JPH1196936A - Color picture tube device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color picture tube device capable of simply and effectively demagnetizing a convergence yoke, even if it is magnetized. SOLUTION: In a color picture tube device equipped with an electron gun 7 disposed in a neck 5 of a funnel 2 and emitting plural beams 6B, 6G, 6R, a deflection yoke 10 mounted on the outside of the funnel and deflecting the plural beams, and a convergence yoke 12 mounted on the outside of the neck behind the deflection yoke and generating a magnetic field for converging the plural beams on one point in the middle of a screen, a degaussing coil 23 situated near the convergence yoke 12 and demagnetizing its magnetization is disposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube apparatus, and more particularly to a convergence tube for converging a plurality of beams emitted from an electron gun of a color picture tube to one point on a screen.
The present invention relates to a color picture tube device having a yoke.

[0002]

2. Description of the Related Art As shown in FIG. 7, a color picture tube device generally has an envelope composed of a panel 1 and a funnel 2, and a three-color fluorescent light emitting blue, green, and red on the inner surface of the panel. A phosphor screen 3 made of a body layer is provided, and a shadow mask 4 is arranged inside the phosphor screen 3 so as to face the phosphor screen 3. On the other hand, an electron gun 7 for emitting three electron beams 6B, 6G, 6R is arranged in a neck 5 of the funnel 2. Inside the large diameter portion 8 of the funnel 2, an internal magnetic shield 9 attached to the shadow mask 4 is arranged. Further, a deflection yoke 10 is mounted from the large diameter portion 8 of the funnel 2 to the portion adjacent to the neck 5. Then, the three electron beams 6B, 6G, 6R emitted from the electron gun 7 are deflected by the magnetic fields generated by the horizontal and vertical deflection coils of the deflection yoke 10, and the phosphor screen 3 is moved horizontally and vertically via the shadow mask 4. By scanning, a color image is displayed.

At present, such a color picture tube device emits three electron beams 6B, 6G, 6R arranged in a line consisting of a center beam 6G and a pair of side beams 6B, 6R passing through the electron gun 7 on the same horizontal plane. The in-line type, on the other hand, the magnetic field generated by the horizontal deflection coil is a pincushion type, and the magnetic field generated by the vertical deflection coil is a barrel type. These three magnetic beams 6B, 6G, 6R passing in the same horizontal plane by these magnetic fields are used. A self-convergence, in-line type color picture tube device for causing convergence (dynamic convergence) over the entire surface of a screen has been widely put to practical use.

In such a color picture tube device, in order to concentrate the three electron beams 6B, 6G, 6R emitted from the electron gun 7 at one point on the screen, a convergence beam is provided outside the neck 5 behind the deflection yoke 10. There is one in which a yoke 12 is arranged. This convergence yoke 12
For example, eight or twelve protrusions are radially provided inside the annular magnetic core, and a coil is wound around each protrusion. The magnetic core may be made of a material that is easy to magnetize in consideration of cost and performance.

[0005] The magnetic core of the convergence yoke 12 may be inspected by applying a magnetic field stronger than a normal use condition at the time of manufacture, so that magnetization may remain. Also affected by geomagnetism and magnetic fields during transport,
May be magnetized. When magnetized and magnetized in this way, the magnetic field changes the trajectory of the electron beam, and the original characteristics of the color picture tube device cannot be maintained.

In general, a color picture tube device includes:
Many magnetic materials are used, such as the core of the deflection yoke 10, the shadow mask 4 and the internal magnetic shield 9 disposed in the color picture tube. However, the core of the deflection yoke 10 is usually made of an expensive material that has a small coercive force and is hard to be magnetized, so that there is almost no problem of magnetization and magnetization. On the other hand, the shadow mask 4, the internal magnetic shield 9, etc.
Usually, it is easy to be magnetized because it is made of mild steel or the like. However, as shown in FIG.
Can be demagnetized by the degaussing coil 15 attached to the outer periphery of the.

