The present invention provides a technique relating to a frame rate conversion which enables display of an image of extended definition by smoothening the movement of the image. Therefore, the invention fixes the direction of interpolation using information on a first frame which appeared before the insertion time of the interpolated frame, a second frame appeared before the first frame, a third frame appeared after the insertion time, and a fourth frame appeared after the third frame, based on the insertion time of the interpolated frame. The interpolated pixel is generated from pixels of the second frame and the third frame located in the direction of interpolation, and generates the interpolated frame. Then, the interpolated frame is inserted into the inputted image signal to convert the frame rate.