JP2001155661A - Deflection yoke - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deflection yoke, which is more reasonably priced, without affecting horizontal and vertical deflection magnetic field. SOLUTION: The distance between outer face of horizontal deflection coil 1 and inner face of ferrite core 4 is defined as Xc in the horizontal direction of screen and Yc in the horizontal direction, the Xc and Yc being different values from each other. Xc and Yc are expressed as Y/X=Yc/Xc×α when distance between outer face of horizontal deflection coil 1 and outer face of vertical deflection coil 3 is defined as X and Y in the horizontal and vertical directions, respectively, and trilemma can be amended by adjusting α.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke used for a cathode ray tube image display device such as a color television receiver and a video display device.

[0002]

2. Description of the Related Art A cathode ray tube used for an image display device such as a color television receiver and a video display device generally has an in-line arrangement of electron guns for emitting three RGB electron beams. It is a target. In order to focus the three electron beams over the entire screen, of the deflection magnetic fields of the mounted deflection yoke, the horizontal deflection magnetic field is a pincushion-type pinion magnetic field, and the vertical deflection magnetic field is a barrel-type barrel magnetic field. do it.

However, in reality, focusing of the electron beam remains due to compatibility with the structure of the cathode ray tube and other characteristics such as screen distortion, and a correction residue called a trilemma occurs.

In general, the amount of trilemma is defined by the convergence of the R beam and B beam, which are side beams in an in-line arrangement, and the amount of misconvergence XH in the horizontal direction at both ends of the raster in the X-axis direction and the amount of Y-axis in the screen. Misconvergence amount YH in the horizontal direction at both ends in the horizontal direction and misconvergence amount PQ in the vertical direction in the screen diagonal direction
Calculated using V.

[0005] XH and PQV are influenced by the horizontal deflection magnetic field, and YH and PQV are changed by the vertical deflection magnetic field. That is, the amount of trilemma can be adjusted by the form and strength of the magnetic field formed by the horizontal and vertical deflection coils of the deflection yoke. However, since XH and PQV or YH and PQV are in mutually opposite directions, only the main coil itself of the deflection yoke is used. Adjustment is difficult.

In order to solve this problem, there are known a method of partially adjusting a horizontal deflection magnetic field and a method of partially adjusting a vertical deflection magnetic field. In the former method, a bias coil and a permanent magnet are added, and the inductance of the horizontal deflection coil is varied according to the vertical deflection period, so that the deflection current flowing in the horizontal deflection coil is generally adjusted.
It is used for correction.

[0007] The latter is equipped with a coil for generating a quadrupole magnetic field separately from the vertical deflection coil.
Is a method of focusing. In this case, a correction coil called a convergence yoke mounted near the electron gun behind the deflection yoke is generally used to correct the aberration of the center beam with respect to the side beam. This is a method of generating a magnetic field. JP-A-7-184220, JP-A-59-23671
Japanese Patent Application Laid-Open Publication No. H10-205163 is a known example.

[0008]

As described above, the range of the trilemma is limited when the correction is performed by forming the magnetic fields of the main horizontal and vertical deflection coils of the deflection yoke. It is essential to make corrections. For this reason, the number of parts increases, productivity decreases, and the cost increases.

[0009] In addition, with the recent trend toward multimedia and high quality, the deflection frequency has shifted to higher speeds.
The added compensating component must be sufficiently satisfactory even under conditions such as sufficient temperature characteristics. In particular, since the means for adjusting the inductance of the horizontal deflection coil using the bias coil uses the horizontal deflection current, the selection of the electric wire to be used and the magnetic material of the coil core is limited to higher quality, and the cost increases. Becomes Further, the side effect due to the addition of the correction component cannot be neglected, and the deflection efficiency may be degraded and other screen characteristics may be adversely affected.

SUMMARY OF THE INVENTION An object of the present invention is to perform trilemma correction more effectively without mounting other components or while minimizing the amount of correction by other components as much as possible. It is an object of the present invention to provide a less expensive deflection yoke that does not provide.

[0011]

In order to achieve the above object, a first means is to provide a horizontal deflection coil and a vertical deflection coil mounted on a television receiver or an image display device using a color cathode-ray tube in an in-line arrangement. And a main core, the shape of which is a non-conical deflection yoke having a major axis direction and a minor axis direction, wherein the distance between the horizontal deflection coil outer surface and the vertical deflection coil outer surface is X in the major axis direction and X in the minor axis direction. Y, and the distance between the outer surface of the horizontal deflection coil and the inner surface of the main core is Xc in the long axis direction and Yc in the short axis direction, Yc / Xc is more than ± 10% of Y / X with respect to Y / X. The distance is set.