However, even if the degaussing coil 15 is attached to the outer periphery of the envelope 14, the convergence yoke is provided outside the neck 5 away from the degaussing coil 15. When the core is magnetized and magnetized, it is difficult to demagnetize by the degaussing coil 15.

Conventionally, as the degaussing coil 15 attached to the outer periphery of the envelope 14 of a color picture tube, in addition to the degaussing coil 15 shown in FIG. Are arranged in Japanese Patent Laid-Open No. 5-2833.
Japanese Patent Publication No. 43-27079 discloses a demagnetizing coil 15 in which a coil is wound around a magnetic shield 16 disposed so as to cover the outer surface of the large diameter portion 8 of the funnel 2. However, since all of these degaussing coils 15 are separated from the convergence yoke arranged outside the neck, when the magnetic core of the convergence yoke is magnetized or magnetized, it is difficult to demagnetize it. is there.

[0009]

As described above, in the color picture tube apparatus, in order to concentrate the three electron beams emitted from the electron gun at one point on the screen, a convergence beam is provided outside the neck behind the deflection yoke. Some have a yoke arranged. In some cases, the convergence yoke is made of a material which is easy to magnetize, in consideration of cost and performance.

When the magnetic core of the convergence yoke is made of a material which is easily magnetized, if the magnetic core is undesirably magnetized and magnetized, it is attached to the outer periphery of the conventional color picture tube envelope. It cannot be demagnetized by the degaussing coil,
The orbit of the electron beam changes due to its magnetization and magnetization,
There is a problem that the original characteristics of the color picture tube device cannot be maintained.

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 provide a color picture tube device which can easily and effectively demagnetize a convergence yoke even if it is magnetized. Aim.

[0012]

An electron gun for emitting a plurality of beams disposed in a neck of a funnel and a horizontal and vertical deflection magnetic field mounted outside the funnel and deflecting the plurality of beams emitted from the electron gun are provided. A color picture tube apparatus comprising: a deflection yoke that generates a magnetic field; and a convergence yoke that is mounted on the outside of the neck behind the deflection yoke and generates a magnetic field that concentrates a plurality of beams emitted from the electron gun at one point on the screen. A degaussing coil for demagnetizing the convergence yoke was arranged close to the convergence yoke.

The degaussing coil is connected to a convergence coil.
It was wound directly around the magnetic core of the yoke.

The degaussing coil is connected to a convergence coil.
It was located outside the neck close to the yoke.

[0015]

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

FIG. 1 shows a color picture tube device which is one embodiment of the present invention. This color picture tube device has an envelope composed of a panel 1 and a funnel 2, and a phosphor screen 3 composed of a three-color phosphor layer that emits blue, green, and red light is provided on the inner surface of the panel 1. A shadow mask 4 is arranged inside the phosphor screen 3 so as to face the phosphor screen 3. On the other hand, three electron beams 6B and 6B are placed in the neck 5 of the funnel 2.
An electron gun 7 for emitting G, 6R is provided. Also, from the large diameter portion 8 of the funnel 2 to the adjacent portion of the neck 5,
The three electron beams 6B, 6G,
A deflection yoke 10 having a horizontal deflection coil for generating a horizontal deflection magnetic field for deflecting 6R and a vertical deflection coil for generating a vertical deflection magnetic field is mounted. A convergence yoke 12 for concentrating the three electron beams 6B, 6G, and 6R emitted from the electron gun 7 at one point on the center of the screen is disposed outside the neck 5 behind the deflection yoke 10.

The convergence yoke 12 is shown in FIG.
As shown in the figure, eight protrusions 21 are provided inside the annular magnetic core 20.
Are radially provided, and are formed in a structure in which a coil 22 is wound around each protrusion 21. Further, in the color picture tube device, the convergence yoke 1
A demagnetizing coil 23 is wound around the outer periphery of the second magnetic core 20, and is connected to a demagnetizing current supply device (not shown) that generates an attenuated alternating current 24 having a waveform shown in FIG.

As described above, the convergence yoke 12
When the demagnetizing coil 23 is arranged on the magnetic core 20, if the magnetic core 20 is magnetized for any reason, the magnetization of the magnetic core 20 can be easily and effectively demagnetized.

