JPS58146190A - Purity correction system of color receiver - Google Patents

Abstract

PURPOSE:To correct automatically the purity deterioration due to external magnetic change by detecting the change in the external magnetic field with a magnetic sensor and generating a correcting magnetic field with a magnetic generator in a display with the output of the sensor. CONSTITUTION:A coil 3 is provided around the outer circumference of a CRT fluorescent screen in matching with the tube axis of a CRT2 provided in a display 1 and a coil 4 is provided near the rear prt of the neck. The direction and amount of magnetism are detected at a sensor 5, and after the output is amplified, it is applied to the correction coil 4. The magnetic force of lines generated from the coil 4 generates a correcting magnetic field corresponding to the horizontal component of the earth magnetism at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a utility correction method for a display device using a three-electron beam type color picture tube.

Recently, C1aT display devices have been widely used as display terminals for various information devices, and within 1% of these devices, color display devices, which have a strong intuitive appeal to operators, are becoming more common. In these devices, the display color itself, which is used to give some meaning to the display color itself, must be prevented from changing due to the influence of external factors. This is an extremely important problem, especially when displaying graphic patterns in multiple colors. For this purpose, it is necessary to prevent variations in the beauty quality of the color CRT due to external factors. However, due to its principle and structure, color CRTs are inherently highly influenced by external magnetic fields, and to keep this in mind, CRTs have traditionally been
Countermeasures have been taken, such as incorporating a magnetic shielding device into the T itself or using it in combination with an external magnetic shielding device. However, even if such a magnetic shield is applied, it is impossible to cover the fluorescent surface of the CRT, so it is extremely difficult to obtain a complete magnetic shielding effect. ) If CR, T
No matter how strong the external magnetic shield gold is, the fluorescent surface area that serves as the information display window must be left as an open area, as the influence of external magnetic fields through this area cannot be avoided. It is. This problem becomes especially serious in the case of vehicles, ships, etc. that are constantly on the move.

This is the biggest cause of deterioration of quality and quality.

In particular, display devices using in-line self-focusing color CRTs, which have recently been put into practical use, tend to be used in large quantities because of their cost, quality, and maintainability. This point often became a problem, canceling out the many advantages of the in-line self-concentrating CRT, making it difficult to put it into practical use in such applications.

An object of the present invention is to provide a display device that eliminates such defects, and the key point is to detect changes in an external magnetic field using a magnetic sensor provided outside the display device, and use the output to detect changes in the external magnetic field. The purpose of this device is to generate a correction magnetic field that corresponds to magnetic changes using a magnetic generator, and automatically correct the utility degradation due to magnetic changes in a color picture tube in a display device, and its industrial value is considered to be extremely high. It will be done.

The present invention will be explained below with reference to the drawings. Figures 1 and 2
The figure shows the geomagnetic distribution on the earth, with Figure 1 showing the vertical force component and Figure 2 showing the horizontal force component. Third. Figure 4 shows how the landing, which determines the quality of color CRTs, is affected by the geomagnetic component. Figure 3 shows the vertical component force. Figure 4 shows the effect of the horizontal component force. be. FIG. 5 is a color CRTf: a cross-sectional view of a display device used, and FIG. 6 is a block diagram of the present invention. FIG. 7 is a cross-sectional view of a display device according to an embodiment of the present invention.

First thing first. As is clear from Figure 2, all areas on earth are under the influence of the geomagnetic field, which is common knowledge. In short, the vertical component is the largest and the horizontal component is the smallest at both poles, and the opposite is true near the equator. These geomagnetic components are shown in Figure 31 and Figure 4. They have a very large effect on the landing state of the CRT. In other words, the horizontal components are shown in Figure 4 and Figure 4. The beam is moved in the same manner as shown in Fig. 3, and the amount of movement is maximum at the periphery of the CRT.
The beam 9 moves the beam almost uniformly to the left and right over the entire surface of the CRT. Therefore, in order to always maintain a constant level of priority quality, it is necessary to prevent fluctuations in the landing state due to changes in the earth's magnetic field, but as mentioned above, there is a problem with the magnetic shielding characteristics for the horizontal component, and its influence cannot be avoided. . To make matters worse, when mounted on a moving device such as a vehicle or ship, it must be taken into account that direction changes from east to west, north to south are extremely frequent within a short period of time, and in this case, only the horizontal component is required. This will cause a large change in the amount of air flow, making it even more important to prevent this from affecting the landing condition.

The present invention is intended to prevent such drawbacks, and its configuration is shown in FIG. That is, a sensor 7 that detects the direction and magnitude of the earth's magnetic field, an amplifier 8 that amplifies the sensor output, and a correction magnetic field generator 9. To explain the embodiment shown in FIG. 7, a ring is provided in the vicinity of the outer periphery of the fluorescent surface of the CRT in alignment with the response axis of the CRT 2 provided in the display device 1 so as to surround the outer periphery of the fluorescent surface. A pair of geomagnetic correction coils, ie, coil 4, which are similarly provided near the rear of the coil 3 and CRTz, are connected so that the magnetic fields generated by both coils are in phase. On the other hand, a predetermined sensor element 5 such as a search coil or a Hall element capable of detecting the amount of magnetic change is installed and fixed in accordance with the installation direction of the display device. - This sensor output is amplified by an amplifier 6 to a predetermined level and supplied to a correction coil 4. - For the CRT 2 mounted on the display device 1, the amount of landing movement with respect to changes in the geomagnetic horizontal component is determined in advance, and the display device 1 is adjusted under the conditions of the amount of the geomagnetic horizontal component. After that, the magnetic sensor 5 is used to change the geomagnetic horizontal component, and the polarity of the amplifier 6 is changed so that the amount of landing movement with respect to the horizontal component determined in advance and the amount of landing movement by the correction coil are the same in opposite directions. Set medium. As a result of the above, the correction magnetic force generated by the correction coil 4 is +! I7 always generates a correction magnetic field corresponding to the horizontal component of the earth's magnetic field, making it possible to keep the landing quality constant at all times, and to significantly improve the performance of the display device mounted on the moving device.

Above - Examples and 1. Although the correction for the geomagnetic horizontal component has been described above, the same applies to other magnetic field fluctuations, and it is presumed that the field of application of the present invention is extremely wide.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams showing the geomagnetic distribution, Figures 3 and 4 are explanatory diagrams showing the relationship between the landing state of a color CRT and the earth's magnetism, and Figure 5 is a cross section of a conventional display device using a color CRT. FIG. 6 is an explanatory diagram showing the structure of the present invention, and FIG. 7 is an explanatory diagram showing a cross section of a display device in which the present invention is implemented. ]...Display device, 2...CRT, 3.4
......Coil, 5,7...Sensor% 8
......Amplifier, 9...Correction magnetic field generation coil.

Claims (1)

[Claims] 3. A display device using an electron beam type color receiver tube is equipped with a magnetic detection sensor, its amplification device, and a magnetic field generation device, and the sensor detects the magnetic change that the display device receives and uses the output. A color damage device characterized in that a correction magnetic field corresponding to magnetic changes is generated by a magnetic generation device provided in a color picture tube in a display device, and a deterioration in visual quality caused by magnetic changes in a color picture tube in the display device is automatically corrected. utility correction method.