JPH11238479A - Deflection yoke - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deflection yoke which can reduce the leakage magnetic field without provision of any cancel coil. SOLUTION: An electron gun side fringe of a horizontal deflection coil is wound in such a way as overlapping in the tube axis direction of a cathode-ray tube, while a screen side fringe is wound parallel with the tube surface in conical shape in such a way that a step is formed in the tube axis direction, wherein the length of a ferrite core 37 is set to more than 70% and less than 80% of the side inductor length of the horizontal deflection coil. The distance from the front extremity of the ferrite core 37 to the screen side fringe of the horizontal deflection coil is set to more than 20% and less than 40% of the side inductor length of the horizontal deflection coil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke combined with a cathode ray tube used in a television receiver.

[0002]

2. Description of the Related Art First, a conventional deflection yoke will be described with reference to the drawings. FIG. 4 is a configuration diagram of a conventional deflection yoke, FIG. 5 is a schematic diagram of the horizontal deflection coil, FIG. 6 is a diagram showing a magnetic field generated by the horizontal deflection coil, and FIG. 7 is a magnetic field on the tube axis of the deflection yoke. FIG. 8 is a side view of the deflection yoke.

FIG. 4A is a side view of a pair of saddle-type horizontal deflection coils 1 wound in a saddle shape, 2 is a side inductor portion of the saddle-type horizontal deflection coil 1, and 3 is a saddle-type horizontal deflection coil. The electron gun side fringe portion 4 of the deflection coil is a screen side fringe portion.

FIG. 4B is a side view of a pair of saddle-type horizontal deflection coils 1 wound in a saddle shape. Reference numeral 5 denotes a side inductor portion of the saddle-type vertical deflection coil, and reference numeral 6 denotes a saddle-type vertical deflection coil. An electron gun side fringe portion 7 of the coil is a screen side fringe portion. FIG. 4C shows a ferrite core 8.
FIG. 2 is a side view of a core (hereinafter, referred to as a “core”).

[0005] A saddle-type vertical deflection coil 9 wound in a saddle shape is mounted on the outer periphery of the side inductor portion 2 of the saddle-type horizontal deflection coil 1 configured as described above from the left and right. A pair of cores 8 is assembled around the inductor 9 of the coil 9 to form a deflection yoke 10 as shown in FIG.

In this deflection yoke 10, when a horizontal deflection current is supplied to a horizontal deflection coil, the current flows through a pair of horizontal deflection coils 11 as shown in FIG. Here, horizontal deflection currents for the side inductor portion, the electron gun side fringe portion, and the screen side fringe portion constituting the horizontal deflection coil 11 are distinguished as follows. One is a current 12 flowing to the side inductor part, the second is a current 13 flowing to the electron gun side fringe part, and the third is a current 14 flowing to the screen side fringe part.

FIG. 6 shows a magnetic field when a magnetic field generated on the tube axis by the currents thus distinguished is viewed in a section along the tube axis.
Shown in In FIG. 6, 15 indicates the direction of the main magnetic field generated by the current flowing through the side inductor portion. Numeral 16 indicates the direction of the magnetic field generated by the current flowing through the fringe on the electron gun side. Reference numeral 17 indicates the direction of a magnetic field generated by a current flowing through the screen-side fringe. Here, by mounting the ferrite core, the main magnetic field generated by the current flowing through the side inductor part is emphasized via the ferrite core, and the magnetic field generated by the current flowing through the screen side fringe part is partially removed by the ferrite core. It will be weakened because it is cut off.

Next, in FIG. 7, reference numeral 18 denotes a magnetic field generated on the tube axis by a current flowing through the side inductor portion. Reference numeral 19 denotes a magnetic field generated on the tube axis by a current flowing through the fringe portion on the electron gun side. Reference numeral 20 denotes a magnetic field generated on the tube axis by a current flowing through the screen side fringe portion. Reference numeral 21 denotes a magnetic field obtained by combining the above three types of magnetic fields, that is, a magnetic field actually generated on the tube axis.

[0009]

In this deflection yoke, when a horizontal deflection current is supplied to a horizontal deflection coil, a magnetic field which does not contribute to the deflection of the electron beam (XX in FIG. 7).
The magnetic field component outside the ', YY' line) leaks out of the deflection yoke. Conventionally, in order to reduce this leakage magnetic field,
As shown in FIG. 8, a cancel coil 22 connected in series to a horizontal deflection coil is installed on the screen side of the deflection yoke, and a horizontal deflection current is supplied to the cancellation coil 22 to cancel the leakage magnetic field. However, such a method has a problem that the horizontal deflection efficiency LI2 increases because the cancel coil 22 connected in series with the horizontal deflection coil is installed.

