US Patent 7636456 Selectively displaying information based on face detection

A display arrangement comprises an image display device having two or more sets of images for display; a camera directed towards positions adopted by users viewing the display; a face detector for detecting human faces in images captured by the camera, the face detector being arranged to detect faces in at least two face categories; and means, responsive to the a frequency of detection of categories of faces by the face detector at one or more different periods, for selecting a set of images to be displayed on the image display device at that time of day.