JPH11127446A - Geomagnetic correction device and television receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively correct raster rotation of a CRT screen and color smear of upper and lower parts of a screen with one magnetic correction coil by providing a geomagnetic correction coil with a circular part and an almost rectangular part. SOLUTION: A geomagnetic correction coil 1 integrally winds a circular part 1A and an almost rectangular part 1B. The part 1A of the geomagnetic correction coil is located almost at the center of the part 1B. A neck part of a CRT (Braun tube) 2 is additionally touched to almost the center of the part 1A and the part 1B is additionally touched onto a funnel surface of the CRT 2 vertically. That is, the part 1A of the geomagnetic correction coil is arranged so that it may surround a deflecting yoke 4 and that it may be an equal distance, and the fixture to a CRT surface of the part 1A assigns fixed tables 7. The part 1B of the geomagnetic correction coil is arranged in an almost longitudinal symmetrical shape with the coil 4 as the center. It is fixed to the CRT surface funnel surface with the tables 7 and clampers 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a geomagnetic compensator and a television receiver having the same.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 5-145936, which has been proposed as a conventional technique, has a problem that when the geomagnetism correction circuit starts the geomagnetism correction operation in a state where the screen is shown, the screen suddenly moves. It is to prevent the color and the color unevenness from changing rapidly, and does not perform the tube axis correction and the adjustment of the color unevenness at the same time. Further, the shape is not described.

In a terrestrial magnetism correction circuit of a television receiver, when the size of a cathode ray tube is increased, for example, in a size such as 36 inches, the raster of the screen of the television receiver is rotated by the influence of terrestrial magnetism. In particular, when the screen of the television receiver faces the geomagnetic south and north, the screen rotates.

Conventionally, in order to correct raster rotation, a circular geomagnetic correction coil is wound about 60 turns as shown in FIG. 6, and a direct current is supplied to correct the raster rotation. In particular, a large television receiver such as a 36-inch television tends to have uneven colors on the screens 1 and 2 as shown in the cathode ray tube in FIG.

[0005]

SUMMARY OF THE INVENTION A television receiver,
Geomagnetic south-facing, north-facing, especially with a large 36 inches.
At about 4 gauss and +0.4 gauss, the conventional geomagnetic correction coil shown in FIG. 3 cannot correct the color shift and the like simultaneously with the raster rotation.

[0006]

According to the present invention, there is provided a television receiver comprising a demagnetizing coil, a geomagnetic correction circuit, and a geomagnetic correction coil, wherein the geomagnetic correction coil has a circular portion and a substantially rectangular portion. And a configuration including:

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a first aspect of the present invention, a geomagnetic correction coil has a circular portion and a substantially rectangular portion, and a neck portion of a cathode ray tube is provided substantially at the center of the circular portion, and a vertical portion of the funnel surface of the cathode ray tube is provided. A television receiver characterized by having the general rectangular portion attached thereto,
Geomagnetic south-facing, north-facing, especially with a large 36 inches.
At about 4 gauss and +0.4 gauss, it has the effect of correcting raster rotation and color misregistration.

Further, according to a second aspect of the present invention, the geomagnetic correction coil includes a circular portion and a substantially rectangular portion, wherein the neck portion of the cathode ray tube is provided at substantially the center of the circular portion, and the substantially rectangular portion is provided in the vertical direction of the funnel surface of the cathode ray tube. A television receiver characterized in that it is abutted and combined so that the circular portion is located within one ring of a demagnetizing coil having an approximately figure eight shape. In the direction, northward of about −0.4 gauss and +0.4 gauss, it has an effect of correcting raster rotation and color misregistration.

Hereinafter, a geomagnetic correction circuit of a television receiver according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a front view of a terrestrial magnetism correction coil constituting a terrestrial magnetism correction device according to a first embodiment of the present invention. FIG. 2 is a front view showing a state in which a geomagnetic correction coil is attached to a CRT (CRT). 1 and 2, reference numeral 1A denotes a coil circular portion, 1B denotes a substantially rectangular portion of the coil, 2 denotes a CRT (CRT), 3 denotes a demagnetizing coil having an approximately 8-shaped shape, 4 denotes a geomagnetic correction coil connector,
Denotes a deflection yoke, 6 denotes a terrestrial magnetism correction coil, 7 denotes a tape for fixing the terrestrial magnetism correction coil, 8 denotes a demagnetizing coil having an approximately figure eight shape, and a clamper for fixing the terrestrial magnetism correction coil.

The terrestrial magnetism correction coil 1 is constructed by winding a circular portion 1A and a substantially rectangular portion 1B integrally. FIG.
As shown in (1), the circular portion 1A of the geomagnetic correction coil is located substantially at the center of the substantially rectangular portion 1B. A neck portion of a cathode ray tube (CRT) 2 is attached substantially at the center of the circular portion 1A, and the substantially rectangular portion 1B is vertically attached to the funnel surface of the CRT 2 in the vertical direction. Further, in the geomagnetic correction device shown in FIG.
A terrestrial magnetism correction circuit for generating two direct currents is connected.

In the above configuration, when no current is flowing through the terrestrial magnetism correction circuit, the cathode ray tube faces the terrestrial magnetism north,
Or, when facing south, the raster position on the CRT screen moves or rotates as indicated by dimension A, as shown in FIG. At the same time, as shown in FIG. 5, the north magnetic field and the south magnetic field (tube axis magnetic field) at the positions of the upper part 11 and the lower part 10 of the CRT screen.
Color shift occurs due to the influence of about +0.5 to -0.5 Gauss.

