NVG-compatible AMLCD backlight having a ridged prismatic TIR with an embedded diffuser doped with an IR absorbing dye

DETAILED DESCRIPTION In accordance with the present invention an improved night vision goggle (NVG) compatible backlight assembly for AMLCDs, LCDs, or other displays is provided.
The backlight assembly includes a plurality of layers, one of which is a total internal reflective (TIR) layer embedded with a diffuser material and doped with an IR absorbing dye.
The IR dye doped TIR with embedded diffuser layer, which is located between the light source of the backlight assembly and the display element, collects and uniformly distributes the light supplied to the display element, and absorbs infrared (IR) light that is incompatible with NVGs.
In accordance with other aspects of this invention, the IR dye doped TIR with embedded diffuser layer has a ridged prismatic surface, i.
e.
, includes parallel prismatic protrusions on one surface.
Thus, this layer is an IR dye doped ridged prismatic TIR with embedded diffuser layer.
In accordance with further aspects of this invention the backlight assembly includes additional layers.
Beginning at the light source, the IR dye doped ridged prismatic TIR with embedded diffuser layer is oriented such that the prismatic surface faces away from the light source.
A second TIR layer also having prismatic protrusions on one surface is juxtaposed against the prismatic surface of the IR dye doped ridged prismatic TIR with embedded diffuser layer.
The prismatic protrusions of the second TIR layer are oriented orthogonal to the prismatic protrusions of the IR dye doped ridged prismatic TIR with embedded diffuser layer.
In accordance with other aspects of this invention, the illumination optics also include a custom diffuser disposed between the second TIR layer and the display element.
The custom diffuser improves off-axis luminance and uniform light distribution.
In accordance with other further aspects of this invention, the custom diffuser is a holographic diffuser or a lenticular lens array.
The holographic diffuser or lenticular lens array increases luminance in specific viewing directions