A projection video display that projects video image suppresses deterioration of its quality which is attributed to a change in an optical path of the video image. A video signal generator performs control such that a second subframe in an N-th frame in a left-eye image is displayed on DMDs and then a second subframe in an N-th frame in a right-eye image is displayed on the DMDs. Furthermore, the video signal generator performs control such that a displayed location is not changed on a screen and the same types of subframes are displayed at the time when frames are switched.