Patent ID: 6789921
Filing Date: 2004-09-14
Classification: F21V,F21Y,G02F,G09F

Abstract:
A backlight for a dual mode night vision image system liquid crystal display comprising:a first array of light emitting diodes (LEDs) disposed on a first circuit card; said first array having a substantially planar illuminated first side and having a substantially rectangular shape of a predetermined sized rectangle; said first circuit card having a predetermined first circuit card thickness; a second array of LEDs disposed on a second circuit card; said second array having a substantially planar illuminated second side and having said substantially rectangular shape of said predetermined sized rectangle; said second circuit card having a second circuit card thickness; said second side being disposed behind said first side; said first circuit card having a plurality of night mode enabling apertures therethrough which permit light generated from behind said first side by said second array to pass through; a heat sink disposed behind said second side; said heat sink having a front side with said substantially rectangular shape of said predetermined sized rectangle; and, said heat sink not being separated from said second side by a substantially planar air gap which is more than 4 times as thick as said second circuit card thickness.