An image projector is adapted to change the magnification of a projected image by moving a zoom lens with its focal length being changed, wherein the zoom lens is moved to and then stopped at a goal position from the initial position in the first direction. When it is desired to move the zoom lens to another goal position in the second direction opposite to the first direction as viewed from the initial position, the zoom lens is once moved to its reversal position beyond the second goal position and thereafter moved from the reversal position to the second goal position.