KR20030081661A - A quadrangle ferrite core and deflection yoke with the core - Google Patents

Abstract

PURPOSE: A rectangular ferrite core and a deflection yoke having the same are provided to reduce an error rate due to the dimensional distribution by improving the dimensional distribution. CONSTITUTION: A deflection yoke having a rectangular ferrite core includes a couple of vertical coils(14), a couple of horizontal deflection coils(12), a rectangular ferrite core(20), and a coil separator(10). The vertical and the horizontal deflection coils(14,12) are used for deflecting electron beams. The rectangular ferrite core(20) includes a small-sized opening portion(16) and a large-sized opening portion(18). A projected structure is formed on an inner surface of the rectangular ferrite core(20). The coil separator is used for fixing the vertical and the horizontal deflection coils(14,12) and the rectangular ferrite core(20) and insulating the vertical and the horizontal deflection coils(14,12).

Description

A QUADRANGLE FERRITE CORE AND DEFLECTION YOKE WITH THE CORE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to deflection yokes for cathode ray tubes, and more particularly, to rectangular ferrite cores with improved dimensional dispersion and deflection yokes for cathode ray tubes having these cores.

As is well known, a cathode ray tube is an electron tube that realizes an image by deflecting an electron beam emitted from an electron gun in a horizontal and vertical direction with respect to a screen so that the electron beam lands on a phosphor of the screen. Here, the deflection of the electron beam is made by a deflection yoke mounted on the outer periphery of the funnel of the cathode ray tube to form horizontal and vertical magnetic fields.

The deflection yoke generally includes a vertical deflection coil for deflecting the electron beam in the vertical direction, a horizontal deflection coil for deflecting the electron beam in the horizontal direction, and a magnetic deflection of the vertical deflection magnetic field generated in the vertical deflection coil to reduce magnetic efficiency. And a coil separator for fixing the vertical and horizontal deflection coils and the ferrite core in a predetermined position and insulating between the vertical and horizontal deflection coils.

In particular, among the deflection yokes of such a configuration, the ferrite core is made of ferrous oxide (Fe ₂ O ₃ ), which is a basic material, and magnesium-copper-zinc (Mg-Cu), which is a transition metal that enhances magnetic properties. -Zn), magnesium-manganese-zinc (Mg-Mn-Zn), nickel-copper-zinc (Ni-Cu-Zn), manganese-zinc (Mn-Zn), etc. It is then manufactured through a complex process of dividing. The size of the ferrite core produced through this process is reduced by about 10 to 20% compared with the size before firing. That is, the ferrite core has a machining tolerance of ± 2% due to the manufacturing process limitation of shrinkage of 10 to 20%.

In addition, a rectangular ferrite core, which has been recently developed to improve the sensitivity of the deflection yoke, that is, the ferrite core formed so that the shape of the inner surface changes from circular to non-circular shape from the inlet portion on the neck side to the large opening portion on the panel side is fired. At the time of subsequent contraction, the circular inlet portion contracts in a constant amount toward the center portion, but in the non-circular large opening portion, the contraction does not occur in a constant amount depending on each position such as the long side, the short side, and the corner portion. Since the shrinkage of each product is not constant, the dimensional dispersion is large.

This shrinkage defect causes a convergence characteristic defect of the deflection yoke, and the convergence characteristic defect due to the shrinkage defect phenomenon accounts for about 30 to 40% of the total causes of the defective convergence characteristic.

Accordingly, an object of the present invention is to solve the above problems by providing a rectangular ferrite core having improved dimensional dispersion and a deflection yoke for a cathode ray tube having the rectangular ferrite core.

The object of the present invention described above,

A pair of vertical and horizontal deflection coils for deflecting the electron beam, a square ferrite core used to increase magnetic efficiency by reducing magnetic force loss of the vertical deflection magnetic field generated in the vertical deflection coil, and vertical and horizontal deflection coils and ferrite core In the deflection yoke for a cathode ray tube comprising a coil separator for fixing the to a predetermined position and insulated between the vertical and horizontal deflection coil,

The rectangular ferrite core is formed in a circular to non-circular shape gradually from the inlet portion of the neck portion to the generally opening portion of the funnel side, and protrudes to suppress the contraction of the portion where the shrinkage after firing is relatively large on the outer surface of the square ferrite core. The structure is achieved by a square ferrite core provided.

The shrinkage inhibiting protrusion may be formed of a rib formed from the corner side of the introduction port portion to the opening portion side, and in another embodiment, may be embossed.

1 is a perspective view schematically showing a deflection yoke according to the present invention;

FIG. 2 is a perspective view of the ferrite core of FIG. 1. FIG.

