JP2002252787A - Linearity coil and display device provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linearity coil that gives less effect at the outside of a magnetic field, and has an excellent bias characteristic and less characteristic dispersion. SOLUTION: The linearity coil 10 is provided with a drum type core 4 with a core wind section 2 and guards 3a, 3b placed on both ends of the section 2, winding 1 that is wound around the core wind section 2 of the drum core 4 and whose terminal is conductively joined with an external connection terminal 4, and a permanent magnet 15 attached to the drum core 4. Especially one face 15a of the permanent magnet 15 is attached so as to bridge circumferential faces 7a, 7b of both the guards 3a, 3b of the drum core 4 and only one face 15a of the permanent magnet 15 opposed to part (lower side) of the circumferential faces 7a, 7b of both the guards 3a, 3b is dipole magnetized and the linearity coil is structured with a closed magnetic path where leakage magnetic flux is very small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CRT (cathode-raytube) for a television or a personal computer.
The present invention relates to a linearity coil used in a horizontal deflection circuit of a display device.

[0002]

2. Description of the Related Art Linearity coils are mainly used in CRs for monitors of televisions and personal computers.
A coil component used for correcting a horizontal scanning line in a horizontal deflection circuit of the T display device, and is usually mounted on a printed circuit board arranged below the rear surface of the CRT or close to the side surface.

The basic structure of the linearity coil is, for example, as shown in a schematic cross-sectional view of a linearity coil 80 shown in FIG. It has a plate-shaped permanent magnet 5 such as a ferrite magnet mounted and fixed on a base 8, a core part 2, and flanges 3 a and 3 b disposed at both ends of the core part 2. ), The lower end surface of the lower flange 3a is fixed to the upper surface of the permanent magnet 5 with an adhesive or the like, and the core is wound around the core portion 2 of the drum type core 4 and the terminal is connected to the outside. And a winding 1 conductively joined to the connection terminal 9. In the linearity coil 90 shown in the schematic sectional view of FIG. 6B, the core axis Z of the drum-type core 4 is horizontally positioned on the permanent magnet 5a mounted and fixed on the insulating base 8. In this case, the lower surface of the flanges 3a and 3b is fixed with an adhesive or the like, and the permanent magnet 5b is fixed above the peripheral surface of the flanges 3a or 3b with an adhesive or the like. .

In the linearity coils 80 and 90,
The magnetic field of the attached permanent magnets 5, 5a, 5b affects the winding 1 of the drum type core 4, and the inductance of the coil with respect to the DC bias current has a magnetostrictive characteristic as shown in FIG.

The drum-type core 4 used in the linearity coil is generally an oxide magnetic core (ferrite core) such as nickel-zinc ferrite, and the permanent magnet 5 is a permanent magnet such as a ferrite magnet. Further, the insulating base 8 is formed by injection molding of, for example, an epoxy-based synthetic resin material, and the winding is formed of an insulated conductor having a diameter of about 0.3 to 0.8 mm or a diameter of about 0.1 to 0.2 mm. It is a stranded wire in which several to several tens of insulated conductors are twisted (polyurethane, polyamide imide as an insulated covering material).

The permanent magnets 5 used in the conventional linearity coils 80 and 90 are magnetized in a so-called "through magnetization" in the manufacturing process.
That is, as shown in FIG. 7A, the opposite end faces 11 and 12 of the ferrite sintered body 14 (isotropic ferrite or anisotropic ferrite) are connected between the N pole and the S pole in a high magnetic field ( A permanent magnet as shown in FIG. 7B in which the N pole and the S pole are magnetized on both end surfaces 11 and 12 of the ferrite sintered body 14 with the magnetic field lines from the N pole to the S pole indicated by arrows). 5 is used.

[0007]

In the linearity coils 80, 90 in which the permanent magnets 5, 5a, 5b as described above are attached to the flange 3a and / or 3b of the drum type core 4, the permanent magnets 5, 5a, The influence of the magnetic field created by 5b on the external world cannot be ignored and poses a problem.

