KR20000025809A - 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 independently compensate upper sides and lower sides of a tilt and YV mis convergence. CONSTITUTION: A circuit for compensating mis convergence of a deflection yoke for a CRT(Cathode Ray Tube) use comprises: a first and a second vertical deflection coil connected in series; a first diode to which an anode is connected through the first vertical deflection coil and resistance; first variable resistance connected with a cathode of the first diode; a second diode to which the cathode is connected with the first variable resistance; second variable resistance which one end is connected with the anode of the second diode, and which the other end is connected with the second vertical deflection coil through resistance. Upper sides and lower sides of a tilt and YV mis convergence are independently compensated, according to adjustments of the first variable resistance and the second variable resistance.

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 is 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 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 ferrite core 44 is fixed to the position 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.

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

2 is a view showing a configuration of a misconvergence correction circuit of a deflection yoke according to the related art, FIGS. 3A and 3C are views showing a magnetic field formed by a vertical deflection coil, and FIGS. 4A to 4B are examples of generating tilt misconvergence. 5A to 5B are diagrams showing examples of YV misconvergence generation.

The configuration of the misconvergence correction circuit of the deflection yoke according to the related art is in parallel through the series of vertical deflection coils 42-1 and 42-2 and resistors R1 and R2 connected in series, as shown in FIG. The first variable resistor VR1 connected, the first diode D1 connected to one end of the first variable resistor VR1, and the cathode and the cathode of the first diode D1 are connected, and the anode is connected to the first variable resistor VR1. The second diode D2 connected to the other end of the first variable resistor VR1, the third diode D3 connected to the anode and the cathode of the second diode D2, and the anode and edge of the third diode D3. A fourth diode D4 connected to a node and a cathode connected to an anode of the first diode D1, a cathode connection line of the first and second diodes D1 and D2, and a third and fourth diode ( The second variable resistor VR2 is connected to both ends of the anode connection line of D3) (D4).

In this case, the variable contacts of the first and second variable resistors VR1 and VR2 are commonly connected to the connection lines of the vertical deflection coils 42-1 and 42-2.

The misconvergence correction operation of the misconvergence correction circuit of the deflection yoke according to the related art thus constructed is as follows.

Part of the current flowing through the vertical deflection coils 42-1 and 42-2 flows through the resistors R1 and R2, and part of the first and third diodes D1 when the vertical deflection current is positive. (D3) flows through the second and fourth diodes (D2) and (D4) when the vertical deflection current is negative, and the first variable resistor (VR1) when the vertical deflection current is positive. If the value is set to an intermediate value, a uniform magnetic field is formed as shown in FIG. 3A.

At this time, by adjusting the value of the first variable resistance VR1 to increase the value of the current flowing in the vertical deflection coil 42-2 rather than the vertical deflection coil 42-1, a magnetic field as shown in FIG. 3B is formed. When the magnetic field is formed, the R beam is larger than the B beam so that the deflection amounts are different from each other when moved in the 12 o'clock direction. Thus, the tilt misconvergence as shown in FIG. 4A is corrected.

On the contrary, when the value of the current flowing through the vertical deflection coil 42-1 is increased by adjusting the value of the first variable resistance VR1, the magnetic field as shown in FIG. 3C is formed. When the magnetic field is formed, the B beam is larger than the R beam so that the movement amount is different when moving in the 12 o'clock direction, so that the tilt misconvergence as shown in FIG. 4B is corrected.

In addition, when the vertical deflection current is negative, the direction of the magnetic field is reversed. Therefore, if the first variable resistance VR1 is adjusted in the same manner as the vertical deflection current is positive, the direction of the magnetic field is reversed. Tilt misconvergence such as

Meanwhile, when the YV misconvergence as shown in FIG. 5A or 5B occurs, the direction of the magnetic field should not be changed regardless of the vertical deflection current positive or negative, so that the first variable resistance VR2 is adjusted to adjust the first variable. YV misconvergence as shown in FIG. 5A or 5B is corrected by causing the vertical deflection current to be full-wave rectified by the fourth to fourth diodes D1 (D2) (D3) (D4).

The misconvergence correction circuit of the deflection yoke for a cathode ray tube according to the prior art has to correct the tilt misconvergence by adjusting the first variable resistance and adjust the YV misconvergence by adjusting the second variable resistance, which is a complicated and step-by-step correction process. There is a problem that the correction efficiency is lowered due to the correction.

Accordingly, an object of the present invention is to provide a misconvergence correction circuit for a deflection yoke for a cathode ray tube that can easily and accurately correct tilt and YV misconvergence.