That is, as shown in FIG. 4, when the magnetic core 20 of the convergence yoke 12 is magnetized, the three electron beams 6B, 6G, and 6R produce a magnetic flux 25 generated by the magnetization.
, And its trajectory is bent.
Normally, when the trajectories are corrected by the convergence yoke 12 so that the three electron beams 6B, 6G, and 6R concentrate on one point on the screen, the magnetic core 20 is not operated until it reaches the saturation region. Therefore, if the magnetic core 20 of the convergence yoke 12 is magnetized for any reason as described above,
The magnetization due to the magnetization is superimposed, and the three electron beams 6B, 6
The trajectory of G and 6R changes, and it is no longer concentrated at one point on the center of the screen. Such magnetization could not be demagnetized by a conventional degaussing coil arranged at a position away from the convergence yoke arranged outside the neck behind the deflection yoke. As in the embodiment, a demagnetizing coil is wound around the magnetic core 20 of the convergence yoke 12, and the demagnetized alternating current 24 shown in FIG.

The magnitude, frequency and decay time of the decaying alternating current 24 depend on the magnetic core 2 of the convergence yoke 12.
It is appropriately set as appropriate depending on the material of No. 0, the distance to the magnetic core 20, and the like.

In the above embodiment, the degaussing coil is arranged on the outer periphery of the magnetic core of the convergence yoke, but the relationship between the convergence yoke and the degaussing coil is, as shown in FIG. The degaussing coil 23 may be divided and wound around each of the projections 21 radially projecting inside the magnetic core 20, and as shown in FIG.
May be wound between the respective projecting portions 21. Also, as shown in FIG.
Even if the degaussing coil 23 is arranged outside the above, demagnetization can be performed simply and effectively as in the above embodiment.

In the above embodiment, the case where the magnetic core of the convergence yoke is formed of an annular magnetic core having eight projections has been described, but the present invention has a magnetic core different from the above-mentioned magnetic core. The convergence yoke is also applicable.

[0023]

As described above, when the degaussing coil is arranged close to the convergence yoke mounted outside the neck of the funnel, if the magnetic core of the convergence yoke is magnetized for some reason, The magnetization can be simply and effectively demagnetized, the problem caused by the magnetization of the convergence yoke can be eliminated, and a color picture tube device which maintains required characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a color picture tube device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a convergence yoke around which the degaussing coil is wound.

FIG. 3 is a diagram showing a waveform of an attenuated alternating current supplied to the degaussing coil.

FIG. 4 is a diagram for explaining a problem when a magnetic core of a convergence yoke is magnetized.

5 (a) and 5 (b) show different arrangements of the degaussing coil with respect to the convergence yoke.

FIG. 6 is a view showing a different arrangement of the degaussing coil with respect to the convergence yoke.

FIG. 7 is a diagram showing a configuration of a conventional color picture tube device.

FIG. 8 is a diagram showing an arrangement of a conventional degaussing coil in a color picture tube device.

[Explanation of symbols]

 2 Funnel 5 Neck 6B, 6G, 6R 3 Electron beam 7 Electron gun 10 Deflection yoke 12 Convergence yoke 20 Magnetic core 21 Projection 22 Coil 23 Demagnetizing coil

Claims (3)

[Claims] 1. An electron gun for emitting a plurality of beams disposed in a neck of a funnel, and a horizontal and vertical deflection magnetic field mounted outside the funnel and deflecting the plurality of beams emitted from the electron gun. A color picture tube device comprising: a deflection yoke; and a convergence yoke mounted outside the neck behind the deflection yoke and generating a magnetic field for concentrating a plurality of beams emitted from the electron gun at one point on a screen. A color picture tube device, wherein a degaussing coil for demagnetizing the convergence yoke is arranged near the convergence yoke. 2. The convergence yoke according to claim 1, wherein the degaussing coil is wound directly around the magnetic core of the convergence yoke.
A color picture tube device as described in the above. 3. The color picture tube device according to claim 1, wherein the degaussing coil is disposed outside the neck close to the convergence yoke.