PURPOSE: To perform the flickerless processing by using one frame memory at the time of converting the video signal of the line sequence scanning from a computer system into the signal of interlaced scanning.

CONSTITUTION: The line sequence scanning signal from a video signal input section 1 is applied to digital conversion by an A/D conversion section 2 and recorded on a line memory 3. An interpolation coefficient arithmetic section 6 calculates the interpolation coefficient at separate next number of scanning lines. A multiplier 7 multiplies the interpolation coefficient of the scanning line by the data of the scanning line from the line memory 3. A multiplier 8 multiplies the interpolation coefficient of the pertinent scanning line by the data of the next scanning line. These two scanning line data are added by an adder 9. A multiplier 10 multiplies the required coefficient and recordes it on a line memory 11. A mixing section 12 mixes the data from the line memory 11 with the next scanning line data from the multiplier 10, writes them in a frame memory 13. The odd-number scanning line data and the even-number scanning line data are separately read out from a frame memory through a scanning conversion section 14. A D/A conversion section 15 converts it into an analog signal to output the result.