JPH04280046A - Deflection yoke for black-and-white display monitor - Google Patents

Abstract

PURPOSE:To reduce the emitted magnetic field of a black-and-white display monitor with toroidal type vertical deflecting coils. CONSTITUTION:In a deflection yoke DY for a black-and-white display with toroidal type vertical deflecting coils, a ring-shaped core 7 made of a high- magnetic permeability magnetic material is arranged between the front end FE and the rear end RE of a deflection yoke core to surround the deflection yoke DY. The emitted magnetic field in the horizontal direction of the display monitor can be reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke for a black and white display monitor, and more particularly to a deflection yoke for a black and white display monitor in which a radiated magnetic field is reduced.

0002

2. Description of the Related Art In consideration of the influence of magnetic fields radiated from display monitors on other equipment or the human body, certain regulations have been established. Such radiated magnetic fields originate from the horizontal and vertical deflection coils of the deflection coils.

[0003] Color display monitors mainly use a deflection yoke in which horizontal and vertical deflection coils are saddle-shaped, and in this case, the problematic radiated magnetic field is mainly present in front of the display monitor. As a way to reduce the radiated magnetic field that exists in front of this display monitor,
There is a device disclosed in JP-A-1-217839. This means that there are two
A ring-shaped ferrite core with two coils is arranged.

On the other hand, in monochrome display monitors, a deflection yoke in which the vertical deflection coil is of a toroidal type is often used. FIG. 5 shows a schematic configuration of a toroidal vertical deflection coil. In this vertical deflection coil 50, 51
is an upper vertical deflection coil core, 52 is a lower vertical deflection coil core, 53 is an upper vertical deflection coil, and 54 is a lower vertical deflection coil. H1 is a radiated magnetic field generated by the upper vertical deflection coil 53, and H2 is a radiated magnetic field generated by the lower vertical deflection coil 52. These radiated magnetic fields H1 and H2 spread in the lateral direction of the display monitor.

[0005]

[Problem to be solved by the invention] JP-A-1-21783
The device disclosed in Japanese Patent No. 9 reduces the radiated magnetic field that exists in front of the display monitor, and is effective for color display monitors that use a deflection yoke with saddle-shaped vertical and horizontal deflection coils.

However, in a black and white display monitor using a deflection yoke in which the vertical deflection coil is of a toroidal type, the radiated magnetic field exists in the lateral direction of the display monitor, so it is not possible to effectively reduce the radiated magnetic field. There is a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a deflection yoke for a black-and-white display monitor that can effectively reduce the radiated magnetic field even in a black-and-white display monitor whose vertical deflection coil is of a toroidal type.

[0008]

[Means for Solving the Problem] The deflection yoke for a black and white display monitor of the present invention has a deflection yoke for a black and white display monitor in which the vertical deflection coil is of a toroidal type, and has high magnetic permeability between the front end and the rear end of the deflection yoke core. The structure is characterized in that a ring-shaped core made of a magnetic material is arranged to surround the deflection yoke.

[0009]

In the deflection yoke for a black and white display monitor of the present invention, a ring-shaped core made of a high magnetic permeability magnetic material is arranged to surround the deflection yoke between the front and rear ends of the deflection yoke core. Therefore, the radiation magnetic field that spreads in the lateral direction of the deflection yoke passes through the ring-shaped core with low magnetic resistance, and can be prevented from leaking to the outside in the lateral direction. Therefore, it becomes possible to reduce the radiated magnetic field even in a black and white display monitor using a deflection yoke in which the vertical deflection coil is of a toroidal type. Furthermore, since a ring-shaped core made of a high magnetic permeability magnetic material is used, problems of heat generation and loss do not occur.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a deflection yoke for a monochrome display monitor according to the present invention will be described with reference to the drawings.

FIG. 1 is a rear view showing the structure of a deflection yoke DY for a black and white display monitor according to an embodiment of the present invention (the screen side of the display monitor is the front), and FIG.
is a right side view of the same. 1 is a toroidal type upper vertical deflection coil, 2 is a toroidal type lower vertical deflection coil, 3 is an upper vertical deflection coil core, and 4 is a lower vertical deflection coil core.

A ferrite core 7 is a ring-shaped ferrite core having a magnetic permeability of 1000 or more, and is arranged to surround the deflection yoke DY between the front end FE and the rear end RE of the deflection yoke core.

Reference numeral 8 denotes a ferrite core case for supporting and protecting the ferrite core 7. 9a, 9
b and 9c are guide pieces protruding from the ferrite core case 8. A long hole 10a is bored in the center of the guide piece 9a. Note that elongated holes 10b and 10c are similarly formed in the guide pieces 9b and 9c (not shown in the figure). 11a, 11b, 11c are yoke base YB
It is a support pillar that protrudes from the ground. 12a, 12b, 12c
is a set screw, which passes through the elongated holes 10a, 10b, 10c of the guide pieces 9a, 9b, 9c, and is attached to the support columns 11a, 11.
They are screwed into the screw holes formed in b and 11c, respectively. By loosening the setscrews 12a, 12b, 12c, the position of the ferrite core 7 can be moved back and forth by the length of the elongated holes 10a, 10b, 10c. In general, deflection yokes have large individual variations, so the position of the ferrite core 7, which is most effective in reducing the radiated magnetic field, is not constant. However, as described above, the position of the ferrite core 7 can be moved back and forth, so It can be easily adjusted for the most effective reduction.

