KR20040006520A - Deflection yoke for crt - Google Patents

Abstract

PURPOSE: A deflection yoke for a cathode ray tube is provided to correct a miss convergence, while reducing the generation of the miss convergence in another part except for a part to be corrected. CONSTITUTION: A deflection yoke for a cathode ray tube comprises a horizontal and a vertical deflection coil for deflecting an electron beam toward a horizontal direction and a vertical direction, a cone shape ferrite core for increasing a magnetic efficiency by reducing of magnetic force generated from the horizontal and the vertical deflection coil, a holder for insulating between the horizontal deflection coil and the vertical deflection coil, and fixing the horizontal deflection coil, the vertical deflection coil, and ferrite core at setting position. An auxiliary coil(18) is formed at 1/3 position of the vertical deflection coil from a screen direction toward length of the vertical deflection coil, within 40 degree criterion of window part center of the vertical deflection coil.

Description

Deflection yoke for cathode ray tube {DEFLECTION YOKE FOR CRT}

The present invention relates to a deflection yoke for a cathode ray tube, and more particularly, to a deflection yoke for a cathode ray tube such that horizontal misconvergence is corrected by attaching an auxiliary coil to a holder of a deflection yoke for a cathode ray tube.

1 is a cross-sectional view illustrating the structure of a cathode ray tube.

Referring to FIG. 1, a cathode ray tube is mounted on a panel 11 mounted on a front surface of a cathode ray tube, and is disposed on an inner surface of the panel 11 and coated with phosphors of red (R), green (G), and blue (B). The fluorescent surface 13, a shadow mask 14 positioned on the rear surface of the fluorescent surface 13 to color-select the electron beam incident on the fluorescent surface 13, and a rear surface of the panel 11 to be vacuumed inside. A funnel 12 for maintaining the state, an electron gun 16 mounted inside the tubular neck portion that is the rear portion of the funnel 12 to generate and fire an electron beam, and an outer portion of the neck portion of the funnel 12. And it consists of a deflection yoke 15 for causing the electron beam emitted from the electron gun 16 to deflect in a horizontal or vertical direction.

In particular, the deflection yoke 15 has a pair of horizontal deflection coils 21 for deflecting the electron beam emitted from the electron gun 16 in the horizontal direction, and a pair of horizontal deflection for the deflected electron beam in the vertical direction. A deflection coil 22, and a conical ferrite core 24 is provided to reduce the loss of magnetic force generated by the current flowing in the horizontal deflection coil 21 and the vertical deflection coil 22 to improve the deflection efficiency, A holder 23 directly coupled to the neck portion of the funnel 12, a comma precoil 25 installed at the rear of the holder 23 to improve comma aberration, and a rear of the holder 23. Ring band 26 is provided to couple the funnel 12 and the deflection yoke 15, and the magnet 27 is provided outside the opening end of the holder 23 to correct the raster distortion of the screen.

Referring to the operation of the conventional deflection yoke 15 having such a configuration, first, a current having a frequency of 15.75 KHz or more is applied to the horizontal deflection coil 21, and the electron beam is deflected in the horizontal direction by using the magnetic field generated accordingly. In addition, a current having a frequency of 60 Hz is applied to the vertical deflection coil 22 to deflect the electron beam in the vertical direction by using a magnetic field generated accordingly.

The deflection of the electron beam is generally based on a self-convergence method in which a non-uniform magnetic field enables the trigeminal beam to achieve screen convergence without using an additional circuit and an additional device. And a barrel or pincushion type magnetic field for each of the front, middle, and rear portions of the deflection yoke 15 by adjusting the winding distribution of the vertical deflection coil 22, so that the three electron beams 17 have different deflection forces according to their positions. In this case, the electron beam 17 can be collected at the same point.

In such a self-convergence method, it is difficult to deflect an electron beam to a desired place only by the magnetic fields of the horizontal and vertical deflection coils 21 and 22, so that a high permeability ferrite core 24 is used to compensate for this. Minimize the loss to increase the magnetic force.