That is, as shown in FIGS. 8 (a) and 8 (b), the linearity coils 80 and 90 are provided on the printed circuit board 1 disposed close to the lower rear (or side) of the CRT.
3, the magnetic field is spread around the linearity coils 80 and 90 as shown in FIG.
T may be adversely affected. To avoid this adverse effect, some degree of linearity coils 80 and 90 and CR
It is necessary to keep the distance from T and other circuit elements,
The demand for miniaturization of the entire display device cannot be satisfied.

The diffusion of the magnetic flux emitted from the permanent magnet 5 to parts other than the drum core 4 is, in other words, a large leakage magnetic flux. No bias is given,
Variations in characteristics also increase.

In order to improve the characteristics, it is necessary to obtain a large magnetic field. However, for this purpose, the size of the permanent magnet 5 must be increased, and it is not possible to meet the demand for downsizing the coil components.

The present invention has been made in view of the above circumstances, and provides a linearity coil which solves the current problems of miniaturization, improved characteristics, and improved reliability, and a display device using the same.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides: (1) a drum core having a winding core and flanges provided at both ends thereof, and a winding of the drum core. In a linearity coil including a winding wound around a core portion and a terminal conductively joined to an external connection terminal, and a permanent magnet attached to the drum-type core, one surface of the permanent magnet is the drum The permanent magnet is provided so as to bridge the peripheral surfaces of both flanges of the mold core, and only one surface of the permanent magnet facing a part of the peripheral surface of both flanges is two-pole magnetized. Is provided. (2) Also, an insulating base on which the external connection terminals are implanted, a ferrite magnet on which only the upper surface mounted on the insulating base is magnetized in two poles, and a winding core and both ends thereof are provided. A drum-type core having a set flange and fixed on the ferrite magnet with the core axis horizontal so that the lower sides of the peripheral surfaces of both flanges facing the upper surface of the ferrite magnet are bridged; and the drum-type core. And a terminal wound around the core portion of the first and second terminals and conductively joined to the external connection terminal. (3) Further, in a display device using a linearity coil mounted on a printed circuit board as a circuit element, the display device is characterized in that the linearity coil is the linearity coil according to claim 1 or 2. .

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a linearity coil according to the present invention will be described with reference to the drawings.

FIG. 1A is a schematic sectional view of a linearity coil according to the present invention, and FIG. 1B is a perspective view thereof. FIG. 2 is a view for explaining two-pole magnetization of a permanent magnet used in the linearity coil according to the present invention. FIG.
Or (a), (b), (c), (d),
(E), (f) is a cross-sectional schematic diagram which shows the structure of the linearity coil of other form which concerns on this invention. FIG. 5 is a side view showing a printed circuit board on which a CRT and a linearity coil are mounted in the display device according to the present invention. The same members as those of the conventional linearity coils 80 and 90 described above are denoted by the same reference numerals.

In FIG. 1, a linearity coil 10 according to the present invention comprises a core 2 and flanges 3 disposed at both ends thereof.
a, 3b; a winding 1 wound around the core portion 2 of the drum core 4 and having a terminal conductively joined to an external connection terminal 9; And a permanent magnet 15 attached thereto, and in particular, one surface 15a of the permanent magnet 15 is provided.
Are each peripheral surface 7a of both flanges 3a, 3b of the drum type core 4,
7b are attached so as to bridge the bridge 3b.
Only one surface 15a of the permanent magnet 15 facing a part (lower side) of each of the peripheral surfaces 7a and 7b of the a and 3b has a structure in which two poles are magnetized (hereinafter, magnetized). The other surface 15a is also referred to as a magnetized surface 15a.)

In the linearity coil 10 shown in FIG. 1, the external connection terminals 9 are implanted on the insulating base 8, and the permanent magnet 15 mounted on the insulating base 8 has only the upper surface 15a. Are two-pole magnetized ferrite magnets. As shown in FIG. 2 (a), the two-pole magnetized permanent magnet 15 is magnetized in one of the ferrite sintered bodies 14 (isotropic ferrite or anisotropic ferrite) in the manufacturing process. N that applies a high magnetic field to both edges on the surface 14a
Pole-S pole (magnetic lines of force from the N pole to the S pole are indicated by arrows) are brought into contact with each other and magnetized so that the N pole and the S pole are formed only on one surface 14a side of the ferrite sintered body 14. Manufactured by As shown in FIG. 2B, the manufactured permanent magnet 15 is a magnetic field whose magnetic field is concentrated and spreads only on one surface 15a side.

