KR100426410B1 - Circuit for compensating mis convergences of a color braun tube - Google Patents

Abstract

The present invention relates to a misconvergence correction circuit of a color CRT.

When the vertical deflection current is full-wave rectified and flowed through the pair of correction coils 15c and 15d, the current is controlled by the first variable resistor VR1a to miss the gap between the outer beams R and B that appear on the upper and lower sides of the screen. A first correction circuit 60 which first corrects the convergence YBH; When the vertical deflection current flowing through the first correction circuit 60 is full-wave rectified and flowed through the pair of correction coils 15e and 15f, the current is adjusted by the second variable resistor VR1b to display the upper and lower sides of the screen. A second correction circuit 70 for secondly correcting the misconvergence YBH between the two outer beams R and B; And a third for correcting the cross-shaped misconvergence YCH by adjusting the vertical deflection current flowing through the second correction circuit 70 to the pair of correction coils 15g and 15h by the third variable resistor VR3. Comprising a correction circuit 80,

Accordingly, the misconvergence (YBH, YCH) between the outer beams (R, B) appearing on the screen can be easily adjusted, and the outer beams (R, B) are displayed at the center of the screen when correcting the cross-shaped misconvergence (YCH). It is possible to prevent misconvergence spaced apart from the intermediate portion between the and top and bottom.

Description

CIRCUIT FOR COMPENSATING MIS CONVERGENCES OF A COLOR BRAUN TUBE}

The present invention relates to a misconvergence correction circuit of a color CRT, and more particularly, two outer beams R and B are spaced apart from each other in a horizontal direction at an intermediate portion between a screen center portion and an upper side and a middle portion between a screen center portion and a lower side. The present invention relates to a misconvergence correction circuit of a color CRT for correcting misconvergence.

Referring to FIG. 1, in the general color CRT 10, an electron beam of three colors (R, G, B) emitted from the electron gun 11 is deflected in the vertical / horizontal direction by the deflection yoke 12 and the shadow mask 13 When it hits a specific point, the screen 14 displays a color screen by reproducing a specific light. The deflection yoke 12 includes a vertical deflection coil 12a, a horizontal deflection coil 12b, and the vertical direction. Conical ferrite core 12c for reducing the magnetic force generated in the deflection coil 12a to increase the magnetic efficiency, and the holder 12d for insulating between the vertical / horizontal deflection coils (12a, 12b).

In addition, various forms of misconvergence due to manufacturing errors of the deflection yoke 12 and the color CRT 10 appear on the screen displayed on the screen 14. Compensated by a convergence yoke 15 and a pair of ring-shaped permanent magnets 16 installed in the neck, ie, the upper and lower symmetry, with reference to FIG. 2, the convergence yoke 15. The four correction coils 15c, which are wound around the bobbin 15b surrounding the iron piece 15a, the bobbin 15b, and the bobbin 15b, which are stacked in three to four sheets, form a four-pole or two-pole magnetic field. 15d, 15e, 15f).

In particular, in order to correct various types of misconvergence caused by the manufacturing error of the deflection yoke 12 and the color CRT 10 by the convergence yoke 15, the vertical misalignment correction circuit is used by using a known misconvergence correction circuit. The current flowing through the correction coils 15c, 15d, 15e, and 15f was adjusted via the deflection coil 12a.

Referring to FIG. 3, the conventional misconvergence correction circuit includes a vertical deflection coil unit 20, a conversion coil unit 30, a rectifier circuit unit 40, and a variable resistor unit 50.

The vertical deflection coils 20 are connected to each other in series and have a pair of vertical deflection coils 12a and 12a 'through which a vertical deflection current flows, and the pair of vertical deflection coils 12a and 12a' connected to each other in series. It is composed of a pair of resistors (R1, R2) connected in parallel with respect to), the connection point (a) of the pair of vertical deflection coils (12a, 12a ') and the pair of resistors (R1, R2) The connection point (b) of is shorted.

