| abstract |
A compact LED lighting unit, (1) for camera flash applications, comprising a reflective housing having (14) having a reflective base (15) and an open top (51); an LED (10) mounted within the reflective housing (14) and a beam shaping foil stack (12) provided over the open top of the housing (14); wherein, the foil stack (12) comprises first and second microstructured sheets (50, 52), each having an array of elongate locally parallel ridges (41) facing away from the LED, wherein the ridges of one sheet locally cross the ridges of the other sheet by an angle in the range 30 to 150 degrees. |