The pincushion type horizontal deflection magnetic field is generated by the horizontal deflection coil 21. As shown in FIG. 3, the upper and lower horizontal deflection coils are configured in parallel, and then a sawtooth wave-shaped horizontal deflection current is implemented. Doing.

When the three red, green, and blue electron beams 17 generated by the electron gun 16 pass through the horizontal deflection magnetic field region, the electron beam 17 is deflected in the horizontal direction by Fleming's left hand law.

Since the recent CRT is flattened, when the three-color electron beam 17 reaches the fluorescent surface 13, the distance between the center and the outer portion of the screen is much different from that of the CRT, so the raster forms a pincushion distortion at the top and bottom of the screen. do.

Therefore, the magnet 27 is installed above and below the front part of the holder 23 of the deflection yoke 15 so that the distortion is corrected.

In addition, the electron beam 17 emitted from the electron gun 16 passes through the deflection section of the deflection yoke 15, and the deflection coil or other deflection yoke 15 formed on the deflection yoke 15, the deflection yoke 15 In general, misconvergence occurs due to an error in assembly.

Such misconvergence may occur on the axis of the screen and may occur at the outer edge of the screen. The misconvergence is primarily corrected at the time of manufacture of the deflection yoke 15, and is again performed when the CRT and the deflection yoke 15 are combined. Secondary corrections are made.

It is a figure explaining the conventional transverse misconvergence.

As shown in FIG. 4, the arrangement state of the horizontal lines R and B in the 2 o'clock direction is that R is above B, and the arrangement of the horizontal lines R and B in the 2.5 o'clock direction is B in the upper side of R.

In order to improve such lateral misconvergence, it is essential to improve the characteristics of the winding product itself or the design basic characteristics before assembling the coil of the deflection yoke 15, but it is generally generated through the assembly process even in the improved state.

Therefore, the horizontal misconvergence can be corrected to some extent in the manufacturing process of the deflection yoke 15, but there is a limit to completely eliminate the amount of the misconvergence.

In order to solve this problem, a soft ferrite correction material is attached to the inside of the horizontal deflection coil 21 to artificially deform the horizontal deflection magnetic field and the vertical deflection magnetic field, thereby correcting the horizontal misconvergence.

However, there is a limit to this correction since another misconvergence is generated by the deformed horizontal deflection magnetic field and the vertical deflection magnetic field.

In addition, in the high-definition CDT, the misconvergence is difficult to be 0.2mm or less, so when the final correction of each corner of the screen is 0.1mm or less, the basic convergence pattern at the bottom of each corner is the horizontal lines R and B at the corners. Normal fertilization by the ferrite sheet can be done if it is not in the same direction or at least in the opposite direction. However, as shown in FIG. 4, R and B of the corner portion (2 o'clock direction) are within 0.2 mm within the ferrite sheet. When one step below (2.5 o'clock) B becomes larger in the upward direction, there is a problem that the correction by the ferrite sheet is virtually impossible.

The deflection yoke for a cathode ray tube according to the present invention has an object of correcting misconvergence while reducing the occurrence of misconvergence of portions other than the portion to be corrected.

In addition, the deflection yoke for the cathode ray tube according to the present invention is to reduce the defective rate of the deflection yoke is to reduce the manufacturing cost and improve the productivity.

BRIEF DESCRIPTION OF THE DRAWINGS The figure explaining the structure of the conventional cathode ray tube.

2 is a view for explaining the structure of a conventional deflection yoke.

3 is a cross-sectional view of a conventional ferrite core and a horizontal deflection coil, a vertical deflection coil.

4 is a view for explaining the inversion phenomenon of the conventional horizontal lines R, B.

5 is a view for explaining the structure of a holder of a deflection yoke for a cathode ray tube according to the present invention;

6 is a view illustrating a position where the auxiliary coil of the deflection yoke for the cathode ray tube according to the present invention is attached.