The conversion coil unit 30 is connected to each other in series and the first pair of correction coils (15c, 15d) through which the vertical deflection current is full-wave rectified and the second pair of serially connected and the vertical deflection current flows It consists of correction coils 15e and 15f.

The rectifier circuit 40 is composed of the first pair of diodes D1 and D4 connected to each other and the second pair of diodes D2 and D3 connected to the cathodes of each other to form a diode bridge to form the vertical deflection current. Full-wave rectification.

The variable resistor unit 50 has a first pair of correction coils 15c and 15d of the conversion coil unit 30 connected between an intermediate tap and one end thereof, and the first pair of diodes D1 and D4. A first variable resistor VR1 connected between the positive connection point c and the negative connection point d of the second pair of diodes D2 and D3 to adjust a current flowing through the first pair of correction coils 15c and 15d. ), A protection resistor (R3) and a thermistor (Rth) connected in parallel with the first variable resistor (VR1) between the positive connection point (c) and the negative connection point (d) to protect the rectifier circuit portion 40, An intermediate tap is connected in series with the positive connection point c and the first variable resistor VR1 and connected in parallel with the first pair of diodes D1 and D4 to connect the second pair of correction coils 15e, A second variable resistor VR2 for adjusting the current flowing through 15f) and a protection resistor R4 connected in parallel with the second variable resistor VR2 to protect the circuit.

The conventional misconversion correction circuit configured as described above operates as follows.

4 to 7, the misconvergence that appears on the screen of the screen 14 due to the manufacturing error of the deflection yoke 12 and the color CRT 10 is as shown in FIG. 4A. The misconvergence (YBH) between the two outer beams (R, B) appearing on the upper and lower sides of the screen by the magnetic field generated by the vertical deflection current, and the manufacturing error of the CRT as shown in Fig. 4B. Due to the misconvergence (YCH) between the two outer beams (R, B) appearing in the cross shape due to the above, the magnetic field generated by the vertical deflection current as shown in (c) of FIG. There is a misconvergence (VCR) between the center beam G and the outer beams R and B that appear.

As shown in FIG. 4A, the misconvergence YBH between the two outer beams R and B, which appear on the upper and lower sides of the screen due to the magnetic field generated by the vertical deflection current, is formed in the rectifier circuit 40. Is corrected by flowing the electric wave rectified by the current through the first variable resistor VR1 of the variable resistor unit 50 to the first pair of correction coils 15c and 15d of the conversion coil unit 30. . At this time, the waveform of the vertical deflection current applied to the rectifier circuit portion 40 and the full-wave rectified current by the rectifier circuit portion 40 is a waveform as shown in (a) and (b) of FIG.

If the vertical deflection current indicates positive polarity, diodes D1 and D2 of the diode bridge are on and D3 and D4 are off, so that the vertical deflection current propagated along the arrow indicated by the thin dotted line in FIG. Flows to the correction coils 15c and 15d, and when the vertical deflection current shows negative (-), the diodes D1 and D2 of the diode bridge are turned off and D3 and D4 are turned on. A vertical deflection current flows into the first pair of correction coils 15c and 15d.

As described above, when the first variable resistor VR1 is adjusted when a current flows in a predetermined direction regardless of the polarity of the vertical deflection current through the first pair of correction coils 15c and 15d, the convergence yoke 15 is shown in FIG. As shown in Fig. 6, a four-pole magnetic field is generated in which the direction of the magnetic field does not change to generate magnetic fields B1 and B2. Accordingly, the forces F1 and F2 are applied to the two outer beams R and B appearing on the upper and lower sides of the screen. As shown in Fig. 4A, the misconvergence YBH between the two outer beams R and B, which are spaced horizontally from the upper and lower sides of the screen, is corrected.

