JPH0955955A - Intermonitor interference reducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the horizontal stripes of interference to the level of not visually recognizable even in the case of arranging monitors closely to each other by providing cancel coils so as to extend to the neighborhood of an explosion-proof band on a front side from the side of a CRT display monitor and making vertical deflection current flow through the cancel coils. SOLUTION: Both sides and the back of the CRT display 1 are covered with metallic plates 4 to 6 so as to surround a deflection yoke 3 and internal electronic parts excepting for the part of a face plate 2. Then the cancel coils 7 and 8 are fixed from the neighborhood of the explosion-proof band on the side of the face plate 2 to the metallic plate 6 at the back through the upper/ lower movable parts of the metallic plates 4 and 5. These cancel coils 7 and 8 are provided to cancel a leaking magnetic field from the deflection yoke 3, etc. These cancel coils 7 and 8 are serially connected to a vertical deflection coil and supplied with vertical deflection current from a vertical output circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitor-to-monitor mutual interference suppressor, and more particularly to a monitor-to-monitor mutual interference suppressor capable of reducing the influence of magnetic flux leakage when CRT display monitors are arranged adjacent to each other.

[0002]

2. Description of the Related Art In a market such as a bank or a securities company that sequentially handles information, several CRT display monitors are arranged adjacent to each other on a table to monitor information. However, due to space limitations, the CRT display monitors are often arranged in close contact with each other, and magnetic field radiation from adjacent monitors appears in a horizontal stripe pattern on the screen, making the image difficult to see.

The cause of this interference is that abrupt changes in the current flowing through the horizontal and vertical deflection coils during the vertical blanking period shown in FIG. It is considered that this is due to the leak from the computer and affecting the adjacent monitor.

[0004]

In order to deal with such a problem, conventionally, a coil to which a vertical deflection current is applied from the side surface to the back surface of a monitor is arranged so as to cancel a vertical magnetic field, and horizontal stripes due to interference are generated. A method of reducing the pattern is being considered. Also, as the deflection coil,
Although it is possible to reduce the leakage magnetic flux by using a saddle type coil instead of the conventional toroidal type coil, it is still impossible to completely eliminate the horizontal stripe pattern due to interference. The cause is that the leakage magnetic field leaks from the front and the rear of the cathode ray tube.

Therefore, the main object of the present invention is to provide a C
An object of the present invention is to provide a mutual interference suppressing device between monitors that can reduce the horizontal stripe pattern of interference to a level at which it cannot be visually confirmed even if RT display monitors are arranged close to each other.

[0006]

The invention according to claim 1 is
The image is displayed on the screen by scanning the electron beam with the horizontal and vertical magnetic fields generated from the horizontal and vertical deflection coils.
In an RT display monitor, there is provided a mutual interference suppressing device between monitors for preventing a vertical magnetic field from leaking and interfering with an adjacent CRT display. The side and back surfaces of the CRT display monitor are covered with metal plates. Further, a cancel coil is provided so as to extend from the side surface of the CRT display monitor to the vicinity of the explosion-proof band on the front side, and the cancel coil is connected in series to the vertical deflection coil, whereby the vertical deflection coil is generated by the magnetic field from the cancellation coil. Cancels the leakage magnetic field from.

In the invention according to claim 2, the cancel coil is provided so as to extend from the side surface to the back surface.

[0008]

1 is a plan view of a CRT display monitor to which an embodiment of the present invention is applied.
2 is a front view, FIG. 3 is a side view, and FIG. 4 is a rear view.

The CRT display 1 has metal plates 4, 5 and 6 on both sides and back so as to surround the deflection yoke 3 and internal electronic components (not shown) except for the face plate 2.
Covered by Then, the cancel coils 7 and 8 are attached so as to pass from the vicinity of the explosion-proof band on the side surface of the face plate 2 to the upper and lower movable parts of the metal plates 4 and 5 and reach the metal plate 6 on the back surface. The cancel coils 7 and 8 are provided to cancel and cancel the leakage magnetic field from the deflection yoke 3 and the like. As the canceling coils 7 and 8, a coated lead wire is preferable, for example, a wire rod 1007.
A AWG22 wound one turn is used.

FIG. 5 is a diagram showing the connection relationship between the cancel coil and the vertical deflection coil. In FIG. 5, the cancel coils 7 and 8 are connected in series with the vertical deflection coils 9 and 10, and a vertical deflection current is supplied from the vertical output circuit 11.

