JP2003209852A - Deflection yoke, color cathode ray tube, and color cathode ray tube receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem of a conventional color cathode ray tube receiver that has had to separately prepare a drive circuit for a convergence correction signal generating circuit and a convergence correction device for generating a convergence correction signal on the basis of correction by a pseudo parabolic current in order to perform dynamic convergence correction. <P>SOLUTION: A deflection yoke is provided with a convergence correction device 12 for adjusting convergence in the horizontal direction by a 4-pole magnetic field for convergence of three electron beams emitted from electron guns: and a pseudo parabolic current generating device 30 having a saturable reactor characteristic, and a horizontal deflection current flowing through a horizontal deflection coil 8 is supplied to primary coils Dh1, Dh2 of the pseudo parabolic current generating device 30, a bias magnet 33 adjusts the magnitude of a parabolic current with a horizontal deflection period induced in secondary coils Dp1, Dp2 by its angle adjustment and the induced current is supplied to coils 14a to 14d so as to correct the convergence in the horizontal direction. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke mounted on a color cathode ray tube used in a television receiver, a display monitor of a computer, etc., and more particularly to a deflection yoke equipped with a device for correcting horizontal misconvergence. The present invention relates to a yoke, a color cathode ray tube using this deflection yoke, and a color cathode ray tube receiver using this deflection yoke.

[0002]

2. Description of the Related Art FIG. 9 is a schematic diagram of a color cathode ray tube. In the figure, 1 is a cathode ray tube bulb, 2 is a panel, 3 is an electron gun, 6 is a deflection yoke, 7 is a convergence purity magnet, 8 is a horizontal deflection coil, and 9 is a vertical deflection coil.

In FIG. 9, a panel 2 having a phosphor screen on which phosphors of three colors of red, green and blue are formed in stripes or dots is mounted inside the opening of the cathode ray tube bulb 1, An electron gun 3 that emits three electron beams is enclosed at the rear end of the tube valve 1. Further, a cone-shaped deflection yoke 6 and a convergence purity magnet 7 for deflecting the electron beam emitted from the electron gun 3 are provided in a cone portion (not shown) extending from the neck portion 4 to the funnel portion 5 of the cathode ray tube valve 1. It is installed.

The deflection yoke 6 is equipped with a horizontal deflection coil 8, a vertical deflection coil 9, a coil bobbin 10 and a core 11.

Horizontal deflection current is passed through the horizontal deflection coil 8 and vertical deflection current is passed through the vertical deflection coil 9 along the orbits of three electron beams (not shown) emitted from the electron gun 3. A vertical deflection magnetic field is formed, and the deflection magnetic field deflects the electron beam vertically and horizontally.

The core 11 is usually made of ferrite and is mounted so as to cover the horizontal deflection coil 8 and the vertical deflection coil 9 in order to enhance the efficiency of the magnetic field generated from the horizontal deflection coil 8 and the vertical deflection coil 9. .

FIG. 10 is a diagram for explaining the operation of horizontal deflection of an electron beam in an in-line array electron gun type color cathode ray tube. As shown in the figure, in a color cathode ray tube having an in-line arrangement of electron guns in which an electron beam for illuminating a green phosphor is a center beam G and electron beams for illuminating red and blue phosphors are side beams R and B, respectively,
A color selection electrode (not shown) such as an aperture grill or a shadow mask is provided for the three electron beams emitted from the electron gun 3.
A desired color image is reproduced on the screen by allowing one point on the phosphor screen to converge. At this time, if a phenomenon in which three electron beams are not concentrated on one point on the phosphor screen, that is, so-called misconvergence occurs, this causes color misregistration or color unevenness on the screen.

Convergence Purity Magnet 7
Is for correcting an assembly error of the electron gun 3, and is provided on the electron gun 3 side of the neck portion 4. The convergence purity magnet 7 is composed of several ring-shaped multi-pole magnets (not shown). For example, one line of R, G, and B colors that intersect at the center of the screen (generally a black background The angles of these ring-shaped magnets are adjusted so that the white crosshair signal is displayed) at the center of the screen. Generally, this adjustment is called static convergence correction.

In a color cathode ray tube having an electron gun arranged inline as shown in FIG. 10, the horizontal deflection magnetic field is shown in FIG.
In the case of the uniform magnetic field shown in (A), horizontal misconvergence occurs on the screen as shown in FIG.
That is, even if the three electron beams are aligned on the Y axis,
At the left and right edges of the screen, the red side beam R is shifted to the left and the blue side beam B is shifted to the right. In general, when three color vertical lines are displayed at the left and right edges of the screen, each is slightly distorted, so it is defined as horizontal misconvergence at the left and right edges on the X-axis (hereinafter referred to as XH). .