As shown in (b) of FIG. 4, the misconvergence (YCH) between two outer beams (R, B) appearing in the cross shape due to the manufacturing error of the CRT is as shown in (a) of FIG. In order to correct the misconvergence (YBH), the second variable resistor (VR2) is simultaneously adjusted to adjust the correction amount by adjusting the first variable resistor (VR1) of the variable resistor unit (50).

That is, by adjusting the second variable resistor VR2 together with the first variable resistor VR1, when the vertical deflection current is positive (+) and negative (-), The cross-shaped misconvergence YCH is corrected by adjusting so that the full-wave rectified currents flowing through the pair of correction coils 15c and 15d are not equal to each other.

In fact, when the second variable resistor VR2 is adjusted together with the first variable resistor VR1, when the vertical deflection current is positive, some of the current passing through the second variable resistor VR2 is shown in FIG. 3. A part of the current passing through the second variable resistor VR2 when the vertical deflection current is negative (-) flows to the first pair of correction coils 15c and 15d along the arrow indicated by the thick solid line. Flows to the first pair of correction coils 15c and 15d along an arrow indicated by a thick dotted line of the crossover shape, and thus the amount of correction of misconvergence YBH as shown in FIG. The misconvergence (YCH) of is corrected.

As shown in (c) of FIG. 4, the misconvergence VCR between the center beam G and the outer beams R and B, which appear on the upper and lower sides of the screen due to the magnetic field generated by the vertical deflection current, is variable. The vertical deflection current of the second pair of correction coils 15e and 15f of the conversion coil unit 30 connected in series with the second variable resistor VR2 through the second variable resistor VR2 of the resistor unit 50. Adjust it by letting it flow.

If the vertical deflection current indicates positive polarity, a bipolar magnetic field is generated in the convergence yoke 15 to generate magnetic fields B3 and B4, and forces F3, F4, and F5 act. Accordingly, the center beam G receives a stronger magnetic field than the two outer beams R and B at the upper side of the screen, and thus the misconvergence between the center beam G and the outer beams R and B appearing at the upper side of the screen. (VCR) is corrected.

On the other hand, if the vertical deflection current indicates a negative polarity (-), the convergence yoke 15 generates a two-pole magnetic field opposite to the two-pole magnetic field shown in FIG. 7, and accordingly, a center beam appearing on the upper side of the screen. In accordance with the principle that the misconvergence (VCR) between (G) and the outer beams (R, B) is corrected, the misconvergence (VCR) between the center beam (G) and the outer beams (R, B) appearing on the lower side of the screen. Is corrected.

However, in the conventional misconvergence correction circuit as described above, in order to correct the misconvergence YBH as shown in FIG. 4A, the first variable resistor VR1 of the variable resistor unit 50 is provided. When adjusting the correction amount by adjusting the second variable resistance VR2 together to correct, the cross-shaped misconvergence YCH can be corrected as shown in (b) of FIG. 4, but the second As shown in FIG. 3, the current Ia flowing through the protection resistor R4 of the variable resistor unit 50 and the current Ib flowing through the second variable resistor VR2 are shown in FIG. 3 according to the adjustment state of the variable resistor VR2. And two outer beams appearing on the upper and lower sides of the screen by the magnetic field generated by the vertical deflection current as shown in FIG. 4A because the current Ic applied to the rectifying circuit part 40 is different. The misconvergence (YBH) between (R, B) and the bra as shown in (b) of FIG. The first variable resistor VR1 and the second variable resistor VR2 are adjusted in order to correct the misconvergence YCH between the two outer beams R and B appearing in a cross shape due to the manufacturing error of the tube. The disadvantage is that you have to adjust it once.

In particular, when the second variable resistor VR2 is adjusted to allow a large amount of current to flow through the first pair of correction coils 15c and 15d of the conversion coil unit 50 when the vertical deflection current is positive. The cross-shaped misconvergence (YCH) can be corrected, but the voltage applied to the diode bridge of the rectifying circuit unit 50 is different, and as shown in FIG. 8, the middle portion between the screen center portion A and the upper portion D is shown. (BC) and a misconvergence (also referred to as a “ice” phenomenon) in which two outer beams R and B are spaced apart from each other in the horizontal direction in the middle between the center and the bottom of the screen are severely generated.

