US 11,945,256 B2
Laser marked optically variable device
Thivaharan Thurailingam, Stittsville (CA); and Silviu Crisan, Gatineau (CA)
Assigned to CANADIAN BANK NOTE COMPANY, LIMITED, Ottawa (CA)
Filed by Canadian Bank Note Company, Limited, Ottawa (CA)
Filed on Sep. 23, 2021, as Appl. No. 17/482,522.
Claims priority of application No. CA 3094381 (CA), filed on Sep. 24, 2020.
Prior Publication US 2022/0088958 A1, Mar. 24, 2022
Int. Cl. G02B 5/18 (2006.01); B42D 25/29 (2014.01); B42D 25/342 (2014.01); B42D 25/351 (2014.01); B42D 25/435 (2014.01)
CPC B42D 25/435 (2014.10) [B42D 25/29 (2014.10); B42D 25/342 (2014.10); B42D 25/351 (2014.10); G02B 5/1852 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A security device for a security document, the security device comprising:
at least two interlaced laser engraved images forming an angle dependent parallax effect wherein first and second images are laser engraved at a surface of a substrate of the security document, and
a colour image printed on at least one non-laser-engravable layer situated between laser engravable layers, wherein the colour image is in registration with the laser engraved images, whereby the combination of the colour image and the at least two interlaced laser engraved images results in a colour changing effect.