KR910006643Y1 - Miss convergence control circuit for yoke - Google Patents

Abstract

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Description

Miss convergence correction circuit of deflection yoke

1 is a circuit diagram of the present invention.

2 is a waveform diagram of a deflection current.

3 is a schematic view showing the improvement of the image quality of the present invention.

* Explanation of symbols for main parts of the drawings

11: vertical inner toroidal coil

14: vertical outer toroidal coil

21, 22, 28: variable resistor 27: bridge circuit

29: correction coil 10: inverted trimema correction unit

20: vertical isotropic astigmatism correction unit

The present invention relates to a miss convergence correction circuit of a deflection yoke.

The deflection yoke is attached in front of the neck of the cathode ray tube, and applies a magnetic field to the beam generated from the electron layer to deflect the traveling direction of the electron beam and finally produce an image on the screen.

In the in-line color display tube, when the electron beam is deflected to the middle part of the screen, the barrel distortion of the diagonal magnetic field is strong on the track, and when it is deflected to the periphery, the pincushion distortion is strong. If two corrections are made, the other one deteriorates, which means that any one of the beam components, X _H (X-axis horizontal), Y _H (X-axis horizontal), and CV (Corner Vertical), deteriorates. , Which usually means deterioration of the CV), has been a problem in improving the performance of the deflection yoke.

This problem is conventionally corrected by making the barrel distortion of the vertical magnetic field stronger when the electron beam is deflected to the middle of the screen, and the barrel distortion when the electron beam is deflected to the periphery.

In addition, a vertical outer saddle coil (pincushion distortion enhancement) and a vertical inner saddle coil (barrel distortion enhancement) were added to correct the switch characteristics of the diode. However, the saddle coil is added to the outside and the inside, the price increases, the property control function is required, and there is a problem of adding more than necessary process when assembling the deflection yoke. There arises a problem that it is difficult to freely correct the upper and lower edges.

In order to solve the above problems, the present invention facilitates misconvergence adjustment by winding coils that emphasize pincushion distortion and coils that emphasize barrel distortion on the vertical core at the same time. It is an object of the present invention to provide a misconvergence correction circuit of a deflection yoke that enables the adjustment of the.

Hereinafter, with reference to the accompanying drawings will be described in detail.

The rear end of the vertical inner toroidal coil 11 is simultaneously connected to the front end of the forward diode 13a and the rear end of the reverse diode 13b connected in parallel via a resistor 12, and the rear end of the forward diode 13a. The rear end of the reverse diode 13b is connected to the grounded vertical outer toroidal coil 14 in common, and the rear end of the vertical inner toroidal coil 11 is connected in parallel with a variable resistor ( The front ends of the first diodes 23 connected to the front ends of 21 and 22, respectively, connected in the forward direction to the variable ends of the variable resistors 21, and the rear ends of the first diodes 23 are connected in the reverse direction. It is connected to the rear end of the third diode 25.

The rear end of the second diode 24 connected in the reverse direction is connected to the variable end of the variable resistor 22, and the front end of the second diode 24 is connected to the front end of the fourth diode 26 connected in the forward direction. It is grounded with three diodes 25. The correction coil 29 and the bypass variable resistor 28 are connected in parallel to the connection points between the first diode 23, the third diode 25, the second diode 2, and the fourth diode 26. Connection is made.

Referring to the operation of the present invention configured as described above in detail as follows.

If the vertical outer toroidal coil 14 is connected in series with the diodes 13a and 13b so that the vertical deflection voltage is lower than the forward voltage of the diodes 13a and 13b, i.e. when the electron beam is deflected toward the middle of the screen 13a and 13b are turned off so that the vertical outer toroidal coil 14 does not operate, and only the vertical inner toroidal coil 11 operates to strengthen the barrel distortion of the vertical magnetic field.

At this time, the screen is corrected in the middle portion as shown in the schematic diagram of improving the image quality of FIG.

If the vertical deflection voltage is higher than the forward voltage of the diodes 13a and 13b, i.e., when the electron beam is deflected to the periphery of the screen, the diodes 13a and 13b are turned on to operate the vertical outer toroidal coil 14 to produce a vertical magnetic field. To strengthen the pin cushion distortion.

At this time, the peripheral portion of the screen is corrected as shown in the schematic diagram of improving the image quality of FIG. Meanwhile, the input deflection current I is equal to the second.

At this time, when the deflection current I is positive, current is applied to the correction coil 29 through the first and fourth diodes 23 and 26 of the bridge circuit 27. The amount of current at this time is adjusted by the variable resistor 21 to correct the deflection error on the upper side of the screen as shown in the schematic diagram B of FIG. 3. However, when the deflection current I is negative, current is applied to the correction coil 29 through the second and third diodes 24 and 25 of the bridge circuit 27. If the amount of current at this time is adjusted by the variable resistor 22, the bias error at the lower side of the screen is corrected as shown in the schematic diagram (b) of FIG.

In this case, after correcting the upper and lower sides of the screen and adjusting the amount of current flowing through the correction coil 29 with the bypass variable resistor 28 to correct the overall error, the beam is reduced as shown in FIG. The mutually matched state can be obtained to correct the vertical isotropic astigmatism due to the inversion tree theme correction.

As described above, since the saddle coil does not need to be used, the present invention does not require the characteristic control function of the coil, and it is economical because it can shorten the time and the process when assembling the deflection yoke, and the vertical isotropic astigmatism is fundamental. As a result, the upper and lower surfaces can be freely corrected, thereby greatly improving the image quality.

Claims (1)

Parallel the diodes 13a and 13b in opposite directions between the rear end of the vertical inner toroidal coil 11 and the front end of the vertical outer toroidal coil 14 so as to correct the peripheral and middle portions of the screen according to the vertical deflection voltage. 1 is connected in parallel to the bridge circuit 27 so that the upper and lower sides of the screen can be corrected by adjusting the amount of current of the deflection current I flowing through the inversion trirema correction unit 10 and the correction coil 29 configured to be connected. The pair of variable resistors 21 and 22 and the variable resistor 28 for final control of the deflection current I output from the foregoing variable resistors 21 and 22 are in parallel with the correction circuit 29 described above. A miss convergence correction circuit for a deflection yoke, characterized in that it is composed of a vertically isotropic astigmatism correction number (20) connected thereto.