It is widely known that this XH can be corrected by changing the horizontal deflection magnetic field to the pinned magnetic field shown in FIG. 11 (B). Generally, a pin magnetic field is widely generated by adjusting the winding distribution of the horizontal deflection coil. However, by winding the horizontal deflection coil so that the horizontal deflection magnetic field becomes a pinned magnetic field, the side beams R and B become substantially coincident with each other as shown in FIG. 13, but the misconvergence of the center beam G in the horizontal direction is generated. Occurs. The horizontal misconvergence at the left and right ends on the X-axis is defined by the difference between the average value of the side beams R and B and the center beam G (hereinafter, HCR (Horizontal Center).
Raster))).

In this HCR, the horizontal deflection magnetic field on the neck side of the horizontal deflection coil is shown in FIG. 11 (C).
It is widely known that a magnetic field can be used for correction.
However, in reality, the size of the HCR is not always constant at each position on the screen, so the center beam G at the left and right ends of the screen X axis and the left and right ends of the upper and lower parts of the screen (screen corner).
And the side beams R and B may deviate from each other. For example, as shown in FIG. 14A, the center beam G is inside the side beams R and B at the left and right ends of the screen X axis.
At the corners of the screen, misconvergence may be left in a shape that is outward.

Since the misconvergence on the X-axis is conspicuous, the winding distribution is further adjusted, and as shown in FIG. 14B, the center beam G and the side beams R, B are formed at the left and right ends on the screen X-axis. To match. At this time, a deviation (hereinafter referred to as dHCR) between the center beam G at the left and right ends on the X axis and the side beams R and B at the screen corners remains.

The above-mentioned misconvergence XH, HCR,
Since each dHCR has a delicate trade-off relationship,
It is very difficult to adjust the winding distribution to such an extent that they can be ignored. The limit of winding distribution adjustment is 17
For inch display monitors, the design center value is 0.
It is about 3 mm, and about 0.35 mm including manufacturing variations. Characters and thin lines are often displayed on the display monitor. In this case, misconvergence of 0.05 m
The difference in m becomes a problem visually.

It is desirable that the display monitor of 17 inches or less has a misconvergence of 0.3 mm or less and the television receiver of 29 inches or less has a thickness of 1 to 2 mm or less. Conventionally, winding distribution adjustment has been the mainstream because it is not enough but almost satisfactory performance can be obtained.

However, the winding distribution adjustment cannot cope with the large size and high definition of the display monitor and the television receiver. For example, the misconvergence of a 21-inch display monitor is 0.2
It has been impossible to adjust the winding distribution to 0.25 mm or less by the conventional winding distribution adjustment. On the other hand, the aspect ratio is 16: 9, 3
Since a deflection angle becomes large in a television receiver of 2 inches or more, there is a new problem that misconvergence becomes very large.

Therefore, as shown in FIG. 15, a convergence correction device 12 is added to the deflection cathode 6 on the electron gun 3 side of the color cathode ray tube shown in FIG. 9, and a convergence correction current is passed to adjust the HX. A method is used. This adjustment is generally called Dynamic Convergence correction.

FIG. 16 is a diagram showing an example of the convergence correction device 12. As shown in the figure, the convergence correction device 12 includes two U-shaped cores 13a and 13b and four coils 14 connected in series for generating a quadrupole magnetic field.
It is composed of a, 14b, 14c and 14d.

In FIG. 16, when a current flows in the direction of the arrow, a quadrupole magnetic field having a polarity shown by a broken line in the figure is generated in the U-shaped cores 13a and 13b. Since the R, G, and B electron beams move from the back side of the paper toward the front side, the side beams R and B are bent outward. The center beam G is not affected by the convergence correction device 12. That is, the position of the center beam G does not move,
Since the side beam R moves to the right side and the side beam B moves to the left side, the side beams R and B can be moved in a direction corresponding to the center beam G in FIG.
Can be made smaller.

FIG. 17 shows an example of the horizontal deflection current and the convergence correction current, and FIG. 18 shows an example of the drive system for the horizontal deflection coil and the convergence correction coil.

Since the misconvergence is small near the Y axis and becomes larger toward the left and right ends, the horizontal deflection current in the sawtooth waveform shown in FIG. 17A (hereinafter referred to as the sawtooth current) is compared with that in FIG. A current having a shape close to that of the parabola shown in (B) (hereinafter referred to as pseudo parabola current) is generally used.

As shown in FIG. 18A, a sawtooth wave current is passed through the horizontal deflection coil 8 by the horizontal deflection coil drive circuit 23. Further, as shown in FIG. 18B, a pseudo parabola current is passed through the convergence correction coil 12 by the convergence correction coil drive circuit 15.

FIG. 19 is a block diagram of a conventional color cathode ray tube receiver by dynamic convergence correction. In the figure, 2 is a panel, 3 is an electron gun, 6 is a deflection yoke, 7 is a convergence purity magnet, 8 is a horizontal deflection coil, 9 is a vertical deflection coil, 12 is a convergence correction device, 15 is a convergence correction coil drive circuit, 16
Is a convergence correction signal generation circuit, 19 is a video signal processing circuit, 20 is an RGB cathode drive circuit, and 21 is horizontal.
A vertical deflection signal generation circuit, 22 is a horizontal deflection coil drive circuit, and 23 is a vertical deflection coil drive circuit.

