US 11,921,303 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 Feb. 23, 2021, as Appl. No. 17/182,622.
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 (EP), filed on Aug. 7, 2015.
Prior Publication US 2021/0173130 A1, Jun. 10, 2021
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)] 7 Claims
OG exemplary drawing
 
1. A method for manufacturing an optical element comprising a region with an anisotropic surface relief microstructure, which has zones with different anisotropy directions θi, wherein information is encoded in a frequency distribution of the zones with the different anisotropy directions, the method comprising
providing the information to be encoded;
defining the number of different anisotropy directions θi to be used for encoding;
defining a frequency distribution fi(θi) of zones with different anisotropy directions, the frequency distribution fi(θi) representing the information to be encoded;
determining a positional orientation distribution of zones with different anisotropy directions θi, the positional orientation distribution fitting with the determined frequency distribution, and
manufacturing the optical element comprising the region with the anisotropic surface relief microstructure, which has zones with different anisotropy directions θi, according to the determined positional orientation distribution,
wherein the manufacturing the optical element comprises manufacturing the anisotropic surface relief microstructure, and
wherein the manufacturing the anisotropic surface relief microstructure comprises:
coating a thin photo-alignment film on a substrate,
exposing the photo-alignment film to linearly polarized ultraviolet (UV) 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.