JPH053189B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a pink distortion correction circuit used to correct left and right pink distortion in a horizontal deflection circuit of a television receiver.

BACKGROUND TECHNOLOGY AND PROBLEMS As a circuit for correcting left and right pink distortion in the horizontal circuit of a television receiver, for example, as shown in FIG. 1, a circuit has been proposed in which the power supply is modulated with a parabolic wave having a vertical period.

In the figure, reference numeral 1 denotes a horizontal output transistor, the base of which is supplied with a drive signal from a horizontal drive circuit (not shown). Also, 2
is a damper diode, 3 is a resonance capacitor,
4 is a horizontal deflection coil, 5 is a capacitor for S-shaped correction, and 6 is a chiyoke coil. Reference numeral 7 indicates a modulator, and the power supply +B is modulated by a vertically periodic parabolic wave signal _SP supplied from a terminal 8.

The pink distortion correction circuit shown in the example in Figure 1 has the disadvantage that when the left and right edges of the screen are corrected so that they are straight, a larger amount of correction remains at the center of the screen, as shown by the solid line in Figure 2. There is. That is, in the pink-tension distortion correction circuit shown in the example of FIG. 1, it was impossible to completely correct the pink-tension distortion.

OBJECTS OF THE INVENTION The present invention has been made in view of the above points, and is intended to enable more complete correction of pink tension distortion.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a horizontal deflection circuit which includes a horizontal deflection coil and an S-shaped correction capacitor, and whose power source is modulated by a vertically synchronized parabolic wave. A secondary winding of a transformer for voltage/current conversion is provided between the correction capacitor and a voltage that becomes large at the center of the vertical period is supplied to the primary winding of this transformer.

The present invention is configured as described above, and when correcting the pink tension distortion caused by modulating the power supply with a parabolic wave with a vertical period, the distortion that still remains is modulated in the horizontal deflection current with a signal that becomes large at the center of the vertical period. Correction is made by superimposing the substantially S-shaped current. Therefore, it is possible to more completely correct pink distortion distortion.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to FIG. In this Figure 3, the first
Portions corresponding to those in the figures are given the same reference numerals, and detailed explanation thereof will be omitted.

In this example, a secondary winding 9b of a voltage/current conversion transformer 9 is connected between the horizontal deflection coil 4 and the S-shaped correction capacitor 5. and,
A correction voltage V _P is supplied from a modulator 10 to the primary winding 9 a of this transformer 9 . This correction voltage V _P is
For example, as shown in FIG. 4D, it is a triangular wave having a peak at the center of the horizontal period _TH . Also, modulator 1
0 is supplied with a vertically periodic parabola wave S _P from a terminal 11, and the correction voltage V _P is modulated by this vertically periodic parabola wave S _P . That is, it is modulated so that it is 0 at the beginning and end of the vertical period and maximum at the center.

This example is configured as described above and operates as follows.

First, at both ends in the vertical direction of the screen, a correction voltage V _P shown by a broken line a in FIG. 4D is applied to the primary winding 9a of the transformer 9. Since the inductance of the horizontal deflection coil 4 is very large, in addition to the normal horizontal deflection current I _Y shown in FIG. A substantially S-shaped correction current I _S flows. What is indicated by the broken line a in FIG. 4B is the voltage V _S obtained at the connection point between the capacitor 5 and the secondary winding 9b of the transformer 9 at this time. Further, at the center in the vertical direction of the screen, a correction voltage V _P (at a higher level than that shown by the broken line a) is applied to the primary winding 9a of the transformer 9 as shown by the solid line b in FIG. 4D. Therefore, in addition to the horizontal deflection current I _Y in the horizontal deflection coil 4, the horizontal deflection current C
A substantially S-shaped correction current _IS as shown by the solid line b (at a higher level than that shown by the broken line a) flows. Figure B
What is shown by the solid line b is the voltage V _S obtained at the connection point of the capacitor 5 and the secondary winding 9b of the transformer 9 at this time.

In this example, the horizontal deflection current I _Y
Since a substantially S-shaped correction current I _S having a horizontal period T _H is superimposed on the current, deflection is suppressed on the left side of the screen, and deflection is promoted on the right side of the screen. The level of this correction current I _S is low at both ends of the screen in the vertical direction, and high at the center, so that the above-mentioned suppression and promotion are small at both ends of the screen in the vertical direction, and are greatest at the center.

Therefore, according to this example, the correction remaining by the conventional correction circuit as shown by the solid line in FIG. 2 can be almost completely corrected as shown by the broken line in the same figure.

According to the above embodiment, the correction voltage V _P applied from the modulator 10 to the primary winding 9a of the transformer 9
is a triangular wave voltage, but is not limited to this. In short, any waveform (parabolic wave, trapezoidal wave, etc.) that allows a substantially S-shaped current to flow as the correction current _IS may be used. Further, according to the above embodiment, the correction voltage
V _P is modulated by a parabolic wave S _P with a vertical period, but is not limited to this, and any signal (such as a triangular wave) that becomes large at the center of the vertical period may be used.

Effects of the Invention According to the present invention described above, in a horizontal deflection circuit that includes a horizontal deflection coil and a capacitor for S-shaped correction, and whose power source is modulated by a vertically synchronized parabolic wave, the horizontal deflection coil and the S-shaped correction capacitor are used. A secondary winding of a transformer for voltage/current conversion is provided between the vertical capacitor and a voltage that becomes large at the center of the vertical period is supplied to the primary winding of this transformer. Therefore, it is possible to more completely correct pink distortion distortion.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an example of a conventional pink distortion correction circuit, and FIG. 2 is a diagram for explaining the circuit.
FIG. 3 is a configuration diagram showing one embodiment of the present invention, and FIG. 4 is a diagram for explaining the same. 4 is a horizontal deflection coil, 7 and 10 are modulators, and 9 is a transformer for voltage/current conversion.

Claims (1)

[Claims] In a horizontal deflection circuit that has a horizontal deflection coil and a capacitor for S-shaped correction, and whose power source is modulated by vertically synchronized parabolic waves, the horizontal deflection coil and S
A pink tensioner characterized in that a secondary winding of a transformer for voltage/current conversion is provided between the capacitor for character correction, and a voltage that becomes large at the center of the vertical period is supplied to the primary winding of the transformer. Distortion correction circuit.