7 is a view illustrating a magnetic field when a current in the same direction as a vertical deflection coil is applied to an auxiliary coil in a deflection yoke for a cathode ray tube according to the present invention;

8 is a view illustrating a current flowing in the auxiliary coil and the vertical deflection coil in the deflection yoke for a cathode ray tube according to the present invention.

9 is a view for explaining a magnetic field when a current in the direction opposite to the vertical deflection coil is applied to the auxiliary coil in the deflection yoke for a cathode ray tube according to the present invention;

10 is a view illustrating that the reversal phenomenon of R and B of lateral misconvergence is improved by a doubled magnetic field by an auxiliary coil in a deflection yoke for a cathode ray tube according to the present invention.

<Explanation of symbols for main parts of drawing>

11; Panel 12; Funnel

13; Fluorescent surface 14; Shadow mask

15; Deflection yoke 16; Electron gun

17; Electron beam 18; Auxiliary coil

21; Horizontal deflection coil 22; Vertical deflection coil

23; Holder 24; Ferrite core

25; Comma precoil 26; Ring band

27; Magnet

In order to achieve the above object, the present invention provides a horizontal deflection coil and a vertical deflection coil for deflecting the electron beam in a horizontal or vertical direction, and a conical shape for reducing magnetic loss generated from the horizontal deflection coil and the vertical deflection coil to increase magnetic efficiency. In a deflection yoke for a cathode ray tube comprising a ferrite core, a horizontal deflection coil, a vertical deflection coil and a ferrite core at a predetermined position, and a holder for insulation between the horizontal deflection coil and the vertical deflection coil.

In the longitudinal direction of the vertical deflection coil, the auxiliary coil formed within 40 degrees of the 1/3 position of the vertical deflection coil from the screen side, the window center of the vertical deflection coil is included.

It is a figure explaining the structure of the holder of the deflection yoke for cathode ray tubes which concerns on this invention.

Referring to Figure 5, the groove is formed so that the rectangular auxiliary coil can be attached along the outer curved surface of the screen side of the holder.

The groove is a groove so that the vertical portion of the auxiliary coil can be formed between 30 degrees to 40 degrees with respect to the 1/3 position of the vertical deflection coil and the window center of the vertical deflection coil so that the auxiliary coil can be easily coupled. The auxiliary coil is coupled to a position where the groove is formed.

6 is a view illustrating a position where the holder of the deflection yoke for the cathode ray tube according to the present invention is coupled to the auxiliary coil coupled to the holder.

As shown in FIG. 6, the auxiliary coil 18 extends in the longitudinal direction of the vertical deflection coil, within a third position of the vertical deflection coil from the screen side of the holder, and within 40 degrees of the window center of the vertical deflection coil. ) Is formed.

More preferably, the auxiliary coil 18 has a vertical portion formed between 30 degrees and 40 degrees with respect to the 1/3 position of the vertical deflection coil and the window center of the vertical deflection coil.

As shown in FIG. 4, the misconvergence occurs at 2.5 o'clock on the screen, and also occurs at 3.5 o'clock, 8.5 o'clock, and 9.5 o'clock because the deflection coil is symmetrical.

Each direction is 30 degrees to 40 degrees with respect to the X axis on the screen, and it is necessary to adjust the position corresponding to the position on the screen even in the deflection coil, and in this case, it is necessary to adjust the magnetic field only for a specific portion.

In the related art, when the magnetic field adjustment is performed in the deflection coil, the magnetic field distribution of the entire coil is changed, so that not only the portion to be adjusted but also the peripheral portion are linked to each other, misconvergence is also displayed.

Accordingly, a groove is formed in the holder such that the portion of the auxiliary coil 18 to form the auxiliary magnetic field 18 to form the effective magnetic field overlaps the corresponding portion of the vertical deflection coil.

In this case, the actual required magnetic field is a vertically formed portion, and the magnetic field is formed by the direction of the current flowing through the portion. In this case, the direction of the current flowing through the auxiliary coil depends on the arrangement of the horizontal lines R and B in the 2.5 o'clock direction. The current direction of the coil is determined circuitically and applied.

