JP3784297B2 - Deflection yoke and color cathode ray tube apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a deflection yoke used for a color cathode ray tube such as a television receiver and a computer display, and a color cathode ray tube device including the deflection yoke.
[0002]
[Prior art]
In general, in the deflection yoke, the magnetic field strength at the small-diameter portion of the deflection yoke is the strongest, and therefore the positional deviation of the small-diameter portion in the ferrite core of the deflection yoke greatly affects the convergence characteristics. As a countermeasure, the following technique is disclosed in Japanese Utility Model Laid-Open No. 5-11292.
[0003]
As shown in FIGS. 5 and 7, the deflection yoke is provided with a horizontal deflection coil 1, an insulating frame 2, a vertical deflection coil 3, and a ferrite core 4, each having a truncated cone shape, from the inside to the outside. ing. In addition, the insulating frame 2 is provided with a plurality of symmetrically erected on the small-diameter outer wall 2a and abuts on the small-diameter inner wall 4b of the ferrite core 4 to regulate the positional deviation of the ferrite core 4 in the left-right direction. Elastic protrusions 5 are formed. In order to fix the ferrite core 4 to the insulating frame 2, the large diameter portion 2 b of the insulating frame 2 and the large diameter portion 4 d of the ferrite core 4 are fixed by the hot melt adhesive 6.
[0004]
[Problems to be solved by the invention]
However, in general, as shown in FIG. 6, in the cross section perpendicular to the tube axis Z, the inner surface of the vertical deflection coil 3 is substantially circular, whereas the outer surface is substantially elliptical with the horizontal axis X as the major axis. It is. That is, the thickness on the vertical axis Y of the vertical deflection coil 3 is smaller than the thickness on the horizontal axis X. Therefore, a gap δ2 in the vertical axis Y direction may occur between the outer wall surface of the vertical deflection coil 3 and the small-diameter inner wall 4b of the ferrite core 4.
[0005]
In addition, when the ferrite core 4 is mounted on the insulating frame 2 in the deflection yoke assembly process, as shown in FIG. 5, the small-diameter inner wall 4b of the ferrite core 4 is tapered at the end of the small-diameter portion. The elastic force of the elastic protrusion 5 acts in the direction of the arrow C inclined with respect to the tube axis Z with respect to the tapered portion of the small-diameter inner wall 4b. Alternatively, when the tip 5a of the elastic projection 5 is bent downward with respect to the small-diameter inner wall 4b of the ferrite core 4 as shown in FIG. The elastic force 5 acts on the small-diameter inner wall 4b in the direction of the arrow C inclined with respect to the tube axis Z as described above. As a result, in any of the configurations described above, the elastic force generated by the elastic protrusion 5 is such that the large diameter portion 4d of the ferrite core 4 is separated from the large diameter portion 2b of the insulating frame 2 in the tube axis Z direction. In some cases, a gap δ1 in the tube axis direction is generated between the vertical deflection coil 3 and the ferrite core 4 in some cases.
[0006]
As a result, when this deflection yoke is mounted on a color cathode ray tube, there is a problem that the ferrite core 4 is displaced in the vertical axis Y direction and the tube axis Z direction of the color cathode ray tube, and the ferrite core 4 cannot be held in the optimum position. . Therefore, due to this problem, the YH cross-type misconvergence shown in FIG. 8 is generated, which adversely affects the image.
[0007]
The present invention has been made to solve such problems, and a first object thereof is to provide a deflection yoke that can hold a ferrite core in an optimum position in the vertical axis direction. A second object of the present invention is to provide a deflection yoke that can hold a ferrite core in an optimum position in the tube axis direction in addition to the vertical axis direction. It is a third object of the present invention to provide a color cathode ray tube apparatus in which the occurrence of YH cross-type misconvergence is suppressed by holding the ferrite core at a desired position.
[0008]
[Means for Solving the Problems]
Deflection yoke of the present invention, from the inside outward, a horizontal deflection coil, an insulating frame, a vertical deflection coil and the ferrite core to a deflection yoke that is provided in this order, the small diameter portion an outer wall of the insulating frame, wherein a plurality of elastic protrusions for holding said small diameter outer wall of the ferrite core by applying a pressing force directed toward the tube axis with respect to the small-diameter outer wall of the ferrite core and is erected, the pressing force The large diameter portion of the ferrite core is pressed to the large diameter portion side of the insulating frame by a force component in a direction parallel to the tube axis direction .