In FIG. 19, a video signal received by the television antenna 17 and the tuner 18 or a video input signal from an external device such as a computer is an R signal, a G signal, and a B signal for display in the video signal processing circuit 19 (hereafter , RGB display signals). The RGB cathode drive circuit 20 drives a cathode electrode (not shown) that controls the intensity of the R, G, and B electron beams of the electron gun 3 according to the level of the RGB display signal.

Further, in the video signal processing circuit 19, a horizontal synchronizing signal H-Sync and a vertical synchronizing signal V- of the video signal.
Sync is taken out. In the horizontal / vertical deflection signal generation circuit 21, a sawtooth-shaped horizontal deflection signal and a vertical deflection signal are generated based on H-Sync and V-Sync.
The horizontal deflection coil 8 is driven by the horizontal deflection coil drive circuit 22.
However, the vertical deflection coil drive circuit 23 drives the vertical deflection coil 9.

As described above, the color image is displayed on the panel 2 of the color cathode ray tube receiver, but if the convergence correction is not performed, the display image has a misconvergence as shown in FIG.

The operation of the dynamic convergence correction in which the convergence correction signal generating circuit 16 and the convergence correction coil driving circuit 15 supply a convergence correction current to the convergence correction device 12 to correct the convergence will be described below.

The convergence correction signal generation circuit 16 comprises a basic waveform memory 16a, a control circuit 16b, a correction waveform memory 16c, and a convergence correction signal calculation circuit 16d. A standard pseudo parabolic waveform is stored in the basic waveform memory 16a, which is sent to the convergence correction signal calculation circuit 16d by a timing signal output from the control circuit 16b based on H-Sync.
The convergence correction device 12 is driven via the convergence correction coil drive circuit 15.

In the normal dynamic convergence correction, a grid-shaped adjustment signal (usually drawn with a white line on a black background) as shown in FIG. 20 is displayed on the panel 2, and the center beam G and the side beam R at the intersection of the grid and The convergence adjustment signal is input to the control circuit 16b so that the deviation amount of B is reduced, and the convergence correction signal calculation circuit 1 is input.
Adjust the 6d gain.

Then, the shift amount of the center beam G and the side beams R and B, which cannot be corrected by the previous adjustment, is input to the control circuit 16b as a convergence correction amount setting signal. In the control circuit 16b, a correction waveform is calculated from the convergence correction amount setting signals of the side beams R and B at each lattice point, and is temporarily stored in the correction waveform memory 16c.

Basic waveform memory 16a and corrected waveform memory 1
The waveform stored in 6c is read out based on the timing signal from the control circuit 16b, combined in the convergence correction signal calculation circuit 16d, and sent to the convergence correction coil drive circuit 15. Further, the shift amount of the center beam G and the side beams R and B, which cannot be corrected by the previous adjustment, is input to the control circuit 16b as a convergence correction amount setting signal. By repeating the adjustment as described above, the convergence can be accurately corrected.

According to the dynamic convergence correction as described above, the misconvergence can be corrected extremely accurately to 0.2 mm or less. That is, it is possible to obtain a color cathode ray tube image receiver having a good convergence characteristic by adjusting the electronic circuit instead of adjusting the winding distribution.

However, the above-described dynamic convergence correction is a technique used for a color cathode ray tube receiver having a narrow tolerance of misconvergence such as a large-sized television receiver of 32 inches or more and a display monitor of 21 inches or more, and 29 inches or less. There is a problem that it is too expensive to be used for the television receiver of No. 1 and a display monitor of 17 inches or less, and it takes a lot of time and effort to improve the accuracy of misconvergence correction.

[0033]

In the conventional deflection yoke, color cathode-ray tube and color cathode-ray tube receiver as described above, in order to perform dynamic convergence correction by adding a convergence correction device, correction by pseudo parabola current is performed. A convergence correction signal generation circuit that generates a basic convergence correction signal and a drive circuit of the convergence correction device must be separately prepared, which is expensive, and adjustment for accurately correcting the convergence is troublesome.

The present invention has been made in order to solve the above problems, and an object of the present invention is to add a simple and inexpensive pseudo parabola current generating device to a deflection yoke so that a pseudo parabola current can be obtained. It is an object of the present invention to provide a deflection yoke, a color cathode ray tube and a color cathode ray tube receiver which do not require an external circuit for generating a convergence correction signal based on the above.

[0035]

[Means for Solving the Problems] Claim 1 according to the present invention
The deflection yoke of 1 is a convergence correction device that corrects the horizontal convergence of the three electron beams emitted from the electron gun by a quadrupole magnetic field, and a pseudo parabola current is generated from the sawtooth wave current flowing through the horizontal deflection coil. And a pseudo parabola current generator having a saturable reactor which is supplied to the convergence correction device.

