JP2000149819A - Deflection yoke - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deflection yoke correcting lateral pin distortion in an intermediate part without badly affecting a convergence characteristic. SOLUTION: In winding of at least one of wires wound into a saddle shape integrally with a horizontal deflection coil wound into the saddle shape, the wire is wound so as to be positioned within a range of 40 deg.±10 deg. by measurement from the horizontal axis from the central part of a pipe axis directional coil length to a screen side edge part. From the central part to the neck side edge part, a correcting coil 1 bent in the central part is wound so as to be positioned within a range of 60 deg.±10 deg. by measurement from the horizontal axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke for an in-line type color cathode ray tube, and more particularly to a deflection yoke having improved left and right pin distortion at an intermediate portion of a screen without affecting convergence performance.

[0002]

2. Description of the Related Art As is well known, a deflection yoke used for a color cathode ray tube equipped with an in-line type electron gun includes a horizontal deflection coil for deflecting an electron beam in a horizontal direction and a vertical deflection coil for deflecting an electron beam in a vertical direction. A winding frame formed of a plastic resin for winding these coils and a bosh-shaped ferrite core are assembled as main components. The deflection yoke is formed so that the horizontal deflection coil has a pincushion type magnetic field distribution,
The vertical deflection coil is formed so as to have a barrel type magnetic field distribution, thereby realizing self-convergence which does not require a convergence correction circuit. By using such a deflection yoke for a television receiver or a display device, cost reduction is achieved. by the way,
In recent years, in particular, there has been a demand for higher definition of images and characters displayed on CRTs for displays, and the demand for flattening the panel surface of the CRT has become stronger, which has led to severe improvements in deflection distortion and convergence quality. Has been requested. Therefore, left and right pin distortions in the middle portion of the screen as shown in FIG.

As a conventional technique for correcting distortion, a magnet is generally used.
Japanese Patent No. 40473 discloses means for correcting distortion in the vertical direction of a screen using six magnets. FIG. 8 is an explanatory diagram for explaining how to attach six magnets. Six magnets are attached to the outer periphery of the screen-side end of the horizontal deflection coil bobbin 3, and these magnets can correct the vertical distortion of the screen and also correct the left and right pin distortion of the middle part. It should be noted that the correction of the left and right pin distortion at the intermediate portion is corrected by the magnets 8a to 8d arranged at the corners. That is, due to the magnets 8a to 8d arranged at the corners, the outermost vertical line changes position outward in the horizontal direction of the screen, and the middle vertical line changes inward. Combining both actions,
The pin distortion of the middle vertical line is improved on the basis of the outermost vertical line. In FIG. 8, details of the horizontal deflection coil winding frame 3 are omitted. X is the horizontal axis and Y is the vertical axis.

[0004]

In the conventional deflection yoke as described above, the right and left pin distortion at the intermediate portion as shown in FIG. 7 can be corrected, but the distortion correction is performed only by the magnet. Therefore, there is a problem that the convergence characteristics are adversely affected. That is, since the magnetic fields of the magnets at the center of the upper and lower three magnets shown in FIG. 8 give different effects to the blue B, green G, and red R beams as shown in FIG. Misconvergence is triggered. For this reason, there has been a problem that it is difficult to achieve both improvement in distortion and convergence particularly in a deflection yoke for a display device having strict standards. The present invention has been made in order to solve the above-mentioned problems, and has an adverse effect on the convergence characteristics by optimizing the magnetic field distribution of the horizontal deflection coil and further optimizing the magnetic field distribution of the magnet. It is an object of the present invention to obtain a deflection yoke capable of correcting left and right pin distortion in an intermediate portion without using a deflection yoke.

[0005]

SUMMARY OF THE INVENTION A deflection yoke according to the present invention is a deflection yoke mounted on a color cathode ray tube and generating a magnetic field for deflecting an electron beam in a horizontal and vertical direction. In the neck side, the deflection force in the direction within the first angle range measured from the horizontal axis becomes strong and the contribution ratio to the convergence correction is high,
A magnetic field generating means for generating a magnetic field is provided so that a deflection force in a direction within a second angle range measured from the horizontal axis is increased. Further, the magnetic field generating means is wound in a saddle shape, and at least one of the windings has a first angle range measured from the horizontal axis from the center of the tube axial coil length to the screen side end. A horizontal deflection coil wound from the center to the neck end, bent at the center and wound within a second angle range measured from the horizontal axis. Is what is being done.