Accordingly, an object of the present invention is to provide a deflection yoke which can reduce a leakage magnetic field without installing a cancel coil.

[0011]

A deflection yoke according to the present invention comprises:
The electron gun side fringe of the horizontal deflection coil is wound so as to overlap in the tube axis direction of the cathode ray tube, and the screen side fringe is stepped in the tube axis direction and wound in parallel to the conical tube surface, and the horizontal deflection coil is wound. The length of the ferrite core is set to be more than 70% and less than 80% with respect to the side inductor length.

Further, the distance between the front end of the ferrite core and the screen-side fringe of the horizontal deflection coil is set to be more than 20% and less than 40% with respect to the side inductor length of the horizontal deflection coil.

According to the present invention, a deflection yoke with a reduced leakage magnetic field can be obtained without installing a cancel coil.

[0014]

According to the first aspect of the invention, the electron gun side fringe of the horizontal deflection coil is wound so as to overlap along the tube axis direction of the cathode ray tube, and the screen side fringe is further wound in the tube axis direction. The ferrite core is wound so as to overlap along the conical tube surface, and the length of the ferrite core is set to be more than 70% and less than 80% with respect to the side inductor length of the horizontal deflection coil.

According to a second aspect of the present invention, the distance between the front end of the ferrite core and the screen-side fringe of the horizontal deflection coil is set to 20 with respect to the side inductor length of the horizontal deflection coil.
% And set to less than 40%.

According to this configuration, a deflection yoke with a reduced leakage magnetic field can be obtained without installing a cancel coil.

(Embodiment 1) FIG. 1 is a structural view of a deflection yoke according to Embodiment 1 of the present invention, and FIG. 2 is a magnetic field distribution diagram on a tube axis of the deflection yoke. FIG. 1A is a side view of a pair of horizontal deflection coils wound in a saddle shape. Reference numeral 31 denotes a side inductor portion of a saddle type horizontal deflection coil 30;
Is a fringe portion on the electron gun side of the saddle type horizontal deflection coil 30,
33 is a screen side fringe portion.

In the saddle type horizontal deflection coil 30, the electron gun side fringe portion 32 is wound so as to overlap in parallel along the tube axis direction of the cathode ray tube. The screen-side fringe portion 33 is wound in a petal shape along the conical tube surface of the cathode ray tube. FIG. 1B is a side view of a pair of vertical deflection coils wound in a saddle shape.
Is a side inductor portion of the saddle type vertical deflection coil 39, 35 is an electron gun side fringe portion of the saddle type vertical deflection coil 39, and 36 is a screen side fringe portion. In the saddle type vertical deflection coil 39, the electron gun side fringe portion 35 is wound so as to overlap in parallel along the tube axis direction of the cathode ray tube. FIG. 1C shows a ferrite core 37.
FIG. 2 is a side view of a core (hereinafter, referred to as a “core”). This core 3
7, the performance of the conventional deflection yoke can be obtained by setting the total core height H to be more than 70% and less than 80% with respect to the side inductor length A of the horizontal deflection coil (see FIG. 1A). It becomes possible.

A saddle-type vertical deflection coil 39 wound in a saddle shape is mounted on the outer periphery of the side inductor portion 31 of the saddle-type horizontal deflection coil 30 configured as described above in the left-right direction, and the saddle-type vertical deflection coil is mounted. As shown in FIG. 2D, a pair of cores 37 is assembled around the outer periphery of the inductor portion of the coil.
Such a deflection yoke 40 is formed.

In this deflection yoke 40, when the electron gun side fringe 41 of the horizontal deflection coil is wound so as to overlap in the tube axis direction of the cathode ray tube as shown in FIG. 2, a tube shaft generated by a current flowing through the electron gun side fringe portion is formed. In the magnetic field 42 above, the electric wire wound around the conventional electron gun side fringe portion is wound near the tube axis with respect to the electric wire wound around the conventional electron gun side fringe portion. Against the magnetic field on the tube axis generated by the current flowing through the tube.

The magnetic field on the tube axis generated by the current flowing in the fringe portion on the electron gun side is approximately the main deflection magnetic field (magnetic field due to the current flowing in the side inductor portion) on the screen side from the center of the fringe portion. On the other hand, on the electron gun side, the direction is opposite to the main deflection magnetic field.

Therefore, as shown in FIG. 2, the combined magnetic field 43 of the main deflection magnetic field (the magnetic field generated by the current flowing through the side inductor portion) and the magnetic field on the tube axis generated by the current flowing through the fringe portion on the electron gun side is: On the electron gun side, it is reduced with respect to the conventional combined magnetic field. That is, the leakage magnetic field to the outside decreases.

