JPH0715738A - Image display device - Google Patents

Abstract

PURPOSE:To effectively reduce the magnetic field which is leaked out of a deflection yoke of a CRT. CONSTITUTION:The eliminating coils 14a and 14b are placed at the upper and lower positions of a deflection yoke 8 together with the position control jigs 15a and 15b which control the horizontal positions of coils 14a and 14b. Then a magnetic field 16 leaked out of a horizontal deflecting coil is eliminated by the eliminating magnetic fields 17 which are generated by both coils 14a and 14b. Thus a leakage magnetic field is effectively reduced. Therefore the leakage magnetic field caused by the deflection coil of a CRT can be effectively reduced in accordance with the change of the environmental conditions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device capable of reducing a leakage magnetic field generated from a deflection yoke device of a cathode ray tube.

[0002]

2. Description of the Related Art FIG. 7 is a schematic view showing the structure of a cathode ray tube. In FIG. 7, 1 is a cathode ray tube, 2 is a panel which is an image shadow portion, and 3 is formed on the inner surface of the panel 2. It is a phosphor film. Reference numeral 4 denotes a funnel which is joined to the panel 2 and which is formed in a substantially pyramidal shape. Reference numeral 5 denotes a neck portion made of a glass cylinder, which is joined to the funnel 4. 6 is an electron gun for generating at least one electron beam, 7 is a base for supplying various voltages for operating the electron gun 6, and 8 is an electron beam emitted from the electron gun 6 for the phosphor. A deflection yoke for deflecting the film 3 so that the film 3 strikes a predetermined position.

By the way, the deflection yoke 8 has an external structure as shown in FIG.
9b and vertical deflection coils 10a and 10b. The vertical deflection coils 10a and 10b may be formed in a toroidal shape with the core 11. Further, the horizontal deflection coils 9a and 9b are each formed in a saddle shape in a loop shape as shown in FIG.

Next, the operation of the above configuration will be described. To project an image on the face surface of the panel 2 shown in FIG. 7, the electron beam emitted from the electron gun 6 is applied to the panel 2.
Of the phosphor film 3 on the inner surface of the
Therefore, the deflection yoke 8 applies an appropriate deflection magnetic field to deflect the electron beam.

Specifically, as shown in FIG. 10, since the electron beam is deflected in the vertical direction, the horizontal direction 12a, 1
A deflection current is passed through the vertical deflection coils 10a and 10b so that an appropriate magnetic field is generated in the direction 2b, and similarly, in order to deflect the electron beam in the horizontal direction, the vertical directions 13a and 1b
A deflection current is passed through the horizontal deflection coils 9a and 9b so that an appropriate magnetic field is generated in the direction of 3b.

[0006]

Although the conventional deflecting device in the cathode ray tube is constructed as described above, in recent cathode ray tubes, there is a strong demand for high resolution and high density display of images. As one of the means, there is a tendency to increase the frequency of the horizontal deflection current.

The deflection magnetic field generated by the high-frequency current of which the frequency is increased is essentially required to be generated only for deflecting the electron beam inside the deflection yoke, but in reality,
It is also generated as a leakage magnetic field outside. It is known that this leakage magnetic field not only adversely affects peripheral equipment such as electronic devices and electric appliances existing in the vicinity, but also adversely affects human bodies and animals. There has been a demand for measures to reduce it.

The present invention has been made to solve the above problems, and an object thereof is to provide an image display device capable of effectively reducing a leakage magnetic field generated from a deflection yoke of a cathode ray tube. To do.

[0009]

In order to achieve the above object, in the invention of claim 1, there is provided a canceling coil disposed at at least one of the upper and lower positions of the deflection yoke and wound so as to cancel the leakage magnetic field. A position adjusting jig for adjusting the horizontal position of the canceling coil is provided.

According to a second aspect of the present invention, the canceling coil according to the first aspect of the invention is connected in series with the horizontal deflection coil of the deflection yoke and wound so as to cancel the leakage magnetic field generated from the horizontal deflection coil. It is characterized by being.

[0011]

According to the first aspect of the invention, the leakage magnetic field generated from the deflection yoke and the canceling magnetic field generated from the canceling coil have opposite directions. , The leakage magnetic field is reduced.
Moreover, the horizontal position of the canceling coil can be freely adjusted by the position adjusting jig, so that it can be installed in any monitor set, effectively canceling the leakage magnetic field even if the environmental conditions change, depending on the purpose. It is possible to reduce the leakage magnetic field.

Further, according to the invention of claim 2, since the canceling coil is connected in series with the horizontal deflection coil,
The leakage magnetic field generated from the horizontal deflection coil can be effectively reduced by the cancellation magnetic field generated from the cancellation coil.

[0013]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of an image display device according to the present invention. The same or corresponding parts as in FIG. 7 showing a conventional example are designated by the same reference numerals and detailed description thereof will be omitted.

In the figure, 14a and 14b are canceling coils wound so as to cancel the leakage magnetic field generated from the horizontal deflection coils 9a and 9b, and extend backward from the upper and lower front portions of the deflection yoke 8. Two props 15
It is supported by a and 15b.

As shown in FIG. 2, the columns 15a and 15b are
This is a horizontal position adjusting jig capable of freely adjusting the horizontal positions of the canceling coils 14a and 14b to some extent, and one end thereof is fixed to the front portion of the deflection yoke 8.
In FIG. 2, the position adjusting jig 15b provided below the deflection yoke 8 is not shown.

A fitting groove 18 is formed on the side of the position adjusting jigs 15a, 15b which supports the canceling coils 14a, 14b, and the canceling coils 14a, 14b are temporarily fitted in the fitting grooves 18 and are temporarily placed. It is fixedly supported and can slide horizontally along the fitting groove 18. Although not shown, the horizontal position adjusting jigs 15a, 15b
Has means for fixing the canceling coils 14a, 14b at an arbitrary position within a slidable range.

