I have data sheets on Sharp ( electronics corporation ) LCD units circa 1988. They Show a LM64015T Display which was also 640 X 400. Its logic was 5.0 V (MAX 6 V) and the Supply (LCD) drive is Typical -21V (Min- 32V. Max -14V) It was driven with a Yamaha V6366 display controller. There is also a TDK CXA-1301 Inverter spec'd which provides CCFT backlight voltage ( Typical 1000 Vrms @ 400hz) The Sharp LM64015T display is a 12 pin device, Pin 1 labelled S for Scan Start up high Pin 2 CP1 (clock pulse 1) Input Data latch (High to low) Pin 3 CP2 Data Input Clock Signal ( High to low) Pin 4 open Pin 5 NC Pin 6 Power supply for Logic Pin 7 Gnd potential Pin 8 Power for LCD Drive with pins 9-12 being display Data, D0 - D4 respectively - (High on)(Low off) This gives an Idea of typical voltages and interfaces of the era. This may not apply to the Specific Matsushita device you asked about. It points out that there are often Display Controllers Like Yamaha V6366 and High Voltage inverters like TDK CXA -1301 ( 100V- 1000V) for backlighting. Sincerely Larry Truthan