Further, the first angle range is 40 ° ± 10 °.
In addition, the second angle range is set to 60 ° ± 10 °. Further, a magnet for deflecting the electron beam in the tube axis direction is attached to the screen side end of the horizontal deflection coil so as to be located within a second angle range measured from the horizontal axis. . Furthermore, the second
Is set to 60 ° ± 10 °. Furthermore, a magnet for deflecting the electron beam in a direction away from the tube axis is attached to the screen side end of the horizontal deflection coil so as to be located within a first angle range measured from the horizontal axis. Things. The first angle range is set to 40 ° ± 10 °.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a front view of a deflection yoke according to a first embodiment of the present invention as viewed from a screen side, in which only main parts are illustrated. Reference numeral 1 denotes a coil portion for correcting distortion and convergence entangled in a saddle-type horizontal deflection coil (hereinafter simply referred to as a horizontal deflection coil);
Reference numeral 2a denotes a distortion correcting magnet, and 3 denotes a winding frame around which a horizontal deflection coil is wound. Next, the distortion and convergence correction coil unit (hereinafter, referred to as a correction coil unit) 1 will be described in detail. The correction coil portion 1 is a one-turn coil portion that is wound at a center portion of the coil length in the tube axis direction while being wound around the horizontal deflection coil so that the winding position is changed. And the winding method is as follows. That is, one of the saddle-shaped wires is
From the center of the coil length in the tube axis direction to the end on the screen side, 30 to 50 degrees (40 ° ± 10 °) measured from the horizontal axis.
°) and is bent at the center from the center to the neck side end, and 50 to 70 degrees as measured from the horizontal axis (referred to as the first angle range). 60
(° ± 10 °) (referred to as a second angle range).

The correction coil unit 1 is wound around the upper and lower horizontal deflection coils, and the one including the correction coil unit 1 is a horizontal deflection coil. In FIG. 1, if the entire horizontal deflection coil is illustrated, it is difficult to understand the existence of the correction coil unit 1. Therefore, only the correction coil unit 1 is illustrated, and other parts are not illustrated. The above-described angle is an angle measured by rotating a straight line passing through the central axis of the deflection yoke, that is, the tube axis with respect to the horizontal axis X, but in this specification, it is simply measured from the horizontal axis. It is written like angle.

Next, a description will be given of a point that the left and right pin distortions at the intermediate portion can be corrected without adversely affecting the convergence characteristics by configuring the horizontal deflection coil as described above. Here, when considering the effect of the magnetic field of the deflection yoke on the convergence / distortion characteristics, as shown in FIG. 2, the influence on the convergence is the contribution ratio from the neck side of the deflection yoke to the center of the coil length in the tube axis direction. The effect on distortion is high from the screen side of the deflection yoke to the center. The reason is R, G, B
It is described by the distance between the three beams and the amount of deflection from the central axis. From the neck side to the center, the distance between the R, G, and B beams is large, so that the difference in the influence of the magnetic field distribution on each of R, G, and B increases. This means that the difference in the amount of movement between the three colors is large, and the convergence change is large. Conversely, the closer to the screen, the narrower the interval between the three colors, the less the effect on convergence. On the other hand, the amount of deflection from the central axis is small on the neck side and large on the screen side. In a region where the amount of deflection is small, the influence of the magnetic field distribution occurs on the entire screen, so that the influence on the distortion is small. In the region where the amount of deflection is large,
The distance between the beam and a magnetic field source such as a winding or magnet
Since a large difference occurs depending on the deflection position on the screen, the influence is localized, and the contribution rate of changing the distortion increases.

