JPH05190113A - Core for deflecting yoke - Google Patents

Abstract

PURPOSE:To obtain a core for a deflecting yoke whose shape distribution is reduced in manufacturing process by allowing a slot core used for deflecting yoke to be provided with the high deflection sensitivity and heat generation suppressing performance, suppressing the generation of cracks. CONSTITUTION:A core for a deflecting yoke is constituted so that a plurality of projecting parts 10 are formed, extending in a prescribed pitch in the circumferential direction from the rear edge side of the inner surface 1a of the core at least to an intermediate part where the inside diameter becomes large, and a recessed part 20 having the depth corresponding nearly to the height dimension of the projection part 10 is formed on the outer surface of the core on the opposite side to the projection part 10. Accordingly, the partial thickness difference of the core is removed, and the thickness of the whole core can be made nearly uniform.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke core used in a cathode ray tube such as a television.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for large-sized and wide-angle TV cathode ray tubes and high-speed scanning mainly for display monitor cathode ray tubes. Therefore, the deflection yoke used for the cathode ray tube is required to be able to efficiently deflect with a magnetomotive force as small as possible.

In order to meet the above requirements, for example, there is a deflection yoke disclosed in Japanese Utility Model Laid-Open No. 62-144053 shown in FIG. 3, and the structure of the slot core used in this deflection yoke is as follows.

That is, in FIG. 3, 1 is a slot core (hereinafter, also referred to as a deflection yoke core).
Then, on the inner surface 1a of the core, a plurality of portions are arranged at a predetermined pitch in the circumferential direction from a portion 1b near the trailing edge (hereinafter referred to as a trailing end 1b), which is the neck side when mounted on a cathode ray tube, to an intermediate portion where the inner diameter increases. The convex portion 10 is extended. 1c
Is a portion close to the front edge on the funnel side when the slot core 1 is attached to the cathode ray tube (hereinafter referred to as the front end 1c), and a slot for winding a deflection coil (not shown) between adjacent protrusions 10. Are formed.

Next, the operation of the above configuration will be described. Since the slot core 1 has the plurality of convex portions 10 provided at a predetermined pitch in the circumferential direction of the core inner surface 1a, the effective air gap magnetic path for deflecting the electron beam can be shortened, and the deflection Efficiency of sensitivity can be improved. Further, either or both of the horizontal deflection coil and the vertical deflection coil can be wound around a slot (not shown) formed between the convex portions 10 and, as a result, a frequency for high-speed scanning can be obtained. It is possible to reduce the chance that the high deflection magnetic field of the magnetic field will interlink with the conductor forming the coil.

As a result, there is an advantage that the eddy current loss generated in the coil conductor can be reduced and the heat generation of the deflection yoke can be reduced.

[0007]

As described above, the conventional slot core 1 is provided with the slots for winding the deflection coil between the plurality of convex portions 10 extending on the core inner surface 1a side. Yes, with a deflection yoke using this,
It is possible to improve the deflection sensitivity and reduce heat generation.

However, considering the manufacturing process of the slot core 1, the core thickness in the portion where the convex portion 10 is present on the inner surface 1a of the core naturally becomes thicker, and between the adjacent convex portions 10 and the convex portions 10. The core wall thickness at the slot portion of the formed core inner surface 1a becomes thin.

As described above, the partial thickness difference of the slot core causes unevenness in the press molding process of the slot core, and as a result, the shape of the slot core after high temperature firing by the ferrite powder sintering technique. There are inconveniences such as a decrease in accuracy and cracks in the slot core.

The present invention has been made in order to solve the above problems, and has good dimensional accuracy without impairing the high deflection sensitivity and low heat generation property of the slot core, and
It is an object of the present invention to provide a deflection yoke core having a high yield.

[0011]

A deflection yoke core according to the present invention comprises a plurality of convex portions extending at a predetermined pitch in the circumferential direction from the rear end side of the inner surface of the core to at least an intermediate portion having a large inner diameter. , In a deflection yoke core in which a plurality of slots for winding a deflection coil between adjacent protrusions are formed, on the core outer surface on the opposite side of each of the protrusions,
The configuration is such that a concave portion having a depth substantially corresponding to the height dimension of the convex portion is formed.