Accordingly, an object of the present invention is to overcome the above-described problems, and an object of the present invention is to provide a vertical deflection current using first and second compensation circuits connected in series and having different cut-in voltages. Correct the misconvergence (YBH) between the two outer beams (R, B) appearing on the upper and lower sides of the screen by the magnetic field generated by the magnetic field, and using a third correction circuit separately connected to the rear end of the second correction circuit. A misconvergence correction circuit of a color CRT is provided to correct a misconvergence (YCH) between two outer beams R and B appearing in a cross shape due to a manufacturing error of the CRT.

The misconvergence correction circuit of a color CRT for achieving the object of the present invention is a first variable when a vertical deflection current applied from a conventional vertical deflection coil portion is full-wave rectified by a diode bridge and flows into a pair of correction coils. A first correction circuit for first adjusting a current by a resistor to first correct the misconvergence YBH between two outer beams R and B appearing on the upper and lower sides of the screen by a magnetic field generated by a vertical deflection current; A diode bridge connected in series with the first compensation circuit and having a cut-in voltage having a higher cut-in voltage than the diode bridge of the first compensation circuit, the vertical deflection current applied via the first compensation circuit. When full-wave rectified and flowed into a pair of correction coils, the current is controlled by a second variable resistor, and between two outer beams R and B appearing on the upper and lower sides of the screen by a magnetic field generated by a vertical deflection current. A second correction circuit for secondly correcting the misconvergence YBH; And a third deflection resistor connected in series with the second compensation circuit and adjusting the vertical deflection current flowing through the second compensation circuit by the third variable resistor to appear in a cross shape due to a manufacturing error of the CRT. And a third correction circuit for correcting the misconvergence YCH between the two outer beams R, B.

1 is a block diagram showing a color CRT,

FIG. 2 is a configuration diagram illustrating the convergence yoke illustrated in FIG. 1;

3 is a block diagram showing a conventional misconvergence correction circuit;

4 is a block diagram showing misconvergence appearing on a screen of a screen;

5 is a waveform diagram showing a current obtained by full-wave rectification of the vertical deflection current and the vertical deflection current;

6 is a configuration diagram showing a 4-pole magnetic field generated in a convergence yoke as a conventional misconvergence correction circuit operates.

7 is a configuration diagram showing a two-pole magnetic field generated in a convergence yoke as a conventional misconvergence correction circuit operates.

FIG. 8 is a diagram illustrating a misconvergence of two outer beams spaced apart from each other in a horizontal direction between a screen center and an upper side of the screen and between a screen center and a lower side of the screen;

9 is a block diagram showing a misconvergence correction circuit of a color CRT according to the present invention;

FIG. 10 is a waveform diagram showing a vertical deflection current and cut-in voltage of diodes forming a diode bridge of a first compensation circuit and a second compensation circuit;

11 is a waveform diagram showing a current flowing through a correction coil of a first conversion coil unit and a second conversion coil unit;

12 is a configuration diagram showing a state in which three pairs of correction coils are wound on a bobbin of a converged yoke;

13 is a configuration diagram showing misconvergence appearing on a screen of a screen;

14 is a block diagram showing a 4-pole magnetic field generated in the convergence yoke as the misconvergence correction circuit according to the present invention operates.

15 is a block diagram showing a two-pole magnetic field generated in the convergence yoke as the misconvergence correction circuit according to the present invention operates.

