JP2000050297A - Color cathode-ray tube device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the beam mis-landing that is caused by the vertical deflection of a horizontal magnetic field at a location near a panel corner by dividing an external magnetism shielder into the right and left sides at the outer circumferences of a panel and a funnel with a prescribed space secured between the shielding bodies to shield the magnetic flux which are applied from outside. SOLUTION: Divided right and left external magnetism shilders(EMS) 21 are placed outside of a panel 2 and a funnel 3 of a CRT 1 with a proper space secured between both EMSs 21. Thus, the EMSs 21 are placed at right and left sides, to cover the panel 2 and the funnel 3 and the gaps 21a are secured at upper and lower parts of both EMSs 21. With such a constitution, each gap 21a functions as a high magnetism resistance means, which increases the resistance to the magnetism that is horizontally permeated in each EMS 21. As a result, a horizontal magnetic field applied to each EMS 21 with not receive deflection which would permeate through the upper and lower sides of the EMS 21. Then since no vertical component is given to the horizontal magnetic field, the beam mis-landing that is caused by a vertical component will not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extended mask (aperture grill) type color cathode ray tube apparatus, and more particularly, to a color cathode ray tube capable of reducing beam mislanding caused by a horizontal magnetic field applied to the color cathode ray tube. The present invention relates to a cathode ray tube device.

[0002]

2. Description of the Related Art FIG. 4 is a view showing a panel and an external magnetic shield (external magnetic shield) of a conventional color cathode ray tube device. In the figure, reference numeral 1 denotes a color cathode ray tube (hereinafter, CR
T), and the CRT 1 has a panel 2 constituting an outer package and a funnel 3 joined to the panel 2. An external magnetic shield (hereinafter, referred to as EMS) 11 that shields lines of magnetic force applied from the outside is provided on the outer periphery of the panel 2 and the funnel 3. The magnetic lines of force applied from the outside of the color cathode ray tube apparatus pass through the EMS 11, whereby the influence on the CRT 1 is reduced.

[0003]

However, in such a conventional color cathode ray tube device, the EMS 11
Has a structure in which the panel 2 and the funnel 3 of the color cathode ray tube device are surrounded by a continuous annular body, so that a magnetic field component Bh orthogonal to the tube axis in the horizontal direction becomes a magnetic field having a component in the vertical direction at the EMS corner. The beam is deflected by the distribution and enters the color cathode ray tube. In the aperture grill tube, there is a problem that the vertical component causes a beam mislanding, and causes a color shift. This problem will be described in detail below.

FIG. 5 shows a CRT equipped with a normal EMS11.
FIG. 7 is a diagram showing a result obtained by observing a beam mislanding caused by a horizontal magnetic field applied to a microscope with a scope (microscope). FIG. 6 is a diagram for explaining the principle in which the phenomenon of FIG. 5 occurs. FIG. 6 is a view of the CRT viewed from the front, similarly to FIG.

A magnetic field is applied horizontally to the panel 2 from the right to the left (this is referred to as the -X direction). In addition, since the electron beam 7 is emitted from the electron gun in the neck portion toward the face surface, the direction of the current 反 対 is the opposite direction (the neck direction from the face surface) (this is the Z direction).

[0006] As shown in FIG.
When a horizontal magnetic field in the Χ direction was applied, inward beam mislanding was observed at the upper corners A and B of the panel surface, and outward beam mislanding was observed at the lower corners C and D. On the other hand, when a horizontal magnetic field in the + X direction is applied, beam mislanding toward the outside occurs at the upper corners A and B of the panel surface, and beam mislanding toward the inside occurs at the lower corners C and D, respectively. Was observed.
Since FIG. 5 is a scope view, the relative deviation direction of the actual electron beam irradiation position is the opposite direction to that shown. That is, when a horizontal magnetic field in the −Χ direction is applied, the electron beam irradiation position with respect to the phosphor shifts outward at the upper corners A and B of the panel surface and inward at the lower corners C and D. Shift. The opposite is true for a + 磁 界 horizontal magnetic field.

The following description is valid for the occurrence of mislanding near the corner of the panel due to the application of the horizontal magnetic field. In the normal EMS 11, the horizontal magnetic field applied to the EMS 11 has a distribution shown in FIG. That is, a vertical magnetic field component is generated near the corner of the panel. Assuming that this is the Y-direction component Bv, the + Y and -Y-direction components of the magnetic field are converted into the -X and + Χ directions according to Fleming's law with respect to the current component (Z-direction component) Ι perpendicular thereto. Exerts a deflecting force. The angle of incidence of the deflected electron beam on the aperture grill is changed, and the electron beam irradiation position with respect to the phosphor is relatively -X direction and +
ず Shift in the direction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a color which can prevent beam mislanding due to vertical deflection due to a horizontal magnetic field applied to an aperture grill type color cathode ray tube. An object is to obtain a cathode ray tube device.