[0010] The relationship between the direction in which the electron beam is deflected and the pin distortion in the left and right portions in the middle will be considered. FIG. 4 shows the operation of the distortion correcting magnet. In the figure, θ is the direction of the deflection force from the peripheral portion to the tube axis and is the angle from the horizontal axis, mRL is the distortion of the intermediate portion, and RL is the distortion of the peripheral portion. FIG. 5 is a graph showing a simulation result of the amount of change in the distortion mRL in the middle part and the distortion RL in the peripheral part according to the angle θ from the horizontal axis under the conditions of FIG. In the figure, the amount of change in distortion represents a percentage with respect to the horizontal length of the screen, and the direction away from the Y axis is positive. For example, when θ = 70 °, RL = 0.6
8, mRL = 0.47, and RL> mRL. That is, the distortion of the left and right pins in the peripheral portion is larger than that in the intermediate portion. In this case, the right and left pin distortion of the vertical line in the peripheral portion is corrected in the Y-axis direction by RL = 0.68 by using a pin distortion correction circuit used in a television receiver or the like. The pin distortion is corrected in the Y-axis direction to mRL = 0.47 or more, and tends to be a barrel. This indicates that it works in the direction of eliminating the pin distortion in the middle part in FIG. Therefore, the range of RL> mRL in the graph of FIG. 5 is an effective range for correcting the pin distortion in the middle part.

In this simulation, when the deflection force is in the direction from the tube axis to the peripheral portion, the positive and negative signs of the distortion change amount in FIG. 5 are reversed. Therefore, in the case of this deflection force, the range of RL <is an effective range for correcting the pin distortion at the intermediate portion. FIG. 3 shows a phenomenon when an actual machine is considered. FIG. 3 is an explanatory diagram for explaining a relationship between a direction in which a deflected force is applied and a change in strain. FIG. 3 (a) shows that when the deflection force goes from the tube axis to the periphery, it is 40 ° from the horizontal axis.
It is shown that if the force of deflecting the electron beam in the direction of (1) is strong, pin distortion in the left and right peripheral portions becomes larger than that in the intermediate portion. Therefore, when the left and right pin distortion of the peripheral portion is corrected to be a straight line, the barrel direction of the intermediate portion is corrected so as to eliminate the conventional pin distortion shown in FIG. Becomes smaller.

FIG. 3B shows that when the deflecting force is directed from the tube axis to the peripheral portion, if the force for deflecting the electron beam in the direction of 60 ° from the horizontal axis is strong, the left and right pin distortions in the peripheral portion with respect to the intermediate portion are large. Indicates small. Therefore, when the left and right pin distortions in the peripheral portion are corrected to be linear, the pin distortion in the middle portion is not eliminated, and in addition to the conventional pin distortion shown in FIG.
As a result, the left and right pin distortion at the intermediate portion increases. However, as described above, when the deflection force is set in the direction from the tube axis to the peripheral portion so that the positive and negative signs of the distortion change amount in FIG. The distortion increases. In other words, when the left and right pin distortions of the peripheral portion are corrected to be straight lines, the barrel direction of the intermediate portion is corrected so as to eliminate the conventional pin distortion shown in FIG.
Left and right pin distortion in the middle part is reduced. Note that FIG.
According to the simulation of FIG. 7, in order to correct the pin distortion in the middle part of FIG.
Is an effective range.

As described above, in order to reduce the left and right pin distortion at the intermediate portion by correcting the left and right pin distortion at the peripheral portion so as to be a straight line, the angle from the tube axis to the peripheral portion at 40 ° on the clean side is reduced. It is effective to apply a deflecting force in the direction, and to apply a deflecting force in the direction from the periphery to the tube axis at 60 °. Here, it is necessary to eliminate misconvergence caused by the correction of the right and left pins in the middle portion. As shown in FIG. 2, a deflection force in the direction opposite to the distortion correction may be provided from the neck side of the deflection yoke having a high contribution rate to the convergence characteristic to the center of the coil length in the tube axis direction. Actually, when the deflection force is constituted by the winding of the magnet and the coil, the deflection correction magnet in which the direction of the deflection force is directed from the periphery to the tube axis is located on the screen side of the deflection yoke from the horizontal axis when viewed from the front of the tube axis. It is arranged in the direction of 60 °. Further, it is preferable that the windings forming the correction coil portion in which the direction of the deflection force is the peripheral portion from the tube axis are arranged in a direction at 40 ° from the horizontal axis.

