in video signal d is read out from field memory 33 in response to memory read signal e 34 during the above even field period and component e1 included in video signal d is read out in response to memory read signal e 34 during the odd field period in the next frame the same operations are repeated read out component o1 included in video signal d is input to adder 37 and added to component e1 in the video signal d directly input to adder 37 from a d converter 32 during the same period as o1 i e the even field period at the same time a division o1 e1 n is performed by adder 37 and signal f having a predetermined brightness level is output the same operations are repeated after the next field period subsequently the video signal having a brightness level corresponding to o1 e1 n during the even field period and the video signal having a brightness level corresponding to e1 o2 n during the odd field period in the next frame are respectively output so as to constitute one frame these video signals are converted into analog signals by d a converter 34 and input to tv monitor 36 as video signal g.