Digital video display system with a plurality of gray-scale levels

A video display system comprising:

• a video monitor operated in a raster scan mode for the display of information in the form of alpha-numeric characters and other symbols formed of individual picture elements;
• a video synthesizer coupled to said video monitor said video synthesizer including means to generate video signals selected from three or more different discreet voltage levels to form a video signal corresponding to different levels of luminance to be displayed by said video monitor for each of said picture elements;
• a character generator coupled to said video synthesizer, said character generator including a character storage to store binary codes corresponding to said different levels of luminance;
• buffer means coupled to said character generator, said buffer means including means to temporarily store a sequence of character codes representing different alpha-numeric characters to be displayed by said video monitor, said character codes being transmitted to said character generator to select a sequence of binary codes for the different picture elements forming an alpha-numeric character;
• and
• timing means coupled to said video monitor, said video synthesizer and said character generator to generate timing signals representing picture elements to be displayed to form said different alpha-numeric characters and symbols, which picture elements make up the respective scan line of said video monitor.