The deflection yoke of claim 2 is the deflection yoke of claim 1.
In the deflection yoke described in the paragraph (1), the pseudo parabola current generating device is provided with a means for changing the DC bias magnetic field by adjusting the angle of the bias magnet forming the saturable reactor.

The deflection yoke according to claim 3 is the deflection yoke according to claim 1.
In the deflection yoke described in (1), a plurality of coils forming a saturable reactor of the pseudo parabola current generation device are insulated.

The deflection yoke according to claim 4 is the deflection yoke according to claim 1.
In the deflection yoke described in (1), a sub magnet for correcting the DC bias magnetic field generated by the bias magnet of the pseudo parabola current generating device is arranged.

The deflection yoke of claim 5 is the deflection yoke of claim 1.
The deflection yoke described in (1) above is provided with a magnetic shield plate for magnetically shielding the pseudo parabola current generation device.

Further, a color cathode ray tube according to a sixth aspect is characterized by including the deflection yoke according to any one of the first to fifth aspects.

A color cathode ray tube image receiver according to a seventh aspect is characterized by including the deflection yoke according to any one of the first to fifth aspects or the color cathode ray tube according to the sixth aspect.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. FIG. 1 is a schematic configuration diagram of a color cathode ray tube according to one embodiment of the present invention, and FIG. 2 is a horizontal deflection system circuit of a deflection yoke according to one embodiment of the present invention. In the figure, 2 is a panel, 3 is an electron gun, 7 is a convergence purity magnet, and 8
Is a horizontal deflection coil, 9 is a vertical deflection coil, 12 is a convergence correction device, 23 is a horizontal deflection coil drive circuit, 3
Reference numeral 0 is a pseudo parabola current generator, and 40 is a deflection yoke.

1 and 2, the configuration other than the pseudo parabola current generator 30 and the deflection yoke 40 is shown in FIG.
Since it is the same as that described in the description of the conventional example of FIG. 19, description thereof will be omitted. As shown in FIGS. 1 and 2, the pseudo parabola current generation device 30 is connected to the horizontal deflection coil 8. The winding method of the horizontal deflection coil 8 is a saddle type, and the coils Lh1 and Lh2 of the horizontal deflection coil 8 are deflection coils attached to the upper and lower portions of the deflection yoke, respectively. One ends of the coils Lh1 and Lh2 are connected to the terminal 24, and the other ends are connected to the terminal 25 via the pseudo parabola current generation device 30. Then, the terminals 24 and 25
A horizontal deflection coil drive circuit 23 is connected to the, and a sawtooth wave current for horizontal deflection is supplied.

In the pseudo parabola current generator 30, the horizontal deflection coil 8 is connected in series to the series circuit of the primary side coil Dh1 and the coil Dh2, and the series circuit of the secondary side coil Dp1 and the coil Dp2 is converged. The series circuit of the coils 14a to 14d of the correction device 12 is connected.

Next, an example of the structure of the pseudo parabola current generating device 30 shown in FIG. 2 will be described with reference to FIG.
As shown in the figure, a pair of drum cores 31 and 32 are arranged so as to face each other around a bias magnet 33 that applies a DC bias magnetic field to the drum cores 31 and 32. The primary side coil Dh1 and the secondary side coil Dp1 forming the pseudo parabola current generating device 30 are wound around the drum core 31 while being insulated by the interlayer insulating paper 34. Further, the primary side coil Dh2 and the secondary side coil Dp2 that form the pseudo parabolic current generation device 30 are wound around the drum core 32 while being insulated by the interlayer insulating paper 35.

The coils Dh1 and Dh2 on the primary side are
Direction of the magnetic field generated in the coil Dh1 and the coil Dh
They are connected or wound so that the directions of the magnetic fields generated in 2 are opposite to each other. Also,
The secondary coils Dp1 and Dp2 are connected or wound such that the direction of the current generated in the coil Dp1 and the direction of the current generated in the coil Dp2 are opposite to each other.

Next, the operation of the pseudo parabola current generating device 30 when a sawtooth wave current for horizontal deflection is supplied between the terminals 24 and 25 will be described with reference to FIGS. 2 and 3. In FIG. 2, the current when the electron beam is deflected on the left side of the screen is IL, and the current when the electron beam is deflected on the right side of the screen is IR.

The case of deflecting the electron beam on the left side of the screen (first half of horizontal deflection) will be described. When the current IL is supplied to the pseudo parabola current generator 30, the magnetic field generated by the coil Dh1 is in the opposite direction to the DC bias magnetic field of the bias magnet 33, as shown in FIG. Act to cancel each other out, the magnetic saturation of the drum core 31 is released, and the coil Dh
The inductance of 1 becomes large. On the other hand, the coil Dh2
The magnetic field generated by the magnetic field has the same direction as the DC bias magnetic field of the bias magnet 33, and acts so as to mutually strengthen the magnetic fields in the drum core 32, and the drum core 32 is magnetically saturated to reduce the inductance of the coil Dh2.

