JPS593654Y2 - Vertical line distortion correction device - Google Patents

Description

[Detailed description of the invention] The present invention relates to the configuration of a device used to correct pincushion distortion of vertical lines on a cathode ray tube in a deflection device of a television receiver, and particularly improves correction of the corners of the screen. The aim is to provide a device that can do this.

First, the circuit of a conventionally used vertical line distortion correction device will be described with reference to FIG.

In the figure, reference numeral 1 denotes a vertical sawtooth wave voltage input terminal, to which a sawtooth wave voltage with a vertical period such as A is applied from a vertical deflection circuit.

This is applied via a first resistor 2 to a series circuit of a second resistor 3 and a first capacitor 4.

These resistors 2 and 3 and the capacitor 4 constitute an integrating circuit, in which the vertical sawtooth wave voltage A is integrated like B.

The integrated output voltage B is taken out from the connection point between the first resistor 2 and the series circuit, applied to the base of the transistor 5 connected as an emitter-farrow, and taken out from its emitter to the control winding 6 of the correction reactor 6. Added.

As a result, a parabolic current having a vertical period such as C is caused to flow through the control winding 6.

This correction reactor 6 is a saturable reactor, and the horizontal deflection coil 7 is connected in series to its output winding 6H, so that its horizontal deflection current is modulated in a parabolic manner with a vertical period as shown by D. As a result, pincushion distortion of vertical lines on the screen is corrected.

However, in such a conventional circuit, the amplitude of the integrated output voltage B is insufficient at the beginning and end of vertical scanning due to the series resistor 3 provided in the integrating circuit, as shown by the solid line in FIG. However, for this reason, the parabolic current C flowing through the correction reactor 6 is also insufficient at the beginning and end of the vertical scan.
As a result, the correction of the pincushion distortion at the upper and lower ends of the screen is insufficient, resulting in the raster 8 as shown by the solid line in FIG. 4, with the drawback that some pincushion distortion remains.

FIG. 3.4 shows this state, and the solid line in the figure is the operating state of the conventional circuit.

Therefore, it is an object of the present invention to provide a device that eliminates such conventional drawbacks.

FIG. 2 shows a circuit diagram of an embodiment of the present invention.

It should be noted that the same parts as in the prior art are given the same reference numerals as in FIG. 1, and their explanation will be omitted.

In this device, a second capacitor 9 having a relatively small value is connected in parallel with the second resistor 3 in the integrating circuit.
The feature is that the high frequency components are slightly bypassed.

When the capacitor 9 is provided in this way, the integration ratio of the vertical sawtooth wave voltage A at the beginning and end of the vertical scan becomes smaller, and the amplitude of the integrated output voltage B at those parts becomes as indicated by the broken line in FIG. becomes larger as shown in .

Therefore, the amplitude of the parabolic current C flowing through the distortion correction reactor 6 also increases at the beginning and end of the vertical scan, as shown by the broken line in FIG.

As a result, the amount of correction for pincushion distortion at the beginning and end of vertical scanning is increased, and the amount of correction for pincushion distortion at the four corners of the screen is fully satisfied, as shown by the broken lines in Figure 4. , the vertical line distortion of raster 8 is sufficiently corrected and accurate vertical lines are displayed.

As described above, according to the present invention, it is possible to obtain an excellent device that can accurately correct pincushion distortion at the four corners of the screen of a cathode ray tube with a simple configuration that only requires the addition of one capacitor. .

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a conventional vertical line distortion correction device, Fig. 2 is a circuit diagram of a vertical line distortion correction device according to an embodiment of the present invention, Fig. 3 is a waveform diagram of each part thereof, and Fig. 4 is a circuit diagram of a vertical line distortion correction device according to an embodiment of the present invention. It is a schematic diagram of those rasters. 1... Input terminal, 2... First resistor,
3... Second resistor, 4... First capacitor, 5... Transistor, 6...
Distortion correction reactor, 6V... Control winding, 6H.
...Output winding, 7...Horizontal deflection coil,
8...Second capacitor.

Claims (1)

[Scope of utility model registration request] A vertical sawtooth wave voltage is added to a series circuit of a second resistor and a first capacitor via a first resistor to form an integral circuit, and an integral output is generated from a connection point between the first resistor and the series circuit. The output winding of the correction reactor is connected in series to the horizontal deflection coil, and a second resistor is connected in parallel to the second resistor. Vertical line distortion correction device formed by connecting two capacitors.