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

2 is a diagram showing a configuration of a misconvergence correction circuit of a deflection yoke according to the related art.

3a and 3c show magnetic fields formed by vertical deflection coils

4A to 4B show examples of tilt misconvergence

5A to 5B show examples of YV misconvergence generation

6 is a diagram showing the configuration of a misconvergence correction circuit of a deflection yoke 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

The present invention relates to a cathode yoke deflection yoke, comprising: first and second vertical deflection coils connected in series, a first diode connected to an anode through a resistance and a first vertical deflection coil, and a first variable connected to a cathode of the first diode. And a second variable resistor connected to the resistor, the first variable resistor and the cathode, and a second variable resistor connected to one end of the anode of the second diode and connected to the second vertical deflection coil through the resistor.

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.

Fig. 6 is a diagram showing the configuration of the misconvergence correction circuit of the deflection yoke 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 vertical deflection coils 42-1 of the vertical deflection coils 42-1 and 42-2 connected in series are shown. A first diode D11 connected with an anode through a resistor R1, a first variable resistor VR11 connected with a cathode of the first diode D11, and a first diode connected with a cathode of the first variable resistor VR11. One end of the second diode D22 and an anode of the second diode D22 is connected to the second diode D22 and the other end of the second variable resistor VR22 is connected to the vertical deflection coil 42-2 through a resistor.

The misconvergence correction operation of the misconvergence correction circuit of the deflection yoke according to the present invention configured as described above is as follows.

First, when a positive current is applied, a vertical deflection current flows through the vertical deflection coils 42-1 and 42-2, the first diode D11, and the first variable resistor VR11, and the second diode ( D22) and the second variable resistor VR22 prevent the vertical deflection current from flowing.

At this time, if the amount of current flowing through the vertical deflection coil 42-2 is greater than the amount of current flowing through the vertical deflection coil 42-1 by adjusting the first variable resistor VR11, a magnetic field as shown in FIG. Since the deflection amount of the R beam is larger, only the upper misconvergence of the misconvergence as shown in FIGS. 4A and 5A can be independently corrected.

In addition, if the value of the current flowing in the vertical deflection coil 42-1 is made larger by adjusting the value of the first variable resistance VR11, the magnetic field is formed as shown in FIG. 3C. Since the deflection amount of the B beam becomes larger than the R beam, only the upper misconvergence of the misconvergence as shown in FIGS. 4B and 5B can be independently corrected.

On the other hand, when a negative current is applied, a vertical deflection current flows through the vertical deflection coils 42-1 and 42-2, the second diode D22, and the second variable resistor VR22, and the first diode ( D11) and the first variable resistor VR11 prevent the vertical deflection current from flowing.

At this time, the second variable resistor VR22 is adjusted in the same manner as the case where the vertical deflection current is positive (+), and the amount of current flowing through the vertical deflection coil 42-1 and the amount of current flowing through the vertical deflection coil 42-2. Differently, since the magnetic field in the opposite direction of the magnetic field is formed in the same form as in FIG. 3B or 3C, and the deflection amounts of the B beam and the R beam are different, the lower misconvergence of the lower convergence of FIGS. 4A to 5B is independently You can correct it.

The misconvergence correction circuit of the deflection yoke for cathode ray tubes according to the present invention has the following effects.

First, since the upper and lower sides of the tilt and YV misconvergence are independently corrected, misconvergence correction is easy and the correction efficiency is improved.

Second, unlike the prior art, since only two diodes are used, the convergence effect due to drift is reduced and the manufacturing cost can be lowered.

Claims (4)

In deflection yoke for cathode ray tube, First and second vertical deflection coils connected in series; A first diode having an anode connected to the first vertical deflection coil and a resistor; A first variable resistor connected to the cathode of the first diode; A second diode to which the first variable resistor and the cathode are connected; And a second variable resistor having one end connected to an anode of the second diode and the other end connected to a second vertical deflection coil through a resistor. The method of claim 1, The upper and lower sides of the tilt and YV misconvergence are independently corrected according to the adjustment of the first variable resistance or the second variable resistance. The method of claim 2, If the vertical deflection current is positive, the misconvergence correction circuit of the cathode yoke for the cathode ray tube, characterized in that the upper side misconvergence of the tilt and YV misconvergence is corrected as the first variable resistance value is adjusted. The method of claim 2, The negative convergence correction circuit for cathode ray tube deflection yoke, characterized in that the lower misconvergence of the tilt and YV misconvergence is corrected according to the adjustment of the second variable resistance value when the vertical deflection current is negative.