Therefore, the pseudo parabola current generator 30
Lh of primary side coils Dh1 and Dh2
1 and Lh2 have a relationship of Lh1> Lh2, and the secondary coils Dp1 and Dp wound around the drum cores 31 and 32, respectively.
The currents Ip1 and Ip2 generated in p2 are | Ip1 |> | I
p2 | At this time, currents (Ip1-Ip) for correcting the convergence on the left side of the screen (first half of horizontal deflection) generated by Dp1 and Dp2 are generated in the coils 14a to 14d.
2) flows from the connection point P1 toward the connection point P2.

Next, the case of deflecting the electron beam on the right side of the screen (the latter half of the horizontal deflection) will be described. When the current IR is supplied to the pseudo parabola current generation device 30, the magnetic field generated by the coil Dh1 is generated by the bias magnet 3 as shown in FIG.
The same direction as the bias magnetic field of No. 3 is set, and the drum core 31 is magnetically saturated. On the other hand, the magnetic field generated by the coil Dh2 is in the opposite direction to the bias magnetic field of the bias magnet 33, the magnetic saturation of the drum core 32 is released, and the primary side coils Dh1 and Dh
Inductances Lh1 and Lh2 of h2 are Lh1 <Lh2
It becomes a relationship.

Therefore, the currents Ip1 and Ip2 generated in the secondary coils Dp1 and Dp2 wound around the drum cores 31 and 32 respectively have a relationship of | Ip1 | <| Ip2 |. At this time, the convergence correction coils 14a to 14d
Is a current (Ip2) for correcting the convergence on the right side of the screen (the latter half of the horizontal deflection) generated in the secondary side Dp1 and Dp2.
-Ip1) flows from the connection point P1 toward the connection point P2.

As described above, the pseudo parabola current generator 3
0 operates as a saturable reactor whose impedance changes according to the magnitude of the horizontal deflection current. FIG. 5 shows an example of saturable reactor characteristics due to horizontal deflection currents of the primary side coils Dh1 and Dh2 of the pseudo parabola current generation device 30. In the figure, (A) shows a case where the bias magnetic field is small, (B) shows a magnetic field strength (optimum) at which the saturable reactor characteristic with the maximum bias magnetic field is obtained, and (C) shows a case where the bias magnetic field causes both the drum cores 31 and 32 to be magnetic. This is the case when it is large enough to saturate. Normally, as the bias magnetic field of the bias magnet 33, the magnetic field strength between those shown in FIGS.

Pseudo parabolic current generator 30 shown in FIG.
When a sawtooth wave current for horizontal deflection shown in FIG. 4A is supplied to the primary side coils Dh1 and Dh2 of the secondary coil Dp1 due to the characteristics of the saturable reactor.
A current similar to the shape of a parabola having a horizontal period as shown in FIG. 4B is induced in Dp2 and Dp2, and in the coils 14a to 14d of the convergence correction device 12, in the direction from the connection point P1 to the connection point P2. Pseudo parabolic current comes to flow.

When this pseudo parabola current flows through the convergence correction device 12, the quadrupole magnetic field shown in FIG. 16 is generated, and the deflection of the side beams R and B is corrected. As a result, the horizontal misconvergence XH shown in FIG. 12 is corrected so as to approach zero.

Unlike the parabolic current shown in FIG. 17B, the pseudo parabolic current shown in FIG. 4B has an offset component on the negative side in the central portion of the screen, but static convergence correction by the convergence purity magnet 7 is performed. Will be corrected comprehensively.

As described above, the misconvergence XH can be reduced by adding a simple and inexpensive device including the pseudo parabola current generating device 30 having the saturable reactor characteristic and the convergence correction device 12 to the deflection yoke. Further, it is not necessary to distort the horizontal deflection magnetic field in order to correct XH, and the winding distribution adjustment of the vertical deflection coil and the horizontal deflection coil can focus on fine adjustment. Therefore, it becomes easy to design and manufacture a deflection yoke having a good convergence characteristic, and for example, a 21-inch display monitor having a misconvergence of 0.3 mm or less can be realized.

As shown in FIG. 3, in the pseudo parabola current generator 30, a cylindrical bias magnet 33 is arranged between a pair of drum cores 31 and 32. By rotating the bias magnet 33, the angle is changed. The structure is adjustable. By adjusting the angle of the bias magnet 33, it is possible to increase or decrease the DC bias magnetic field applied to the drum cores 31 and 32 to adjust the magnitude of the pseudo parabola current. This makes it possible to accurately correct misconvergence due to manufacturing variations.