Of course, in the case of one circuit, one winding 1 of the linearity coil 10 is wound, and both ends thereof are respectively tied to two external connection terminals 9 and conductive by soldering or thermocompression bonding. In the case of two circuits, two windings are wound and conductively connected to different external connection terminals 9 respectively.

According to an evaluation experiment conducted by the present inventors, the spread of each magnetic field formed by the permanent magnets 5 and 15 of the conventional linearity coils 80 and 90 and the linearity coil 10 of the present invention were compared and evaluated three-dimensionally. , Conventional vertical linearity coil 8 magnetized through a permanent magnet
0 and the linearity coil 90 have a large leakage of magnetic flux in the vertical and horizontal directions, and the linearity coil 10 in which only one surface of the permanent magnet opposed to the peripheral surfaces of both flanges of the drum-type core has two poles is almost vertically and horizontally expanded. It turned out that the leakage magnetic flux was extremely small. Schematically, as shown in FIG. 5, the spread of the magnetic field of the linearity coil 10 mounted on the printed circuit board 13 disposed below the CRT in the display device 100 is small and slightly formed on the printed circuit board 13 side. It is just done. This is because only the one surface 15a side of the permanent magnet 15 in FIG.
Due to the pole magnetization, magnetic lines of magnetic force (magnetic flux) generated from the N pole of the magnetized surface 15a almost pass through the peripheral surface 7b of the flange 3b of the drum type core 4 to reach the peripheral surface 7a of the flange 3a from the core 2 and are magnetized. Face 15
This is because the magnetic flux leakage is suppressed by forming a closed magnetic circuit to enter the S pole of a.

Therefore, the loss is reduced and the bias characteristics are increased due to the reduction of the leakage magnetic flux, and variations in the characteristics are suppressed. Also, the adverse effect of the linearity coil on the outside world can be suppressed. Further, the size of the permanent magnet 15 can be reduced as compared with a conventional equivalent product, so that the size can be reduced.

Next, the linearity coil 1 shown in FIG.
Reference numeral 0 denotes a structure in which one permanent magnet 15 is disposed below the drum-shaped core 4.
Other arrangement structures satisfying the condition that the peripheral surfaces 7a and 7b are provided so as to bridge each other are also conceivable. For example, in the linearity coil 20 of FIG. 3A, the magnetized surface 15a is vertically set so as to bridge the flanges 3a and 3b of the vertical drum core 4, and two poles are formed on the peripheral surfaces 7a and 7b of each flange. Is an abutment. The linearity coil 30 shown in FIG. 3B has two permanent magnets 15 disposed above and below the horizontal drum-shaped core 4 in such a manner that the two poles of the magnetized surface 15a thereof are in contact with the peripheral surfaces 7a and 7b of each flange. is there. The linearity coil 40 shown in FIG. 3C has a magnetized surface 25a in which the inner surface of a ring-shaped (cylindrical) permanent magnet 25 is magnetized in two poles. It is inserted so as to surround the side surface, and the peripheral surfaces 7a and 7b of each flange and the two poles of the magnetized surface 25a are arranged in contact.

Next, in the three linearity coils shown in FIG. 4, the insulating base is omitted and the external connection terminal 19 is connected to the drum type core 4 by utilizing the characteristics of the ferrite core having the characteristic of high resistivity. It is planted directly on the tsuba, making the structure more compact. In the linearity coil 50 shown in FIG. 4D, the magnetized surface 15a of the permanent magnet 15 is set upright and the peripheral surfaces 7
In the linearity coil 60 of (e), the permanent magnets 15 are arranged on the drum-type core 4 and the magnetized surfaces 15a are directed horizontally downward to form the two flanges 3a, 3b. In the linearity coil 70 shown in (f), the permanent magnet 1 is in contact with a part of the peripheral surfaces 7a and 7b.
5 is arranged below the drum core 4 and the magnetized surface 15
a with the horizontal surface facing upward, and the peripheral surfaces 7a, 7b of both flanges 3a, 3b
It is structured to be in contact with a part of.

