Security system with optical waveguide
AssigneeOrell FüSsli Sicherheitsdruck AG
InventorMartin Eichenberger
Life of this patent
Estimating the term…
Abstract
A security document comprises a substrate (1) and an optical waveguide (7). Couplers (10a, 10h) are provided in the waveguide (7) for coupling light into and out of the waveguide. The couplers (10a, 10b) can e.g. by gratings, scattering objects, holograms, luminescent dyes or perforations. The authenticity of the document can be verified using methods based on the properties of the waveguide.
Claims18
A security document comprising:
- a substrate,
- an optical waveguide arranged on and/or in said substrate, and
- at least a coupler for coupling light into said waveguide or out from said waveguide,
- wherein said security document comprises a periodic microlens-array, and
- wherein said coupler has a periodic structure, with the microlens-array having a period substantially equal to said periodic structure.
The security document of claim I, comprising a first and a second coupler, wherein light coupled into said waveguide by means of said first coupler is at least partially transmitted to and coupled out by said second coupler.
A security document comprising:
- a substrate,
- an optical waveguide arranged on and/or in said substrate, and
- at least a coupler for coupling light into said waveguide or out from said waveguide,
- wherein said security document comprises a periodic microlens-array, and
- wherein said coupler has a periodic structure, and
- wherein a period of the microlens-array deviates by 10% or less from a period of the periodic structure of the coupler.
Dependencies are inferred from the claim text.