[0009]

According to a first aspect of the present invention, there is provided a color cathode ray tube device comprising: a cathode ray tube having a panel having a phosphor and a funnel having an electron gun; In a color cathode ray tube device using an expansion mask method for a color selection electrode having a hole through which an electron beam passes, an outer magnetic shield that shields lines of magnetic force applied from the outside to the outer periphery of a panel and a funnel is divided into right and left, and It is characterized by being arranged separately at predetermined intervals.

[0010] The color cathode ray tube device according to claim 2 is
A cathode ray tube having a panel having a phosphor and a funnel having an electron gun, and a color cathode ray tube using a spreading mask method as a color selection electrode provided in the cathode ray tube and having a hole for passing an electron beam from the electron gun. In the apparatus, an outer magnetic shield is provided on the outer periphery of the panel and the funnel to shield a magnetic field line applied from the outside, and the outer magnetic shield increases a magnetic resistance against a magnetic field transmitted horizontally in the outer magnetic shield. A resistance means is provided.

Further, the gap generated by dividing and arranging the external magnetic shield on the left and right may be a gap in a range of 0.5 to 30 mm.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
The present invention will be specifically described.

Embodiment 1 FIG. FIG. 1 is a perspective view schematically showing a configuration of a color cathode ray tube device according to Embodiment 1 of the present invention. FIG. 2 is a perspective view showing the configuration of the color cathode ray tube shown in FIG. In the description of the color cathode ray tube device according to the first embodiment, the same components as those in FIG. 4 are denoted by the same reference numerals.

1 and 2, the color cathode ray tube device according to the first embodiment includes a CRT 1,
1 has a panel 2 and a funnel 3 joined thereto.

Further, as shown in FIG. 1, the color cathode ray tube device according to the first embodiment is divided into right and left parts outside the panel 2 and the funnel 3 and arranged at appropriate intervals.
MS 21 is provided. That is, the present color cathode ray tube device has a configuration in which the EMS 21 covering the funnel 3 and the panel 2 is divided into right and left parts and these parts are separately arranged. As shown in FIG. ) 21a. E
Void 21 generated by dividing and arranging MS 21 left and right
a has a function as a high magnetic resistance means for increasing the magnetic resistance with respect to the magnetism transmitted in the horizontal direction in the EMS 21.

In FIG. 2, three types of phosphors that emit red, green, and blue light upon irradiation with an electron beam 7 are arranged in a vertically long stripe shape inside the image display surface of the panel 2. The phosphor layer 4 is formed.
An electron gun 6 that emits three electron beams 7 for red, green, and blue is installed in the neck 5 of the funnel 3. In the position facing the phosphor layer 4 in the CRT 1,
An aperture grille 8 as a color selection electrode having a number of slits for passing an electron beam 7 from an electron gun 6 is arranged. A deflection yoke 9 for deflecting the electron beam in up, down, left and right directions is arranged outside the funnel 3, and an internal magnetic shield (IMS) 10 for the purpose of magnetic shielding is arranged inside the funnel 3. I have.
The electron beam 7 from the electron gun 6 is selectively irradiated on the phosphor layer 4 by the aperture grill 8 and the IMS 10 to project a predetermined color image.

Hereinafter, the operation of the color cathode ray tube device configured as described above will be described.

As shown in FIG. 1, the color cathode ray tube apparatus according to the first embodiment has an EMS 21 which is divided into right and left parts and arranged at appropriate intervals outside the panel 2 and the funnel 3.
It has.

The space 21a between the right and left generated by dividing and arranging the EMS 21 on the left and right plays a role of increasing the magnetic resistance in these portions. In other words, the horizontal magnetic field applied to the EMS 21 does not undergo deflection such that it passes through the upper and lower sides having high magnetoresistance, and draws a distribution as shown in FIG. 3 in which no Y-direction component occurs at the EMS corner.

FIG. 3 is a diagram showing a state of a horizontal magnetic field distribution applied to the color cathode ray tube device of the first embodiment.

As shown in FIG.
a increases the magnetic resistance in this region,
The horizontal magnetic field applied to S21 is not deflected so as to pass through the upper and lower sides having high magnetoresistance, and therefore does not generate a Y-direction component at the EMS corner. As a result, there is no deflection of the electron beam in the X direction, and no beam mislanding occurs.

The gap 21a increases the reluctance only for the magnetism transmitted in the horizontal direction in the EMS 21 and has the same low reluctance for the magnetic field existing in the vertical direction as before the division. It is. The size of the interval is EM
Although it depends on the material and shape of S21, it is approximately 0.5 to
It is considered that an appropriate value exists in the range of 30 mm.

As described above, in the color cathode ray tube device according to the first embodiment, the EMS 2 having an appropriate space 21a divided into right and left around the panel 2 and the funnel 3 is provided.
1, the magnetic resistance is increased with respect to the magnetism transmitted in the EMS 21 in the horizontal direction.
The horizontal magnetic field applied to the MS 21 is not deflected so as to pass through the upper and lower sides of the high magnetic resistance and does not give a vertical component to the horizontal magnetic field, so that beam mislanding due to this does not occur.

