JP2002373602A - Deflection yoke - Google Patents

Abstract

PROBLEM TO BE SOLVED: To standardize the definition of a cross sectional shape of a horizontal deflection coil, while maintaining a wound thickness distribution proper in convergence characteristic. SOLUTION: The deflection yoke is used in a cathode-ray tube with a cross sectional rectangular cone part ranging from a neck part to a funnel part, and it has the horizontal deflection coil 16 wound into a saddle shape. In the cross sectional shape of the horizontal deflection coil 16 corresponding to the neck part, the inside is defined by a circular shape of a radius R and the outside is defined, by a shape connecting three arcs 24, 25, 26 of radiuses Rx, Ry, and Rd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke (DY) used for a cathode ray tube.

[0002]

2. Description of the Related Art In a cathode ray tube, an image is assembled on a screen by deflecting a traveling direction of an electron beam emitted from an electron gun up and down and left and right. A deflection yoke is used to deflect the electron beam. The deflection yoke has a deflection coil (horizontal deflection coil and vertical deflection coil) and a core, and is mounted on a cone portion from a neck portion of the cathode ray tube to a funnel portion. In this deflection yoke, the electron beam emitted from the electron gun is deflected up, down, left, and right by the electromagnetic action of the deflection current (horizontal deflection current, vertical deflection current) flowing through the deflection coil.

Generally, the cross-sectional shape of the cone of a cathode ray tube on which a deflection yoke is mounted is circular. On the other hand, since the screen of the cathode ray tube has a rectangular shape, the area of the deflection magnetic field necessary for scanning the electron beam on the screen is also rectangular. In such a case, in a cathode ray tube having a circular cross section, the deflection coil forms a magnetic field at a position apart from a region that actually contributes to the electron beam deflection (hereinafter, referred to as an effective magnetic field region). In the meantime, an invalid magnetic field is formed. Therefore, the deflection power is unnecessarily consumed.

Therefore, conventionally, as shown in FIG. 6A, the cross-sectional shape of a cone portion 32 from a neck portion 34 of a cathode ray tube 31 to a funnel portion 33 is made substantially rectangular, and this cone portion (hereinafter, referred to as a square cone) is used. A technology is known in which a deflection yoke corresponding to the cross-sectional shape of a section 32 is mounted to arrange a deflection coil near the effective magnetic field region to form a magnetic field. If this technique is adopted, the above-mentioned ineffective magnetic field can be reduced and the consumption of deflection power can be suppressed.

In general, the cross-sectional shape of the rectangular cone portion 32 is, as shown in FIG. 6 (B), an XY coordinate system orthogonal to the central axis (tube axis) of the cathode ray tube, and on the X axis which is a horizontal axis. An arc having a radius Rx having a center, an arc having a radius Ry having a center on the Y axis serving as a vertical axis, and an arc having a radius Rd having a center near a diagonal axis are connected. The cross-sectional shape of the neck portion 34 extending in the central axis direction of the cathode ray tube from the rectangular cone portion 32 is circular (true circle).

On the other hand, the horizontal deflection coil incorporated in the deflection yoke is disposed on the innermost side of the deflection yoke in a state close to the surface of the cathode ray tube. A horizontal deflection coil is attached from the cone part 32 to the neck part 34 in the direction of the center axis of the cathode ray tube. Therefore, the cross-sectional shape of the horizontal deflection coil wound in a saddle shape is
2 and the cross-sectional shape of the neck portion 34. However, in the case of a horizontal deflection coil, in order to improve the convergence characteristics of the electron beam, the thickness of the coil (hereinafter, also referred to as a winding thickness) must be gradually reduced from the horizontal axis to the vertical axis. .

In such a case, the cross-sectional shape of the horizontal deflection coil corresponding to the neck portion 34 is a circle (true circle) on the inner side following the cross-sectional shape of the neck portion 34, and X on the outer side.
It has a substantially elliptical shape with a major axis on the axis. So conventionally,
As shown in FIG. 7, the outer cross-sectional shape of the horizontal deflection coil 35 corresponding to the neck portion 34 is defined using an arc having a radius Rf whose center is at a point offset in the Y-axis direction from the center of the XY coordinates. I have.