13a, 13b, 13c, and 13d are magnets for finely adjusting the deflection magnetic field attached to the yoke base YB. 14a, 14b, 14c, and 14d are rectangular adjustment driver insertion holes formed at the center of the magnets 13a, 13b, 13c, and 13d, respectively. These adjustment operation driver insertion holes 14a, 1
A driver is inserted into 4b, 14c, and 14d from the cathode side of the cathode ray tube, and by rotating the magnet, the position of the magnet is adjusted, and the deflection magnetic field is finely adjusted. The inner diameter dimensions of the ferrite core 7 and ferrite core case 8 are:
Adjustment operation driver insertion holes 14a, 14b, 14c, 1
4d is set so that it is not hidden. Further, in consideration of strength against impact, etc., the outer diameter dimensions of the ferrite core 7 and the ferrite core case 8 are set to be approximately the same as the outer diameter of the yoke base YB.

In the deflection yoke DY for a black and white display monitor having the above configuration, the toroidal vertical deflection coil 1,
The lateral radiated magnetic field by 2 passes intensively through the high permeability ferrite core 7. Therefore, the intensity of the radiated magnetic field outside the display monitor is sufficiently small.

[0016] In a high resolution black and white display monitor,
Since the horizontal frequency is high (approximately 80 kHz; approximately 60 kHz for color display monitors), heat generation and loss become a problem, but since the ferrite core 7 is made of a high magnetic permeability material with a magnetic permeability of 1000 or more, this problem can be overcome. . Note that if a yoke or the like is used, it will be difficult to overcome the problems of heat generation and loss.

Another embodiment is one in which a radiation magnetic field canceling winding is added to the ferrite core 7. FIG. 3 shows this, where 25 is an upper winding for vertical cancellation wound around the ferrite core 7, and 26 is a lower winding for vertical cancellation wound around the ferrite core 24. 27 is a horizontal canceling left winding wound around the ferrite core 24, and 28 is a horizontal canceling right winding wound around the ferrite core 24.

The vertical canceling upper winding 25 and the vertical canceling lower winding 26 are connected in series with vertical deflection coils 53 and 54, as shown in FIG. However, the direction of the magnetic field generated in the vertical deflection coils 53 and 54 due to the flow of the vertical deflection current and the vertical canceling windings 25 and 2
The connection direction or winding direction is determined so that the direction of the magnetic field generated at 6 is opposite to the direction of the magnetic field. The relationship between the horizontal canceling windings 27 and 28 and the horizontal deflection coil is also similar.

In this embodiment, the vertical deflection coils 53, 5
It is possible to more effectively reduce the radiation magnetic field generated by 4. At the same time, it is also possible to effectively reduce the radiated magnetic field generated by the horizontal deflection coil.

[0020]

According to the deflection yoke DY for a black-and-white display monitor of the present invention, it is possible to reduce the radiated magnetic field in a black-and-white display monitor using a toroidal vertical deflection coil.

[Brief explanation of the drawing]

FIG. 1 is a rear view of a deflection yoke for a monochrome display monitor according to the present invention.

FIG. 2 is a right side view of the deflection yoke for a monochrome display monitor of the present invention.

FIG. 3 is a schematic diagram showing the main parts of another embodiment of the deflection yoke for a monochrome display monitor according to the present invention.

FIG. 4 is a connection diagram of a vertical cancellation winding and a vertical deflection coil.

FIG. 5 is a schematic explanatory diagram of a toroidal vertical deflection coil.

[Explanation of symbols]

DY Deflection yoke 1 for black and white display monitor
Upper vertical deflection coil 2 Lower vertical deflection coil 3 Upper vertical deflection coil core 4 Lower vertical deflection coil core 7 Ferrite core 8 Ferrite core cases 9a, 9b, 9c Guide pieces 10a, 10b, 10c Elongated holes 11a, 11b, 11c Support column 12a , 12b, 12c Set screws 13a, 13b, 13c, 13d Magnet 14a
, 14b, 14c, 14d Driver insertion hole for adjustment operation 25 Upper winding for vertical cancellation 26 Lower winding for vertical cancellation 27 Left winding for horizontal cancellation 28 Right winding for horizontal cancellation

Claims (4)

[Claims] Claim 1: A deflection yoke for a black and white display monitor in which the vertical deflection coil is of a toroidal type, in which a ring-shaped core made of a high magnetic permeability magnetic material surrounds the deflection yoke between the front end and the rear end of the deflection yoke core. A deflection yoke for a black-and-white display monitor characterized by being arranged in a. Claim 2: A first coil that reduces the radiated magnetic field in the vertical deflection coil and a second coil that reduces the radiated magnetic field in the horizontal deflection coil are attached to a ring-shaped core made of a high permeability magnetic material. The deflection yoke for a black and white display monitor according to claim 1, characterized in that: 3. The ring-shaped core made of a high permeability magnetic material is configured to be movable in the direction of the central axis of the cathode ray tube by a ring-shaped core moving means. Deflection yoke for black and white display monitors. Claim 4: The inner diameter of the ring-shaped core made of a high magnetic permeability magnetic material is larger than the diameter of the circle connecting the adjusting operation parts of the magnets for fine adjustment of the vertical deflection magnetic field and the horizontal deflection magnetic field, and the outer diameter is the front end of the deflection yoke. 4. The deflection yoke for a black and white display monitor according to claim 1, wherein the deflection yoke is smaller than or slightly larger than the diameter of the deflection yoke.