JPH01307367A - deflection circuit - Google Patents

Abstract

PURPOSE:To improve the orthogonality of raster by applying a sawtooth waveform current having a vertical period to an S-shaped correction capacitor. CONSTITUTION:A horizontal pulse is given to a base of a horizontal output transistor(TR) 2 from a horizontal drive transformer 1 and a deflection current flows to a horizontal deflection coil 5 by charge/discharge of a CR capacitor 4. The DC level of a deflection current in this case depends on the DC level at a point 9. Thus, the sawtooth wave current is superimposed on the point 9 by a sawtooth wave superimposing TR 12 from the sawtooth wave with a vertical period generated by a vertical sawtooth wave generator 10 to vary the DC level of the horizontal deflection current at the vertical period thereby improving a parallelogram distortion of the raster. Thus, even if the relation of position between the vertical coil and the horizontal coil of the deflection yoke has a dispersion, no inclined raster takes place and its orthogonality is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a deflection circuit for a television receiver.

[Conventional technology]

FIG. 2 is a diagram showing a deflection circuit of a model currently produced, for example. In this figure, l is a water damper diode, 4 is a CR capacitor, 5 is a horizontal deflection coil, and 6 is an 8
The character correction capacitors 7 and 8 are variable resistors and guiodes for superimposing DC voltage.

Next, the operation will be explained. A current flows through the horizontal deflection coil 5 of the deflection yoke via the drive transformer.

[Problem to be solved by the invention]

A conventional deflection circuit is configured as described above, and the positional relationship between the vertical coil and horizontal coil of the deflection yoke should be such that the vertical deflection magnetic field and the horizontal deflection magnetic field intersect perpendicularly. However, due to a manufacturing problem with the deflection yoke, this positional relationship varied, causing the raster to be tilted diagonally.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and even if the positional relationship between the vertical coil and the horizontal coil of the deflection yoke varies, it prevents the raster on the screen from tilting diagonally. , the object is to obtain a deflection circuit that can improve raster orthogonality.

[Means to solve the problem]

The deflection circuit according to the present invention is configured to apply a sawtooth wave current with a vertical period to an S-shaped correction capacitor.

[Effect]

In this invention, by superimposing a sawtooth wave current with a vertical period on the S-shaped correction capacitor, the DC level of the horizontal deflection current changes in the vertical period, and the distortion of the parallelogram in which the raster is tilted diagonally is eliminated. is removed, improving raster orthogonality.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, l is a horizontal pulse drive transformer, 2 is a horizontal output transistor, 3 is a damper diode, and 4 is a C
R capacitor, 5 is a horizontal deflection coil, 6 is an S-shaped correction capacitor, 10 is a vertical period sawtooth wave generator that generates a sawtooth wave with a vertical period, 11 is a sawtooth wave generator l
A variable resistor 12 changes the level of the sawtooth wave voltage outputted by O, and a sawtooth wave superimposing transistor 12 superimposes a sawtooth wave current on the figure-8 correction capacitor 6.

Next, the operation will be explained. A horizontal pulse is input from the horizontal drive transformer 1 to the base of the horizontal output transistor 20, and a deflection current flows through the horizontal deflection coil 5 by charging and discharging the CR capacitor 4.

At this time, the DC level of the deflection current is determined by the DC level at point 9. Therefore, the vertical sawtooth wave generator lO
By superimposing a sawtooth wave current at point 9 using the sawtooth wave superimposing transistor 12 from the vertical period sawtooth wave created by , the DC level of the horizontal deflection current is changed in the vertical period, and the raster parallelogram distortion is generated. improve. Therefore, even if the positional relationship between the vertical coil and the horizontal coil varies due to problems in the construction of the deflection yoke, the raster will not be tilted diagonally and its orthogonality will be maintained.

〔Effect of the invention〕

As described above, according to the deflection circuit according to the present invention, since a sawtooth wave current with a vertical period is applied to the S-shaped correction capacitor, even if the positional relationship between the horizontal coil and the vertical coil of the deflection yoke varies. It is possible to prevent the raster on the screen from tilting diagonally, and it is possible to improve the orthogonality of the raster.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a deflection circuit according to an embodiment of the present invention;
FIG. 2 is a diagram showing a conventional deflection circuit. 5 is a horizontal deflection coil, 6 is an S-shaped correction capacitor, 10 is a vertical sawtooth wave generator, 11 is a sawtooth wave output voltage variable resistor, and 12 is a sawtooth wave superimposition transistor. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A deflection circuit for a television receiver, comprising a circuit for applying a vertically synchronized sawtooth wave current to an S-shaped correction capacitor.