[0008]

However, the cone 3
Since the cross-sectional shape of the horizontal deflection coil 35 corresponding to 2 is defined by connecting three arcs in accordance with the cross-sectional shape of the cone portion 32 shown in FIG. And the definition of the coil cross-sectional shape corresponding to the neck portion 34 is different. Therefore, when specifying the cross-sectional shape of the horizontal deflection coil 35 at each position in the center axis direction of the cathode ray tube, it is necessary to change the shape definition in the middle, and it has not been possible to connect both cross-sectional shapes smoothly.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to define a cross-sectional shape of a horizontal deflection coil while maintaining a winding thickness distribution that is excellent in convergence characteristics. Is to provide a deflection yoke in which

[0010]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and is directed to a deflection yoke used in a cathode ray tube having a substantially rectangular cross-sectional shape of a cone portion from a neck portion to a funnel portion. In addition to having a horizontal deflection coil wound in a saddle shape, the cross-sectional shape of the horizontal deflection coil corresponding to the neck is defined as a shape in which the inside is circular and the outside is connected by three arcs. ing.

In the deflection yoke according to the present invention, the cross-sectional shape of the horizontal deflection coil corresponding to the neck portion is defined by a shape in which the inside is circular and the outside is connected by three arcs, so that the inner circumference of the horizontal deflection coil is formed. In a state where the surface is in close contact with the outer peripheral surface of the neck portion, it is possible to obtain a winding thickness distribution having good convergence characteristics. This eliminates the need to switch the definition of the cross-sectional shape of the horizontal deflection coil midway along the center axis direction of the cathode ray tube.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic perspective view showing an overall image of a cathode ray tube. In FIG. 1, the main body (glass bulb) of the cathode ray tube 10 includes a panel section 11, a funnel section 12 and a neck section 13. On the inner surface of the panel section 11, a phosphor screen (not shown) in which red, blue, and green phosphors are arranged in a predetermined pattern is formed. On the other hand, an electron gun (gun) 1 serving as an electron beam emission source is
4 are furnished. A deflection yoke 15 for deflecting the electron beam is mounted on a cone portion extending from the neck portion 13 to the funnel portion 12. The cone portion is a rectangular cone portion having a substantially rectangular cross section.
Further, the deflection yoke 15 is arranged such that the center axis of the yoke is the cathode ray tube 1.
It is mounted so as to coincide with the central axis (Z axis) of 0.

FIG. 2 is a side view including a partially broken cross section of the deflection yoke according to the present invention. In FIG. 2, the deflection yoke 15
Are equipped with components such as a horizontal deflection coil 16, a vertical deflection coil 17, a separator 18, a DY core 19, and a ring magnet 20. The horizontal deflection coil 16 is installed on the inner peripheral side of the separator 18, and the vertical deflection coil 17 is installed on the outer peripheral side of the separator 18. The separator 18 is made of an insulating material such as a resin, and has a substantially trumpet shape as a whole.

As shown in FIG. 3, the horizontal deflection coil 16 has crossover portions (bend portions) 21 and 22 formed on one side and the other side in the yoke center axis direction, and is wound in a saddle shape. Thus, they are arranged in pairs above and below the deflection yoke 15. The vertical deflection coil 17 is used for the horizontal deflection coil 1.
6, and the deflection yoke 1
5 are arranged in pairs on the left and right sides. Then, on the trajectory of the electron beam emitted from the electron gun 14, the pair of horizontal deflection coils 16 cause the electron beam to move right and left (in the horizontal direction).
And a pair of vertical deflection coils 17 generate a magnetic field (vertical deflection magnetic field) for deflecting the electron beam up and down (vertically). The vertical deflection coil 17 may be wound around the DY core 19 in a toroidal shape.

The DY core 19 is made of a magnetic material such as ferrite, and has a cylindrical structure with one opening in the direction of the center axis of the yoke larger than the other. This DY core 19
In order to enhance the effectiveness of the magnetic field generated by the horizontal deflection coil 16 and the vertical deflection coil 17,
It is attached so as to cover 6,17. The ring magnet 20 is attached to the rear end side of the deflection yoke 15 in order to correct a trajectory shift of the electron beam due to an assembly error of the electron gun 14 or the like.

FIG. 4 is a view for explaining the cross-sectional shape of the horizontal deflection coil at a portion corresponding to the neck of the cathode ray tube. In FIG. 4, an X axis and a Y axis indicate a horizontal axis and a vertical axis, respectively, which are orthogonal to the central axis of the cathode ray tube. As can be seen from the figure, the radial thickness T of the horizontal deflection coil 16 is:
For the reasons described above, the thickness gradually decreases from the X axis to the Y axis. Further, on the Y axis, as shown in FIG. 3, there is a window portion (non-winding portion) 23 where the coil wire of the horizontal deflection coil 16 is not wound.

Here, the horizontal deflection coil 16 in FIG.
Is defined as a circular shape (true circle) following the cross-sectional shape of the neck portion 13 of the cathode ray tube 10, that is, only an arc having a radius R centered at the intersection of the XY axes. The radius R is the same as or slightly larger than the radius that defines the outer diameter of the neck portion 13.