When the screen side fringe 44 of the horizontal deflection coil is wound so as to overlap in the tube axis direction of the cathode ray tube as shown in FIG. 2, a magnetic field 45 on the tube axis generated by a current flowing through the screen side fringe portion is generated. Since the wound wire is wound near the tube axis with respect to the wire wound on the conventional screen side fringe,
The magnetic field 45 on the tube axis generated by the current flowing through the screen-side fringe becomes stronger against the magnetic field on the tube axis generated by the current flowing through the conventional screen-side fringe.

The magnetic field on the tube axis generated by the current flowing through the fringe portion on the screen side is approximately equal to the main deflecting magnetic field (magnetic field due to the current flowing through the side inductor portion) on the screen side from the center of the fringe portion. In the opposite direction, the electron gun side is in the same direction as the main deflection magnetic field.

Therefore, as shown in FIG. 2, the combined magnetic field 43 of the main deflection magnetic field and the magnetic field on the tube axis generated by the current flowing through the screen side fringe portion is reduced on the screen side with respect to the conventional combined magnetic field. I do. That is, the leakage magnetic field to the outside decreases.

(Embodiment 2) FIG. 3 is a diagram showing the effect of a ferrite core of a deflection yoke according to Embodiment 2 of the present invention on a magnetic field. In the first embodiment, the leakage magnetic field can be reduced by changing the shape of the fringe portion of the horizontal deflection coil. However, as shown in FIG.
For the side inductor length A of the horizontal deflection coil, the distance D between the front end of the ferrite core and the screen side fringe of the horizontal deflection coil is set to the side inductor length A of the horizontal deflection coil.
By setting the ratio to more than 20% and less than 40%, the main deflection magnetic field 46 generated by the side inductor portion on the screen side attenuates the effect of amplifying the magnetic field by the ferrite core near the screen side. A side inductor when the distance D between the front end of the ferrite core and the screen side fringe of the horizontal deflection coil is 20% or less of the side inductor length A of the horizontal deflection coil. It becomes weak against the main deflection magnetic field generated by the section.

Also, since the amount of the magnetic field 47 generated by the screen-side fringe portion is cut off by the ferrite core, conventionally, the front end of the ferrite core and the screen of the horizontal deflection coil with respect to the side inductor length A of the horizontal deflection coil. When the distance D to the side fringe is 20% or less of the side inductor length A of the horizontal deflection coil, the magnetic field generated by the screen side fringe becomes strong. That is, the leakage magnetic field to the outside decreases.

[0028]

As described above, according to the present invention, the fringe on the electron gun side of the horizontal deflection coil is wound so as to overlap in the tube axis direction of the cathode ray tube, so that the leakage magnetic field to the electron gun side is reduced. Can be done. Further, since the screen side fringe is provided with a step in the tube axis direction and wound in parallel with the conical tube surface, the leakage magnetic field to the screen side can be reduced. Further, by setting the length of the ferrite core to be more than 70% and less than 80% with respect to the length of the side inductor of the horizontal deflection coil, the performance of the deflection yoke equivalent to the conventional one can be secured. Also, the distance between the front end of the ferrite core and the screen-side fringe of the horizontal deflection coil is 20% of the side inductor length of the horizontal deflection coil.
And less than 40%, it is possible to reduce the leakage magnetic field to the screen side.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a deflection yoke according to a first embodiment of the present invention.

FIG. 2 is a magnetic field distribution diagram on a tube axis of the deflection yoke according to the first embodiment of the present invention.

FIG. 3 is a diagram showing an effect of a deflection yoke on a magnetic field of a ferrite core according to a second embodiment of the present invention;

FIG. 4 is a configuration diagram of a conventional deflection yoke.

FIG. 5 is a schematic view of a conventional horizontal deflection coil.

FIG. 6 is a diagram showing a magnetic field generated by a conventional horizontal deflection coil.

FIG. 7 is a magnetic field distribution diagram on a tube axis of a conventional deflection yoke.

FIG. 8 is a side view of a conventional deflection yoke.

[Explanation of symbols]

 Reference Signs List 30 saddle type horizontal deflection coil 31, 34 side inductor part 32, 35 electron gun side fringe part 33, 36 screen side fringe part 37 ferrite core 39 saddle type vertical deflection coil 40 deflection yoke

Claims (2)

[Claims] An electron gun side fringe of a horizontal deflection coil is wound so as to overlap along a tube axis direction of a cathode ray tube, and a screen side fringe is overlapped along a conical tube surface in a tube axis direction. A deflection yoke, wherein the length of the ferrite core is set to be more than 70% and less than 80% with respect to the side inductor length of the wound horizontal deflection coil. 2. The method according to claim 1, wherein the distance between the front end of the ferrite core and the screen-side fringe of the horizontal deflection coil is set to be more than 20% and less than 40% with respect to the side inductor length of the horizontal deflection coil. Deflection yoke.