Projection type display device

A projection type display device for projecting a quadrilateral image that is displayed on an image display device onto a screen is provided. The device comprising a vertical angle detector for detecting an angle of a projection optical axis in a vertical direction with respect to the screen, a horizontal angle detector for detecting an angle of the projection optical axis in a horizontal direction with respect to the screen, and a distortion corrector. The distortion corrector is adapted to receive outputs from the vertical angle detector and the horizontal angle detector and to find a vertical tilt angle and a horizontal tilt angle of the projection optical axis with respect to the screen and to correct the projected image using the vertical tilt angle and the horizontal tilt angle. One of the four vertexes of the quadrilateral image is a fixed point on the image display device, and the vortex being the fixed point is selected depending on the tilt direction of the projection optical axis with respect to the screen.