JPS62237649A - Deflecting yoke device - Google Patents

Abstract

PURPOSE:To reduce the loss produced by an eddy current of a magnetic piece, by furnishing an opening or a groove to cut off the eddycurrent circuit in the magnetic piece. CONSTITUTION:A magnetic piece 11 is furnished at the inside of a core 4, for example, in deflecting coils 3 and 5, and it has an opening 11a of a cutting form to cut off the eddy-current circuit, whereby an eddy-current circuit produced in the magnetic piece 11 is cut off to restrict the eddy-current loss. Therefore, the unit is adaptable for a high resolution unit scanned by a high frequency waves. By furnishing an opening or groove in the magnetic piece arranged in the deflecting magnetic field in such a way, the eddy-current loss produced in the magnetic piece can be restricted at minimum.

Description

[Detailed Description of the Invention] [F$: Field of Application on a Beam] This invention relates to a shadow W having an in-line electron gun, for example
This invention relates to a deflection yoke device for an i-tube (hereinafter referred to as CRT).

[Conventional technology]

A conventional deflection yoke device of this type is shown in FIG. In the figure, (1) is a magnetic piece, (2) is a separator, (3) is a horizontal deflection coil /L/ wound in a saddle shape and placed inside the separator (2), and (4) is a ferrite core. , (5) are vertical deflection coils wound toroidally around the ferrite core (4). (6) is a core clip for integrating the vertical deflection coil μ core (4) with the separator (2) side, (7) is the horizontal deflection coil A/ (3)
and a lead wire for supplying current to the vertical deflection coil N (5), and (8) a neckband for fixing the deflection yoke device to the neck of the CRT. The above magnetic piece (1)
The shapes shown in FIGS. 5(5) to 5(C) are used.

Next, the necessity of the magnetic piece (1) will be explained.

In a CRT deflection yoke device having an in-line electron gun, the horizontal deflection coil has a pincushion magnetic field as a self-convergence condition.

In contrast, the vertical deflection coil must have a barrel-shaped magnetic field. Furthermore, it is well known that it is necessary to make the magnetic field distribution variable in the tube axis direction in consideration of the conditions for achieving both strain and self-convergence.

For example, considering the magnetic field generated by the vertical deflection coil, in order to reduce the left-right distortion, the electron gun side should have a barrel-shaped magnetic field.
The screen side needs to have a pincushion type magnetic field.

However, if both self-convergence and no distortion cannot be achieved by coil distribution alone, a ferromagnetic material can be pasted on the outer surface of the separator (2) as described in, for example, Japanese Patent Application Laid-open No. 114117/1983. It is attached to achieve the required magnetic field distribution.

Here, when current is passed through the horizontal deflection coil (3) and the vertical deflection coil (5), an eddy current is generated in the magnetic piece (1), causing loss.

In particular, when the magnetic piece (1) is a ferromagnetic material, the magnetic flux is large, so the induced electromotive force is large (or the eddy current loss is increased).

Eddy current loss is generally expressed by the following formula.

S: Vortex outflow N: Thickness of material in the direction perpendicular to the direction of magnetic flux [m) f
: AC frequency [(g) Bm: Maximum magnetic flux density of material (wb/) ρ: Resistivity of material [Ωm] As can be seen from equation (1), eddy current loss is proportional to the frequency and the square of magnetic flux density. It turns out that it is inversely proportional to the resistivity of the material.

In recent years, demands for higher resolution have been increasing in television receivers, display devices, and the like. When obtaining high resolution, for example, conventional 15, 75 kl-iz
must be scanned at a higher frequency.

[Problem that the invention seeks to solve]

However, in a deflection yoke device having a magnetic piece (1), heat generation due to eddy current loss in the magnetic piece (1) becomes a temperature problem the higher the frequency of scanning becomes, and the reliability of the deflection yoke device is significantly reduced. become.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a highly reliable deflection yoke device by reducing losses caused by eddy currents in magnetic pieces.

[Means for solving problems]

In the deflection yoke device according to the present invention, the magnetic piece is provided with an opening or a groove for separating the eddy current circuit.

[Effect]

In this invention, eddy current loss in the openings or grooves of the magnetic piece is reduced, making it possible to cope with high frequency scanning.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an example of a deflection yoke device according to the present invention, and parts that are the same as those of the conventional device are given the same reference numerals and explanations will be omitted. In the same figure, (6) is in the magnetic field of the deflection coil iv (3) l (5), for example, the core (
4) is a magnetic piece placed inside the magnetic piece qυ
As shown in FIG. 2, a cutout-shaped opening (lla) is formed for cutting off the eddy current circuit.

According to the above configuration, the opening (lla) allows the magnetic piece αυ
The eddy current circuit that occurs in the eddy current circuit is separated, and eddy current loss is suppressed. Therefore, it is applicable to high-resolution scanning at high frequencies.

In addition to the shape described above, the opening (lla) of the magnetic piece C1,) may be formed of a plurality of slits as shown in FIG. It may be composed of small holes, or it may have the shape shown in Q)l, (El in the same figure).
).

Fig. 3 (Fl, (Groove (xlb) as shown in Gl)
A similar effect can also be obtained by forming a .

〔Effect of the invention〕

As described above, according to the present invention, since the opening or groove is formed in the magnetic piece disposed within the deflection coil magnetic field,
It is possible to provide a deflection yoke device that can minimize the eddy current loss caused by this magnetic piece, is extremely stable in terms of temperature, and can easily handle 1 MJ frequency scanning.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing an example of a deflection yoke device according to the present invention, Fig. 2 is a perspective view showing a magnetic piece used in the device, and Fig. 3 (5) to (Gl is a deformation of the magnetic piece. A perspective view showing the structure, FIG. 4 is an exploded perspective view of a conventional deflection yoke device,
FIG. 5 is a perspective view showing a magnetic piece in a conventional device. (3)...Horizontal deflection carp, (4)...Core, (5
)...Vertical deflection coil, αυ...Magnetic piece, (lla
)...opening, (llb)...groove. In addition, in FIG. 1, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] (1) In a deflection yoke device in which a magnetic piece is arranged to adjust the magnetic field distribution in the magnetic field generated by the deflection coil,
A deflection yoke device characterized in that the magnetic piece is provided with an opening or a groove for separating an eddy current circuit. (2) The deflection yoke device according to claim 1, wherein the magnetic piece is arranged inside the core. (3) The deflection yoke device according to claim 1, wherein the opening is comprised of a slit or a small hole.