JP2000175211A - Color picture tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a high quality picture by providing a vertical magnetic field generating member that controls a vertical magnetic field to a lower part of an assembly consisting of a deflection coil and a device for adjusting a beam to a neck part of a cathode ray tube. SOLUTION: A loop coil 10 that is a vertical magnetic field generating member controlling a vertical magnetic field is placed to a lower part of a deflection coil 2. In general, the vertical magnetic field in the northern hemisphere is +45 uT and the vertical magnetic field in the southern hemisphere is -50 uT. There is a vertical magnetic field difference of 95 uT between the northern and southern hemispheres. The vertical magnetic field around an ITC of a color picture tube even in the southern hemisphere is equal to the vertical magnetic field in the northern hemisphere and stable quality of screen image can be ensured by eliminating this vertical magnetic field difference. In order to eliminate the vertical magnetic field by 95 uT, it is required to generate a cancellation vertical magnetic field of about 10 um. The loop coil 10 can sufficiently eliminate an undesired vertical magnetic field component within a changing range by about 10 um in a center landing of the cancellation vertical magnetic field.

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 provided with an assembly (ITC system, hereinafter referred to as ITC) comprising a cathode ray tube and a deflection coil and a beam adjusting device for a neck portion, and more particularly to a periphery of ITC. And the optimization of the vertical magnetic field in the above.

[0002]

2. Description of the Related Art In general, an in-line color cathode ray tube is a cathode ray tube (CRT) as shown in FIG.
, A deflection coil 2, and a beam adjusting device 4 provided in the neck 3.

[0003] Such in-line color cathode ray tubes are mostly used in the northern hemisphere in the worldwide market, and cathode ray tubes and deflection coils are produced based on a vertical magnetic field in the northern hemisphere. For this reason,
For the southern hemisphere market, cathode ray tubes and deflection coils produced based on the southern hemisphere vertical magnetic field must be used, but producing cathode ray tubes and deflection coils for the southern hemisphere increases production costs.

Therefore, in practice, a color picture tube device for the southern hemisphere has been produced using a cathode ray tube and a deflection coil for the northern hemisphere. In this case, the difference in the exposure condition of the cathode ray tube or the difference in the production condition of the deflection coil greatly affects the screen quality, and causes a quality difference between the one for the northern hemisphere and the one for the southern hemisphere.

As a specific phenomenon, the difference between the vertical magnetic field in the northern hemisphere and the vertical magnetic field in the southern hemisphere causes a problem that the center beam is largely shifted, which mainly deteriorates the purity and trapezoidal distortion. In the current production process, production tact is reduced to improve screen quality.

[0006]

As described above, in the conventional color picture tube device, since a color picture tube device for the southern hemisphere is produced by using a cathode ray tube and a deflection coil for the northern hemisphere, the color picture tube device for the southern hemisphere is produced. There is a problem that the screen quality deteriorates.

[0007] The quality of the ITC is also largely related to the center shift due to the combination of the components constituting the ITC, and the center shift deteriorates the purity and convergence at the corners. This phenomenon is also a problem in ITC production that cannot be ignored.

The present invention solves the above-mentioned conventional problems, and can eliminate unnecessary vertical magnetic fields to improve the quality of the screen. Therefore, the quality for the southern hemisphere is equivalent to that for the northern hemisphere. It is an object of the present invention to provide a color picture tube device having a configuration that can be secured and that does not increase the production cost.

[0009]

In order to achieve the above object, the present invention relates to a color picture tube device provided with an ITC in which a cathode ray tube is provided with a deflection coil and a beam adjusting device for a neck portion. A vertical magnetic field generating member for controlling the vertical magnetic field is provided. For this reason, by generating a canceling vertical magnetic field by the vertical magnetic field generating member, unnecessary vertical magnetic fields around the ITC can be removed. It is possible to stabilize, and it is possible to absorb the influence of the dispersion of ITC parts by appropriately setting the vertical magnetic field of the vertical magnetic field generating member. Further, by adjusting the vertical magnetic field, it is possible to use the ITC for the northern hemisphere. Product for the Southern Hemisphere.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In the following description, members corresponding to the members described with reference to FIG. 5 are denoted by the same reference numerals, and detailed description is omitted.

FIG. 1 is a block diagram showing an ITC portion for explaining a first embodiment of the present invention. A loop-shaped coil 10 which is a vertical magnetic field generating member for controlling a vertical magnetic field is connected to a deflection coil 2. Installed at the bottom. The coil 10 is used to generate an appropriate canceling magnetic field in the vertical and vertical directions, thereby removing an unnecessary vertical magnetic field around the ITC.