The second means is characterized in that, in the first means, a convex portion or a concave portion is formed on each of the inner surface in the major axis direction and the inner surface in the minor axis direction of the main core.

The third means is characterized in that, in the first means, at least one pair of magnetic bodies is mounted between the horizontal deflection coil and the vertical deflection coil and the inner surface of the main core.

In recent deflection yokes, in order to effectively prevent a leakage magnetic field, a ferrite core provided is generally mounted outside each deflection coil, so that the deflection of an electron beam can be more effectively performed. For this purpose, the ferrite core is generally installed at the shortest distance from the horizontal deflection coil and the vertical deflection coil.

A deflection yoke having a non-conical shape having a long axis side and a short axis side is known.
There is a feature that the deflection efficiency is improved by reducing the diameter of the opening forming the trumpet shape. In this deflection yoke, the shapes of the horizontal deflection coil and the vertical deflection coil have different diameters in the horizontal and vertical directions, and the present invention works more effectively.

The ferrite core naturally has a non-conical shape so as to be positioned at the shortest distance with respect to the horizontal and vertical deflection coils forming the non-conical shape. In the axial direction, the distance from the deflection coil can be determined so as to be the best distance in consideration of convergence.

That is, by changing the shape of the inner surface of the ferrite core so that the ferrite core can be arranged at different positions in the horizontal axis direction and the vertical axis direction, the axial direction closer to the core is deflected. Is enhanced, and the magnetic field of the deflection coil decreases in the axial direction away from the axis.

As a result, XH and YH, which are misconvergences in the horizontal and vertical axis directions, change and do not significantly affect the misconvergence in the diagonal portion of the screen. Therefore, the PQV does not change and the amount of trilemma can be adjusted by itself. It becomes possible. Also, unlike the general conical deflection yoke, the non-conical ferrite core has a special manufacturing method, so it is possible to form a partial uneven shape on the inner surface, which was difficult with the conventional conical ferrite core. Become.

Therefore, it is also possible to make the inner surface of the ferrite core in the major axis and minor axis directions uneven so that the distances from the horizontal and vertical deflection coils are different from each other. further,
If the required shape of the inner surface of the ferrite core cannot be obtained,
By mounting a pair of magnetic pieces as separate pieces between the ferrite core and the horizontal and vertical deflection coils and closely contacting the ferrite core, this is equivalent to securing a different distance from the deflection coil.

With these structures, one of the long axis side and the short axis side of the ferrite core is made closer to the horizontal and vertical deflection coils, and the other is made farther away, whereby the horizontal and vertical deflection magnetic fields are locally operated. , The trilemma can be adjusted. The distance from the deflection coil itself is different from the case of operating over the entire surface of the ferrite core, and the deflection efficiency does not change significantly. In addition, it is not necessary to mount a dedicated component for correction separately added, so that an increase in the number of components can be avoided, and an inexpensive deflection yoke can be provided.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a deflection yoke according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a non-conical deflection yoke showing positions of a ferrite core according to the embodiment, a horizontal deflection coil, and a vertical deflection coil. The pair of horizontal deflection coils 1 has a shape conforming to the shape of an aspherical cathode ray tube to be mounted, and a pair of vertical deflection coils 3 have the same shape via a molded part 2.

In this figure, as the vertical deflection coil 3, a coil formed by energization and pressurization is shown as an embodiment. The ferrite core 4 is mounted outside the vertical deflection coil 3 and has a non-conical shape. The inner surface of the ferrite core 4 has the shortest distance along the outer shape of the vertical deflection coil 3 and the outer shape of the horizontal deflection coil 1 or the shape of the molded product 2 in order to more efficiently deflect the electron beam. Placed at a distance.

Here, with respect to the screen of the cathode ray tube, the horizontal direction is the long axis which is the longitudinal direction, the vertical direction is the short axis, and the distance between the outer surface of the horizontal deflection coil 1 and the outer surface of the vertical deflection coil 3 is the long axis. , X and Y on the short axis side. The horizontal deflection coil 1 and the vertical deflection coil 3 are generally not arranged on the short axis and the long axis, respectively, as shown in FIG. 1 for the purpose of forming the deflection magnetic field. The extension of the outer surface of the coil may be considered.

