PURPOSE: To zero amount of trilemma by connecting a coil to be controlled of a saturable reactor in series with a horizontal deflection coil, flowing a vertical deflection current to the control coil, changing the inductance of the coil to be controlled in the vertical period and changing the horizontal deflecting magnetic field distribution in up and down directions of the screen.

CONSTITUTION: When a vertical deflection output voltage Vout and a horizontal deflection output voltage Hout are applied to each terminal, a current flowing to a vertical deflection coil 3 is applied to control coils 4b, 4b' of saturable reactors 4, 4' also. Since the directions of winding of the coils 4b, 4b' are reverse, the reactors 4, 4' are saturated alternately. Thus, the magnetic field distribution around the deflection center of a cathode-ray tube is as shown in fig. (a) at the first half of the vertical scanning. On the other hand, the distribution is as shown in Fig. (b) at the latter half. Since the magnetic field of the upper part shown in Fig. (a) acts effectively at the first half of the vertical scanning to the vertical deflecting operation and the magnetic field of the lower position shown in fig. (b) acts effectively at the latter half as a result, it is equivalent that a barrel magentic field is formed virtually around the deflection center of the cathode-ray tube at the full vertical scanning period, allowing the amount of trilemma to access nearly zero.