DE1259936B - Circuit arrangement for horizontal raster correction in color television picture tubes - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

H04n

German class: 21 al -34/11

Number: 1259 936

File number: F 46980 VIII a / 21 al

Filing date: August 25, 1965

Opening day: February 1968

In color television receivers with color picture tubes of the type of the so-called shadow mask tubes Due to the arrangement of the three beam systems of the tube, a pillow-shaped distortion of the Deflection grid. As is known, the radiation systems are arranged in three axes inclined to the tube axis, so that the electron beams enter the deflection field with a certain inclination. Through this it is necessary that the grids appearing on the luminescent screen have the shape of mutually displaced and have pillow shapes that are not identical to one another. But it is already known that one an equalization and a congruence of these grid shapes can be achieved if one considers the horizontal deflection currents with a parabolic deflection current and the vertical deflection currents with a current one Superimposed waveform, roughly the shape of garland or parabolic line frequency oscillations has, which are modulated with a sawtooth signal with a field frequency such that the Amplitude of the parabolic oscillation in the middle line of image 0 and in the upper and lower lines Line is maximum.

Various circuits are already available for generating these line-frequency modulated parabolic oscillations have been specified, which are, however, quite complex and with regard to the accuracy of the curve shape do not fully meet the high demands on the picture quality of color television pictures.

The invention is based on the object of a circuit for generating a correction current for indicate the vertical deflection with which the correction function described above with very little Effort and with a high degree of efficiency produced in the exactness that meets today's requirements can be.

The invention is based on a circuit arrangement for generating arcuate currents, which is the subject of the earlier patent application F 44017 VIII 8 / 2Ia ¹ . This parabolic generator described there has the advantage that it can be operated with a single switch controlled by the pulses determining the frequency of the parabolic oscillation and has a high degree of efficiency, since the magnetic energy generated during the current flow when the switch is closed is largely recovered. In this circuit arrangement for generating periodic, arc-shaped currents, the load coil, from which the desired arc-shaped or parabolic currents can be coupled out, is connected in parallel with a capacitor which, with the load coil, is almost half the recirculation to the horizontal
Correction of raster in color television tubes

Additional information on registration: F 44017 VIII a / 21 al ■
Interpretation document 1 247 379

Applicant:

Television G. m. B. H.,

6100 Darmstadt, Am Alten Bahnhof 6

Named as inventor:

Dieter Spannhake, 6100 Darmstadt

Formation frequency tuned oscillation circuit, and is also in series with the resonance circuit Coil of lower inductance than that of the load coil and a switch, preferably a transistor, as well placed a DC voltage source, such that with pulsed control of the switch the additional Coil with current permeability of the switch in terms of alternating voltage parallel to the resonant circuit is placed. The circuit works in such a way that when the switch is open in the oscillating circuit parabolic half-oscillation is generated, which when the switch is closed by a second parabolic Half oscillation of opposite amplitude and shorter duration is added.

According to the invention, two circuit arrangements for generating arc-shaped currents according to patent application F 44017 VIII 3 / 2Ia ^{1 with the} same repetition frequency and with switches or transistors that act in push-pull to each other and which each work in opposition are used to generate the above-described parabolic oscillations modulated with field frequency

709 747/392

Claims (4)

