KR20000025808A - Circuit for compensating misconvergence of deflection yoke for cathode ray tube use - Google Patents

Abstract

PURPOSE: A circuit for compensating mis convergence of a deflection yoke for a CRT(Cathode Ray Tube) use is provided to improve coma compensation efficiency, and to independently compensate YBH mis convergence and YCH mis convergence for a twelve o'clock direction and a six o'clock direction. CONSTITUTION: A circuit for compensating mis convergence of a deflection yoke for a CRT(Cathode Ray Tube) use has a first to a sixth coil which is connected in series to a vertical deflection coil of a deflection yoke in order. A first diode and first variable resistance are connected in parallel with the first and a second coil. A second diode and second variable resistance are connected with the first variable resistance in series, and are connected with a third and a fourth coil in parallel. The second diode, the second variable resistance and first resistance, third variable resistance are connected in parallel. Second resistance and a thermistor are connected between the second coil and the third coil, and between the first variable resistance and the second diode in parallel.

Description

Misconvergence correction circuit of deflection yoke for cathode ray tube

The present invention relates to a cathode ray tube, and more particularly, to a misconvergence correction circuit of a deflection yoke for a cathode ray tube.

Generally, the cathode ray tube is composed of a screen 1, a shadow mask 2, an electron gun 3, and a deflection yoke 4.

At this time, the deflection yoke 4 has a horizontal deflection coil 41 for deflecting the electron beam emitted from the electron gun 3 in the horizontal direction, a vertical deflection coil 42 for deflecting the electron beam in the vertical direction, It is surrounded by the vertical deflection coil 42 and conical to improve the magnetic efficiency by reducing the loss of magnetic force generated in the horizontal and vertical deflection coils 41 and 42 so that the electron beam can be deflected exactly on the front of the screen 1. The ferrite core 44, the horizontal deflection coil 41 and the vertical deflection coil 42 and the position of the ferrite core 44 is fixed, and between the horizontal deflection coil 41 and the vertical deflection coil 42 It consists of main parts, such as the holder 43 which insulates.

The deflection yoke 4 configured as described above flows a current having a frequency of 15.75 KHz or higher to the horizontal deflection coil 41, and deflects the electron beam inside the cathode ray tube in the horizontal direction by using the magnetic field generated thereby. The vertical deflection coil 42 is supplied with a current having a frequency of 60 Hz, and the electron beam is deflected in the vertical direction by using a magnetic field generated accordingly.

In addition, the self-convergence type allows the three electron beams to achieve convergence on the screen without using additional circuits and additional devices by using non-uniform magnetic fields by horizontal and vertical deflection coils 41 and 42. The deflection yoke 4 is mainly developed.

In other words, by adjusting the winding distribution of the horizontal and vertical deflection coils (41, 42) to create a barrel or pin cushion type magnetic field for each part (opening part, middle part, neck part) The electron beams experience different deflection forces according to their positions, allowing them to be collected at the same point at different distances from the starting point of the electron beam to the screen of the arrival point.

In addition, when a current is applied to the horizontal and vertical deflection coils 41 and 42 to create a magnetic field, it is difficult to deflect the electron beam to the front of the screen by using only the magnetic field, thereby using the ferrite core 44 of high permeability to return to the magnetic environment of the magnetic field. By minimizing the loss of the phase, the magnetic field is increased to increase the magnetic force.

However, as the TV screen (1) is flattened, enlarged and fixed, only the horizontal and vertical deflection coils 41 and 42 cannot satisfy the raster distortion and convergence characteristics simultaneously, so that the deflection yoke (4) and the cathode ray Convergence yoke 45 and a pair of ring-shaped permanent magnets 46 are attached to the neck portion of the deflection yoke 4 to correct misconvergence due to a manufacturing error of the tube.

In particular, the convergence yoke 45 has left and right symmetrical 'E' shaped iron pieces 451 and 452, and a vertical deflection coil on each leg of the iron pieces 451 and 452. It consists of coma correction coils (CF1 to CF6) of six windings connected in series.

Coma is also referred to as VCR misconvergence.

Hereinafter, a misconvergence correction circuit according to the related art will be described with reference to the accompanying drawings.

3 is a view showing the configuration of a misconvergence correction circuit according to the prior art, FIGS. 4A and 4B are views showing a magnetic field formation state by the convergence yoke of FIG. 3, and FIGS. 5A to 5C are examples of misconvergence generation examples. The figure shown.

As shown in FIG. 3, the misconvergence correction circuit according to the related art has the first and second diodes D1 and D2 in parallel with the vertical deflection coils 42 in which the resistors R1 and R2 are connected in parallel. ) Is connected to the first diode (D1), the cathode is connected to the vertical deflection coil 42, the anode is connected in series with the first and second comma correction coil (CF1) (CF2), the second diode (D2) The anode is connected with the vertical deflection coil 42 and the cathode is connected in series with the third and fourth comma correction coils CF3 and CF4.

