JPS61259441A - Deflection yoke - Google Patents

Abstract

PURPOSE:To prevent magnetic material strips from being heated by eddy current and avoid permeability drop, by forming the magnetic material strips with plural magnetic material thin plates piled through insulation layers or insulated spaces, composing slits at respective magnetic material thin plates so that slits of neighboring thin plates are not overlapped. CONSTITUTION:A pair of magnetic material strips 1 and 2, which enhance barrel tendency at the electron-gun side of a vertical deflection magnetic field in a deflection yoke, are mounted inside the electron-gun side of a pair of toroidal coils 3 and 4 for vertical deflection, with plural magnetic material thin plates insulated and piled to compose the respective magnetic strips 1 and 2. Slits 1a'-1d'' are formed at the respective first-fourth magnetic material thin plates 1a-1d of the magnetic material strip 1, with those slits 1a'-1d'' positioned so as not to overlap slits of neighboring magnetic material thin plates 1a-1d. The magnetic material strip 2 is also composed of slits. Genera tion of eddy current and its causing heat is prevented at the magnetic material strips 1 and 2 for regulating a magnetic-field distribution, to avoid permeability drop.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a deflection yoke suitable for driving a color picture tube equipped with an in-line electron gun in a self-convergence manner.

Conventional Technology When a color picture tube equipped with an in-line electron gun is driven by a self-convergence method, a horizontal deflection magnetic field of a pincushion-shaped valve cloth as shown in FIG. 8 and a barrel-shaped distribution as shown in FIG. It is necessary to attach a deflection yoke capable of generating a vertical deflection magnetic field to the color picture tube.

However, when the electron beam is deflected by generating distorted horizontal and vertical deflection magnetic fields in this way, the raster obtained on the phosphor screen surface has a shape as shown in Figure 8.
Pincushion distortion occurs on the left and right sides. Therefore, in the past, the pincushion distortion as described above was corrected by a correction circuit, but in recent years, the correction has been made by adjusting the deflection magnetic field distribution for the purpose of resource saving and cost reduction. In this case, it is most effective to make the portion of the barrel-distributed vertical deflection magnetic field on the side of the phosphor screen surface have a bottle cushion tendency, and at the same time, it is desirable to strengthen the barrel tendency of the portion of the vertical deflection magnetic field on the electron gun side.

As a means to obtain a vertical deflection magnetic field with such a distribution, there are two methods: ■ Increasing the diagonal winding tendency of the toroidal coil for vertical deflection, and ■ Inserting a bottle cushion tendency on the outer periphery of the toroidal coil on the phosphor screen surface side. Method of providing a magnetic piece: ■ A method of providing a magnetic piece for generating a bottle cushion tendency on the inside of the same coil on the fluorescent screen side, and a method of providing a magnetic piece for reinforcing the barrel tendency on the inside on the electron gun side. etc. have been proposed.

By the way, the tendency of raster pincushion distortion as shown in Figure 8 is
This is particularly noticeable in color picture tubes with wide deflection angles and color picture tubes with nearly flat phosphor screen surfaces. Preferably, a correction means is added.

Problems to be Solved by the Invention However, the magnetic material piece provided on the electron gun side or phosphor screen side of the vertical deflection coil generates eddy currents due to crosstalk with the horizontal deflection magnetic field and generates heat. do. The eddy current can be reduced by providing a slit in the magnetic piece as disclosed in Japanese Utility Model Application Publication No. 56-49050, but even if there is only one slit, the equal measurement of the magnetic piece This is not preferable because it greatly reduces magnetic permeability.

Therefore, an object of the present invention is that even if the horizontal deflection magnetic field crosstalks to the barrel tendency reinforcement or other magnetic material piece provided on the electron gun side of the vertical deflection coil, eddy currents will occur in the magnetic material piece. It is an object of the present invention to provide a deflection yoke that does not generate heat or decrease in magnetic permeability.

Means for Solving the Problems According to the deflection yoke of the present invention, the magnetic piece is formed by a plurality of magnetic thin plates stacked with an insulating layer or an insulating space in between, and each magnetic thin plate has a , the slits do not overlap with the slits of adjacent thin magnetic plates.

