JPH09331540A - Earth magnetism correction and leaked electric field suppression device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a tilt of an image and color slurring, to rationalize a device and to reduce the cost by using a coil mounted around a cathode ray tube so as to correct the tilt and the color slurring, applying a leaked electric field suppression pulse to the coil and using it thereby cancelling a change in a direction of the TV set in an output image at all times. SOLUTION: On the occurrence of an earth magnetism in the TV set, an earth magnetism detector 3 detects it and an output voltage is fed to a correction amount control circuit 4 as its reference voltage so as to supply an earth magnetism correction current to a coil 2 mounted around a cathode ray tube in an optional direction thereby correcting the image tilt and color slurring at all times depending on the earth magnetism. Simultaneously a pulse generated from a leakage electric field suppression circuit 6 is fed to the coil 2, in which image correction, color slurring correction and leaked electric field suppression are conducted in the same system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a geomagnetic field correction / leakage field suppressor.

[0002]

2. Description of the Related Art It is said that in a display device, a television receiver, or the like, in order to correct adverse effects on the screen (screen tilt, color unevenness) against various geomagnetisms, the geomagnetism is canceled and the human body is adversely affected. It is necessary to minimize the radiated leakage field.

Conventionally, in order to solve this problem, a geomagnetic correction coil is used so that the screen does not suddenly move or the color unevenness does not change abruptly when the geomagnetic correction circuit starts its operation in a state where the screen appears. However, after a lapse of time from turning on the power supply of the set until the operation of the degaussing circuit is almost completed, the direction of the geomagnetic correction current and the necessary value are set based on the detection result of the geomagnetism to correct the geomagnetism.

Such a technique is disclosed in Japanese Patent Laid-Open No. 14593/1993.
No. 6 publication.

[0005]

In the above prior art, after the power supply of the set is turned on, the geomagnetism is detected after the operation of the degaussing circuit is completed, and the direction of the geomagnetic correction current and the necessary value are set. When the orientation of the set is changed after a while, there are problems such as screen tilt and color unevenness, and the means for suppressing the leakage electric field becomes expensive.

An object of the present invention is to correct the geomagnetism in any state (destination, direction) of the set by correcting with a coil mounted near the cathode ray tube in order to solve problems such as screen tilt and color unevenness, and The cost is reduced by applying the leakage electric field suppressing pulse to the coil and using them together.

[0007]

To achieve the above object, the present invention provides one coil for geomagnetic correction and leakage electric field suppression.

The output voltage of the correction amount control circuit is used as a reference voltage used in the correction current generation circuit, and a current for geomagnetism correction is applied to a coil mounted near the surface of the cathode ray tube in any direction to tilt the screen. Color unevenness is constantly corrected according to the earth's magnetism, and a pulse from the leakage electric field suppressing circuit is applied to the same coil.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In FIG. 1, 1 is a cathode ray tube, 2 is a coil for geomagnetic correction and leakage electric field suppression, 3 is a geomagnetic detector,
Reference numeral 4 is a correction amount control circuit, 5 is a correction current generating circuit, and 6 is a leakage electric field suppressing circuit.

In FIG. 1, when geomagnetism is generated in the set, it is detected by the geomagnetism detection device 3, and its output voltage is supplied as a reference voltage of the correction amount control circuit 4. The pulse generated from the leakage electric field suppressing circuit 6 is supplied to the coil 2 at the same time as the current required for the geomagnetic correction amount by the correction current generating circuit 5 to which the reference voltage is applied.

[0013]

According to the present invention, since a correction current according to the geomagnetism can be supplied, even if it changes during image output, it can always be canceled and screen tilt and color unevenness can be corrected, and at the same time the same coil can be used. Rationalization and cost reduction can be achieved by applying the leakage electric field suppressing pulse.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... CRT, 2 ... Geomagnetic correction and leakage electric field suppression coil, 3 ... Geomagnetic detection device, 4 ... Correction amount control circuit, 5 ... Correction current generation circuit, 6 ... Leakage electric field suppression circuit.

Claims (1)

[Claims] 1. A coil for a geomagnetic field correction / leakage field suppressor,
It has a geomagnetism detection device, a correction amount control circuit, a correction current generation circuit, and a leakage electric field suppression circuit, and a detection device is provided to correct screen tilt and color unevenness due to geomagnetism, and the output voltage of the detection device is a reference voltage. , The current equivalent to the correction amount,
A geomagnetic correction / leakage field suppressor characterized in that screen correction, color unevenness correction, and leakage electric field suppression are performed in the same system by applying an output pulse of a leakage electric field suppression circuit to a coil in both the current direction.