FIG. 6 is a view showing a mounting method for mounting the cancel coil on the sheet metal. That is, FIG.
Is a leg body 13 having a bulge portion to be inserted into the hole 12 of the sheet metal 4.
An elastic body 14 elastically contacting the upper surface of the sheet metal 4 to prevent backlash, and a holding body 15 formed on the upper portion of the leg body 13 and through which the cancel coil 7 is inserted, which are integrally formed of synthetic resin. Is. The cancel coils 7 and 8 can be easily attached only by attaching such a holding device to the metal plates 4, 5 and 6 shown in FIGS.

6B, an ear portion 16 is provided in place of the holding body 15 shown in FIG. 6A, and the cancel coil 7 is held by twisting the ear portion 16. Figure 6
The example shown in (c) is an example suitable for disposing the cancel coil close to the sheet metal 4. FIG. 6D shows the base portion 15.
Inverted J-shaped supporting leg portions 16 are provided from both ends of the support leg 16, and the cancel coil 7 is held by the supporting leg portions 16 and 16 by being fixed to the metal plate 4 by engaging recesses 17 provided between the base portion 15 and the supporting leg portion 16. Other than the one shown in FIG. 6, the sheet metal 4,
Any type can be applied as long as the cancel coil 7 is attached to 5 and 6.

FIG. 7 is a diagram showing a vertical magnetic field component around the CRT display when the cancel coil according to the embodiment of the present invention is not provided, and shows the left half viewed from above.
FIG. 8 shows a magnetic field produced only by the cancel coil. In this case, a vertical deflection current was applied to the cancel coil from outside without turning on the power supply of the device. FIG. 9 is a diagram showing a magnetic field when the CRT display device is operated and the cancel coil is operated.

In FIGS. 7 to 9, all the numbers indicate the peak value detected by the search coil. It can be seen that the magnetic field from the cancel coil shown in FIG. 8 is generated in the direction of canceling the magnetic field generated from the CRT display shown in FIG. As shown in FIG. 9, the total leakage magnetic field when the cancel coil is actually attached and the CRT display is operated is reduced as compared with the case where the cancel coil is not provided in FIG. Recognize. In particular, since it is possible to suppress the generation of the leakage magnetic field in the front panel portion, it is possible to remarkably improve the interference in this portion.

[0015]

As described above, according to the present invention, the CR
A cancel coil is provided so as to extend from the side surface of the T display monitor to the vicinity of the explosion-proof band on the front side, and a vertical deflection current is caused to flow through the cancel coil, thereby the CR
Not only the side surface of the T display monitor but also the leakage magnetic field from the front can be canceled, and the CRT display monitor can be placed in a 90 ° position in addition to the aspect in which the monitor is placed sideways.
It is possible to suppress the occurrence of a horizontal stripe pattern due to a leakage magnetic field even if the device is inclined and placed adjacent to each other.

[Brief description of drawings]

FIG. 1 is a plan view of a CRT display monitor to which an embodiment of the present invention is applied.

FIG. 2 is a front view of a CRT display monitor to which an embodiment of the present invention is applied.

FIG. 3 is a side view of a CRT display monitor to which an embodiment of the present invention is applied.

FIG. 4 is a rear view of a CRT display monitor to which an embodiment of the present invention is applied.

FIG. 5 is a diagram showing a connection relationship between a cancel coil and a vertical deflection coil.

FIG. 6 is a diagram showing an attachment method for attaching the cancel coil to the sheet metal.

FIG. 7 is a diagram showing a vertical magnetic field component around the CRT display monitor when the cancel coil according to the embodiment of the present invention is not provided.

FIG. 8 is a diagram showing a magnetic field generated only by a cancel coil.

FIG. 9 is a diagram showing a magnetic field when the CRT display device is operated and the cancel coil is operated.

FIG. 10 is a diagram showing a rapid change in vertical deflection current during a vertical blanking period.

[Explanation of symbols]

 1 Braun tube 2 Face plate 3 Deflection yoke 4, 5, 6 Sheet metal 7,8 Canceling coil 9,10 Vertical deflection coil 11 Vertical output circuit

Claims (2)

[Claims] 1. A CRT display monitor for displaying an image on a screen by scanning an electron beam with horizontal and vertical magnetic fields generated from horizontal and vertical deflection coils, wherein the vertical magnetic field leaks to an adjacent CRT display monitor. Mutual interference suppressing device for preventing mutual interference between monitors, wherein a side surface and a rear surface of the CRT display monitor are covered with a metal plate, and further, a vicinity of an explosion-proof band from a side surface to a front surface side of the CRT display monitor. A mutual interference suppressing device between monitors, wherein a cancel coil is provided so as to extend up to, and the cancel coil is connected in series to the vertical deflection coil. 2. The mutual interference suppressing device between monitors according to claim 1, wherein the cancel coil is provided so as to extend from the side surface to the back surface.