Raster correction circuit

Claim 1

IN A TELEVISION RECEIVER COMPRISING A DEFLECTION YOKE HAVING A RESPECTIVE VERTICAL AND HORIZONTAL DEFLECTION WINDINGS, A HORIZONTAL DEFLECTION SYSTEM INCLUDING A HORIZONTAL OUTPUT TRANSFORMER SERVING AS A SOURCE OF HORIZONTAL SCANNING CURRENT FOR SAID HORIZONTAL DEFLECTION WINDING, AND A VERTICAL DEFLECTION SYSTEM INCLUDING A VERTICAL OUTPUT TUBE, HAVING RESPECTIVE ANODE AND CATHODE CIRCUITS, AND A VERTICAL OUTPUT TRANSFORMER, DRIVEN BY SAID ANODE CIRCUIT AND SERVING AS A SOURCE OF VERTICAL SCANNING CURRENT FOR SAID VERTICAL DEFLECTION WINDING; SIDE PINCUSHION CORRECTION APPARATUS COMPRISING THE COMBINATION OF: A SATURABLE REACTOR INCLUDING A CONTROL WINDING AND A CONTROLLED WINDING, THE IMPEDANCE OF SAID CONTROLLED WINDING VARYING IN RESPONSE TO CHANGES IN CURRENT THROUGH SAID CONTROL WINDING: MEANS CONNECTING SAID CONTROLLED WINDING TO SAID HORIZONTAL OUTPUT TRANSFORMER FOR CAUSING ANY OF SAID VARIATIONS OF THE IMPEDANCE OF SAID CONTROLLED WINDING TO MODULATE THE AMPLITUDE OF THE SCANNING CURRENT TRAVERSING SAID HORIZONTAL DEFLECTION WINDING; MEANS FOR DERIVING FROM SAID VERTICAL OUTPUT TRANSFORMER A PERIODIC VOLTAGE WAVEFORM OF VERTICAL FREQUENCY; MEANS INCLUDED IN SAID VERTICAL OUTPUT TUBE CATHODE CIRCUIT FOR DEVELOPING A SUBSTANTIALLY PARABOLIC VOLTAGE OF VERTICAL FREQUENCY IN RESPONSE TO THE CATHODE CURRENT OF SAID VERTICAL OUTPUT TUBE; AND MEANS APPLYING A COMBINATION OF SAID VERTICAL FREQUENCY VOLTAGE WAVEFORM DERIVED FROM SAID VERTICAL OUTPUT TRANSFORMER AND SAID PARABOLIC VOLTAGE DERIVED FROM SAID CATHODE CIRCUIT TO SAID CONTROL WINDING FOR CAUSING THE IMPEDANCE OF SAID CONTROLLED WINDING TO SO VARY IS TO PRODUCE PINCUSHION CORRECTING CHANGES IN SAID HORIZONTAL SCANNING CURRENT AMPLITUDE.