[0009]
With this configuration, the position of the center of the ferrite core is regulated on the tube axis by the plurality of elastic protrusions.
[0010]
In the above, it is preferable that the outer wall of the small-diameter portion of the ferrite core is provided with a tapered portion that decreases in diameter toward the end of the small-diameter portion, and the elastic projection portion holds the tapered portion.
[0011]
Thus, in the assembly process, when the ferrite core is mounted on the insulating frame, the elastic projection portion applies an elastic pressing force in an oblique direction to the taper surface with respect to the tube axis direction. Accordingly, the tube axial direction component of the elastic pressing force acts to press the large diameter portion of the ferrite core toward the large diameter portion side of the insulating frame in the tube axis direction. As a result, the position of the ferrite core in the tube axis direction can be accurately regulated.
[0012]
Next, a color cathode ray tube apparatus according to the present invention includes the deflection yoke according to the present invention. As a result, since the small diameter portion of the ferrite core can be held at a desired position, it is possible to display a good image with less occurrence of YH cross type misconvergence.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
As shown in FIG. 4, a color cathode ray tube apparatus according to an embodiment of the present invention includes a panel 11 having a phosphor screen 11a, a frame 13 having a shadow mask 12 provided at a position facing the phosphor screen 11a, and The neck tube portion 14 a has an electron gun 15, and is composed of a color cathode ray tube including a funnel portion 14 connecting the neck tube portion 14 a and the panel 11 and the deflection yoke 10. For convenience of the following description, as shown in the figure, the horizontal axis passing through the tube axis and perpendicular to the tube axis is the horizontal axis X, the vertical axis passing through the tube axis and perpendicular to the tube axis is vertical. An XYZ three-dimensional orthogonal coordinate system is set with the axis Y and the axis of the tube axis as the tube axis Z.
[0015]
The deflection yoke 10 is provided on the outer periphery of the funnel portion 14 in order to deflect the electron beam from the electron gun 15. As shown in FIG. 1, the deflection yoke 10 has a frustoconical surface, each of which includes a horizontal deflection coil 1, an insulating frame 20, a vertical deflection coil 3 and a ferrite core 4 that are sequentially provided from the inside to the outside. The large-diameter portion 20 b of the insulating frame 20 and the large-diameter portion 4 d of the ferrite core 4 are fixed by the adhesive 6. As shown in FIG. 2, the ferrite core 4 is configured by combining a pair of halves divided into two by a plane including the vertical axis Y and the tube axis Z. Further, the small-diameter portion outer wall 4a of the ferrite core 4 has a tapered portion 4e whose diameter decreases toward the end of the small-diameter portion on the entire circumferential surface.
[0016]
As shown in FIG. 2, the insulating frame 20 includes a plurality of elastic protrusions 21 and a ferrite core that are erected on the small-diameter outer wall 20 a and hold the tapered portion 4 e in the small-diameter outer wall 4 a of the ferrite core 4. A plurality of projections 22 for regulating the position of the four small-diameter inner walls 4b are formed.
[0017]
FIG. 3 shows the tip of the elastic protrusion 21. The plurality of elastic protrusions 21 are for restricting the position of the ferrite core 4 so that the center thereof coincides with the tube axis Z. For example, the small diameter of the ferrite core 4 is provided at the tip of the elastic protrusion 21. A pair of bent portions 21d that elastically hold the tapered portion 4e in the partial outer wall 4a is formed. The bent portion 21 d is made of a bent plate spring made of a resin that is integrally formed with the elastic projection portion 21, and is in pressure contact with the tapered portion 4 e of the small-diameter outer wall 4 a of the ferrite core 4. As shown in FIG. 2, the pair of bent portions 21 d press the pair of halves constituting the ferrite core 4. The pair of bent portions 21d are formed so that the direction of the elastic pressing force F acting on the tapered portion 4e of each half is directed to the tube axis Z in a plane orthogonal to the tube axis Z.
[0018]
The elastic protrusion 21 is composed of a pair of elastic protrusions 21a and 21b arranged symmetrically with respect to the plane including the horizontal axis X and the tube axis Z when the deflection yoke 10 is mounted on the color cathode ray tube. Therefore, the positional deviation of the ferrite core 4 in the vertical axis Y direction is regulated.