The distance between the outer surface of the horizontal deflection coil 1 and the inner surface of the ferrite core 4 is defined as Xc and Yc. In FIG. 1, it is assumed that the distance between the inner surface of the ferrite core 4 and the outer surface of the horizontal deflection coil 1 is such that the short axis direction is farther away from the long axis direction.

Therefore, Xc and Yc in FIG.
Xc <Y with respect to the distance between X and Y described above.
It is assumed that c has a more prominent relationship. That is,
The ratio of X, Y and the ratio of Xc, Yc are established by a certain coefficient α, and each positional relationship has a relationship by the following formula.

Y / X = Yc / Xc × α (1) FIG. 2 is a diagram showing the horizontal deflection magnetic field when the ferrite core 4 having the shape of FIG. 1 is provided. Normally, to focus three electron beams in a cathode ray tube having an in-line electron gun, the horizontal deflection magnetic field is a pincushion pincushion magnetic field, and the vertical deflection magnetic field is a barrel-type barrel magnetic field.

Here, the core 4 is closer to the long axis side of the horizontal deflection coil 1 and farther away to the short axis side due to the inner surface shape of the ferrite core 4 in FIG. 1, so that the horizontal deflection magnetic field 5 shown by a solid line in FIG. As described above, the pincushion magnetic field is further emphasized in the portion in the long axis direction, and the horizontal deflection magnetic field in the short axis direction is reduced. Although the pincushion magnetic field is emphasized even at the distance Xc of only the long axis, the short axis has a larger barrel magnetic field than the long axis in the horizontal deflection coil 1. Will be encouraged.

As a result, the convergence becomes the pattern shown in FIG. 3, and the amount of misconvergence (a, b) of the horizontal R beam and the B beam at both ends in the X-axis direction of the screen, which is called XH, changes in the negative direction. Will do.

Since the horizontal deflection magnetic field 5 is partially operated as shown in FIG. 2, XH changes further, and then YH which is the horizontal misconvergence (c, d) at both ends in the Y-axis direction of the screen.
Changes. However, the arrangement of the vertical deflection coil 3 is generally such that the interval between the pair of coils is not as close to that of the horizontal deflection coil 1, and the vertical deflection coil 3 itself is located in the short axis portion where the distance from the core 4 is different. Are not disposed as close as the horizontal deflection coil 1. Therefore, the relationship between Xc and Yc shown in FIG. That is, the change in convergence is dominated by XH, and there is little change in other portions.

FIG. 4 shows the residual convergence which is called a trilemma. The amounts are XH, the horizontal misconvergence YH at both ends in the Y-axis direction of the screen, and the vertical misconvergence amount in the diagonal direction. k,
1, m, n).

That is, XH = (a + b) / 2, YH = (c
+ D) / 2, PQV = (k + 1 + 1m + n) / 4, and the trilemma = XH-YH + PQV.

When this calculated value becomes negative, it becomes a negative trilemma, and it is desirable that it becomes zero. Here, the variation of XH shown in FIG. 3 is adjusted by forming a large barrel magnetic field by the horizontal deflection coil 1 itself. In this case, since the entire screen changes, PQV also changes in the negative direction. become. Therefore, since XH and PQV can be corrected in the same direction, the amount of trilemma is reduced. In the case of a negative trilemma, on the contrary, the distance between the ferrite core 4 and the horizontal deflection coil 1 shown in FIG.

From the above, the distance X between the inner surface of the farite core 4 and the outer surface of the horizontal deflection coil 1 is represented by X, Y, which is the outer surface distance between the horizontal deflection coil 1 and the vertical deflection coil 3.
The trilemma can be adjusted by changing c and Yc, which is equivalent to changing the coefficient α in the above-described equation (1).
That is, the correction can be performed by making the coefficient α larger than Y / X in the case of a positive trilemma, and making the coefficient α smaller than Y / X in the case of a negative trilemma.

The coefficient α varies depending on the neck diameter and the deflection angle of the cathode ray tube to be mounted, but is generally ± Y / X.
10% is a guide. Therefore, when designing the ferrite core 4, the coefficient α may be determined in consideration of the convergence characteristics, and Xc and Yc may be calculated. It is not necessary to ensure the relationship between Xc and Yc uniformly on the tube axis of the cathode ray tube, and the effect can be obtained only at the portion on the opening side where the diameter becomes large.

