JP3217829B2 - Cathode ray tube image display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a deflecting yoke in which a pair of club-type horizontal deflection coils and a pair of club-type vertical deflection coils are disposed inside a wrapper-shaped core.
The present invention relates to an image display device such as a video display device, and more particularly, to a cathode ray tube image display device characterized by a means for reducing unnecessary radiation generated from a deflection yoke.

[0002]

2. Description of the Related Art There are deflection yokes, flyback transformers, and other coils as sources of unnecessary radiation in an image display apparatus. Among them, the main source is a deflection yoke. Unnecessary radiation generated from the deflection yoke is 120K at 15.75 KHz or more to the horizontal deflection coil.
And a very low frequency magnetic field (VLMF) generated by supplying a sawtooth current in the vicinity of 60 Hz to the vertical deflection coil. ELMF) and a very low frequency magnetic field (VLMF) due to harmonic components superimposed on the supply current
It is.

Various techniques have been proposed as means for reducing unnecessary radiation from the deflection yoke, and one example thereof is described in Japanese Patent Application Laid-Open No. 3-114123.

The invention described in this publication is intended to reduce unnecessary radiation generated from a fringe portion at the front end of a horizontal deflection coil using a magnetic material.

[0005]

The above prior art is a countermeasure against unnecessary radiation generated from the front end fringe portion of the horizontal deflection coil. However, unnecessary radiation is generated from the horizontal deflection coil from portions other than the front end fringe portion. ing.

Further, the unnecessary radiation in front of the cathode ray tube includes unnecessary radiation generated not only from the horizontal deflection coil but also from the vertical deflection coil.

Accordingly, in order to reduce unnecessary radiation in front of the cathode ray tube, it is necessary to take measures against unnecessary radiation from both horizontal and vertical deflection coils.

Therefore, a method of using a magnetic shield for the deflection yoke is conceivable. However, when incorporated in an image display device, there is a problem that unnecessary radiation is unbalanced.

By the way, when the unnecessary radiation from the deflection yoke was measured in front of the cathode ray tube, a variation was observed in the horizontal ultra-low frequency magnetic field. This is a magnetic field generated from the vertical deflection coil. In view of the frequency band, this magnetic field is considered to be generated by a harmonic component of the current supplied to the vertical deflection coil.

In view of this, a countermeasure was taken by using a magnetic material for the vertical deflection coil. However, the effect of reducing the variation of the horizontal component of the ultra-low frequency magnetic field is small. There was a problem of being disturbed.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a cathode ray tube image provided with a deflection yoke capable of sufficiently suppressing the extremely low frequency magnetic field and the unnecessary radiation of the very low frequency magnetic field as a whole. A display device is provided.

[0012]

Means for Solving the Problems To achieve the above object,
Therefore, the first aspect of the present invention is that the inside of the wrapper-shaped core is
A pair of club-type horizontal deflection coils and a pair of club-type vertical deflection coils
Tube image with deflection yoke in which directional coils are arranged
In the display device, the horizontal deflection coil and the vertical
A deflection coil can be connected in series with a cancellation coil,
Cans connected in parallel and connected to the vertical deflection coil
The cell coil viewed the deflection yoke from a horizontal deflection direction.
In the case, the tube face is located at the front end of the vertical deflection coil
Side, and on the opposite side of the tube surface from the rear end of the vertical deflection coil,
At a distance, the vertical deflection coil and the core
It is characterized by having a shape covering the body. the above
In order to achieve the object, the second invention has a wrapper shape.
Inside the core, a pair of club-type horizontal deflection coils and a pair
Deflection yoke with a vertical deflection coil
In the cathode ray tube image display device obtained above,
And the vertical deflection coil, respectively.
Connected in series or in parallel, and connected to the vertical deflection coil.
The connected cancel coil is located in front of the vertical deflection coil.
The extension of the line connecting the end fringe and the rear fringe
It has an angle approximately equal to the angle that intersects the pipe axis, and
Symmetrically located on the outside in or near the horizontal deflection direction
It is characterized by having been done.

[0013]

The unnecessary radiation of the extremely low frequency magnetic field generated from the horizontal deflection coil is dominated by the main magnetic field for deflecting the electron beam emitted from the cathode ray tube in the horizontal direction on the front side of the deflection yoke, and on the rear side on the rear side. The partial fringe magnetic field is dominant.

Therefore, unnecessary radiation can be reduced by weakening the main magnetic field on the front surface side of the deflection yoke and the fringe magnetic field on the rear end portion on the rear surface side.

