JP2002042688A - Deflection yoke - Google Patents

Abstract

(57) [Summary] [Problem] Without using a convergence correction unit or externally performing convergence correction with a magnet,
Provided is a deflection yoke capable of obtaining good convergence quality. The deflection yoke (3) includes electron beams (10B, 10B) emitted from the neck of the color cathode-ray tube (1).
A horizontal deflection coil 4 and a vertical deflection coil 5 for deflecting G and 10R in the horizontal and vertical directions are provided. In each quadrant divided into four by a horizontal axis X and a vertical axis Y passing through the tube axis in a plane perpendicular to the tube axis O of the color cathode ray tube 1, the quadrant is within a predetermined angle range from the horizontal axis X. The winding winding thickness shape 4a in the specific portion 14 of the horizontal deflection coil 4 is locally changed.

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 color cathode ray tube of a display device or a television receiver.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for higher precision and higher quality on the screen of a display device, and in particular, a demand for higher convergence quality has been rapidly increasing. .

[0003] In an in-line type color CRT in which three electron beams of blue (B), green (G), and red (R) are radiated from an electron gun in a horizontal line, these three electron beams are emitted.
The magnetic field distribution of the horizontal deflection coil and the vertical deflection coil is mainly adjusted so that good convergence of the electron beam can be obtained over the entire area on the screen.

FIG. 5 is a side view of an upper half showing a schematic configuration of a horizontal deflection coil 24 in a conventional deflection yoke used for such an in-line type color cathode ray tube, and FIG. FIG. 6 shows a cross-sectional view taken along arrow VI. In this horizontal deflection coil 24, in each quadrant divided into four by a horizontal axis X and a vertical axis Y passing through the tube axis in a plane perpendicular to the tube axis O of the cathode ray tube (the upper half 2 in FIG. 6).
(Shown in a quadrant), and the winding thickness shape 24a of the winding is configured to decrease gradually from the horizontal axis X side to the vertical axis Y side. By sparsely and densely distributing the windings in this manner, the horizontal deflection magnetic field B at the time of right deflection by the horizontal deflection coil 24 is obtained.
Is a pin-wound magnetic field as shown in FIG. FIGS. 7B and 7C show the magnetic flux density in the horizontal deflection magnetic field B and the trajectories of the three electron beams 10B, 10G, and 10R deflected to the right by the horizontal deflection magnetic field B, respectively.

However, in the configuration of the horizontal deflection coil 24, since the winding winding thickness shape 24a changes gradually, the horizontal deflection magnetic field B as shown in FIG.
7B, the difference in the magnetic flux density between the central portion and the left and right peripheral portions in the horizontal deflection magnetic field B is small as shown in FIG. 7B, and as a result, as shown in FIG. As described above, on the fluorescent screen 11 of the color cathode ray tube, a convergence pattern is generated in which the three electron beams 10B, 10G, and 10R are shifted. That is, when the three electron beams 10B, 10G, and 10R of blue (B), green (G), and red (R) are deflected to the right by the horizontal deflection magnetic field B, the magnetic flux density of the central portion and the right peripheral portion is reduced. Since the difference is small, the three electron beams 10G, 10
B, 10R tend to converge, and as a result, the fluorescent screen 11
Above, a convergence pattern in which the three electron beams 10G, 10B, and 10R are displaced.

In order to adjust the convergence pattern, a unit for convergence correction is generally provided separately from the horizontal deflection coil and the vertical deflection coil.

However, when such a convergence correction unit is provided, in order to drive this unit,
There is a problem that a power supply and a circuit different from those for driving the deflection yoke are required, and the cost is increased.

Also, when convergence correction is performed by a magnet from outside, a separate magnet must be provided.

SUMMARY OF THE INVENTION An object of the present invention is to provide a deflection yoke which can obtain good convergence quality without using a convergence correction unit or externally performing convergence correction with a magnet.

[0010]

A deflection yoke according to the present invention includes a horizontal deflection coil and a vertical deflection coil for deflecting an electron beam emitted from a neck portion of a color cathode ray tube in horizontal and vertical directions. In each quadrant divided into four by a horizontal axis and a vertical axis passing through the tube axis in a plane perpendicular to the tube axis of the color cathode ray tube, the horizontal deflection coil within a predetermined angle range from the horizontal axis. In the above, the winding thickness shape of the specific portion is locally changed.

In the deflection yoke, the specific portion of the horizontal deflection coil may be provided only on a portion on the small diameter side of the horizontal deflection coil.

A predetermined angle range in which the specific portion of the horizontal deflection coil is provided is 40 ° to 7 ° from the horizontal axis.
The angle range may be 0 °.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the drawings showing the embodiments.

Embodiment 1 FIG. 1 shows a side view of a color cathode ray tube having a deflection yoke according to Embodiment 1 of the present invention. This color CRT 1 has a funnel 1
and an in-line type cathode ray tube having a neck portion 1a and three electron beams 10B, 10G, blue (B), green (G), and red (R) arranged in a horizontal line.
An electron gun 2 for emitting 10R (FIG. 4) is provided, and a deflection yoke 3 is provided between the funnel 1a and the neck 1b. The deflection yoke 3 includes a horizontal deflection coil 4 and a vertical deflection coil 5 (FIG. 2).
To deflect the three electron beams 10B, 10G, and 10R emitted from the electron gun 2 in the horizontal and vertical directions.

