NVIS compatible backlight device and LCD using the same

摘要

A backlight device for a liquid crystal display containing a substantially planar light guide with a light emission surface and a light-collecting portion opposing the light emission surface. A pair of opposing side portions may define the periphery of the light guide. A first plurality of LEDs are placed so as to direct the emitted light into the light-collecting portion. An NVIS filter is preferably placed adjacent to at least one of the side portions. A second plurality of LEDs are placed to direct the emitted light through the NVIS filter and into a side portion of the light guide. Alternative embodiments can contain NVIS filters and LEDs along additional edge portions of the light guide. Some embodiments may use directing elements or slanted surfaces of the light guide to direct the light from the second plurality of LEDs into the edge portions of the light guide.