[0019]
The protrusion 22 includes a pair of protrusions 22a and 22b arranged symmetrically with respect to the plane including the vertical axis Y and the tube axis Z when the deflection yoke 10 is mounted on the color cathode ray tube. Are in contact with the inner walls of the pair of halves. Thereby, the position shift of the ferrite core 4 in the horizontal axis X direction is regulated.
[0020]
In addition, although the pair of elastic protrusions 21a and 21b attached on the vertical axis Y and the pair of protrusions 22a and 22b attached on the horizontal axis X have been described as the elastic protrusions 21 and the protrusions 22, the elastic protrusions The attachment positions and the number of the protrusions 21 and the protrusions 22 are not limited to the above example. For example, when the ferrite core 4 is divided into a plurality of parts such as three parts and four parts in the circumferential direction, the elastic protrusion parts 21 are provided. Corresponding to the division position, the protrusions 22 may be provided in the same number as the division number so as to face the divided cores.
[0021]
Moreover, although the taper part 4e in the small-diameter part outer wall 4a of the ferrite core 4 demonstrated the example provided in the perimeter, you may provide not only in this but only in the part which contacts the elastic protrusion part 21. FIG. In other words, it may be provided at least in a portion in contact with the elastic protrusion 21.
[0022]
The elastic protrusion 21 may have a configuration different from the bent portion 21d as described above as long as the elastic pressing force F described above can be applied to the small-diameter outer wall 4a of the ferrite core 4. Or it does not need to have the bending part 21d.
[0023]
The operation and effect of the deflection yoke configured as described above will be described below.
[0024]
The deflection yoke 10 of the present invention is formed with a plurality of elastic protrusions 21a and 21b which are erected on the small-diameter outer wall 20a of the insulating frame 20 and hold the small-diameter outer wall 4a of the ferrite core 4. In the process, when the ferrite core 4 is attached to the insulating frame 20, the small-diameter outer wall 4a of the ferrite core 4 has the tapered portion 4e. As shown in FIG. 1, the taper portion 4e acts in an oblique direction with respect to the tube axis Z. Due to the force component in the direction parallel to the tube axis Z direction of the elastic pressing force F, the large diameter portion 4d of the ferrite core 4 is pressed to the large diameter portion 20b side of the insulating frame 20, and the position of the ferrite core 4 in the tube axis Z direction. Is regulated. Further, the center of the ferrite core 4 is regulated on the tube axis Z in the vertical axis Y direction by the force component of the elastic pressing force F in the direction orthogonal to the tube axis Z. Therefore, the deflection yoke 10 of the present invention can be simply configured because the tube core Z direction position and the center position of the ferrite core 4 can be held at the optimum positions only by the plurality of elastic projections 21a and 21b provided upright on the insulating frame. In addition, when this deflection yoke 10 is mounted on a color cathode ray tube, YH cross type misconvergence can be reduced.
[0025]
Next, examples in which the effects of the present invention have been confirmed will be described.
[0026]
20 each of the deflection yoke of the present invention shown in FIG. 1 and the conventional deflection yoke shown in FIG. 5 (with the elastic protrusions 21a and 21b of the deflection yoke of FIG. ) Each of the deflection yokes is mounted on one color cathode ray tube for a computer monitor, and YH cross-type misconvergence (hereinafter referred to as “YHc”) of each of the 20 deflection yokes is examined. Was defined as the YHc variation width. The YHc width refers to the maximum horizontal distance E between the R (red) and B (blue) tracks shown in FIG.
[0027]
When the deflection yoke of the present invention was mounted, the YHc variation width was about 100 μm. On the other hand, when the conventional deflection yoke was mounted, the YHc variation width was about 350 μm. That is, the YHc variation width in the color cathode ray tube apparatus equipped with the deflection yoke of the present invention can be reduced to about ½ of 200 μm, which is a value at which misconvergence does not cause a practical problem, and the conventional deflection yoke is installed. Compared to the color cathode ray tube apparatus, the reduction was about 1/3. Thus, it was found that the yield of the deflection yoke with respect to the YHc variation width can be improved.
[0028]
In the present invention, the taper portion 4e of the small-diameter portion outer wall 4a of the ferrite core 4 includes one having a diameter that decreases toward the end side of the small-diameter portion. Therefore, the tapered portion 4e may be configured by a curved surface continuous with the outer wall surface of the frustoconical surface of the ferrite core 4 as in the above example, but the tapered portion of the present invention is not limited to such a configuration. . For example, as shown in FIG. 9, a tapered portion 4 e may be formed at the end portion of the small-diameter outer wall 4 a of the ferrite core 4 so as to be discontinuous with the outer wall surface of the ferrite core 4. With such a configuration, the magnitude of the force component in the direction parallel to the tube axis Z direction of the elastic pressing force F by the elastic protrusions 21a and 21b is freely set by changing the taper angle of the taper portion 4e. be able to.
