PICTURE SIGNAL CONVERTING DEVICE

A picture signal converting device receptive of a picture signal with its frame made up of two fields each having a prescribed number of scanning lines for increasing the number of scanning lines in each field in such a way that a first interpolating signal is formed by using the picture signal for the field correlated to the present field in terms of time, a second interpolating signal is formed by using the picture signal for the field correlated to the present field in terms of space, and the movement of a picture between the preceding and next frames is detected by using the picture signals for the preceding and next fields relative to the present frame. As the value it took before a prescribed time is stored, depending on the difference between the speeds of movement of the picture at the present time and the prescribed time ago, at least one of the first and second interpolating signals is used to form an interpolating picture signal for the present field.