Therefore, a canceling coil is connected to the horizontal deflection coil to generate a main magnetic field on the front side of the deflection yoke and a magnetic field opposite to the rear end fringe field on the rear side, so that the magnetic field from the horizontal deflection coil is reduced. Unwanted radiation can be reduced.

Unwanted radiation generated from the vertical deflection coil is an extremely low frequency magnetic field and an extremely low frequency magnetic field due to a harmonic component superimposed on the supplied deflection current. The unnecessary radiation is dominated by the main magnetic field for vertically deflecting the electron beam emitted from the cathode ray tube.

Accordingly, unnecessary radiation from the vertical deflection coil can be reduced by connecting the cancel coil to the vertical deflection coil and generating a magnetic field in a direction opposite to the main magnetic field.

[0018]

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

[0019] Figure 1 is a schematic side view of a deflection yoke according to an embodiment of the present invention, FIG 2 is a diagram of the deflection yoke is rotated by 90 degrees about the Z axis in FIG. 1, the mounting angle of the canceling coils, and Cancel FIG. 3 is a cross-sectional view taken along line II of FIG. 1, and FIG. 4 is a view showing a state of generation of a magnetic field of the vertical deflection coil.

In these figures, 1, 1 'are horizontal deflection coils, 2, 2' are vertical deflection coils, 3, 3 'are cancellation coils, and 4 is a core.

As shown in these figures, inside the wrapper-shaped core 4, a pair of horizontal deflection coils 1 and 1 'are provided opposite to each other, and a pair of vertical deflection coils 2 are provided. , 2 'are provided between the horizontal deflection coils 1, 1' and the core 4 so as to face each other.

Here, assuming that the center axis of the core 4 is the Z axis, the axis in the vertical deflection direction perpendicular to the Z axis is the Y axis, and the axis in the horizontal deflection direction is the X axis, the horizontal deflection coils 1 and 1 'have the X axis. And the vertical deflection coils 2 and 2 'are symmetrically arranged about the Y axis.

The deflection yoke thus constructed is fitted and attached to a cathode ray tube.

As shown in FIG. 1, the canceling coils 3, 3 'have such a shape that the vertical deflection coils 2, 2' and the core 4 are arranged inside the loop when viewed from the horizontal deflection direction. In particular, the vertical deflection coil front end fringe 5,
The side end of the loop is protruded at a distance L ₁ on the tube side from 5 ′ and at a distance L ₂ on the side opposite to the tube surface from the rear end fringes 6 and 6 ′ of the vertical deflection coil.

The distances L ₁ and L ₂ vary depending on the shape of the deflection yoke.

As shown in FIG. 2, an extension of a line connecting the front end fringes 5, 5 'and the rear end fringes 6, 6' of the vertical deflection coils 2, 2 'and the Z-axis. The angle formed is θ
When _1, the central axis of the canceling coils 3, 3 'intersect with the Z axis and, theta ₁ and substantially the same angle theta _2, and are provided so as to intersect obliquely with X axis. Accordingly, the cancellation coils 3, 3 'are arranged symmetrically about the Y axis and the Z axis.

When the deflection yoke to which the canceling coils 3 and 3 'are connected is incorporated in an image display device, components other than the deflection yoke in the device that can generate unnecessary radiation, magnetic shields, etc. As a result, unbalanced unnecessary radiation is generated in the entire device due to the influence of
3 'may be asymmetrically arranged to accommodate this.

The canceling coils 3, 3 'are connected in series or in parallel to the vertical deflection coils 2, 2' so that a sawtooth-shaped vertical deflection current or a part thereof flows to generate a magnetic field.

The number of turns is determined by the degree of unnecessary radiation,
It is appropriately set according to the relationship with the impedance of the connected vertical deflection coils 2 and 2 '.

Unnecessary radiation from the vertical deflection coils 2, 2 'is dominated by main magnetic fields 7, 7' for vertically deflecting the electron beam emitted from the cathode ray tube, as shown in FIG. is there. Therefore, in order to reduce unnecessary radiation from the vertical deflection coils 2, 2 ', magnetic fields 10, 10' opposite to the main magnetic fields 7, 7 'may be generated from the cancellation coils 3, 3'.

Therefore, in this embodiment, the loop-side ends of the cancel coils 3 and 3 'are connected to the vertical deflection coils 2 and 2' so that the unnecessary radiation effectively acts on the front of the tube surface. From the front end fringe part 5, 5 '
Magnetic fields 10, 10 'opposite to the main magnetic fields 7, 7' are generated.

