LIGHTING UNIT, ESPECIALLY FOR ROAD ILLUMINATION

摘要

A lighting unit comprising a tapering cavity surrounded by a circumferential reflective wall and extending between a light emission window and a light entrance surface where a light source is (to be) mounted. An optical plate having a light outcoupling structure is provided at the light emission window for redirecting and issuing light as a uniform lighting unit light beam. Said uniform lighting unit light beam has a first beam emission angle ß in a first direction and optionally, for example for a rectangular shaped light emission window, a second beam emission angle ɣin a second direction transverse to the first direction. The tapering cavity having a first cut-off angle α in said first direction, wherein ß = α +2*δ with 0° < δ <= 10°,and optionally a second cut-off angle ε in the second direction transverse to the first direction wherein ɣ= ε + Θ with 0° <= Θ <= 10°.