Further, in order to eliminate misconvergence due to the deflection force of the correction magnet,
From the neck side of the deflection yoke to the center of the coil length in the tube axis direction, it is arranged on the screen side of the deflection yoke at a direction of 60 ° from the horizontal axis when viewed from the front of the tube axis. In order to reduce the influence of misconvergence due to the winding for correcting the distortion, the deflection yoke is arranged on the screen side in the direction of 40 ° from the horizontal axis when viewed from the front of the tube axis, in order to reduce the influence of the tube axis of the deflection yoke. The distance from the center of the directional coil length to the end on the screen side. Therefore, the correction coil unit 1 in FIG.
Satisfies the above winding conditions and the effective deflection force arrangement range is ±
Consider that it is 10 °. In other words, while being wound in the saddle shape, one of the windings wound in the saddle shape is 40 ° ± 10 ° measured from the horizontal axis between the center of the tube axial coil length and the screen side end. , And bent at the center of the tube axial coil length, between the center of the tube axial coil length and the end on the neck side, 60 ° ±± measured from the horizontal axis. It is wound so as to be located within a range of 10 °. The correction magnet 2a is arranged within a range of 60 ° ± 10 ° as measured from a horizontal axis not on the screen side of the deflection yoke.

As described above, in the first embodiment, on the screen side having a large contribution to distortion correction, the winding distribution is set so as to correct the left and right pin distortion in the middle portion, and the resulting misconvergence is corrected by the convergence correction. The correction is made with the winding from the neck side to the center part where the contribution ratio is large. The correction coil unit 1 is a one-turn coil, but may be composed of several turns of a coil. By the way, a similar effect can be considered for the vertical deflection coil. However, the vertical deflection coil has a shorter coil length than the horizontal deflection coil. Therefore, it is difficult to make a characteristic difference between the neck side and the screen side, and the obtained effect is reduced. Therefore, the object is achieved by targeting only the horizontal deflection coil.

Embodiment 2 Although the correction coil unit 1 is wound around the horizontal deflection coil as in the first embodiment, the left and right pin distortion at the middle portion of the screen can be improved without affecting the convergence performance. However, the second embodiment further corrects the distortion. The magnet for mounting is attached to the screen side to further improve the effect of improving distortion. FIG. 1 shows Embodiment 1
The distortion correcting magnet 2a is attached to the outer periphery of the screen side end of the horizontal deflection coil winding frame 3 so that its position is within a range of 60 ° ± 10 °. ing. In addition, as described in the first embodiment, in order to correct the left and right center pin distortion,
It is necessary to increase the deflection force in the direction of 40 ° ± 10 ° on the screen side and weaken the deflection force in the direction of 60 ° ± 10 °. Therefore, the distortion correcting magnet 2a is attached with the polarity shown in FIG. 1 so that the electron beam is deflected in the direction of the central axis (that is, the tube axis) of the deflection yoke.

Embodiment 3 The third embodiment is different from the second embodiment in the mounting position of the distortion correcting magnet. FIG. 6 is a front view of a deflection yoke according to a third embodiment of the present invention as viewed from a screen side, in which only main parts are illustrated. 6, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In the third embodiment, the distortion correcting magnet 2b is positioned at the outer periphery of the screen-side end of the horizontal deflection coil bobbin 3 at a position of 40 ° ± 10 °.
It is attached so that it is within the range of °. As described in the first embodiment, the deflection force in the direction of 40 ° ± 10 ° is increased on the screen side, and the deflection force in the direction of 60 ° ± 10 ° Need to be weakened. Therefore, the distortion correcting magnet 2a
Means that the electron beam is centered on the deflection yoke (ie, the tube axis)
It is attached with the polarity shown in FIG.

[0018]

As described above, according to the present invention, in a deflection yoke mounted on a color cathode ray tube and generating a magnetic field for deflecting an electron beam in the horizontal and vertical directions, the screen side having a high contribution to distortion correction has a horizontal axis. The deflection force in the direction within the first angle range measured from the above is increased, and the deflection force in the direction within the second angle range measured from the horizontal axis is increased on the neck side having a high contribution rate to the convergence correction. To
Since it has a magnetic field generating means for generating a magnetic field,
The left and right pin distortion at the intermediate portion can be corrected without adversely affecting the convergence characteristics.