Therefore, if the color cathode ray tube device having such excellent features is applied to an aperture grill type color cathode ray tube, it is possible to reduce beam mislanding caused by a horizontal magnetic field applied to the color cathode ray tube. It is possible to prevent color shift from occurring. In particular, it can contribute to an improvement in image quality accompanying a higher resolution in the future.

In the first embodiment, the color cathode ray tube device is applied to an aperture grill type color cathode ray tube. However, it goes without saying that the color cathode ray tube device can be applied to CRTs in general.

In the first embodiment, the EMS is
It is divided into right and left, and these are separated and arranged. Needless to say, appropriate ones can be applied depending on the material and shape of the EMS as well as the size of the gap, the number of divisions, the position and the shape of the division. No.

The space may be divided into left and right parts as shown in FIG. 1, but is not limited thereto.
Any means may be used as long as it is configured to increase the magnetic resistance with respect to the magnetism transmitted horizontally in S. For example, only the material corresponding to the gap may be formed of a material having a high magnetoresistance, and the entire EMS may be formed as an integrated structure including the material having a high magnetoresistance. Further, the gap may be formed in a notch shape so that the EMS is not completely separated from the left and right. With such a structure, since the EMS is an integrated structure, it can be assembled by the same manufacturing process as in the related art.

In the first embodiment, the EMS is
Although they are divided into right and left parts and are separated at predetermined intervals, this is to reduce beam mislanding caused by a horizontal magnetic field. The influence caused by the vertical magnetic field can be prevented by the same method as in the present embodiment (for example, the EMS is divided into upper and lower parts and arranged at predetermined intervals).
Further, such a configuration is used when the CRT is used sideways (for example, a display device that can be used by rotating the CRT).
It is also effective.

[0029]

According to the color cathode ray tube device of the first aspect, an external magnetic shield for shielding magnetic lines of force applied from the outside on the outer periphery of the panel and the funnel is divided into right and left parts.
And because it was configured to be separated at predetermined intervals,
There is an effect that beam mislanding due to deflection in the vertical direction due to a horizontal magnetic field applied to the aperture grill type color cathode ray tube can be prevented.

According to the color cathode ray tube apparatus of the present invention, an external magnetic shield is provided on the outer periphery of the panel and the funnel for shielding magnetic lines applied from the outside, and the external magnetic shield is arranged inside the external magnetic shield. Since the apparatus is provided with high reluctance means for increasing reluctance to the magnetism transmitted in the horizontal direction, it is possible to prevent beam mislanding due to vertical deflection due to a horizontal magnetic field applied to the aperture grill type color cathode ray tube. It works.

According to the color cathode ray tube apparatus of the third aspect, the gap formed by dividing and arranging the external magnetic shield on the left and right is a gap in the range of 0.5 to 30 mm. If an appropriate value is designed according to the material and shape of the body, there is an effect that beam mislanding due to deflection in the vertical direction due to the horizontal magnetic field can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a color cathode ray tube device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing the configuration of the color cathode ray tube of the color cathode ray tube device according to the first embodiment of the present invention, with a part cut away.

FIG. 3 is a diagram for explaining a state of a horizontal magnetic field distribution applied to the color cathode ray tube device according to the first embodiment of the present invention;

FIG. 4 is a perspective view schematically showing a color cathode ray tube device provided with a conventional EMS.

FIG. 5 is a diagram for explaining a result of observing a beam mislanding due to a change in a horizontal magnetic field distribution due to a conventional EMS shape by a scope view.

FIG. 6 is a diagram for explaining the principle that the beam mislanding phenomenon occurs.

[Explanation of symbols]

1 CRT, 2 panels, 3 funnels, 4
Phosphor layer, 5 neck, 6 electron gun, 7 electron beam, 8 aperture grill, 9 deflection yoke, 1
0 Internal magnetic shield (IMS), 21 EMS (external magnetic shield), 21a air gap (high magnetic resistance means).

Claims (3)

[Claims] 1. A cathode ray tube having a panel provided with a phosphor and a funnel provided with an electron gun, and a color masking electrode provided in the cathode ray tube and having a hole for passing an electron beam from the electron gun. In a color cathode ray tube device using a method, an external magnetic shield that shields lines of magnetic force applied from the outside is divided into right and left and separated at predetermined intervals on the outer periphery of the panel and the funnel. Color cathode ray tube device. 2. A mask extending to a cathode ray tube having a panel having a phosphor and a funnel having an electron gun, and a color selection electrode provided in the cathode ray tube and having a hole for passing an electron beam from the electron gun. In the color cathode ray tube device using the method, an outer magnetic shield that shields lines of magnetic force applied from the outside is provided on the outer periphery of the panel and the funnel, and the external magnetic shield is a magnet that is horizontally transmitted through the external magnetic shield. A color cathode ray tube device comprising high magnetic resistance means for increasing the magnetic resistance of the color cathode ray tube. 3. The color cathode ray tube device according to claim 1, wherein a gap formed by dividing and arranging the external magnetic shield on the right and left is a gap in a range of 0.5 to 30 mm.