Patent · US Active

Optical security device having a high refractive index layer between adjacent diffraction elements which have upper portions uncovered by the high refractive index layer

US9904249B2 · kind B2 · utility

0Cited by

1References

13Claims

0Family size

Assignee

CCL Secure Pty Ltd · AU

Inventors

Phei Lok · Whittlesea, AU
Gary Fairless Power · Penrith, GB
Benjamin Gordon Stevens · Elmore, AU

Key dates

Filing date	May 6, 2013
Grant date	Feb 27, 2018
Priority date	—
Expiry date	Jun 4, 2034

Classification

Technology area (CPC G)Physics
CPC primaryG03H2250/36
WIPO fieldOptics
WIPO sectorInstruments

Abstract

An optical security device is disclosed which includes a diffraction layer having a plurality of diffraction elements and a high refractive index layer, wherein the high refractive index layer is applied on the diffraction layer such that selected regions of the diffraction layer have the corresponding diffraction elements partially uncovered by the high refractive index layer and other regions are substantially covered by the high refractive index layer. Accordingly, the optical security device has a first security feature associated with the diffraction layer and a second security feature associated with the high refractive index layer. An image is viewable from the regions of the high refractive index layer, either, covertly by placed an index matched item over the device or, overtly, through selection of the thickness of the high refractive index layer.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.