For example, if R and B in the 2.5 o'clock direction are formed as shown in FIG. 4, R must be moved upward on the screen. In this case, the magnetic field is formed as shown in FIG. 7.

That is, the magnetic field should be doubled by using the auxiliary coil to the basic magnetic field of the vertical deflection coil.

In order to form a magnetic field as shown in FIG. 7, the current direction of the auxiliary coil 18 should be the same as the current direction of the vertical deflection coil as shown in FIG. 8.

That is, the magnetic field of the portion indicated by the circle in Fig. 8 should be configured to be stronger than the magnetic field of the original vertical deflection coil.

9 is a view for explaining that the magnetic field is reduced so that the current direction of the auxiliary coil is opposite to the current direction of the vertical deflection coil.

The direction of this current or the amount of current is determined by the pattern of R and B at 2.5 o'clock depending on the type of product or the size of the CRT.

In addition, after the auxiliary coils are connected in parallel to the vertical deflection coils so as to vary the amount of current in the current direction of the auxiliary coils, and the auxiliary coils have variable resistors, the current amount of the auxiliary coils can be varied depending on the situation. Since the magnetic field is also variable, the total magnetic field of the dotted line in FIG. 9 can be varied and adjusted according to the degree of R and B spreading.

As shown in FIG. 10, the reversal phenomenon of R and B of the horizontal misconvergence is improved due to the double magnetic field of the auxiliary coil.

That is, in the lateral misconvergence indicated by the dotted line in FIG. 4, an auxiliary coil is installed in the inversion phenomenon of R and B to generate a double magnetic field to move R upward, thereby correcting the misconvergence of the 2.5 o'clock direction, and a deflection coil. Because of this symmetry, the misconvergence generated in the 3.5 o'clock, 8.5 o'clock, and 9.5 o'clock directions can also be solved by the magnetic field of the double coil provided symmetrically.

On the other hand, the present invention is not limited to the above embodiments, and many modifications such as increasing the length of the auxiliary coil in the longitudinal direction or adjusting the doubled magnetic field by adjusting the amount of current are within the scope of the technical idea of the present invention. Of course it is possible by those with ordinary knowledge of.

The deflection yoke for the cathode ray tube according to the present invention has an advantage of reducing misconvergence generated in other parts when the misconvergence is corrected by the deflection coil itself by attaching an auxiliary coil to correct the transverse misconvergence.

In addition, there is an advantage to prevent the deterioration of landing or distortion caused by changing the distribution of the deflection coil in order to suppress misconvergence.

In addition, there is an advantage to improve the productivity by reducing the defects in the manufacture of the deflection yoke.

Claims (3)

A horizontal deflection coil and a vertical deflection coil for deflecting the electron beam in a horizontal or vertical direction, a conical ferrite core for reducing magnetic losses generated from the horizontal deflection coil and the vertical deflection coil to increase magnetic efficiency, the horizontal deflection coil, In a deflection yoke for a cathode ray tube, a deflection yoke for fixing a vertical deflection coil and a ferrite core to a predetermined position and having a holder for insulation between the horizontal deflection coil and the vertical deflection coil, A deflection yoke for a cathode ray tube, characterized in that the auxiliary coil is formed in a length direction of the vertical deflection coil within one-third position of the vertical deflection coil from the screen side and within 40 degrees of the window center of the vertical deflection coil. The method of claim 1, The auxiliary coil is a deflection yoke for a cathode ray tube, characterized in that a vertical portion is formed between 30 degrees and 40 degrees with respect to a 1/3 position of the vertical deflection coil and the window center of the vertical deflection coil. The method of claim 1, The holder is a deflection yoke for the cathode ray tube, characterized in that the groove is formed between 30 ° ~ 40 ° relative to the window center of the vertical deflection coil and 1/3 of the vertical deflection coil so that the auxiliary coil can be easily coupled.