[0029]
In the deflection yoke, the tapered portion 4e is formed on the small-diameter outer wall 4a of the ferrite core 4. However, the tapered portion 4e is not necessarily formed. When the outer diameter of the small-diameter portion outer wall 4a is substantially constant in the tube axis Z direction because the tapered portion 4e is not formed, the elastic pressing force F applied to the small-diameter outer wall 4a of the ferrite core 4 by the elastic protrusion 21 is The direction is substantially perpendicular to the tube axis Z. Therefore, in this case, compared with the above embodiment, the positioning accuracy of the ferrite core 4 in the tube axis Z direction is lowered, but the center position of the small-diameter portion of the ferrite core 4 is the same as in the above example. It is held in a state consistent with Z. Therefore, YH cross-type misconvergence can be suppressed as compared with the conventional deflection yoke.
[0030]
In the above example, the bent portion 21d is obtained by integrally molding the resin together with the elastic projection 21. However, the bent portion 21d is a plate spring formed by bending a metal plate, and the elastic projection portions 21a and 21b are made of resin. It may be integrated when molding.
[0031]
【The invention's effect】
As described above, the deflection yoke of the present invention has a plurality of elastic protrusions for holding the small-diameter portion outer wall of the ferrite core on the outer wall of the small-diameter portion of the insulating frame. The position can be held at the optimum position. As a result, when this deflection yoke is mounted on a color cathode ray tube, an optimum image with reduced YH cross-type misconvergence can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a deflection yoke according to the present invention on a plane including a vertical axis and a tube axis. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 4 is a sectional view showing a color cathode ray tube apparatus according to the present invention. FIG. 5 is a sectional view of a conventional deflection yoke on a plane including a horizontal axis and a tube axis. 6 is a cross-sectional view taken along the line VI-VI in FIG. 5. FIG. 7 is a cross-sectional view of a plane including the horizontal axis and tube axis of another conventional deflection yoke. FIG. 8 is a diagram showing YH cross-type misconvergence. FIG. 9 is a partially enlarged cross-sectional view showing another configuration example of the outer wall of the small-diameter portion of the deflection yoke of the present invention.
DESCRIPTION OF SYMBOLS 1 Horizontal deflection coil 3 Vertical deflection coil 4 Ferrite core 4a Ferrite core small diameter part outer wall 4e Ferrite core taper part 10 Deflection yoke 20 Insulation frame 20a Insulation frame small diameter part outer wall 21a, 21b Elastic projection part 21d Bending part 22a, 22b Projection

Claims (6)

From the inside to the outside, the horizontal deflection coil, an insulating frame, a vertical deflection coil and the ferrite core to a deflection yoke that is provided in this order, the small diameter portion an outer wall of the insulating frame, the small-diameter portion an outer wall of the ferrite core a plurality of elastic protrusions for holding said small diameter outer wall of the ferrite core by applying a pressing force toward the tube axis are erected against, parallel to the tube axis direction of the pressing force A deflection yoke, wherein a large-diameter portion of the ferrite core is pressed against a large-diameter portion side of the insulating frame by force components in various directions .   2. A small-diameter portion outer wall of the ferrite core is provided with a tapered portion whose diameter decreases toward an end side of the small-diameter portion, and the elastic projection portion holds the tapered portion. The deflection yoke described in 1.   The deflection yoke according to claim 1, wherein a bent portion that elastically holds the outer wall of the small diameter portion of the ferrite core is formed at a tip portion of the elastic protrusion portion.   2. The deflection according to claim 1, wherein when the deflection yoke is mounted on a color cathode ray tube, a pair of the elastic projections are arranged symmetrically with respect to a plane including a horizontal axis and a tube axis. yoke.   2. A projection formed symmetrically with respect to a plane including a vertical axis and a tube axis when the deflection yoke is mounted on a color cathode ray tube, is formed on the outer wall of the small-diameter portion of the insulating frame. Item 2. The deflection yoke according to Item 1.   A color cathode ray tube apparatus comprising the deflection yoke according to claim 1.

Images