<Explanation of symbols for the main parts of the drawings>

10: color CRT 11: electron gun

12: Deflection York 13: Shadow Mask

14: Screen 15: Convergence York

16: permanent magnet 20: vertical deflection coil portion

30: conversion coil part 40: rectifier circuit part

50: variable resistor 60: first correction circuit

70: second correction circuit 80: third correction circuit

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

Referring to FIG. 9, the first compensation circuit 60 carries out a full-wave rectification of the vertical deflection current applied from the conventional vertical deflection coil portion 20 by a diode bridge and flows it to the pair of correction coils 15c and 15d. When the current is adjusted by the first variable resistor VR1a, the misconvergence YBH between the two outer beams R and B appearing on the upper and lower sides of the screen by the magnetic field generated by the vertical deflection current is primarily used. Correct it.

The first conversion coil unit 30a of the first correction circuit 60 is composed of a pair of correction coils 15c and 15d in which the vertical deflection current is full-wave rectified and connected in series.

The first rectifier circuit 40a of the first compensation circuit 60 includes a first pair of diodes D5 and D8 connected to the anodes of each other and a second pair of diodes D6 and D7 connected to the cathodes of each other. To form a diode bridge to full-wave rectify the vertical deflection current.

The first variable resistor unit 50a of the first compensation circuit 60 has a positive connection point c1 of the first pair of diodes D5 and D8 and a negative connection point of the second pair of diodes D6 and D7 ( The first variable resistor VR1a connected between d1) regulates a current flowing through the pair of correction coils 15c and 15d, and the first variable resistor between the positive connection point c1 and the negative connection point d1. A protection resistor R3a and a thermistor Rth1 connected in parallel with VR1a protect the first rectifier circuit 40a, and a protection resistor R4a through which a vertical deflection current flows is connected to the first pair of diodes D5, D8) is connected in parallel.

The second compensation circuit 70 is connected in series with the first compensation circuit 60, and the diode bridge of the first compensation circuit 60 receives a vertical deflection current applied through the first compensation circuit 60. When the wave is rectified by a diode bridge having a relatively large cut-in voltage and flows through a pair of correction coils 15e and 15f, the current is controlled by the second variable resistor VR1b to vertically deflect. The misconvergence YBH between the two outer beams R and B appearing on the upper and lower sides of the screen is secondarily corrected by the magnetic field generated by the current.

The second conversion coil portion 30b of the second correction circuit 70 is composed of a pair of correction coils 15e and 15f in which the vertical deflection current is full-wave rectified and flows in series.

The second rectifying circuit part 40b of the second compensation circuit 70 includes a first pair of diodes D9 and D10 connected to the anodes of each other and a second pair of diodes D11 and D12 connected to the cathodes of each other. To form a diode bridge to full-wave rectify the vertical deflection current.

The second variable resistance unit 50b of the second compensation circuit 70 has a positive connection point c2 of the first pair of diodes D9 and D10 and a negative connection point d2 of the second pair of diodes D11 and D12. The second variable resistor VR1b connected between the second and second variable resistors VR1b controls the current flowing through the pair of correction coils 15e and 15f, and the second variable resistor between the positive connection point c2 and the negative connection point d2. A protection resistor R3b and a thermistor Rth2 connected in parallel with VR1b protect the second rectifier circuit 40b, and a protection resistor R4b through which a vertical deflection current flows is connected to the first pair of diodes D9 and D10. ) Are connected in parallel.

Referring to FIG. 10, the vertical deflection current applied to the first and second rectifier circuits 40a and 40b is represented by a waveform as shown in FIG. 10A, and as shown in FIG. Conventional misconvergence (also referred to as “bing”) in which the two outer beams R and B are spaced apart from each other in the horizontal direction at the middle part BC between A) and the upper side D and at the middle part between the screen center and the lower side. Cut-in voltages of the diodes D9 to D12 forming the diode bridge of the second rectifying circuit portion 40b to correct the " phenomena " (D) is set to be relatively larger than the cut-in voltage B of the diodes D5 to D8 forming the diode bridge of the first rectifying circuit portion 40a.