FIG. 2 is a longitudinal sectional view of the deflection yoke 3. The deflection yoke 3 includes a core 6, a vertical separator 7 disposed inside the core 6, a saddle-shaped vertical deflection coil 5 wound inside the vertical separator 7 using a mold, and a It comprises a horizontal separator 8 disposed inside the vertical deflection coil 5 and a saddle-shaped horizontal deflection coil 4 inside the horizontal separator 8 using a mold.

The deflecting coil 3 is formed in a funnel shape so as to extend to some extent along the outer peripheral curved surface extending from the funnel portion 1a to the neck portion 1b of the color cathode ray tube 1.
Both the horizontal deflection coil 4 and the vertical deflection coil 5 have a large diameter at the front end facing the funnel 1a of the color cathode ray tube 1 and a small diameter at the rear end facing the neck 1b.

FIG. 3 is a cross-sectional view of the deflection yoke 3 in which the upper half of the horizontal deflection coil 4 is cut along a plane perpendicular to the tube axis O of the color cathode-ray tube 1. In this horizontal deflection coil 4, each quadrant (in FIG. 3, the upper half 2) is divided into four parts by a horizontal axis X and a vertical axis Y passing through the tube axis O in a plane perpendicular to the tube axis O. (Only quadrants are shown), the winding thickness shape 4a is changed from the horizontal axis X side to the vertical axis Y
In addition to being set to gradually decrease toward the side, the winding thickness shape 4a in the specific portion 14 within a predetermined angle range (40 ° to 70 °) from the horizontal axis X is locally changed.

That is, specifically, the horizontal deflection coil 4
Has a constant diameter φ1 (diameter substantially along the outer shape of the funnel portion 1a or the neck portion 1b) in the cross section over substantially the entire circumference excluding the specific portion 14, and the outer circumference of the horizontal deflection coil 4 is The horizontal axis X side is the long axis and the vertical axis Y
The cross section has a horizontally long oblong section with the short axis as the short axis, and thereby has a substantially arc-shaped cross section in which the winding thickness 4a decreases from the horizontal axis X side to the vertical axis Y side. Further, on the inner peripheral side of the horizontal deflection coil 4, the diameter φ2 of the specific portion 14 is locally larger than the diameter φ1 of the other portion. Thereby, in the specific portion 14, the winding winding thickness shape 4a is locally changed as compared with the other portions.

FIGS. 4 (a) and 4 (b) show a state in which a current is applied to the horizontal deflection coil 4 having the above-described configuration to make the electron beam 10B,
The horizontal deflection magnetic field B when 10G and 10R are deflected rightward, and the magnetic flux density of the magnetic field are shown. That is, since the horizontal deflection coil 4 has the specific portion 14 in which the winding thickness 4a of the winding is locally changed to be thin, compared with the related art, FIG.
As shown in FIG. 4A, the degree of the winding shape of the horizontal deflection magnetic field B is relatively strong, and as shown in FIG. 4B, the magnetic flux density in the left and right peripheral portions is relatively large as compared with the central portion. As a result, as shown in FIG. 4C, on the phosphor screen 11 of the color CRT, the three electron beams 10B, 10G, 1
A convergence pattern in which no shift occurs in 0R.
That is, blue (B), green (G),
When the three electron beams 10B, 10G, and 10R of red (R) are deflected to the right, the difference in magnetic flux density between the central portion and the right peripheral portion is large. In the peripheral portion, the three electron beams 10G, 10B, 10R tend to converge before the phosphor screen 11, but in the present invention, the three electron beams 10G, 10B, 10R move closer to the phosphor screen 11 side. Indicates a tendency to converge. As a result, by arbitrarily and appropriately adjusting the installation angle position, the width dimension, the tube axial length dimension, the winding winding thickness dimension, the local change contour shape, and the like of the specific portion 14, as shown in FIG. As described above, the three electron beams 10
A good convergence pattern with no shift in G, 10B and 10R is obtained.

As described above, in the deflection yoke 3 of the present invention, the winding thickness 4a of the specific portion 14 of the horizontal deflection coil 4 is locally changed as compared with the other portions, so that the horizontal deflection magnetic field B Since the degree of the pincushion shape is adjusted, the degree of freedom of the adjustment is increased by the installation angle position, width dimension, length dimension, winding thickness dimension, local change contour shape, etc. of the specific portion 14, and convergence correction Inexpensive and good convergence quality can be obtained without providing a separate unit or externally performing convergence correction with a magnet.

Further, in the first embodiment, the specific portion 14 of the horizontal deflection coil 4 is set at an angle of 40 ° from the horizontal axis X.
The convergence pattern at the corners of the screen is particularly good according to what the inventor has learned experimentally and experimentally because it is provided in the angle range of 70 °.

