Security document with lightguide having a sparse outcoupler structure

Abstract

The security document, such as a passport, comprises a lightguide having an incoupler structure and in outcoupler structure. The outcoupler structure is sparse in the sense that any part of the protective area is close to a part of the outcoupler structure. However, to secure a large protective area with a limited amount of incoupled light, outcoupler structure covers no more than 20% of the protective area. This allows to protect a large area of the security document, such as a photograph or other personalized information, by means of the lightguide.

Dependencies are inferred from the claim text.