On the other hand, the cross section outside the horizontal deflection coil 16 in FIG.
6 are defined by connecting them. Among them, arc 2
Numeral 4 is an arc having a radius Rx centered on the X-axis.
5 is an arc of a radius Ry centered on the Y axis. Also,
The circular arc 26 is a circular arc having a center at a diagonal portion and a radius Rd, and the circular arc 26 smoothly connects the other two circular arcs 24 and 25. The shape definition by these three arcs 24, 25, and 26 is commonly applied to the first to fourth quadrants of the XY coordinate system.

When the horizontal deflection coil 16 is wound around the separator 18 (section winding), the outer peripheral surface of the horizontal deflection coil 16 is defined by the inner peripheral surface of the separator 18. When the horizontal deflection coil 16 is wound using a mold (not shown) (mold winding), the outer cross-sectional shape of the horizontal deflection coil 16 is defined by a winding guide surface formed on the mold. Will be.

On the other hand, the cross section of the horizontal deflection coil 16 when viewed as a whole has a shape as shown in FIG.
That is, in the Z-axis direction which is the center axis of the cathode ray tube, the cross-sectional shape of the horizontal deflection coil 16 at the position P1 corresponding to the neck portion 13 is such that the inside has a radius R as shown in FIG.
, And the outside is defined as a shape connecting three arcs having radii Rx1, Ry1, and Rd1.

The sectional shape of the horizontal deflection coil 16 at a position P3 corresponding to the cone portion 27 of the cathode ray tube is defined by a shape in which three arcs having radii Rx3, Ry3, and Rd3 are connected on the outer side. The inside is similarly defined by a shape connecting three arcs. Further, the neck portion 13
The cross-sectional shape of the horizontal deflection coil 16 at the position P2 where the transition from to the cone 27 is made is also defined as a shape in which three arcs are connected both inside and outside.

Like the deflection yoke 15 according to this embodiment, the cross-sectional shape of the horizontal deflection coil 16 corresponding to the neck portion 13 is defined by a circular shape on the inner side and a shape connecting three arcs on the outer side. In a state where the inner peripheral surface of the horizontal deflection coil 16 is in close contact with the outer peripheral surface of the neck portion 13, the winding thickness distribution which is excellent in the convergence characteristic, that is, from the X axis to the Y direction
It is possible to obtain a winding thickness distribution in which the thickness gradually decreases toward the axis.

Thus, when specifying the cross-sectional shape of the horizontal deflection coil 16, there is no need to switch the definition of the coil cross-sectional shape in the middle of the Z-axis direction, and the coil cross-sectional shape is specified by a common definition throughout the Z-axis direction. can do. As a result, the coil cross-sectional shape can be smoothly connected between one end (21) and the other end (22) of the horizontal deflection coil 16.

[0025]

As described above, according to the present invention, when specifying the cross-sectional shape of the horizontal deflection coil, the cross-sectional shape of the horizontal deflection coil corresponding to the neck portion is set to be circular inside and three arcs outside. By defining the shapes by connecting them, it is possible to keep the winding thickness distribution, which is considered to be excellent in the convergence characteristics, and to share the definition of the cross-sectional shape of the horizontal deflection coil. As a result, it is possible to smoothly connect the coil cross-sectional shape between one end and the other end of the horizontal deflection coil.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an overall image of a cathode ray tube.

FIG. 2 is a side view including a partially broken surface of the deflection yoke according to the present invention.

FIG. 3 is a perspective view showing the structure of a saddle-type horizontal deflection coil.

FIG. 4 is a diagram illustrating a partial cross-sectional shape of a horizontal deflection coil employed in an embodiment of the present invention.

FIG. 5 is a diagram illustrating an overall cross-sectional shape of a horizontal deflection coil employed in an embodiment of the present invention.

FIG. 6 is a diagram illustrating a structure of a cathode ray tube having a rectangular cone portion.

FIG. 7 is a diagram illustrating a partial cross-sectional shape of a horizontal deflection coil in a conventional deflection yoke.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Cathode ray tube, 11 ... Panel part, 12 ... Funnel part, 13 ... Neck part, 14 ... Electron gun, 15 ... Deflection yoke, 16 ... Horizontal deflection coil, 17 ... Vertical deflection coil, 1
8 separator, 19 DY core, 21, 22, crossover, 24, 25, 26 arc

Claims (1)

[Claims] 1. A deflection yoke for use in a cathode ray tube having a substantially rectangular cross-sectional shape of a cone portion extending from a neck portion to a funnel portion, the deflection yoke having a saddle-shaped horizontal deflection coil and the neck portion. A deflection yoke, wherein the cross-sectional shape of the horizontal deflection coil corresponding to the above (1) is defined by a shape in which the inside is circular and the outside is connected by three arcs.