Referring to FIG. 11, a pair of correction coils 15c and 15d of the first conversion coil unit 30a and the second conversion coil unit are full-wave rectified by the first and second rectifying circuit units 40a and 40b. The current flowing through each of the pair of correction coils 15e and 15f of 30b is represented by a waveform as shown in FIG. 11A, and in fact, the pair of correction coils 15c, 15d, 15e, and 15f. As shown in FIG. 11 (b), the current flowing in is represented by a waveform in which the two currents shown in FIG.

The third compensation circuit 80 is connected in series with the second compensation circuit 70, and receives a vertical deflection current flowing through a pair of correction coils 15g and 15h via the second compensation circuit 70. By adjusting by the triad resistance VR3, the misconvergence YCH between the two outer beams R and B appearing in the cross shape due to the manufacturing error of the CRT is corrected.

The third compensation circuit 80 is connected to each other in series and the third variable resistor VR3 having an intermediate tap connected to the connection point e of the pair of correction coils 15g and 15h through which the vertical deflection current flows. Are connected in parallel to the correction coils 15g and 15h to adjust the current flowing through the pair of correction coils 15g and 15h.

Referring to FIG. 12, three pairs of correction coils 15c, 15d, 15e, 15f, 15g, and 15h included in the first, second, and third correction circuits 60, 70, and 80, respectively, are conventional convergence yokes ( The bobbin 15b of 15 is wound in triplicate to form a 4-pole or 2-pole magnetic field.

The misconvergence correction circuit of the color CRT according to the present invention configured as described above operates as follows.

First, as shown in FIG. 13, the misconvergence YBH between two outer beams R and B appearing on the upper and lower sides of the screen by the magnetic field generated by the vertical deflection current is determined by the first correction circuit 60. A pair of correction coils of the first conversion coil unit 30a through the first variable resistor VR1a of the first variable resistor unit 50a. 15c, 15d) to correct first.

In this case, when the vertical deflection current indicates positive polarity, diodes D5 and D6 of the diode bridge are turned on and D7 and D8 are turned off, so that the vertical deflection current propagated along the arrow indicated by the dotted line in FIG. When the vertical deflection current flows to the coils 15c and 15d and the negative current is negative, the diodes D5 and D6 of the diode bridge are turned off and D7 and D8 are on, so that the vertical deflection rectified along the arrow indicated by the solid line in FIG. Current flows through the pair of correction coils 15c and 15d.

As described above, when the first variable resistor VR1a is adjusted when a current flows in a predetermined direction regardless of the polarity of the vertical deflection current to the pair of correction coils 15c and 15d, the convergence yoke 15 shown in FIG. In Fig. 14, a four-pole magnetic field is generated in which the direction of the magnetic field does not change, thereby generating magnetic fields B1 and B2. Accordingly, the force F1 is applied to the two outer beams R and B appearing on the upper and lower sides of the screen. When F2 and F2 act, the misconvergence YBH between the two outer beams R and B, which are spaced horizontally from the top and bottom sides of the screen, is first corrected.

If the current flowing through the pair of correction coils 15c and 15d of the first conversion coil unit 30a is adjusted by adjusting the first variable resistor VR1a of the first correction circuit 60 as described above, FIG. 13. As shown in (a) of FIG. 13, the misconvergence YBH between two outer beams R and B spaced horizontally from the top and bottom sides of the screen is first shown as shown in FIG. Although it can be corrected, as shown in (b) of FIG. 4, the middle part BC between the screen center part A and the upper side D and the middle part between the screen center part and the lower part 2 There is a misconvergence (also called "ice" phenomenon) in which the outer beams R and B are spaced apart from each other in the horizontal direction.

