| 摘要 |
A diffractive light outcoupling unit (404, 602, 604) for forming a part of a directive light outcoupling system comprising a plurality of diffractive outcoupling units, wherein said diffractive light outcoupling unit comprises a carrier element (401) for accommodating a diffractive surface relief pattern and transporting light, and a diffractive surface relief pattern (406, 416, 502, 504, 506, 508, 510, 702, 704, 706) comprising a plurality of consecutive diffractive surface relief forms defined on a predetermined surface of the carrier element, the diffractive surface relief pattern being arranged to couple light incident thereon via interaction involving at least two surface relief forms of said plurality of consecutive diffractive surface relief forms of said diffractive surface relief pattern so as to enhance the directivity of the light to be out-coupled through collimation, wherein a number of light rays of the incident light to be diffracted penetrate through at least the first surface relief form of said diffractive surface relief pattern comprising said plurality of consecutive diffractive surface relief forms during said interaction. |