In this case, resistors R3 and R4 are connected to the first and second diodes D1 and D2 in parallel, respectively, and a variable resistor (B) between the anode of the first diode D1 and the cathode of the second diode D2 is used. VR1) is connected.

The fifth and sixth coma correction coils CF5 and CF6 are connected in series to the second and fourth coma correction coils CF2 and CF4.

The misconvergence correction operation of the misconvergence correction circuit linked as described above is as follows.

First, when the vertical deflection current flowing through the vertical deflection coil 42 is positive, the second diode D2 is turned on so that the vertical deflection current is generated by the resistor R3, the second diode D2, and the resistor R4. Through the current flows through the first to sixth coma correction coil (CF3 ~ CF6).

Therefore, since the second diode D2 is turned on, the current flowing through the third to fourth coma correction coils CF3 and CF4 is larger than the current flowing through the first to second coma correction coils CF1 and CF2.

At this time, the generated magnetic fields B1 to B7 have a shape as shown in FIG. 4A, and the G beams of the R, G, and B electron beams are hardly moved by the B1, B6, and B7 of the magnetic fields, and are caused by B1 to B5. Since the R and B beams are moved in the 6 o'clock direction, a coma as shown in FIG. 5C is corrected.

At the same time, the R and B beams are moved left / right by B1 to B3, and the YBH misconvergence as shown in FIG. 5A is corrected.

On the other hand, when the vertical deflection current flowing through the vertical deflection coil 42 is negative, the first diode D1 is turned on so that the vertical deflection current is caused by the resistor R3, the first diode D1, and the resistor R4. Through the current flows through the first to sixth coma correction coil (CF3 ~ CF6).

Therefore, since the first diode D1 is turned on, the current flowing through the first to second coma correction coils CF1 and CF2 is greater than the current flowing through the third to fourth coma correction coils CF3 and CF4.

At this time, the generated magnetic fields B1 to B6 have a shape opposite to that of FIG. 4A as shown in FIG. 4B, and the G beams of the R, G, and B electron beams are hardly moved by B1, B6, and B7 of the magnetic fields. Since the R and B beams are moved in the 12 o'clock direction by B1 to B5, the coma as shown in FIG. 5C is corrected.

At the same time, the R and B beams are moved left / right by B1 to B3, and the YBH misconvergence as shown in FIG. 5A is corrected.

The misconvergence correction circuit of a deflection yoke for a cathode ray tube according to the prior art has the following problems.

First, since the coma correction coils are connected in parallel and the vertical deflection current is divided, the coma correction efficiency is lowered.

Second, since the 12 o'clock and 6 o'clock directions are simultaneously corrected in the YBH and YCH misconvergence, it is difficult to correct either of the two directions due to the YBH and YCH misconvergence shape characteristics.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and improves comma correction efficiency, and simultaneously allows YBH and YCH misconvergence to be independently corrected for 12 o'clock and 6 o'clock directions. The purpose is to provide a yoke misconvergence correction circuit.

1 is a cross-sectional view showing the structure of a typical cathode ray tube

2 is a front view showing the configuration of the converged yoke of FIG.

3 is a diagram illustrating a configuration of a misconvergence correction circuit according to the related art.

4A and 4B are views illustrating a magnetic field forming state by the convergence yoke of FIG. 3.

5A to 5C are diagrams showing examples of misconvergence generation;

6 is a diagram showing the configuration of a misconvergence correction circuit according to the present invention;

Explanation of symbols for main parts of the drawings

1: screen 2: shadow mask

3: electron gun 4: deflection yoke

41: horizontal deflection coil 42: vertical deflection coil

43: holder 44: ferrite core

45: Convergence York 46: Permanent Magnet

CFI to CF6: first to sixth coma correction coils

According to the present invention, in a cathode ray tube in which left / right symmetrical 'E' iron pieces, each of which first to sixth coils are wound once, are provided on the neck of the deflection yoke, the first to sixth coils are perpendicular to the deflection yoke. Sequentially connected to the deflection coil, the first diode and the first variable resistor are connected in parallel with the first coil and the second coil, and the second diode and the second variable resistor are connected with the first variable resistor in series. 3 and 4 coils are connected in parallel, the second diode and the second variable resistor and the first and third variable resistors are connected in parallel, between the second coil and the third coil, and the first variable resistor and the second coil. A second resistor and thermistor are connected in parallel between the diodes.

Hereinafter, a misconvergence correction circuit of a deflection yoke for a cathode ray tube according to the present invention will be described with reference to the accompanying drawings.

6 is a diagram showing the configuration of a misconvergence correction circuit according to the present invention.