At the upper end and lower end of the raster rotation and the large-sized CRT, the beam is influenced by the tube axis magnetic field and irradiates not the regular R, G, and B phosphors but the adjacent phosphors, resulting in color shift. This is because the horizontal deflection angle increases due to the CRT having a size of 6 inches or more or by flattening the CRT glass. Also, this is because the average current of the CRT is increased to, for example, about 1.9 mA when a contrast corresponding to an increase in size is configured.

The color shift cannot be solved only by the CRT shadow mask, the panel and the bimetal fixing the shadow mask. In order to solve this, the geomagnetic H shown in FIG.
One magnetic field is applied to the geomagnetic correction circuit 15 of FIG.
1, a direct current of I ↓ 2 may be passed to cancel the geomagnetism. That is, the operation may be performed such that “H1−H2 = 0” with the magnetic field H2 formed by the geomagnetism correction circuit 15.
As a result, the raster rotation shown in FIG.
It is possible to prevent color shift between the first and lower portions 10.

In order to efficiently perform the terrestrial magnetism correction at a high level, the CRT mounting position of the terrestrial magnetism correction coil 1 is also important. In the geomagnetic correction device of the present invention, as the circular portion 1A of the geomagnetic correction coil surrounds the deflection yoke 4,
And it was arranged so that it might be equal distance. CRT with circular section 1A
For fixing to the surface, a fixing tape 7 was attached. As shown in FIG. 2, the substantially rectangular portion 1B of the terrestrial magnetism correction coil was arranged in a substantially vertically symmetrical shape with the deflection yoke 4 as the center. It was fixed to the CRT surface funnel surface by the fixing tape 7 and the fixing clamper 8.

On the other hand, a demagnetizing coil 3 having an approximately eight-letter shape is arranged below the terrestrial magnetism correction coil 1 and is combined so that the circular portion 1A of the terrestrial magnetism correction coil 1 is located within one ring of the demagnetization coil. .

With the above configuration, the raster rotation and the color misregistration shown in FIGS. 4 and 5 coincide with each other, and a more complete geomagnetic correction can be performed.

[0018]

According to the television receiver of the present invention, raster rotation of a CRT screen in a magnetic field of a south direction and a north direction (CRT tube axis direction) in a large-sized cathode ray tube such as a 36-inch screen, and the color of the upper and lower parts of the screen The displacement can be corrected with one magnetic correction coil, and the cost is reduced. Further, the correction of the magnetic field in the south and north directions becomes extremely easy, and color shift is prevented.

[Brief description of the drawings]

FIG. 1 is a front view of a geomagnetic correction coil according to an embodiment of the present invention.

FIG. 2 is a front view of a state where the geomagnetic correction coil of FIG. 1 is attached to a CRT.

FIG. 3 is a configuration diagram of a geomagnetic correction device according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a CRT screen raster rotation in a geomagnetic southward and northward magnetic field.

FIG. 5 is an explanatory diagram of a color shift of a CRT screen and a magnetic field direction in a geomagnetic south-facing and north-facing magnetic field.

FIG. 6 is a front view of a conventional geomagnetic correction coil.

[Explanation of symbols]

 Reference Signs List 1 geomagnetic correction coil 2 CRT (CRT) 3 demagnetizing coil 4 geomagnetic correction coil connector 5 deflection yoke 6 geomagnetic correction coil 7 fixing tape 8 fixing clamper

Claims (12)

[Claims] 1. A geomagnetic correction device comprising a geomagnetic correction coil and a degaussing coil, wherein the geomagnetic correction coil has a circular portion and a substantially rectangular portion. 2. A geomagnetic correction device comprising a geomagnetic correction circuit and a geomagnetic correction coil, wherein the geomagnetic correction coil has a circular portion and a substantially rectangular portion. 3. The geomagnetic correction device according to claim 2, wherein the circular portion of the geomagnetic correction coil is positioned substantially at the center of the substantially rectangular portion. 4. A terrestrial magnetism correction coil comprising a circular portion and a substantially rectangular portion, a neck portion of a cathode ray tube substantially at the center of the circular portion, and the roughly rectangular portion being attached in a vertical direction of a funnel surface of the cathode ray tube. Television receiver characterized by the following. 5. The television receiver according to claim 4, wherein a substantially rectangular portion of the terrestrial magnetism correction coil is disposed across the anode portion of the cathode ray tube. 6. The television receiver according to claim 5, further comprising a terrestrial magnetism correction circuit for flowing a positive / negative DC current to the terrestrial magnetism correction coil. 7. A television receiver comprising a demagnetizing coil, a geomagnetic correction circuit, and a geomagnetic correction coil, wherein the geomagnetic correction coil has a circular portion and a substantially rectangular portion. 8. A geomagnetic correction device comprising: a geomagnetic correction coil having a circular portion and a substantially rectangular portion, and being combined with a substantially eight-shaped demagnetizing coil. 9. The method according to claim 8, wherein the circular portion of the geomagnetic correction coil is positioned substantially at the center of the substantially rectangular portion.
The geomagnetic compensator according to the above. 10. A terrestrial magnetism correction coil comprising a circular portion and a substantially rectangular portion, wherein a neck portion of a cathode ray tube is attached substantially at the center of the circular portion, and the substantially rectangular portion is vertically attached to a funnel surface of the cathode ray tube. A television receiver, wherein the circular portion is combined so as to be located within one ring of a figure-eight demagnetizing coil. 11. The television receiver according to claim 10, wherein a substantially rectangular portion of the geomagnetic correction coil is disposed so as to straddle an anode portion of the cathode ray tube. 12. The television receiver according to claim 11, further comprising a terrestrial magnetism correction circuit for flowing a positive / negative DC current to the terrestrial magnetism correction coil.