[0012]

In the deflection yoke core according to the present invention, a concave portion having a depth substantially corresponding to the height of the convex portion is formed on the outer surface side of the core corresponding to the convex portion extending on the inner surface side of the core. Therefore, the thickness of the core can be made substantially uniform as a whole, the dimensional variation due to the difference in the thickness of the core can be reduced, and the dimensional variation caused in the manufacturing process of the core can be significantly reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 is a partially broken sectional view of a deflection yoke core according to an embodiment of the present invention seen from a side surface, and FIG. 2 is a sectional view taken along the line AA of FIG.

In FIGS. 1 and 2, reference numeral 1 is a deflection yoke core (slot core), 10 is a plurality of convex portions forming teeth extending at a predetermined pitch in the circumferential direction of the inner surface of the core,
Reference numeral 11 denotes a groove portion that forms a slot between the convex portions 10 and 10, and 20 denotes a concave portion provided on the core outer surface 1d on the opposite side of the convex portion 10, and has a width and a length substantially the same as those of the convex portion 10. , And a depth substantially corresponding to the height dimension thereof.

However, in the deflection yoke core according to this embodiment, the convex portion 10 formed on the core inner surface 1a has the core inner surface 1a.
It shows the case where it is extended from the rear end 1b to the front end 1c side.

Since the slot core 1 is constructed as described above, the thickness of the core in the portion where the convex portion 10 is formed on the inner surface of the core and the core in the groove portion 11 between the convex portion 10 and the convex portion 10 are different. The wall thickness is almost uniform, and the wall thickness of the entire slot core can be made uniform. In this way, by making the thickness of the slot core uniform, the core manufacturing process, in particular, density variation of ferrite powder generated in the press molding process, press compression variation is reduced,
It is possible to manufacture a deflection yoke core with high dimensional accuracy of the shape without causing cracks in the core.

Further, since the concave portion 20 is formed on the core outer surface 1d side at the portion opposite to the convex portion 10 provided on the core inner surface side, as a result, the surface area of the core itself becomes large and the groove portion is formed. If a deflection yoke is manufactured by winding a horizontal deflection coil or a vertical deflection coil around 11, there is an advantage in terms of heat dissipation.

Embodiment 2 In the above embodiment, the case where the convex portion 10 formed on the inner surface of the core extends from the rear end side to the front end side of the inner surface of the core has been described. However, in the slot core shown in FIG. like,
The present invention can be applied to the case of the slot core in which the convex portion 10 provided on the inner surface of the core is provided only from the rear end side of the inner surface of the core to the intermediate portion where the inner diameter is large, and the same effect as the above-described embodiment is obtained.

[0019]

As described above, according to the deflection yoke core of the present invention, while the slot core itself has the advantages of high deflection sensitivity and reduced heat generation, it is opposite to the convex portion provided on the inner surface of the slot core. On the outer side of the core, which corresponds to the side, a concave portion having a depth approximately equivalent to the height dimension of the convex portion is provided, so that the thickness of the slot core can be made uniform, the core does not crack, and the dimensional accuracy of the core is also high. Can be improved.

Therefore, in the magnetic field distribution of the deflection yoke manufactured by winding the deflection coil around the slot of the slot core as described above, the variation due to the shape of the slot core is reduced, and the variation of the deflection yoke characteristic is small. There is an effect that the deflection yoke can be manufactured.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a deflection yoke core according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a partially cutaway side view of a conventional deflection yoke core.

[Explanation of symbols]

 1 core for deflection yoke (slot core) 10 convex portion 20 concave portion

Claims (1)

[Claims] 1. A deflection coil is wound between a plurality of convex portions extending at a predetermined pitch in a circumferential direction from a rear end side of an inner surface of a core to at least an intermediate portion having a large inner diameter, and adjacent convex portions. In the deflection yoke core having a plurality of slots formed therein, a concave portion having a depth substantially corresponding to the height of the convex portion is formed on the outer surface of the core opposite to the convex portion. Core for yoke.