VirtualHD Circuitry Hitachi CRT and lens technologies are fully capable of reproducing HDTV picture content. Unfortunately, not all programming is in High Definition today. Hitachi Virtual HD circuitry digitally upconverts conventional sources to a much higher quality level - one nearing that of HDTV. It increases both horizontal and vertical resolution, putting significantly more bits of information on the screen.
Just a fancy way of marketing their line doubler for their sets by giving it a snazzy name so to speak.
actually, increasing horizontal AND vertical resolution makes it a 'scaler'... but Robert's essentially correct. how good of scaler? i dunno.