FIG. 5 is a cross-sectional view showing the ferrite core and the deflection coil according to the second aspect of the present invention when the uneven surface 6 is provided on the long axis and the short axis of the ferrite core 4. The uneven surface 6 may be provided in a mold shape, or may be formed partially by cutting or polishing.

As described above, since the uneven surface 6 does not need to be formed uniformly with respect to the tube axis of the cathode ray tube, the shape may be determined according to the required amount of change in convergence. With the uneven surface 6, the distances Xc and Yc between the horizontal deflection coil 1 and the core 4 are manipulated as in FIG.

FIG. 6 is a detailed side view of a deflection yoke showing an embodiment according to the third aspect of the present invention. A pair of magnetic pieces 7 as separate pieces are mounted on the inner surface of the core 4 so that the distance between the horizontal deflection coil 1 and the ferrite core 4 can be easily changed. The magnetic piece 7 is formed with a curved surface similar to the inner surface of the ferrite core 4 so as to be in close contact with the inner surface of the ferrite core 4, and is made of the same material as the ferrite core 4.

As long as the adhesion with the ferrite core 4 can be ensured, the magnetic body 7 may be attached to the molded part 2 or the vertical deflection coil 3 before assembling the deflection yoke. Further, unlike the above-described configuration, the distance from the horizontal deflection coil 1 can be easily adjusted by the size and the mounting position of the magnetic body 7 to be mounted, so that a delicate operation in consideration of the correction effect becomes possible.

Since these configurations do not change the distance between the horizontal deflection coil 1, the vertical deflection coil 3 and the ferrite core 4 as a whole, the deflection efficiency does not largely change. In addition, since the amount of correction by a dedicated component using a correction coil or the like that has been conventionally required can be reduced, side effects such as deterioration of temperature characteristics and deflection sensitivity can be reduced.

[0040]

According to the present invention, when designing the structure of the deflection yoke, the axial distance between the horizontal deflection coil and the inner surface of the ferrite core may be ensured in accordance with the assumed convergence characteristics. The restriction on the coil design for correcting the trilemma by the coil itself is relaxed, and the correction amount of the correction component, which is conventionally required, is reduced, so that the design margin of the deflection yoke can be further secured. further,
Depending on the degree of correction, additional parts for trilemma correction become unnecessary, and the number of parts is reduced, so that a more inexpensive deflection yoke having characteristics equivalent to those of the related art can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a non-conical deflection yoke according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a cross section of a non-conical deflection yoke and a horizontal deflection magnetic field.

FIG. 3 is a diagram illustrating a misconvergence pattern generated by a change in a horizontal deflection magnetic field.

FIG. 4 is a diagram showing a convergence pattern representing a trilemma.

FIG. 5 is a cross-sectional view of a deflection yoke according to the present invention, which is characterized by a ferrite core inner surface shape.

FIG. 6 is a detailed side sectional view of a deflection yoke provided with a pair of magnetic pieces.

[Explanation of symbols]

 Reference Signs List 1 horizontal deflection coil 2 molded product 3 vertical deflection coil 4 ferrite core 5 horizontal deflection coil magnetic field 6 ferrite core inner surface unevenness 7 magnetic piece

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Tadashi Kazumi, Inventor 1st Kitano, Makino, Mizusawa-shi, Iwate F-term in Hitachi Media Electronics Co., Ltd. (reference)

Claims (3)

[Claims] 1. A non-conical deflection yoke having a horizontal deflection coil, a vertical deflection coil, and a main core and having a major axis direction and a minor axis direction, wherein an outer surface of the horizontal deflection coil and an outer surface of the vertical deflection coil are provided. Is defined as X in the major axis direction and Y in the minor axis direction. The distance between the outer surface of the horizontal deflection coil and the inner surface of the main core is defined as Xc in the major axis direction and Yc in the minor axis direction. When Y / X is Y
A deflection yoke, wherein c / Xc is set to a distance of ± 10% or more of Y / X. 2. The deflection yoke according to claim 1, wherein a convex portion or a concave portion is formed on each of the inner surface in the major axis direction and the inner surface in the minor axis direction of the main core. 3. The deflection yoke according to claim 1, wherein at least one pair of magnetic bodies is mounted between the deflection coil and the vertical deflection coil and an inner surface of the main core.