Multiple-tone display system

A multiple-tone display system for providing multiple-tone representations for display on a display device having a large number of pixels arrayed in a dot matrix, said display system comprising:

• data conversion means for receiving multiple-tone display information containing a plurality of bits per pixel, and sequentially converting said multiple-tone display information into display data corresponding to one horizontal line on the display device;
• drive voltage generation means for producing a plurality of drive voltage levels, said drive voltage generation means including a group of voltage dividing resistors for dividing a reference voltage by respective unequal division ratios to provide the plurality of drive voltage levels, the differences between adjacent ones of the drive voltage levels being non-uniform and being determined so as to make substantially uniform color differences, as seen by a human eye, between every pair of tones adjacent in display intensity among a plurality of tones that can be displayed, according to said multiple-tone display information;
• data drive means connected to said drive voltage generation means and said data conversion means, for selecting one of said plurality of drive voltage levels from said drive voltage generation means for every pixel on one line of the display device and then applying the selected drive voltage level to the display device in accordance with said display data delivered from said data conversion means;
• and
• scan drive means for selecting one horizontal line on the display device which is to be successively displayed, in synchronism with the operation of said data conversion means and said data drive means.