Patent ID: 7997780

Claim:
A lighting device comprising: a housing; a plurality of LEDs arranged in the housing; a first optical plate positioned above the LEDs, the first optical plate comprising: a light input surface; a light output surface opposite to the light input surface; and a plurality of elongated arcuate protrusions formed on the light output surface, the elongated arcuate protrusions being substantially parallel to one another; and a second optical plate positioned above the first optical plate, the second optical plate comprising a light input surface, a light output surface opposite to the light input surface, a plurality of V-shaped ridges and a plurality of elongated arcuate protrusions, wherein the V-shaped ridges and the elongated arcuate protrusions are formed on the light output surface of the second optical plate, and the V-shaped ridges substantially perpendicularly intersect with the elongated arcuate protrusions of the second optical plate.