The magnetic field generating means is wound in a saddle shape, and at least one of the windings has a first axis measured from a horizontal axis measured from the center to the screen side end of the coil length in the tube axis direction. Wound to be within the angle range of
The portion from the center to the neck side end is formed by a horizontal deflection coil which is bent at the center and wound so as to be located within a second angle range measured from the horizontal axis. By simply setting the line position, it is possible to correct the left and right pin distortion at the intermediate portion without adversely affecting the convergence characteristics. Therefore, a deflection yoke with low distortion and good convergence performance can be realized.

Further, a magnet for winding the correction coil section around the horizontal deflection coil and deflecting the electron beam in the tube axis direction is provided at the screen side end of the horizontal deflection coil at the second side measured from the horizontal axis. Since it is mounted so as to be located within the angle range, it is possible to correct the left and right pin distortion at the intermediate portion without adversely affecting the convergence characteristic only by setting the winding position and adding an inexpensive magnet. Therefore, a deflection yoke with low distortion and good convergence performance can be realized.

A magnet for winding the correction coil portion around the horizontal deflection coil and deflecting the electron beam in a direction away from the tube axis is provided at the screen-side end of the horizontal deflection coil at a position measured from the horizontal axis. Since it is attached so that it is located within the angle range of 1,
By simply setting the winding position and adding an inexpensive magnet, it is possible to correct left and right pin distortion in the middle without adversely affecting the convergence characteristics. Therefore, a deflection yoke with low distortion and good convergence performance can be realized.

[Brief description of the drawings]

FIG. 1 is a front view of a deflection yoke according to Embodiments 1 and 2 of the present invention as viewed from a screen side.

FIG. 2 is an explanatory diagram illustrating a contribution ratio of a magnetic field of a deflection yoke affecting convergence and distortion.

FIG. 3 is an explanatory diagram illustrating a relationship between a direction in which a deflected force is applied and a change in strain.

FIG. 4 is a diagram illustrating an operation of a distortion correcting magnet.

FIG. 5 is a diagram showing a result of simulating the amount of change in distortion.

FIG. 6 is a front view of a deflection yoke according to a third embodiment of the present invention as viewed from a screen side.

FIG. 7 is an explanatory diagram showing left and right pin distortions in an intermediate portion of the screen.

FIG. 8 is an explanatory diagram for explaining how to attach a conventional distortion correction magnet.

FIG. 9 is an explanatory diagram for explaining a process of occurrence of misconvergence.

FIG. 10 is an explanatory diagram illustrating misconvergence generated by a magnet magnetic field.

[Explanation of symbols]

1. Correction coil unit, 2a, 2b Distortion correction magnet, 3 horizontal deflection coil winding frame.

Claims (7)

[Claims] In a deflection yoke mounted on a color cathode ray tube and generating a magnetic field for deflecting an electron beam in horizontal and vertical directions, a screen having a high contribution to distortion correction has a first angle range measured from a horizontal axis. In the neck side, where the deflection force in the direction within the direction becomes stronger and the contribution rate to the convergence correction is higher, the magnetic field generation for generating the magnetic field is performed so that the deflection force in the direction within the second angle range measured from the horizontal axis becomes stronger. A deflection yoke characterized by comprising means. 2. The magnetic field generating means is wound in a saddle shape, and at least one of the windings has a first portion measured from a horizontal axis measured from a central portion of a coil length in a tube axial direction to an end portion on a screen side. , And bent from the central portion to the neck-side end portion at the central portion and wound so as to be located within a second angular range measured from the horizontal axis. 2. The deflection yoke according to claim 1, wherein the deflection yoke comprises a horizontal deflection coil. 3. The deflection yoke according to claim 1, wherein the first angle range is set at 40 ° ± 10 °, and the second angle range is set at 60 ° ± 10 °. . 4. A magnet for deflecting the electron beam in the tube axis direction is attached to the screen-side end of the horizontal deflection coil so as to be located within a second angle range measured from the horizontal axis. 3. The deflection yoke according to claim 2, wherein: 5. The deflection yoke according to claim 4, wherein the second angle range is set to 60 ° ± 10 °. 6. A magnet for deflecting the electron beam in a direction away from the tube axis is attached to the screen side end of the horizontal deflection coil so as to be located within a first angle range measured from the horizontal axis. 3. The deflection yoke according to claim 2, wherein: 7. The deflection yoke according to claim 6, wherein the first angle range is set to 40 ° ± 10 °.