The linearity coils 20, 30, 4
0, 50, 60, and 70 all use two-pole magnetized permanent magnets 15 or 25, and their magnetized surfaces 15a or 25a.
Is configured so as to bridge the circumferential surfaces 7a and 7b of both flanges 3a and 3b of the drum type core 4, so that a closed magnetic circuit structure with very little leakage magnetic flux is obtained as in the case of the linearity coil 10 described above. It is clear that is obtained.

The number of the permanent magnets 15 to be used is not limited, and the shape of the drum type core 4, the external connection terminals 9, 19
It is needless to say that various shapes and drawing methods (radial lead type, axial lead type) can be assumed.

[0024]

As described above, the linearity coil according to the present invention is arranged such that the magnetized surfaces of the two-pole magnetized permanent magnets face each other so as to bridge between the flanges of the drum core. It has a closed magnetic circuit structure with very little leakage magnetic flux.
Therefore, the following excellent effects can be obtained. (1) The adverse effect of the magnetic field on the CRT and other components in the display device is suppressed. (2) Since the magnetic field loss is small, variations in characteristic accuracy can be suppressed. (3) A large bias characteristic can be obtained by reducing the loss as compared with the conventional equivalent product, and the size can be reduced as compared with the conventional product if the performance is equivalent.

[Brief description of the drawings]

FIG. 1A is a schematic sectional view of a linearity coil according to the present invention, and FIG. 1B is a perspective view thereof.

FIG. 2 is a diagram illustrating two-pole magnetization of a permanent magnet used in the linearity coil according to the present invention.

FIG. 3 shows three other embodiments (a) according to the present invention;
It is a cross section of each linearity coil of (b) and (c).

FIG. 4 is a schematic cross-sectional view of each of the linearity coils according to three embodiments (d), (e), and (f) without the insulating base according to the present invention.

FIG. 5 is a CRT in the display device according to the present invention.
FIG. 3 is a diagram illustrating a printed circuit board on which a linearity coil is mounted and a magnetic field.

FIG. 6 is a schematic sectional view showing two examples of the structure of a conventional linearity coil.

FIG. 7 is a diagram illustrating through magnetization in a permanent magnet using a conventional linearity coil.

FIG. 8 is a diagram showing a CRT, a printed circuit board on which the linearity coil is mounted, and a magnetic field in a display device using a conventional linearity coil.

FIG. 9 is an example of a characteristic diagram of a linearity coil.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Winding 2 Core part 3a, 3b Flange 4 Drum type core 5, 15, 25 Permanent magnet 7a, 7b Peripheral surface 8 Insulating base 9, 19 External connection terminal 13 Printed circuit board 14 Ferrite sintered body 15a, 25a Permanent One surface (magnetized surface) of the magnet 10, 20, 30, 40, 50, 60, 70, 80, 9
0 Linearity coil Z Core axis

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Atsushi Yamazaki, Inventor Taiyo Electric Works, 6-16-20 Ueno, Taito-ku, Tokyo (72) Inventor Katsushi Ito 6-16-20, Ueno, Taito-ku, Tokyo Taiyo F Term (in reference) 5C068 AA01 JA06 KA15 MA05

Claims (3)

[Claims] 1. A drum core having a core and flanges provided at both ends thereof, and a core wound around the core of the drum core and having a terminal electrically connected to an external connection terminal. In a linearity coil including a wire and a permanent magnet attached to the drum core, one surface of the permanent magnet is attached so as to bridge the peripheral surfaces of both flanges of the drum core, A linearity coil, wherein only one surface of the permanent magnet facing a part of a peripheral surface of the both flanges is magnetized in two poles. 2. An insulating base on which an external connection terminal is implanted,
A double-sided ferrite magnet having only a two-pole magnetized upper surface mounted on the insulating base, and a winding core portion and flanges disposed at both ends thereof; A drum core fixed on a ferrite magnet with the core axis horizontal so that the lower side of the peripheral surface is bridged, and a terminal wound around the core portion of the drum core and a terminal electrically connected to the external connection terminal A linearity coil comprising: a joined winding. 3. A display device comprising a linearity coil mounted on a printed circuit board as a circuit element, wherein the linearity coil is the linearity coil according to claim 1 or 2.