Embodiment 2 FIG. In the first embodiment, the specific portion 14 of the horizontal deflection coil 4 is
It is not mentioned which position in the tube axis direction is set, but the specific portion 14 may be provided in the entire area in the tube axis direction, and the small-diameter side (rear end side, neck side) of the horizontal deflection coil 4 may be provided. May be provided only for If only the small diameter side is provided, the distance to the phosphor screen 11 becomes long, so that the deflection of the electron beams 10B, 10G, and 10R by the specific portion 14 can be more effectively performed.

In order to locally change the winding thickness of the specific portion 14 of the horizontal deflection coil 4, a concave portion may be provided on the inner side of the horizontal deflection coil 4 as shown in FIG. A convex portion may be provided, or a concave portion or a convex portion may be provided on the outer shape side or both. Further, the contour shape of the concave portion is not limited to the shape shown in FIG. 3, but may be any shape that can obtain the effect. The same applies to the convex portions.

In the above embodiment, the case where the horizontal deflection coil 4 is applied to the saddle-shaped deflection yoke 3 using a mold has been described, but the horizontal deflection coil 4 is directly wound around the horizontal separator 8. It is needless to say that the present invention can be applied to a rotating deflection yoke.

[0025]

According to a first aspect of the present invention, there is provided a deflection yoke including a horizontal deflection coil and a vertical deflection coil for deflecting an electron beam emitted from a neck portion of a color cathode ray tube in a horizontal direction and a vertical direction. In each quadrant divided into four by a horizontal axis and a vertical axis passing through the tube axis in a plane perpendicular to the tube axis of the color cathode ray tube, a specific portion of the horizontal deflection coil within a predetermined angle range from the horizontal axis Since the winding thickness shape of the winding is locally changed, the degree of freedom in adjusting the magnetic field strength of the horizontal deflection magnetic field is widened, and without providing a separate convergence correction unit or externally performing convergence correction with a magnet, it is inexpensive and excellent. Convergence quality can be obtained.

In the deflection yoke according to the second aspect of the present invention, in the deflection yoke according to the first aspect, the specific portion of the horizontal deflection coil is provided only on a portion on the small diameter side of the horizontal deflection coil. The distance to the surface becomes longer, and the deflection correction of the electron beam by the specific portion can be performed more effectively.

A deflection yoke according to a third aspect of the present invention is the deflection yoke according to the first or second aspect, wherein the predetermined angle range in which the specific part of the horizontal deflection coil is provided is 40 ° to 70 ° from the horizontal axis. The convergence particularly at the corner of the phosphor screen is improved.

[Brief description of the drawings]

FIG. 1 is a side view of a color cathode ray tube using a deflection yoke according to Embodiment 1 of the present invention.

FIG. 2 is a longitudinal sectional view of the deflection yoke according to the first embodiment of the present invention.

FIG. 3 is a sectional view of an upper half of a horizontal deflection coil in the deflection yoke according to the first embodiment of the present invention.

4A is an explanatory diagram showing a horizontal deflection magnetic field when the horizontal deflection coil deflects rightward, FIG. 4B is an explanatory diagram showing a magnetic flux density of the horizontal deflection magnetic field at that time, and FIG. FIG. 3 is an explanatory diagram illustrating a deflection trajectory of a beam.

FIG. 5 is a side view showing an upper half of a conventional deflection yoke.

FIG. 6 is a sectional view taken along the line VI-VI in FIG. 5;

7A is an explanatory diagram showing a horizontal deflection magnetic field at the time of right deflection by the horizontal deflection coil of FIG. 6, FIG. 7B is an explanatory diagram showing a magnetic flux density of the horizontal deflection magnetic field at that time, and FIG. FIG. 4 is an explanatory diagram showing a deflection locus of an electron beam at the time.

[Explanation of symbols]

1 color cathode ray tube, 3 deflection yoke, 4 horizontal deflection coil, 4a winding thickness, 5 vertical deflection coil, 10
B, 10G, 10R electron beam, 14 specific part of horizontal deflection coil, tube axis of O color cathode ray tube, X horizontal axis, Y vertical axis.

Claims (3)

[Claims] 1. A deflection yoke having a horizontal deflection coil and a vertical deflection coil for deflecting an electron beam emitted from a neck portion side of a color cathode ray tube in horizontal and vertical directions, wherein the deflection yoke is provided with respect to a tube axis of the color cathode ray tube. In each quadrant divided into a horizontal axis and a vertical axis passing through a tube axis in a vertical plane, the winding thickness shape of a specific portion of the horizontal deflection coil within a predetermined angle range from the horizontal axis is locally determined. Deflection yoke that has been dynamically changed. 2. The deflection yoke according to claim 1, wherein the specific portion of the horizontal deflection coil is provided only on a portion on the small diameter side of the horizontal deflection coil. 3. The deflection yoke according to claim 1, wherein the predetermined angle range is from 40 ° to 70 ° from the horizontal axis.
Deflection yoke with an angle range of °.