The operation of adjusting the pseudo parabolic current by adjusting the DC bias magnetic field will be described below. An example of saturable reactor characteristics of the pseudo parabola current generator 30 is shown in FIG.
As described above, the adjustment angle of the bias magnet 33 is 0.
The DC bias magnetic field is maximum at 90 degrees and minimum at 90 degrees. If both the drum cores 31 and 32 are set to the fully saturated state near the adjustment angle of 0 degree, the pseudo parabola current output becomes the minimum. In that case, the adjustment angle is about 45
The maximum saturable reactor characteristic is obtained in the vicinity of 10 degrees, and the pseudo parabola current output becomes maximum. When the adjustment angle is around 90 degrees, the DC bias magnetic field is not applied, so that the saturable reactor characteristic cannot be obtained.

As described above, by adjusting the adjustment angle of the bias magnet 33 in the range from 0 degree to about 45 degrees, the value of the pseudo parabola current flowing in the convergence correction device 12 can be adjusted, and the desired convergence can be obtained. A correction effect can be obtained.

In the present embodiment, as shown in FIG. 3, the pseudo parabola current generator 30 electrically connects the primary side coil Dh1 and the secondary side coil Dp1 wound around the drum core 31 with the interlayer insulating paper 34. The primary side coil Dh2 and the secondary side coil Dp2 wound around the drum core 32 are electrically insulated by the interlayer insulating paper 35. Therefore, 2 of the pseudo parabola current generation device 30
Since the secondary coils Dp1 and Dp2 are separated from the high voltage of the horizontal deflection coil 8, electrical safety can be ensured. By separating the horizontal deflection coil 8, the vertical deflection coil 9 and the convergence correction device 12 from each other in this manner, the degree of freedom of the structure and wiring of the deflection yoke is increased, and the effect of facilitating the assembly is obtained.

Embodiment 2. In the present embodiment, by adding a sub-magnet, imbalance of pseudo parabolic current due to variations in dimensional accuracy and magnetic permeability of the drum cores 31 and 32 is prevented, and optimum convergence correction is maintained. FIG. 6 is a configuration diagram of a pseudo parabola current generation device according to a second embodiment of the present invention. In the figure, 31 and 32 are drum cores, 33 is a bias magnet, 34 and 35 are interlayer insulating papers, 30 is a pseudo parabolic current generator, 36 is a sub magnet, and 37 is a sub magnet guide.

A pseudo parabola current generator 36 shown in FIG.
In the configuration of the pseudo parabola current generating device 30 shown in FIG. 3, the sub magnet 36 is attached to the side surfaces of the pair of drum cores 31 and 32 in a direction parallel to the bias magnetic field generated by the bias magnet.

The ideal waveform of the pseudo parabola current of the pseudo parabola current generator 30 is symmetrical as shown in FIG. 4 (B). However, the drum cores 31 and 32 have variations in dimensional accuracy and magnetic permeability. Due to these variations, for example, assuming that the drum core 31 side is more likely to be saturated, the inductances Lh1 and Lh of the coils Dh1 and Dh2 are
h2 has a relationship of Lh1 <Lh2, and the pseudo parabola current waveform has a small waveform on the left side (Dh1 side) of the screen, as shown in FIG. 4C, resulting in imbalance in the pseudo parabola current waveform.

When the pseudo parabola current waveform is unbalanced as described above, the correction amounts of the side beams R and B are different between the left and right sides of the screen, and it becomes impossible to optimally adjust the left and right convergences of the screen at the same time.

As can be seen from FIG. 5, this imbalance is the same as increasing the magnetic bias by the bias magnet 33 only on the drum core 31 side. Therefore, in order to eliminate this imbalance, it is understood that the magnetic bias by the bias magnet 33 should be lowered only for the drum core 31.

Specifically, as shown in FIG. 6 (A), a sub magnet 36 is attached to the side surface of the drum core 31, and the position can be slid so that the effect of the magnetic field by the sub magnet 36 can be adjusted. It is desirable to do. By attaching the sub magnet 36 to the side surface of the drum core 31 in a direction to cancel the magnetic field of the bias magnet 33, the magnetic saturation of the drum coil 31 is weakened and the pseudo parabola current generated by the coil Dp1 is increased. That is, the current at the left end of the screen in FIG.
It is possible to generate a well-balanced pseudo parabola current as shown in (B).

Further, as shown in FIG. 4D, when the current on the right end side of the screen is small, the sub-magnet 36 is attached to the side surface of the drum coil 32 without changing the direction of the magnetic pole, so that the pseudo parabola current is generated. The balance can be adjusted.

As shown in FIG. 6, if the sub magnet 36 is constructed so as to be slidable along the side surfaces of the drum cores 31 and 32, the balance of the pseudo parabola current due to the variation in the magnetic characteristics of the drum cores 31 and 32 can be adjusted. it can. That is, when the pseudo parabola current on the left side of the screen is small, the sub magnet 36 is balanced on the drum core 31 side, and when the current on the right side of the screen is small, the sub-core 36 is balanced on the drum core 32 side. If it is present, it may be slid in the middle of the drum cores 31 and 32.