Variations in unnecessary radiation due to higher harmonic components of the current supplied to the vertical deflection coils 2 and 2 'are mainly caused by supplying the vertical deflection current or a part thereof to the canceling coils 3 and 3'. As the magnetic fields 7, 7 'fluctuate, the canceling magnetic fields 10, 10' in the opposite direction also fluctuate, and thus are effectively reduced.

The above description relates to the extremely low frequency magnetic field, which is unnecessary radiation from the vertical deflection coils 2 and 2 ', and the reduction of the extremely low frequency magnetic field due to the harmonic components of the supplied current.

The ultralow frequency magnetic field, which is unnecessary radiation from the horizontal deflection coils 1 and 1 ', is reduced by using canceling coils 11 and 11' as shown in FIG.

As described above, as shown in the above embodiment, the horizontal deflection coils 1, 1 'are provided with the cancellation coils 11, 11'.
(See FIG. 6), and the vertical deflection coils 2, 2 '
By connecting the canceling coils 3 and 3 'to the ultra-low frequency magnetic field from the deflection yoke, and unnecessary radiation of the very low frequency magnetic field can be reduced.

In FIG. 4, reference numeral 8 denotes a front end fringe magnetic field of the vertical deflection coils 2 and 2 ', and 9 denotes a rear end fringe magnetic field of the vertical deflection coils 2 and 2'.

[0037]

According to the invention above the claim 1 and 2, wherein, according to the present invention, the unwanted radiation due connexion vertical ELF magnetic field canceling coil connected to the horizontal deflection coil sure
In addition, the canceling coil connected to the vertical deflection coil ensures that the extremely low frequency magnetic field in the horizontal direction and the unnecessary radiation of the extremely low frequency magnetic field due to the harmonic components of the supply current and their variations are ensured. it can be reduced to.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a deflection yoke when a cancel coil is connected to a vertical deflection coil according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a mounting angle of a cancel coil and a cancel effect.

FIG. 3 is a sectional view taken along line II of FIG. 1;

FIG. 4 is an explanatory diagram showing a state of generation of a magnetic field of a vertical deflection coil.

FIG. 5 is a schematic side view of a deflection yoke when a cancel coil is connected to the horizontal deflection coil according to the embodiment of the present invention.

FIG. 6 is a schematic side view of a deflection yoke when a cancel coil is connected to each of the horizontal and vertical deflection coils according to the embodiment of the present invention.

[Explanation of symbols]

1, 1 'horizontal deflection coil 2, 2' vertical deflection coil 3, 3 'cancellation coil connected to vertical deflection coil 4 core 5, 5' front end fringe portion of vertical deflection coil 6, 6 'rear end of vertical deflection coil Fringe part 7, 7 'Main magnetic field of vertical deflection coil 8 Front end fringe magnetic field of vertical deflection coil 9 Rear end fringe magnetic field of vertical deflection coil 10, 10' Magnetic field generated from cancel coil 3, 3 '11, 11' Horizontal Cancel coil connected to deflection coil θ ₁ Front end fringe portions 5 and 5 ′ and rear end fringe portions 6
The angle between the extension of the line connecting 6 'and the Z axis. θ _2-canceling coil mounting angle

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-190041 (JP, A) JP-A-2-148543 (JP, A) JP-A-4-95336 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01J 29/76

Claims (2)

(57) [Claims] 1. A cathode ray tube image display device comprising a wrapper-shaped core and a deflection yoke in which a pair of club-type horizontal deflection coils and a pair of club-type vertical deflection coils are disposed. A cancel coil is connected to the deflection coil and the vertical deflection coil in series or in parallel, respectively.
The cancellation coil connected to the vertical deflection coil is
When the deflection yoke is viewed from the horizontal deflection direction,
The tube face side from the front end of the vertical deflection coil and the vertical deflection coil
At a certain distance from the rear end of the
A cathode ray tube image display device characterized by having a shape that covers a vertical deflection coil and the entire core . 2. A pair of clips are provided inside a flap-shaped core.
LA-shaped horizontal deflection coil and a pair of CL-shaped vertical deflection coils
Image display device equipped with a deflection yoke in which
In the horizontal deflection coil and the vertical deflection coil,
Connect the cancellation coils in series or in parallel, respectively,
The cancellation coil connected to the vertical deflection coil is
Connect the front and rear fringes of the vertical deflection coil.
Angle approximately equal to the angle at which the extension of the
Outside the core and in or near the horizontal deflection direction
A cathode ray tube image display device, which is symmetrically arranged .