Patent ID: 6982730

Claim:
An apparatus for correcting keystone distortions in a display system comprising: a horizontal size generator that receives N horizontal sync signals of an input image and generates N corresponding horizontal output sizes, each of said horizontal output sizes being generated at each of said sync signals based on a horizontal input size, a vertical size, and a desired keystone factor of said input image; and a format converter that receives said input image and generates and output image, by converting the received input image based on the horizontal input size so that each line of said output image has a horizontal output size corresponding to a successive one of the N horizontal output sizes generated by said horizontal size generator; a sync signal generator that generates a read control signal based on said N horizontal sync signals and said horizontal output sizes; and a line memory that stores each line of said output image generated from said format converter and outputs said each stored line of said output image according to said read control signal, where N represents a total number of lines of said output image.