I 259 936 3 4 polarized operating voltages are fed, winding 9 with the main transformer of the line being A sawtooth deflection current generator is connected to these operating voltages. In connection voltage is superimposed with field frequency, and training line is still a choke 10. The the parabolic capacitor 8 and the choke 10 in the two load coils serve the purpose, Generators generated anti-phase parabolic currents 5 that on the one hand the line-frequency parabolic current in the deflection circuit of the vertical deflection coils via the capacitor 8 in the circuit of the deflection a color picture tube is coupled in such a way that the steering coils 7, but not in the Parabolic oscillations at the amplitude of the sawing winding 9 can penetrate. To that end is Tooth tension 0 cancel each other out, while the throttle 10 is made so large that it is partly a positive or negative amplitude of the saw ίο frame-frequency oscillations in sufficient, but tooth tension the amplitude of one or the other line-frequency vibrations only to a small extent The parabolic current predominates. lets through. In a corresponding way prevents the To explain the invention, capacitor 8 is the penetration of the field frequencies below an embodiment on the basis of FIG. 1 and 2 oscillations in the circuit of the secondary winding described in detail. Of these figures, 15 shows 6 and 6 'respectively. Through this type of coupling F i g. 1 the waveform of a sawtooth modulated is superimposed on the sawtooth current in the coils 7 Parabolic oscillation, as used for the corrector of a sawtooth-modulated parabolic current according to FIG. 1, vertical deflection currents for color television picture tubes so that a waveform arises as in the is required, and waveform A is reproduced. The at the Fig. 2 an embodiment of the circuit according to the 20 connection point of the switching elements 7, 8 and 10 oscilloscope Invention. , graphically observed voltage has approximately the form In Fig. 2 are two parabolic generators with opposite curve B. In practical operation, the phase waveforms are shown, which result from the load connection points between, the switches 4 or 4 'coils 1 or 1', resonant circuit capacitors 2 or 2 ', and the coils 3 or 3 'still jRC attenuators additional coils 3 or 3', the complementary 25 of the 11, 12 or 11, 12 'applied, which the total switches 4 and 4' and finally the tension prevent harmonic vibrations,
voltage sources U and U ' exist. As a controlled circuit that has proven itself in practical operation, switches are shown in FIG. 2 controlled diodes or were the following switching elements used:
Thyristors have been used, the only to achieve a push-pull effect differently polarized 30 transformer windings 1, 1 '75 mH are. The control electrodes of the two switches 4 secondary windings 6, 6 '.. 75 mH or 4 'are connected to the secondary windings of a \ Transformer connected, at the primary winding deflection coils 7 15 mH development a pulse-shaped voltage, roughly corresponding to coils 3, 3 '40 μΗ the return pulse of the horizontal deflection, er 35. Capacitors 2 2 '01 uF is procreated. The transformer can be the main ' be the transformer of the line deflection device, on the capacitor 8 0.2 μ ¥ sen core the two secondary windings applied capacitors 11, 11 '1000 pF are. To limit the switching currents, τχ «/ ΐ _β ™ + 8« Λ ». i <» 11> inn r, Control winding circuits Resistors 5 40. ^{Forest status 12} > ^{12 33Ü Ω} or 5 'attached. The two generators become switches 4, 4 'TCR 13 with voltages U or TJ ' with common grounding operating voltages U, U'. . +12 or betneben, where U is equal to - TJ . Instead of _i? V
Thyristors can also be used as switches 4 or 4 ' Complementary transistors are used. At the 45 sawtooth amplitude 10 V This mode of operation arises with constant supply voltages between points A and A ' claims:
and B or B ' one of cosine half-waves composite voltage, the oscillation 1. circuit arrangement for generating a parabola modulated with a sawtooth function in a mirror image of each other at B and B '. Correspondingly, parabolic currents flow in the oscillation for use in color television temp oscillation circuits 1, 2 or 1 ', 2' for horizontal raster rectification, since the form shown has opposite phase. characterized by the fact that two scarfs are now applied to the connected points and A ' processing arrangements to generate two arcuate oscillation circles together with a saw current according to patent application F44017Villa / tooth voltage, the amplitudes of 21 a ¹ (German Auslegeschrift 1247 379) are identical vibrations reduced in both circuits or comparable repetition frequency and with each other enlarges, depending on whether the Sägezahnspannungs- push-pull acting switches or transistors amplitude used for the respective battery voltage Ό (4, 4 ') each with entgegen- or . TJ ' added or subtracted. This results in 60 set polarized operating voltages (TJ, TJ ') that a parabolic current is fed in the resonant circuit 1, 2, that these operating voltages with an amplitude increasing approximately from 0 and in which a sawtooth voltage with a field frequency of the resonant circuit 1', 2 ' such is decreasing and superimposed and that the opposite amplitude arises in the two loads at the same time. These coils (1, V) of the parabolic generators generated two currents are connected in series with 65 antiphase parabolic currents in the deflection windings 6 and 6 'in the circuit of the vertical circuit of the vertical deflection coils (7) of a deflection coil 7 via the separating capacitor 8 - Color picture tube are coupled in such a way that feeds. The deflection coils 7 are over the secondary the parabolic oscillations in the amplitude the sawtooth voltage O cancel each other out, while with a positive or negative The amplitude of the sawtooth voltage outweighs the amplitude of one or the other parabolic current. 2. Circuit arrangement according to claim 1, characterized in that the switch (4, 4 ') for the parabolic generators controlled semiconductor diodes are used. 3. Circuit arrangement according to claim 1, characterized in that complementary transistors are used as switches (4, 4 ') for the parabola generators. 4. Circuit arrangement according to claim 1, 2 or 3, characterized in that the voltage for controlling the switch (4, 4 ') is taken from the horizontal deflection transformer via a secondary winding . 1 sheet of drawings