An image projecting device includes an image display unit that simultaneously displays left and right eye images in a line on a display panel and a projection optical system that projects the left and right eye images displayed on the display panel onto a screen in a superposed state. The display unit performs a transforming process for rotating the left eye image on a left eye image signal used to display the left eye image and for rotating the right eye image on a right eye image signal used to display the right eye image. The transformed left eye image signal and the transformed right eye image signal are synthesized to obtain an image signal for display use.