Patent ID: 7201482

Claim:
A projection type display device comprising: an image display device for processing an input image and displaying a processed image; a projection lens for enlarging a display image of said image display device for display on a screen as a projected image; a distortion corrector for correcting the projected image for distortions when said display image is projected with a projection optical axis tilted with respect to said screen; an angle detector for detecting a tilt angle of said projection optical axis in a vertical direction; and a user interface having a controller for correcting the projected image for distortions in a horizontal direction, wherein said distortion corrector includes a tilt angle generator for receiving outputs from said angle detector and said user interface to find the tilt angle of the projection optical axis of said projection lens with respect to said screen, and a display image corrector for correcting the display image using the tilt angle, and said display image corrector includes a processor for finding four vertexes using a two-dimensional table having corrected coordinates for the four vertexes of the display image or a mathematical expression, said two dimensional table or said mathematical expression employing a vertical tilt angle and a horizontal tilt angle as variables, and a fixed point determiner for selecting one of the four vertex as a fixed point.