Although the magnetic field of the sub-magnet 36 has been described as canceling the magnetic field of the bias magnet 33, the correction effect of the sub-magnet 36 is reversed even if the magnetic field of the bias magnet 33 is strengthened. The same effect can be obtained with respect to the balance adjustment of the pseudo parabola current.

As a further effect of the sub-magnet 36, when the misconvergence shown in FIG. 12 is asymmetrical, for example, when the misconvergence is larger at the right end (when XHL <XHR), the correction on the right end side of the screen is performed. Needs to be larger than the left edge of the screen. In such a case, the misconvergence of the asymmetric component can be adjusted by adjusting the balance of the pseudo parabolic current so that the current on the right end side of the screen becomes large as shown in FIG. 4 (C). As described above, the balance adjustment of the pseudo parabola current by the sub magnet 36 is also effective for correcting the asymmetry of XH.

Although a sub-magnet is used for adjusting the balance of the pseudo parabolic current, a magnetic substance such as ferrite has an effect of slightly weakening the saturation magnetic field (an effect of increasing the current), so that the adjusting effect is reduced, but the same. Can be obtained.

Third Embodiment In the embodiment of the present invention, a leakage magnetic field due to the bias magnet 33 is greatly reduced by providing a structure in which a magnetic shield plate 38 made of a magnetic material is wound around the pseudo parabola current generation device 30. Figure 7
FIG. 3 is a configuration diagram of a pseudo parabola current generation device according to the present invention. In the figure, 31 and 32 are drum cores, 33 is a bias magnet, 34 and 35 are interlayer insulating papers, 36 is a sub magnet, 37 is a sub magnet guide, and 38 is a magnetic shield plate.

When the pseudo parabola current generator 30 as shown in FIG. 3 or 6 is mounted on the deflection yoke 6, a leakage magnetic field is generated by the bias magnet 33 that gives a DC bias magnetic field, which influences the convergence and distortion of the deflection yoke. I have something to do. This leakage magnetic field can be greatly reduced by adopting a structure in which a magnetic shield plate 38 made of a magnetic material is wound around the pseudo parabola current generating device 30 as shown in FIG. 7A. The same effect can be obtained by fitting the U-shaped magnetic shield plate 39 as shown in FIG. 7B.

Fourth Embodiment The present embodiment is a color cathode ray tube image receiver using the color cathode ray tube of the first to third embodiments. FIG. 8 is a block diagram of a color cathode ray tube receiver according to the present invention. In the figure, 2 is a panel, 3 is an electron gun, 6 is a deflection yoke, 7 is a convergence purity magnet, 8 is a horizontal deflection coil, 9 is a vertical deflection coil, 12 is a convergence correction device, 19 is a video signal processing circuit, 2
Reference numeral 0 is an RGB cathode drive circuit, 21 is a horizontal / vertical deflection signal generation circuit, 22 is a horizontal deflection coil drive circuit, 23 is a vertical deflection coil drive circuit, 30 is a pseudo parabola current generation device, and 40 is a deflection yoke.

FIG. 8 is a block diagram of a color cathode ray tube receiver equipped with the color cathode ray tube shown in FIG. As is apparent from the figure, the pseudo-parabolic current generation device 30 replaces the convergence correction coil drive circuit 15 and the convergence correction signal generation circuit 16 in the color cathode ray tube receiver by the conventional dynamic convergence correction shown in FIG. That is, since the dynamic convergence correction is performed in the color cathode ray tube, it is not necessary to newly prepare a circuit related to the dynamic convergence correction.

The pseudo-parabola current generator 30 has a function of adjusting the intensity of the pseudo-parabola current and the shape of the pseudo-parabola current (left-right balance), so that the convergence correction is performed as a single color cathode ray tube shown in FIG. can do. That is, it is possible to provide a color cathode ray tube whose dynamic convergence has been corrected.

Further, the color cathode ray tube receiver shown in FIG. 8 can also perform convergence correction, so that misconvergence occurs due to the characteristics of the horizontal / vertical deflection signal generation circuit 21 and the horizontal deflection coil drive circuit 22. Also, it is possible to optimize the convergence correction by re-executing the convergence correction.

[0078]

The deflection yoke according to the present invention, the color cathode ray tube using this deflection yoke, and the color cathode ray tube receiver using this deflection yoke use the quadrupole magnetic field to achieve the horizontal convergence of three electron beams. A convergence parabolic current generator that generates a pseudo parabola current to be supplied to the convergence correction device from the sawtooth wave current that flows through the convergence correction device and the horizontal deflection coil is used for correction, so that the convergence correction based on the pseudo parabola current is performed. It is possible to provide a simple and inexpensive deflection yoke that does not require an external circuit for generating a signal, and a color cathode ray tube or a color cathode ray tube receiver using the deflection yoke.

