PURPOSE: To correct a deflection distortion caused by a waveform distortion of a horizontal deflection current without increasing the waveform distortion of a horizontal deflection current by applying a deflection correction voltage obtained based on a horizontal output voltage to a sub horizontal deflection coil.
CONSTITUTION: A horizontal output voltage extracted from an output transformer 14 in a horizontal deflection output circuit 10 to supply a horizontal deflection current Im to a main horizontal deflection coil 16 of a picture tube 18 is fed to an integration operation section comprising the series connection between a resistive element 21 and a capacitive element 2. Thus, a deflection correction voltage Vc obtained based on the horizontal output voltage is fed to a sub horizontal deflection coil 24 and a deflection correction circumferential Ic is supplied thereto. As a result, the deflection distortion caused by the waveform distortion of the horizontal deflection current Im is corrected by the deflection by the sub horizontal deflection coil 24. Thus, the deflection by the sub horizontal deflection coil 24 is corrected without increasing a waveform distortion of the horizontal deflection current Im.