US 12,259,569 B2
Azimuthally modulated scattering device
David Pires, Giebenach (CH); and Mohammed Ibn-Elhaj, Allschwil (CH)
Assigned to ROLIC TECHNOLOGIES AG, Allschwil (CH)
Filed by ROLIC TECHNOLOGIES AG, Allschwil (CH)
Filed on Jan. 22, 2024, as Appl. No. 18/418,657.
Application 18/418,657 is a division of application No. 17/182,622, filed on Feb. 23, 2021, granted, now 11,921,303.
Application 17/182,622 is a division of application No. 15/750,228, abandoned, previously published as PCT/EP2016/067980, filed on Jul. 28, 2016.
Claims priority of application No. 15180316.0 (EP), filed on Aug. 7, 2015.
Prior Publication US 2024/0159944 A1, May 16, 2024
Int. Cl. G02B 5/02 (2006.01); B42D 25/23 (2014.01); B42D 25/29 (2014.01); B42D 25/328 (2014.01); B42D 25/355 (2014.01); B42D 25/364 (2014.01); G03H 1/00 (2006.01); G03H 1/02 (2006.01); G06K 19/06 (2006.01); G06K 19/16 (2006.01); G07D 7/00 (2016.01)
CPC G02B 5/0257 (2013.01) [B42D 25/23 (2014.10); B42D 25/29 (2014.10); B42D 25/328 (2014.10); B42D 25/355 (2014.10); B42D 25/364 (2014.10); G02B 5/0252 (2013.01); G03H 1/0011 (2013.01); G03H 1/0244 (2013.01); G06K 19/06009 (2013.01); G06K 19/06037 (2013.01); G06K 19/16 (2013.01); G07D 7/0032 (2017.05)] 6 Claims
OG exemplary drawing
 
1. A method of using an optical element which has been manufactured by a manufacturing method comprising providing information to be encoded, defining different anisotropy directions to be used for encoding, defining a frequency distribution of zones with the different anisotropy directions, the frequency distribution representing the information to be encoded, determining a positional orientation distribution of zones with the different anisotropy directions, the positional orientation distribution fitting with the frequency distribution, and manufacturing the optical element comprising a region with an anisotropic surface relief microstructure, which has zones with the different anisotropy directions, according to the positional orientation distribution,
the method of using the optical element comprising:
applying the optical element to a value document, and
using the optical element as a security feature in the value document,
wherein the manufacturing method of the optical element further comprises manufacturing the anisotropic surface relief microstructure, and
wherein the manufacturing the anisotropic surface relief microstructure comprises:
coating a photo-alignment film on a substrate,
exposing the photo-alignment film to linearly polarized ultraviolet light of different polarization directions according to the determined positional orientation distribution,
coating a blend of crosslinkable and non-crosslinkable liquid crystal materials on top of the photo-alignment film,
cross-linking the liquid crystalline blend, and
removing the non-cross-linked liquid crystal material.