Therefore, the second diode is formed of diodes D5 to D8 having a cut-in voltage relatively smaller than those of the diodes D9 to D12 forming the diode bridge of the second compensation circuit 70. As shown in FIG. 13A, the first compensation circuit 60 is operated primarily at the “B point” of the screen to between the two outer beams R and B spaced apart in the horizontal direction from the upper and lower sides of the screen. After first correcting the misconvergence of YBH as shown in Fig. 13B, the second correction circuit 60 is operated to make a second correction based on the "C point". As shown in (b) of the drawing, two outer beams R and B are horizontally oriented at the middle portion BC between the screen center portion A and the upper side D and the middle portion between the screen center portion and the lower side. The conventional misconvergence (also called "ice" phenomenon) appearing apart from each other is corrected.

In this case, the operation principle of the second compensation circuit 70 is the same as the operation principle of the first compensation circuit 60, and in fact, when the first compensation circuit 60 and the second compensation circuit 70 is operated, As shown in (b) of FIG. 11, less current flows in comparison with the vertical deflection current at the "C point" than the "B point and" D point "of the screen shown in (A) of FIG. The conventional misconvergence (also called "ice" phenomenon) as shown is corrected.

On the other hand, as shown in (b) of FIG. 4, the misconvergence (YCH) between the two outer beams (R, B) appearing in the cross shape due to the manufacturing error of the CRT and the (C) of FIG. As described above, the misconvergence (VCR) between the center beam (G) and the outer beams (R, B) appearing on the upper and lower sides of the screen by the magnetic field generated by the vertical deflection current is one pair of the third correction circuit (80). The vertical deflection current flowing through the correction coils 15g and 15h is adjusted by adjusting the third variable resistor VR3.

If the vertical deflection current indicates positive polarity, a bipolar magnetic field is generated in the convergence yoke 15 to generate magnetic fields B3 and B4, and forces F3, F4, and F5 act. . At this time, in the upper side of the screen, the center beam G is moved by the force F4 acting in the direction perpendicular to the magnetic field B3 and the two outer beams R and B are moved by forces F3 and F5 acting in the direction perpendicular to the magnetic field B3. In particular, since the center beam (G) receives a stronger magnetic field than the two outer beams (R, B), as shown in (c) of FIG. 4, the center beam (G) and the outer edge appearing from the upper side of the screen. The misconvergence VCR between the beams R and B is corrected.

In addition, referring to Figure 15 it can be seen that the force acts in the horizontal direction as well as the vertical direction for the two outer beams (R, B), the two outer beams (R, B) in the horizontal direction As shown in Fig. 4B, a misconvergence YCH is generated between the two outer beams R and B, which appear in the cross shape due to the manufacturing error of the CRT. At this time, the third variable resistor VR3 is adjusted to appropriately vary the current flowing through the pair of correction coils 15g and 15h to adjust the degree of movement of the two outer beams R and B in the horizontal direction. The cross-shaped misconvergence (YCH) as shown in Fig. 4B is corrected.

As described above, the misconvergence correction circuit of the color CRT according to the present invention is connected to the magnetic field generated by the vertical deflection current using the first and second correction circuits connected in series and having different cut-in voltages. By correcting the misconvergence (YBH) between the two outer beams (R, B) appearing on the upper and lower sides of the screen, and by using a third correction circuit connected to the rear end of the second correction circuit separately to the manufacturing error of the color CRT Due to the correction of the misconvergence YCH between the two outer beams R and B appearing in the cross shape, the outer beams R and B appearing on the upper and lower sides of the screen as compared with the conventional misconvergence correction circuit. It is possible to easily adjust the misconvergence (YBH) between the cross-shaped misconvergence (YCH), and in particular, correct the cross-shaped misconvergence (YCH) in the conventional misconvergence correction circuit. There is an advantage that can prevent the "bing" phenomenon that occurs when.

What has been described above is only one embodiment for implementing the misconvergence correction circuit of the color CRT according to the present invention, and the present invention is not limited to the above-described embodiment, but is not limited to the above-described claims. Without departing from the gist of the present invention, one of ordinary skill in the art will have the technical spirit of the present invention to the extent that various modifications can be made.

