Patent ID: 6239773
Filing Date: 2001-05-29
Classification: G09G,H04N

Abstract:
An image display device comprising:an input for receiving information representing an image;drive means for generating a drive signal from the information;a cathode ray tube for displaying the image based on the drive signal, said cathode ray tube being driven by the drive signal; andinput means coupled to the drive means for receiving further information identifying a window of pixels in the image, wherein the drive means changes a relation between the information and the drive signal in the window as compared to a further relation between the information and the drive signal in areas outside the window, so as to enhance a drive signal range in the window,characterized in that the drive means determines the average luminosity on the cathode ray tube, and further changes said relation between the information and the drive signal in the window so as to reduce the enhanced drive signal range when said average luminosity exceeds a threshold value.