Specifically, the northern hemisphere vertical magnetic field is generally plus 45 uT, and the southern hemisphere vertical magnetic field is minus 50 uT. Thus, a vertical magnetic field difference of 95 uT occurs between the northern hemisphere and the southern hemisphere. Therefore, if this vertical magnetic field difference can be eliminated, the periphery of the ITC of the color picture tube device becomes equivalent to the northern hemisphere vertical magnetic field even in the southern hemisphere, and a stable screen quality can be secured.

In order to remove a vertical magnetic field of 95 uT,
When viewed from the center purity landing, it is necessary to generate a canceling vertical magnetic field of about 10 μm. According to the loop-shaped coil 10, in the variation range of the center landing of the canceling vertical magnetic field of about 10 μm, unnecessary vertical The magnetic field component can be sufficiently removed.

This makes it possible to produce products for the southern hemisphere using the ITC for the northern hemisphere, and to freely remove peripheral purity deviation, peripheral misconvergence, distortion, etc., which occur due to variations in parts of the ITC for the northern hemisphere. To be absorbed.

Specifically, the apparatus according to the configuration of the present embodiment
Table 1 shows the test results comparing the characteristics with the conventional device.
It is shown in (Table 2). Table 1 shows the characteristics of the conventional device,
(Table 2) shows the characteristics of the device according to the present embodiment.

[0016]

[Table 1]

[0017]

[Table 2]

As can be seen from these results, according to the present embodiment, the characteristics are improved as compared with the conventional device.
In particular, horizontal trapezoidal distortion is remarkably improved.

FIG. 2 is a configuration diagram showing an ITC portion for explaining a second embodiment of the present invention. In the second embodiment, a coil is provided near the top unit 12 of the electron gun 11 in the cathode ray tube 1 in the ITC. 10 are arranged. This part is a part avoiding the magnetic inner shield 13 in the cathode ray tube 1, and the vertical magnetic field can be controlled with small electric power.

FIG. 3 is a structural view showing an ITC portion for explaining a third embodiment of the present invention. In the third embodiment, the coil 10 is provided with a housing for incorporating a color receiving tube device provided with an ITC. 15 is provided below the deflection coil 2 at the bottom of the coil 15.

FIG. 4 is a block diagram showing an ITC portion for explaining a fourth embodiment of the present invention. In the fourth embodiment, a power source 20 is connected to a coil 10 and
A suitable magnetic field is generated in the vertical and vertical directions by applying a current of an appropriate value to the coil 10 from above.

In the above-described embodiment, the example in which the loop-shaped coil 10 is used as the vertical magnetic field generating member has been described. However, the vertical magnetic field generating member may be another means having the same function. A configuration in which a canceling vertical magnetic field is generated in the vertical direction by inputting an appropriate drive signal or the like may be considered.

[0023]

As described above, according to the present invention,
By generating a canceling vertical magnetic field by the vertical magnetic field generating member, an unnecessary vertical magnetic field around the ITC can be removed, so that the screen quality can be stabilized. By setting the vertical magnetic field appropriately, it is possible to absorb the magnetic field. Further, by adjusting the vertical magnetic field, it is possible to obtain an effect that a product for the southern hemisphere can be easily manufactured using the ITC for the northern hemisphere.

[Brief description of the drawings]

FIG. 1 is an ITC for explaining a first embodiment of the present invention;
Configuration diagram showing parts

FIG. 2 is an ITC for explaining a second embodiment of the present invention;
Configuration diagram showing parts

FIG. 3 is an ITC for explaining a third embodiment of the present invention;
Configuration diagram showing parts

FIG. 4 is an ITC for explaining a fourth embodiment of the present invention;
Configuration diagram showing parts

FIG. 5 is a configuration diagram of a conventional ITC.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CRT 2 Deflection coil 3 Neck part 4 Beam adjusting device 10 Loop-shaped coil 11 Electron gun 12 Top unit of an electron gun 13 Magnetic inner shield 20 Power supply

Claims (6)

[Claims] 1. A color picture tube apparatus comprising a cathode ray tube provided with a deflection coil and a beam adjusting device for a neck portion, wherein a vertical magnetic field generating member for controlling a vertical magnetic field is provided below the assembly. A color picture tube device characterized by the above-mentioned. 2. The color picture tube apparatus according to claim 1, wherein said vertical magnetic field generating member generates a magnetic field in a vertical direction and removes an unnecessary vertical magnetic field. 3. The color picture tube device according to claim 1, wherein the vertical magnetic field generating member is provided near a top unit of the electron gun of the cathode ray tube. 4. The color picture tube device according to claim 1, wherein said vertical magnetic field generating member is a loop-shaped coil. 5. The color picture tube device according to claim 1, wherein said vertical magnetic field generating member is provided at a lower portion inside a housing of the color picture tube device. 6. The color picture tube device according to claim 4, wherein a power supply or a signal is appropriately supplied to operate said vertical magnetic field generating member.