Patent ID: 8035632
Filing Date: 2011-10-11
Classification: G06F,G09G

Abstract:
1. A method for automatically controlling the on/off switching of a display screen of a picture frame for digital photographic images, wherein the picture frame comprises: a display screen suitable for displaying an image in the form of a matrix of pixels; a driver circuit for driving said display screen; processor means suitable for delivering image data to the driver circuit for display on said display screen; memory means for storing image data blocks and co-operating with said processor means; means for lighting said display screen; and means for automatically controlling the brightness level of said screen, including a sensor for sensing an ambient lighting level; wherein said method comprises: a) determining at regular intervals successive mean values of said ambient lighting level; b) determining a mean minimum value and a mean maximal value from said successive mean values over a pre-determined time period; c) deriving from said mean minimum value and said mean maximal value a darkness-to-light transition threshold and a light-to-darkness transition threshold; d) comparing the current ambient lighting level to said darkness-to-light and light-to-darkness transition thresholds; e) switching on said display screen upon crossing of said darkness-to-light transition threshold and switching off said display screen upon crossing of said light-to-darkness transition threshold.