3a and 3b are simulation data showing the amount of displacement due to shrinkage occurring after firing of the existing ferrite core and the ferrite core according to the present invention.

4A and 4B are simulation data each showing a stress due to shrinkage after firing of a conventional ferrite core and a ferrite core according to the present invention.

5 is a half sectional view showing a cathode ray tube equipped with a deflection yoke of the present invention;

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic perspective view of a deflection yoke according to the present invention, and FIG. 2 is a perspective view of the ferrite core of FIG. 1.

As shown, the deflection yoke DY of the present invention is formed by mounting a horizontal deflection coil 12 and a vertical deflection coil 14 inside and outside of the coil separator 10 made of a synthetic resin.

Here, the separator 10 is divided into two divided parts 10a and 10b and formed into a single body having a shape of a trumpet, and the separator 10 has a neck-side introduction opening 16 and a funnel-side large opening ( 18) is provided at both ends.

In addition, the separator 10 has a structure as described above, in order to reduce the deflection power of the cathode ray tube, the inner surface shape gradually from circular to rectangular to non-circular, such as from the introduction opening portion 16 toward the opening portion 18 side. The inner surface shape of the separator 10 helps to reduce the deflection power by bringing the horizontal deflection coil 12 and the vertical deflection coil 14 closer to the path of the electron beam.

The pair of horizontal deflection coils 12 mounted inward of the separator 10 is made of a saddle type or a toroidal type, and also a vertical deflection coil mounted to the outside of the separator 1. (14) also in saddle or toroidal form.

In addition, the ferrite core 20 used to reduce magnetic force loss of the vertical deflection magnetic field generated by the vertical deflection coil 14 to increase magnetic efficiency has a shape similar to that of the coil separator 10 described above.

That is, the ferrite core 20 has a large opening 22 and the introduction opening 24 as shown in Figure 2, the inner surface and the outer surface toward the large opening portion 22 side from the introduction opening portion 24 side Gradually formed from circular to non-circular, such as rectangular.

The ferrite core 20 includes ferric oxide (Fe ₂ O ₃ ), which is a basic material, and magnesium-copper-zinc (Mg-Cu-Zn), and magnesium-manganese-zinc (Mg), which are transition metals that enhance magnetic properties. -Mn-Zn), nickel-copper-zinc (Ni-Cu-Zn), manganese-zinc (Mn-Zn) and the like mixed with a material, it is produced through a complex process of molding and dividing.

At this time, the size of the ferrite core 20 is reduced as described above after the firing process of the ferrite core 20, the present invention is a projecting structure for preventing the large dimensional dispersion of the ferrite core 20 is generated It is provided. Here, the protruding structure may be formed in a rib or embossed shape, where FIG. 2 illustrates a ferrite core 20 having a protruding structure on the rib 26.

The ribs 26 are formed integrally with the ferrite core 20 from the corner side toward the mouth opening 24 of the ferrite core 20 toward the mouth opening 22, which has a large dimensional dispersion at the corner side. Because it occurs.

Of course, the rib 26 may also be formed up to the end of the opening 22.

3 and 4 are diagrams comparing the conventional ferrite core and the ferrite core of the present invention, respectively, and FIGS. 3A and 3B compare displacements caused by shrinkage that occur after firing, and FIGS. 4A and 4B illustrate after firing This is a comparison of stress due to shrinkage.

Referring to FIGS. 3A and 3B, the shrinkage patterns occurring in the respective portions of both ferrite cores show a similar tendency, but the displacement amount (mm) due to the shrinkage is reduced in the ferrite core of the present invention having ribs 26. It can be seen that. Also, referring to FIGS. 4A and 4B, it can be seen that the stress Pa due to shrinkage in each part of the ferrite core 20 is reduced in the ferrite core of the present invention.

As described above, the present invention having the projecting structure (rib or embossing, etc.) on the outer surface is considered to be approximately 30 to 40% of the total defective rate of the rectangular ferrite core (15 to 20%). In the ferrite core, a 4-7% defect reduction effect can be obtained.

However, if the rib 26 affects the magnetic field characteristic of the deflection yoke DY, the convergence characteristic may be lowered. However, the inventor's experiment showed that the rib 26 had little effect on the magnetic field characteristics of the deflection yoke.

As described above, the ferrite core 20 having the ribs 26 is divided into two parts along the long direction or the unidirectional direction of the opening 22, and the divided ferrite cores are installed outside the coil separator 10 and then the core clamp ( It is fixed in one body by a fixing means such as (not shown). In FIG. 2, reference numeral 28 denotes a divided surface of the ferrite core, and reference numeral 30 denotes a mounting portion to which the core clamp is mounted.

