Image Number 4 for United States Patent #5442522.
A backlight system for liquid crystal device display is equipped with a dual lighting system for day viewing and night viewing. The day lighting system uses conventional fluorescent or incandescent lamps for full color display during daytime use. The night lighting system uses a lower intensity light source. The day lighting system is disabled while the night system is in use. The dual lighting system provides an extended dimming range compared to what would otherwise be available.