Effect With this configuration, even if the horizontal deflection magnetic field crosstalks to the magnetic material pieces, the generation of eddy current is prevented by the slits.Furthermore, since the slits do not overlap between the magnetic thin plates, the stacking direction The decrease in magnetic permeability seen from the magnetic field is extremely small, and a good magnetic field distribution adjustment effect can be obtained.

Embodiment In the embodiment shown in FIGS. 1 to 3, a pair of magnetic pieces 1 are used to strengthen the barrel tendency of the vertical deflection magnetic field on the electron gun side.
, 2 are respectively provided inside the pair of vertical deflection toroidal coils 3 and 4 on the electron gun side. It consists of a composite board. That is, as shown in FIG. 1, the magnetic piece 1 includes first to fourth magnetic thin plates 1a,
1b.

It consists of a stack of thin insulator plates 1e, 1f, and 1g that are interposed between them and provide electrical insulation,
First to fourth magnetic thin plates 1a.

1b and 1C11d) 1
a', 1 b', 1 (+', 1 d' occupy positions that do not overlap with the slits of adjacent magnetic thin plates.The other magnetic piece 2 also overlaps the magnetic piece 1. It is constructed in the same manner as 6, 6 is a core, 7 is a saddle-shaped coil for horizontal deflection, and 8 is a frame body.

Although not shown, a pair of magnetic pieces for generating a bottle cushion tendency is provided inside the vertical deflection toroidal coils 3 and 4 on the phosphor screen surface side.

When a vertical deflection current flows through the toroidal coils 3 and 4 and a portion of the barrel distributed magnetic field generated thereby acts on the pair of magnetic pieces 1 and 2, the barrel tendency on the electron gun side is strengthened. Eddy current is generated at slit 1a'
, 1b', 1c', 1d'. and first to fourth magnetic thin plates 1a, 1b.
, 1c, and 1d are substantially closed when viewed from the stacking direction, and as a result, the decrease in magnetic permeability due to the slits is extremely small.

In the above embodiment, one magnetic material piece is made up of four magnetic thin plates, but the number may be two or more. Moreover, the number of slits provided in each magnetic thin plate may be one or more. Furthermore, when providing a member or protrusion for creating a small gap between the magnetic thin plates, the insulating thin plates can be omitted. Furthermore, instead of changing the direction of the slits by 900 as shown in FIG. 1, the directions may be the same as shown in FIG. They may also be formed in a diagonal array that intersects with each other. Further, in the above embodiment, the magnetic material piece disposed on the electron gun side was formed of a laminate of magnetic thin plates, but the magnetic material piece disposed on the phosphor screen side was similar to that described above. It is possible to apply a laminated body of , and these may be appropriately selected depending on the type of deflection yoke.

Effects of the Invention Since the present invention is configured as described above, eddy currents and heat generated by the magnetic material pieces for adjusting magnetic field distribution do not occur, and even though the slits for preventing eddy currents are provided, the magnetic permeability due to the eddy currents is reduced. There is almost no deterioration, and the occurrence of raster distortion can be effectively eliminated especially when applied to a deflection yoke mounted on a wide deflection angle color picture tube.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of a deflection yoke embodying the present invention, Fig. 2 is a partially cutaway side view of the same deflection yoke, Fig. 3 is a sectional view taken along line A-A in Fig. 2, and Figs. 6 and 7 are magnetic field distribution diagrams, and FIG. 8 is a diagram for explaining raster distortion. 1, 2 ----Magnetic piece, 1a, 1b, 1c,
1d...Magnetic thin plate, 1e, 1f, 1g...
...Insulating thin plate, 1a', 1b', 1c', 1d
'----y, Lit, 3.4-... Toroidal coil for vertical deflection, 7... Saddle-shaped coil for horizontal deflection. Name of agent: Patent attorney Toshio Nakao and one other person
- [Belly φ catty 3-m-Cole Fig. 2

Claims (1)

[Claims] a horizontal deflection coil that generates a magnetic field with a pincushion tendency;
It is equipped with a vertical deflection coil that generates a barrel-like magnetic field and a magnetic piece for adjusting magnetic field distribution, the magnetic piece being composed of a plurality of thin magnetic plates stacked with an insulating layer or an insulating space in between, and each thin magnetic plate having a A deflection yoke characterized by having slits that do not overlap slits in adjacent magnetic thin plates.