Claims (5)

When the vertical deflection current applied from the conventional vertical deflection coil portion 20 is full-wave rectified by the diode bridge and flows to the pair of correction coils 15c and 15d, the current is adjusted by the first variable resistor VR1a. A first correction circuit 60 for firstly correcting the misconvergence YBH between the two outer beams R and B appearing on the upper and lower sides of the screen by the magnetic field generated by the vertical deflection current; The vertical deflection current, which is connected in series with the first compensation circuit 60 and is applied via the first compensation circuit 60, is cut relative to the diode bridge of the first compensation circuit 60. in) When full-wave rectification is carried out by a diode bridge with a large voltage and flows to a pair of correction coils 15e and 15f, the current is regulated by the second variable resistor VR1b to control the current by the magnetic field generated by the vertical deflection current. A second correction circuit 70 for second-correcting the misconvergence YBH between two outer beams R and B appearing on the upper and lower sides of the screen; And A third deflection current VR3 is connected in series with the second compensation circuit 70 and flows through the second compensation circuit 70 through a pair of correction coils 15g and 15h. A third correction circuit 80 for adjusting and correcting the misconvergence YCH between the two outer beams R and B, which appear in the cross shape due to the manufacturing error of the CRT. Misconvergence correction circuit of a color CRT. The method of claim 1, wherein the first correction circuit (60) A first conversion coil portion (30a) composed of a pair of correction coils (15c, 15d) in which the vertical deflection current flows in full-wave rectification and connected in series; The first rectification is composed of a first pair of diodes (D5, D8) connected to each other and a second pair of diodes (D6, D7) connected to the cathodes of each other to form a diode bridge to full-wave rectify the vertical deflection current. Circuit portion 40a; And The first variable resistor VR1a connected between the anode connection point c1 of the first pair of diodes D5 and D8 and the cathode connection point d1 of the second pair of diodes D6 and D7 is corrected in the pair. The current flowing through the coils 15c and 15d is controlled, and the protection resistor R3a and thermistor Rth1 connected in parallel with the first variable resistor VR1a are connected between the positive connection point c1 and the negative connection point d1. The first variable resistance part 50a which protects the first rectifier circuit part 40a and has a protection resistor R4a through which a vertical deflection current flows is connected in parallel to the first pair of diodes D5 and D8. Misconvergence correction circuit of a color CRT. The method of claim 1, wherein the second correction circuit 70 A second conversion coil portion (30b) comprising a pair of correction coils (15e, 15f) in which the vertical deflection current flows in full-wave rectification and connected in series; The second rectification is composed of the first pair of diodes (D9, D10) connected to the anode of each other and the second pair of diodes (D11, D12) connected to the cathode of each other to form a diode bridge to full-wave rectify the vertical deflection current. Circuit portion 40b; And The second variable resistor VR1b connected between the anode connection point c2 of the first pair of diodes D9 and D10 and the cathode connection point d2 of the second pair of diodes D11 and D12 is corrected in the pair. The current flowing through the coils 15e and 15f is controlled, and a protective resistor R3b and a thermistor Rth2 connected in parallel with the second variable resistor VR1b are connected between the positive connection point c2 and the negative connection point d2. The second variable resistance part 50b which protects the second rectifier circuit part 40b and has a protection resistor R4b through which a vertical deflection current flows is connected in parallel to the first pair of diodes D9 and D10. Misconvergence correction circuit of a color CRT. The method of claim 1, wherein the third correction circuit (80) A third variable resistor VR3 connected to the connection point e of the pair of correction coils 15g and 15h connected in series with each other and having a vertical deflection current flows is connected to the pair of correction coils 15g and 15h. And a converging correction circuit for color CRT, characterized in that the current flowing through a pair of correction coils (15g, 15h) is connected in parallel. The diodes D5 of claim 2 or 3, wherein the diodes D9 to D12 forming the diode bridge of the second rectifying circuit portion 40b form the diode bridge of the first rectifying circuit portion 40a. Cut-in voltage is relatively larger than ~ D8).