摘要:
A circuit (10) provides North-South pincushion correction and gullwing compensation in a raster display of a television apparatus. A correction circuit (52,60,62,66) generates a generally parabolic, horizontal rate correction signal to correct for North-South pincushion distortion. A gullwing compensation circuit (72) is coupled to the correction circuit and forms a feedback path therein for amplitude modifying the correction signal to further correct for gullwing distortion. The gullwing compensation circuit amplitude modifies the generally parabolic signal (V OUT ) as a function of itself, achieving an equilibrium condition. A vertical deflection circuit drives a vertical deflection coil with the gullwing compensated correction signal. The correction circuit comprises a ramp waveform generator (60,62) having a controllable current source (52,54,56) generating a constant component of current (I DC ) for pincushion correction and a variable component of current (I AC ) responsive to the feedback signal for gullwing compensation. The variable component of current (I AC ) varies inversely to the feedback signal, which is coupled in the feedback path to the controllable current source through an inverting amplifier (72). The output of the inverting amplifier modulates the current supply (54) to modify the resulting shape of the parabolic signal to compensate for gullwing distortion by increasing the slope of the parabola on both lateral sides.
摘要:
A horizontal deflection correcting circuit for a television receiver having a CRT with a horizontal convergence winding includes a device for generating a corrective current which has opposite polarities during first and second halves of each horizontal period respectively. The corrective current is fed to the horizontal convergence winding to correct a distortion of a reproduced image on the CRT in horizontal linearity.
摘要:
Dans un circuit de balayage de lignes à balayage symétrique, on constate un déroulement asymétrique du courant de balayage (ia) pendant chaque ligne. C'est cette déviation du déroulement désiré qu'il s'agit de corriger. La bobine de balayage (AS) est connectée à la sortie (a) d'un amplificateur (V1) à l'entrée de commande (f) duquel est appliquée une valeur de réglage (Us1, Us2) dérivée du courant de balayage (ia) et de la tension (Ud) de la bobine de balayage (AS). Le circuit convient en particulier pour postes récepteurs de télévision à balayage symétrique de systèmes de haute résolution (HDTV).
摘要:
Ablenkschaltung für Fernsehbildröhre Bei einer Ablenkschaltung für eine Fernsehbildröhre, die einen Horizontalgenerator (16) und einen Vertikalgenerator (2) zur Steuerung einer Horizontal (17)- bzw. Vertikalablenkspule (1) umfaßt, soll der Horizontalgenerator (16) einen symmetrischen Ausgangsstrom erzeugen. Erfindungsgemäß wird der Vertikalablenkspule (1) sowohl der Ausgangsstrom (i v ) des Vertikalgenerators (2) als auch ein aus dem Ausgangsstrom (i h ) des Horizontalgenerators (16) gewonnener Korrekturstrom (i k ) zugeführt. Dabei ist der Korrekturstrom (i k ) zeitweise gegenläufig zum Ausgangsstrom (i v ) gerichtet. Eine symmetrische Ablenkung erfordert eine geringere elektrische Leistung als eine Sägezahnablenkung und ist besonders bei großen, lichtstarken Bildröhren zweckmäßig. Mit der erfindungsgemäßen Schaltung wird ein gleichmäßiger Zeilenabstand bei symmetrischer Ablenkung erreicht.
摘要:
In a deflection apparatus which corrects for inside pincushion distortion, a deflection winding (L H ) and a retrace capacitance (C RD ) form a retrace resonance circuit (27) during a retrace interval. A trace capacitance (C s ) forms a trace resonant circuit with the deflection winding (L H ) during the trace interval. A circuit branch (60), that includes a second capacitance (C₄) and an inductance (L₂), is coupled to the trace capacitance (C s ) during the trace interval to form a second resonant circuit with the trace capacitance (C s ) having a resonance frequency that is substantially higher during the trace interval than that of the trace resonant circuit. A current in the circuit branch (60), that is modulated in accordance with the modulated voltage, modulates the trace parabolic voltage across the trace capacitance (C s ) in a manner to reduce inside pincushion distortion. The trace capacitance (C s ) acts as a bypass capacitor around the inductance (L₂) during retrace to prevent the inductance (L₂) from affecting the retrace voltage.
摘要:
In a sawtooth generator for a television deflection system, first (C₁) and second (C₂) capacitors are coupled in series to a first terminal (500a) of a switch (U 6a ). When the switch (U 6a ) is conductive, the two capacitors are discharged by the switch to form a sawtooth signal (V O ʹ) at the first terminal (500a) having a down-ramping portion that corresponds with a retrace interval. When the switch (U 6a ) is nonconductive, the two capacitors are charged by a source (R₂) of current to form an upramping portion of the sawtooth signal that corresponds with a trace interval. An S-shaping arrangement that is coupled to a junction terminal (703) of the two capacitors (C₁,C₂) includes a third capacitor (C₃), two resistances (R₈;R₄,R₅) and a clamping arrangement (D₁,D₂) that provide S-shaping of the sawtooth signal (V O ʹ) at both ends of the trace interval and dc restoring prior to the beginning of each trace interval.
摘要:
A combined top and bottom pincushion and gullwing distortion correction circuit uses a nonlinear reactor (T1) to introduce an appropriately modulated horizontal frequency (if) and second harmonic (i 2f ) of the horizontal frequency component into the vertical scanning current path. The nonlinear reactor (T1) is preferably a transformer with a secondary (W1, W2) that provides a correction voltage in series with the vertical scanning current path. The transformer effectively has two series opposing primary windings (W3, W4) magnetically coupled to the secondary (W1, W2). These primaries, energized by waves at the horizontal frequency and the second harmonic frequency, alternately predominate over each other to a variable degree, and in a manner determined by the vertical scanning current (i v ), for inducing corresponding voltage at the secondary winding (W1, W2). In a preferred embodiment the secondary winding is coupled to a first tuned circuit (L4, 64) that generates a horizontal rate north-south pincushion correction component voltage of the total correction voltage. The secondary winding is also coupled to a second tuned circuit (L3, C4) that generates a horizontal frequency second harmonic rate gullwing correction component voltage of the total correction voltage.