflected to the upper side of the screen when the screen is deflected to the lower side, the distance between the inner wall of the funnel and the side beam is increased, and the side beam is less likely to collide with the inner wall of the funnel. Further, since the magnetic field generated by the coma correction coil is a barrel magnetic field, the preliminary deflection amount of the side beam is larger than that of the center beam, so that the coma error can be corrected.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a coma correction coil of a deflection yoke device according to an embodiment of the present invention and a magnetic field generated therefrom and a force acting on an electron beam from the magnetic field at the time of predeflection. FIG. 4 is a diagram when an electron beam is deflected to the upper side of the screen.

In the figure, 10 is a frame correction coil, 11
Are magnetic lines of force representing the generated magnetic field distribution, 2B, 2G, 2R are B, G, R electron beams, 12B, 12G, 12
R is the electron beam 2B, 2G, 2R is the coma correction coil 10
A reference numeral 13 denotes a slide mechanism which can slide the frame correction coil 10 up and down.

Next, the operation of the frame correction coil 10 will be described. According to this embodiment, when the screen is deflected upward, the frame correction coil 10 is slid upward by the slide mechanism 13, and the electron beams 2B, 2G, and 2R are generated by the magnetic force lines 11 generated by the magnetic field generated from the correction coil 10.
The magnetic force lines 11 are generated in a direction in which the screen is preliminarily deflected to the lower side of the screen. As a result, the distance between the inner wall of the funnel portion 4 and the electron beams 2B, 2G, 2R increases, and the electron beam 2
B, 2G, 2R are less likely to collide with the funnel 3,
There is an advantage that shadows on the screen that occur because the side beams 2B and 2R do not reach the screen are less likely to occur.

The distance L between the pair of frame correction coils 10 is
Are arranged small, the shape of the magnetic field generated from the coma correction coil 10 becomes a barrel magnetic field shape. As described above, when the shape of the magnetic field generated from the coma correction coil 10 is formed into a barrel magnetic field shape, the force acting on the side beams 2B and 2R becomes larger than the center beam 2G, and the center beam 2G is generated from the side beams 2B and 2R. , More pre-deflected. That is, the electron beams 2B, 2G, 2
R receives the forces 12B, 12G from the frame correction coil 10,
The magnitude of the vector of 12R satisfies the relationship of 12B, 12R> 12G, which has the advantage that the coma error can be more effectively corrected.

FIG. 2 shows an example of the electron beam trajectory of the color cathode ray tube in the above embodiment. 14 is a conventional electron beam orbit, 15 is an electron beam orbit of the present embodiment,
1 is an electron gun, 3 is a funnel part of a cathode ray tube bulb. As shown, the electron beam trajectory 1 of the present embodiment is
5 is preliminarily deflected in the direction opposite to the screen deflection direction, so that the distance from the funnel unit 3 is smaller than that of the conventional electron beam trajectory 1.
It becomes larger than 4. When the magnetic field generated from the frame correction coil 10 deflects the electron beams 2B, 2G, and 2R upward in synchronization with the vertical deflection direction, the magnetic field from the frame correction coil 10 predeflects the electron beams 2B, 2G, and 2R upward. Thus, the shadow generated because the side beams 2B and 2R do not reach the phosphor screen can be made less likely to occur.

FIG. 3 is a plan view of a coma correction coil according to a second embodiment of the present invention. In this embodiment, a pair of frame correction coils 20 are arranged on the left and right sides of the electron beams 2B, 2G, 2R by changing the shape of the frame correction coil of the above-described first embodiment, and the frame correction coil 20 is vertically moved. This is provided with a slidable slide mechanism 23.

In this embodiment, the principle of operation is the same as that of the first embodiment. However, the shape of the coma correction coil 20 is changed so that a pair of bar-like coma corrections are provided on the left and right sides of the electron beams 2B, 2G, 2R. By arranging the coil 20, the barrel magnetic field due to the magnetic field lines 21 from the coma correction coil 20 becomes
The shape becomes stronger and stronger than the barrel magnetic field of the first embodiment. As a result, the side beams 2B, 2R
Is more preliminarily deflected than the center beams 2B, 2G, 2R in the first embodiment, so that the distance between the inner wall of the funnel portion 3 and the side beams 2B, 2R can be made larger, and the side beams 2B, 2R can be separated. There is an advantage that shadows due to 2R not reaching the phosphor screen on the screen are less likely to occur.

[0019]

As described above, according to the present invention, the predeflecting direction of the electron beam is set to the vertical direction of the screen and the direction opposite to the deflecting direction by the deflecting yoke by the magnetic field generated from the coma correction coil of the deflecting yoke. By doing so, the distance between the electron beam and the inner wall of the funnel can be increased. Therefore, there is an effect that it is possible to prevent a shadow from being generated because the side beam does not reach the screen. Further, since the pre-deflection amount of the side beam becomes larger than that of the center beam by setting the shape of the magnetic field generated from the frame correction coil to the barrel shape, there is an effect that the frame error can be corrected.

[Brief description of the drawings]

FIG. 1 is a plan view showing a magnetic field generated from a coma correction coil of the present invention and a state where the magnetic field is acting on an electron beam.

FIG. 2 is a view for explaining an electron beam trajectory in the present invention.

FIG. 3 is a plan view showing a magnetic field generated from a coma correction coil and a state in which the magnetic field is acting on an electron beam according to a second embodiment of the present invention;

FIG. 4 is a configuration diagram of a general color cathode ray tube device.

FIG. 5 is a perspective view showing an example of a deflection yoke device for a color cathode ray tube.

FIG. 6 is a diagram illustrating a conventional frame correction coil.

[Description of Signs] 1 Electron gun 2B, 2R Side beam 2G Center beam 3 Funnel section 4 Deflection yoke 4a Vertical deflection coil 8 U-shaped core 9 Coil 10, 20 Frame correction coil 11, 21 Magnetic field lines generated from frame correction coil 12B , 12R, 22B, 22R Force acting on side beam 12G, 22G Force acting on center beam 13, 23 Slide mechanism 14 Electron beam trajectory in the present invention 15 Conventional electron beam trajectory L Frame correction coil interval

Claims (3)

[Claims] 1. A deflection yoke having horizontal and vertical deflection coils for generating magnetic fields for deflecting an electron beam emitted from an electron gun of a color cathode ray tube in horizontal and vertical directions, and a pair of U-shaped vertically arranged coils. A coil directly connected to the vertical deflection coil is wound around each of the cores, and a pair of U-shaped cores around which the coil is wound are provided with a coma correction coil which is disposed vertically above and below with an electron beam interposed therebetween, and A deflection yoke device for a color cathode ray tube, comprising: a slide mechanism capable of sliding an electron beam up and down in synchronization with vertical deflection. 2. A deflection yoke having horizontal and vertical deflection coils for generating magnetic fields for deflecting an electron beam emitted from an electron gun of a color cathode ray tube in horizontal and vertical directions, and a pair of rod-shaped cores arranged in the left and right directions. A coil directly connected to the vertical deflection coil is wound on each of the coils, and a pair of coil correction coils in which a pair of rod-shaped cores wound around the coils are disposed to face left and right across the electron beam, and A deflection yoke device for a color cathode ray tube, comprising: a slide mechanism capable of sliding up and down in synchronization with vertical deflection. 3. A deflection yoke device for a color cathode ray tube according to claim 1, wherein the magnetic field generated from said frame correction coil is a barrel magnetic field.