Abstract text

A projector includes a projection device, a cross line positional information acquiring device for acquiring positional information of a cross line between a projection surface of the projection device and a plane crossing the projection surface, an inclination detecting device for calculating an angle of inclination between a projection optical axis of the projection device and the projection surface based on the positional information acquired by the cross line positional information acquiring device, and an image distortion correcting device for correcting a trapezoidal distortion of an input image supplied to the projection device, based on the angle of inclination calculated by the inclination detecting device.