Patent ID: 8717676

Claim:
A lighting device comprising: a carrier element for transporting light, the carrier element including a surface area and an exit surface area substantially opposite the surface area; and diffractive units individually comprising a plurality of consecutive diffractive surface relief forms defined on the surface area of the carrier element, wherein: the diffractive units are individually configured to outcouple light incident thereon via at least two of the plurality of consecutive diffractive surface relief forms; at least a portion of the incident light penetrates through at least a first diffractive surface relief form of the plurality of consecutive diffractive surface relief forms and reflects toward the exit surface area from at least a second diffractive surface relief form of the plurality of consecutive diffractive surface relief forms; the surface area of the carrier element comprises a first surface area and a nested second surface area surrounded by the first surface area, wherein the first surface area comprises diffractive surface relief forms aligned in a first direction and the nested second surface area comprises diffractive surface relief forms aligned in a second direction different from the first direction; and the diffractive units are semi-randomly organized on the carrier element to avoid a Moire effect.