The canceling coils 14a, 1 described above are also used.
4b is a horizontal deflection coil 9a, 9b, as shown in FIG.
It is assumed that the same alternating current flows as the temporal change of the alternating current flowing in the horizontal deflection coils 9a and 9b.

Further, in the above embodiment, the case where one cancel coil 14a and 14b are arranged at the upper and lower front positions of the deflection yoke is shown as an example. However, the position, the number of the cancel coils, the shape, and the cancel coil are arranged. The number of turns, the material, and the size are not particularly limited, and may be appropriately determined in consideration of the scale and state of the leakage magnetic field. Further, the canceling coils 14a and 14b may take either form of series or parallel.

The horizontal position adjusting jigs 15a, 15b
The shape, material, and effective range of movement are not particularly limited. In short, as long as the horizontal positions of the canceling coils 14a and 14b can be freely changed and adjusted to some extent and fixed, this embodiment It is possible to use without being limited to those exemplified in the examples.

Next, the operation of the above configuration will be described. That is, FIG. 4 shows the leakage magnetic field generated from the deflection yoke 8 and the canceling coils 14a, 14 when the cathode ray tube operates.
It is a figure explaining the generation condition of the cancellation magnetic field generated from b. As is clear from the figure, a leakage magnetic field 16 is generated from the deflection yoke 8 during operation of the cathode ray tube. On the other hand, a canceling magnetic field 17 is generated from the canceling coils 14a and 14b. The directions of these magnetic fields are opposite to each other and cancel each other, and as a result, the leakage magnetic field 16 is reduced.

The canceling coils 14a, 14b are also provided.
The horizontal position adjusting operation will be described with reference to FIGS. FIG. 5 is a model diagram of the canceling magnetic field when the horizontal position of the canceling coil is close to the tube surface of the cathode ray tube, and FIG. 6 is a model diagram of the canceling magnetic field when the horizontal position of the canceling coil is far from the tube surface. As shown in these figures, the cancellation coil 1
The horizontal positions of 4a and 14b are the position adjusting jigs 15a and 1
When moving from the state of FIG. 5 to the state of FIG. 6 along the fitting groove 18 provided in 5b, the generation range of the canceling magnetic field is changed from the state indicated by reference numeral 17a in FIG. 5 to the reference numeral 17b in FIG.
It is possible to move to the state shown by with respect to the deflection yoke and the cathode ray tube.

As is apparent from the above embodiment, the horizontal position adjustment of the canceling coils 14a and 14b is performed by the position adjusting jigs 15a and 15b, and the canceling magnetic field generated can be appropriately changed as described above. Therefore, by utilizing this, it is possible to reduce the leakage magnetic field by adjusting to the optimum horizontal position according to the purpose and according to the monitor set.

Therefore, even if the deflection yoke 8 is the same and the environmental conditions change, the canceling coils 14a, 14a
The horizontal position of 4b can be easily adjusted by appropriately adjusting the horizontal position.

[0024]

As described above, according to the present invention, the leakage magnetic field generated from the deflection yoke can be canceled by the canceling magnetic field generated from the canceling coil, and the horizontal position of the canceling coil can be adjusted. Therefore, there is an effect that the leakage magnetic field can be effectively reduced even if the environmental conditions change, and the present invention can be applied to the conventional image display device with only a slight improvement.

[Brief description of drawings]

FIG. 1 is a side view showing an image display device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an example of a position adjusting jig which is a feature of the present invention.

FIG. 3 is a diagram for explaining a connection state of a cancellation coil and a horizontal deflection coil in the image display device according to the embodiment of the present invention.

FIG. 4 is a diagram showing a generation state of a leakage magnetic field and a canceling magnetic field in the image display device according to the embodiment of the present invention.

FIG. 5 is a model diagram of a canceling magnetic field when the horizontal position of the canceling coil is close to the tube surface.

FIG. 6 is a model diagram of a canceling magnetic field when the horizontal position of the canceling coil is far from the tube surface.

FIG. 7 is a schematic view showing the structure of a conventional cathode ray tube.

FIG. 8 is a perspective view showing an appearance of a deflection yoke.

FIG. 9 is a diagram showing a winding shape of a horizontal deflection coil.

FIG. 10 is a diagram for explaining the directions of magnetic fields generated from a horizontal deflection coil and a vertical deflection coil in a deflection yoke.

[Explanation of symbols]

 8 Deflection yoke 9a, 9b Horizontal deflection coil 14a, 14b Canceling coil 15a, 15b Position adjusting jig 16 Leakage magnetic field 17, 17a, 17b Canceling magnetic field

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[Procedure amendment]

[Submission date] December 6, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

[0022] the Hare by apparent from the above examples, cancel coils 14a, a horizontal position adjustment of 14b, the position adjustment jig 15a, carried by 15b, a magnetic field cancellation occurs as described above, it is appropriately changing Since this is possible, it is possible to reduce the leakage magnetic field by utilizing this fact and adjusting to the optimum horizontal position according to the purpose and the monitor set.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Change

[Correction content]

[Figure 5]

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

Claims (2)

[Claims] 1. A cathode ray tube having at least an electron gun, a phosphor screen and a deflection yoke, which is disposed at at least one of the upper and lower positions of the deflection yoke and is wound so as to cancel a leakage magnetic field from the deflection yoke. An image display device comprising a canceling coil and a position adjusting jig for adjusting the horizontal position of the canceling coil. 2. The image display device according to claim 1, wherein the canceling coil is connected in series with the horizontal deflection coil of the deflection yoke, and is wound so as to cancel a leakage magnetic field generated from the horizontal deflection coil.