Also, by adjusting the angle of the bias magnet that applies the DC magnetic field bias that constitutes the saturable reactor, the DC bias magnetic field applied to the first drum core and the second drum core is changed to change the magnetic saturation characteristics. Therefore, the magnitude of the pseudo parabola current can be varied, and the convergence correction amount can be adjusted easily and accurately.

Further, the first coil and the third coil wound around the first drum core of the pseudo parabola current generator are insulated, and the second coil and the fourth coil wound around the second drum core are insulated. By doing so, since the horizontal deflection coil, the vertical deflection coil, and the convergence correction device are electrically separated from each other, the degree of freedom in the structure and wiring of the deflection yoke is increased, and the assembly is facilitated.

Further, since the sub-bias magnet for correcting the DC bias magnetic field by the bias magnet is arranged on the side surface of the first drum core or the second drum core of the pseudo parabola current generating device so that the position can be adjusted, You can adjust the balance of the parabolic current waveform,
Convergence correction becomes easier.

Further, since the pseudo parabola current generating device is surrounded by the magnetic shield plate, it is possible to reduce the leakage magnetic flux from the bias magnet and the coil which constitute the saturable reactor, and the influence on the convergence and the distortion of the deflection yoke. Can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a color cathode ray tube according to a first embodiment of the present invention.

FIG. 2 is a horizontal deflection system circuit diagram of a deflection yoke according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a structure of a pseudo parabola current generation device according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating an operation of the pseudo parabola current generation device in the first embodiment of the present invention.

FIG. 5 is a diagram showing a saturable reactor characteristic due to a horizontal deflection current of the primary side coil of the pseudo parabola current generation device in the first embodiment of the present invention.

FIG. 6 is a diagram showing a structure of a pseudo parabola current generation device according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a structure of a pseudo parabola current generation device according to a third embodiment of the present invention.

FIG. 8 is a configuration diagram of a color cathode ray tube image receiver in Embodiment 4 of the present invention.

FIG. 9 is a schematic configuration diagram of a color cathode ray tube.

FIG. 10 is a diagram illustrating an operation of horizontally deflecting an electron beam in an in-line array electron gun type color cathode ray tube.

FIG. 11 is a diagram showing an example of a horizontal deflection magnetic field.

FIG. 12 is a diagram illustrating horizontal misconvergence in a uniform magnetic field.

FIG. 13 is a diagram for explaining misconvergence in the horizontal direction after the convergence correction by the pin magnetic field.

FIG. 14 is a diagram for explaining misconvergence in the horizontal direction after convergence correction by a pin magnetic field and a barrel magnetic field.

FIG. 15 is a view showing a conventional color cathode ray tube provided with a convergence correction device.

FIG. 16 is a diagram showing a conventional convergence correction device.

FIG. 17 is a diagram showing an example of a horizontal deflection current and a convergence correction current of a conventional color cathode ray tube.

FIG. 18 is a diagram showing a drive system for a horizontal deflection coil and a convergence correction coil of a conventional color cathode ray tube.

FIG. 19 is a configuration diagram of a conventional color cathode ray tube receiver by dynamic convergence correction.

FIG. 20 is a diagram showing a grid-shaped adjustment signal in conventional dynamic convergence correction.

[Explanation of symbols]

3 electron guns, 7 convergence purity magnets, 8 horizontal deflection coils, 9 vertical deflection coils, 12
Convergence correction device, 30 Pseudo parabolic current generation device, 31, 32 Drum core, 33 Bias magnet, 36 Sub magnet, 38 Magnetic shield plate 40 Deflection yoke.

Claims (7)

[Claims] 1. A deflection yoke mounted on a color cathode ray tube for deflecting an electron beam in a horizontal direction and a vertical direction, comprising: a horizontal deflection coil for deflecting the electron beam in a horizontal direction; A vertical deflection coil that deflects the beam into a horizontal direction, a convergence correction device that corrects the horizontal convergence of the electron beam by a quadrupole magnetic field, and a pseudo parabola current that is generated from a sawtooth wave current that flows through the horizontal deflection coil. And a pseudo parabola current generator having a saturable reactor to be supplied. 2. The deflection yoke according to claim 1, wherein the quasi-parabolic current generation device includes means for changing the DC bias magnetic field by adjusting the angle of the bias magnet forming the saturable reactor. 3. The deflection yoke according to claim 1, wherein in the pseudo parabola current generation device, a plurality of coils forming the saturable reactor are insulated from each other. 4. The deflection yoke according to claim 1, wherein in the pseudo parabola current generation device, a sub-magnet is arranged to correct the DC bias magnetic field generated by the bias magnet. 5. The deflection yoke according to claim 1, wherein the pseudo parabolic current generation device is surrounded by a magnetic shield plate. 6. A color cathode ray tube comprising the deflection yoke according to any one of claims 1 to 5. 7. A color cathode ray tube receiver comprising the color cathode ray tube according to claim 6.