Method of fabricating authentication labels and authenticating patterns incorporating diffraction structures
AssigneeInternational Business Machines Corporation
InventorHans E. Korth
Life of this patent
Estimating the term…
Abstract
An authenticating pattern 20 for valuable objects is fabricated as an integrated structure of a substrate layer 21 and a transparent overcoat layer 22 with a viewable interface therebetween containing a light diffracting structure 10. Unique parameters are randomly defined in the light diffracting structure by anisotropic process steps not under full control of the producer during the manufacturing of the diffracting structure to prevent copying or creating an exact replica thereof. The resultant uniquely coloured authenticating pattern can be verified by simple observation with the naked eye which is a prerequisite for ubiquitous verification.
Claims22
A method of providing an authenticating pattern for an object comprising:
- forming an integrated structure of a substrate layer and a transparent overcoat layer on the object so that the layers define a viewable interface therebetween that includes a light diffracting structure randomly defined by an anisotropic etching process involving photochemical etching with variable illumination that causes random variations in peak-to-valley ratios a:b and line depths c of the light diffracting structure to produce a colored pattern visibly distinguishable by the naked human eye without special lighting or equipment to validate the authenticity of the object.
A method of providing an authentication label as part of an object comprising:
- a) forming an integrated structure of a substrate layer and a transparent overcoat bonded to the substrate layer to define therebetween a viewable interface including a light diffracting structure randomly produced by an anisotropic etching process involving photochemical etching with variable illumination that causes random variation in the peak-to-valley ratios a:b and line depths c of the light diffracting structure to produce an authenticating pattern visibly identifiable by the naked eye without special illumination;
- and
- b) forming graphic personalization information in said integrated structure.
A method of fabricating a light diffracting structure used for authentication purposes comprising:
- providing data for a pattern of a light diffracting pattern structure;
- and
- using an anisotropic photochemical etching process to manufacture said light diffracting structure from the data, said process involving photochemical etching with variable illumination that causes random variation in peak-to-valley ratios a:b and line depths c of the light diffracting structure to provide a randomly defined colored pattern visibly distinguishable from other patterns by the naked eye without the use of special lighting for validating the authenticity of an object attached to the structure.
A method of fabricating an authenticating label for an object comprising:
- providing data for a pattern of a light diffracting structure;
- using an anisotropic process involving photochemical etching with variable lighting that causes random variations in peak-to-valley ratios a:b and line depth c to manufacture a master of the light diffracting structure with random variations in the pattern which variations provide a color pattern visibly distinguishable by the naked human eye without special illumination or equipment;
- replicating the diffracting structure using the master;
- and
- covering the replicated diffracting structure with an overcoat layer.
Dependencies are inferred from the claim text.