Looking at the configuration of the misconvergence correction circuit of the deflection yoke for the cathode ray tube according to the present invention, as shown in Fig. 6, the third, fourth, first, second, fifth and third in series with the vertical deflection coil 42 Sixth coma correction coils CF3, CF4, CF1, CF2, CF5, and CF6 are sequentially connected.

The first diode D11 and the first variable resistor VR11 are connected in parallel with the third and fourth comma correction coils CF3 and CF4, and the first and second coma correction coils CF1 and CF2 are connected to each other. The second diode D22 and the second variable resistor VR22 are connected in parallel, and the resistor R14 and the third variable resistor VR33 are connected in parallel with the second diode D22 and the second variable resistor VR22. Is connected.

In addition, a resistor R13 and a thermistor Rth connected in parallel are commonly connected to the fourth comma correction coil CF4, the first coma correction coil CF1, the first variable resistance VR11, and the second diode D22. do.

Looking at the misconvergence correction operation of the misconvergence correction circuit according to the present invention configured as described above are as follows.

First, when a positive current is applied through the vertical deflection coil 42, the third, fourth, first and second coma correction coils CF3, CF4, CF1, CF2 and the first diode The vertical deflection current flows through D11) and the first variable resistor VR11, and the vertical deflection current does not flow through the second diode D22 and the second variable resistor VR22.

As described above, the magnetic field shown in FIG. 4A is formed by the vertical deflection current, wherein the first deflection resistor VR11 is adjusted to adjust the vertical deflection current flowing through the third and fourth comma correction coils CF3 and CF4. When adjusted, the magnetic fields B1, B2, B3, and B6 are adjusted so that the G beam hardly changes and the R and B beams hardly change in the Y-axis direction, while the Y-B beam of FIG. 5A changes. The misconvergence and the coma of FIG. 5C can be corrected.

On the other hand, when a negative current is applied through the vertical deflection coil 42, the third, fourth, first and second comma correction coils CF3, CFR4, CF1, CF2 and the second diode ( The vertical deflection current flows through D22) and the second variable resistor VR22, and the vertical deflection current does not flow through the first diode D11 and the first variable resistor VR11.

The magnetic field shown in FIG. 4B is formed by the vertical deflection current as described above, wherein the second deflection resistor VR22 is adjusted to adjust the vertical deflection current flowing through the first and second coma correction coils CF1 and CF2. When adjusted, the magnetic fields B1, B4, B5, and B7 are adjusted so that the G beam hardly changes, and the R and B beams hardly change in the Y-axis direction, while they change in the X-axis direction. The misconvergence and the coma of FIG. 5C can be corrected.

In addition, the third variable resistance VR33 is adjusted to change the current values flowing through the first and second coma correction coils CF1 and CF2 and the third and fourth coma correction coils CF3 and CF4, respectively. The YCH misconvergence of FIG. 5B can be corrected by varying the amount of the beam moving in the Y-axis direction when the beam moves in the 12 o'clock and 6 o'clock directions.

The misconvergence correction circuit of the deflection yoke for a cathode ray tube according to the present invention performs an independent correction for each direction when the amount of YBH and YCH misconvergence of the 12 o'clock and 6 o'clock directions is not the same as in the prior art, and a coma correction coil Since the YBH, YCH, and coma correction efficiency are greatly improved, the image quality improvement effect can be expected.

Claims (6)

In the deflection yoke for cathode ray tubes in which the left and right symmetrical 'E' iron pieces, in which the first to sixth coils are wound once, are provided on the neck of the deflection yoke, The first to sixth coils are sequentially connected in series to the vertical deflection coils of the deflection yoke, the first diode and the first variable resistor are connected in parallel with the first and second coils, and the second diode and the second variable coil. The resistor is connected in series with the first variable resistor and simultaneously connected in parallel with the third and fourth coils, the second diode and the second variable resistor, the first resistor and the third variable resistor are connected in parallel, and the second coil And a second resistor and a thermistor are connected in parallel between the third coil and the first variable resistor and the second diode in parallel. The method of claim 1, And YBH misconvergence, YCH misconvergence, or coma are corrected according to the adjustment of the first variable resistance, the second variable resistance, or the third variable resistance value. The method of claim 2, YBH and coma are corrected according to the adjustment of the first variable resistance or the second variable resistance value. The method of claim 3, If the vertical deflection current is positive, the misconvergence correction circuit of the deflection yoke for cathode ray tubes, characterized in that YBH and coma are corrected by adjusting the first variable resistance value. The method of claim 3, And the YBH and coma are corrected by adjusting the second variable resistance value when the vertical deflection current is negative. The method of claim 2, The misconvergence correction circuit of the deflection yoke for cathode ray tubes, characterized in that YCH misconvergence is corrected by adjusting the third variable resistance value.