In FIG. 2, all of the ribs 26 are provided in the four corner portions of the quadrangular ferrite core 20, but the ribs 26 may be provided in only part of the four corner portions.

Fig. 5 is a half cross-sectional view showing a cathode ray tube equipped with a deflection yoke DY of the present invention, wherein the cathode ray tube is a rectangular panel 32 and a funnel-shaped funnel connected to the panel 32. 34) and a tube including a cylindrical neck portion 36 connected to the funnel 34 to form an outer shape.

The phosphor screen 32a is formed on the inner surface of the panel 32, and the deflection yoke DY is mounted on the outer side near the boundary between the funnel 34 and the neck portion 36, and the neck portion 36 is provided. Inside of the electron gun 38 is inserted.

Further, the funnel 34 of the cathode ray tube is adjacent to the neck seal portion 34a which forms a connection portion with the neck portion 36 in the direction of the panel 32 from the neck portion 36 and the neck seal portion 34a. A cone portion 34b and a body 34c which is rapidly expanded from the panel side end of the cone portion 34b and connected to the panel 32 side.

Here, the cone portion 34b is formed in a circular shape having the same diameter as the neck portion 36 on the neck portion 36 side, but gradually follows from the neck portion 36 side toward the panel 32 side. The panel 32 is formed in a non-circular shape such as a rectangle having a maximum diameter in a direction other than the long axis and the short axis.

The cathode ray tube formed as described above has the deflection due to the shape of the ferrite core 20 together with the coil separator 10 of the deflection yoke DY in a state where the cone portion 34b is squared. Since the coils 12 and 14 can be effectively approximated to the trajectories of the electron beams emitted from the electron gun 38, the deflection power for the electron beams can be reduced accordingly.

Meanwhile, in the present invention, the ferrite core 20 may be formed as a single body without dividing as described above. In this case, a flange type deflection coil having a flange toward the neck portion is used, and the ferrite core 20 is formed. In the case of dividing), a flangeless type deflection coil having no flange on the neck side is used.

Although the present invention has been described with reference to the rectangular ferrite core as an example, the present invention is not limited to the rectangular ferrite core, and is applicable to other shapes of ferrite cores manufactured with a plurality of complex curvatures and having large dimensional dispersions.

As described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings. Do.

As described above, the ferrite core according to the present invention exhibits a similar shrinkage to the designed value after the molding process, thereby significantly improving the dimensional dispersion, thereby minimizing the defective rate (corresponding to 30 to 40% of the total defective rate) due to the dimensional dispersion. Can be. Therefore, the deflection yoke having the above-described ferrite core significantly reduces the convergence spread due to the dimensional dispersion of the ferrite core. In addition, when the deflection yoke having the rectangular ferrite core is used, the deflection force with respect to the electron beam can be reduced, and the electron beam can be deflected effectively, thereby reducing the power consumption of the cathode ray tube according to the reduction of the deflection power. It becomes possible.

Claims (4)

A pair of vertical and horizontal deflection coils respectively for deflecting the electron beam; A protruding structure having an inlet and a large opening, the inner surface of which is gradually circular to non-circular as it goes from the neck opening side to the opening side of the funnel, and on the outer surface, a projecting structure that suppresses the contraction of a relatively large amount of shrinkage after firing. A square ferrite core provided; A coil separator that is formed in a circular to non-circular shape as the inner shape gradually goes from the neck side to the funnel side, and fixes the vertical and horizontal deflection coils and the square ferrite core at a predetermined position and insulates between the vertical and horizontal deflection coils; Deflection yoke including. A pair of vertical and horizontal deflection coils for deflecting the electron beam, a square ferrite core used to increase magnetic efficiency by reducing magnetic force loss of the vertical deflection magnetic field generated in the vertical deflection coil, and vertical and horizontal deflection coils and ferrite cores. In the deflection yoke for a cathode ray tube comprising a coil separator for fixing the to a predetermined position and insulated between the vertical and horizontal deflection coil, The rectangular ferrite core is formed in a circular to non-circular shape gradually from the inlet portion of the neck portion to the generally opening portion of the funnel side, and protrudes the outer surface of the rectangular ferrite core to suppress the contraction of a portion having a relatively large shrinkage after firing. Square ferrite core with structure provided. The rectangular ferrite core according to claim 1 or 2, wherein the protruding structure is formed of ribs formed from a corner side of the introduction port portion to a large opening side. The rectangular ferrite core of claim 3, wherein the ferrite core is formed of a divided body.