US 12,306,419 B2
Optical film
Tao Liu, Woodbury, MN (US); Gary T. Boyd, Woodbury, MN (US); Daniel J. Schmidt, Woodbury, MN (US); Caleb T. Nelson, McKinney, TX (US); Owen M. Anderson, Minneapolis, MN (US); and Tri D. Pham, Woodbury, MN (US)
Assigned to 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
Appl. No. 17/769,280
Filed by 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
PCT Filed Oct. 29, 2020, PCT No. PCT/IB2020/060184
§ 371(c)(1), (2) Date Apr. 14, 2022,
PCT Pub. No. WO2021/090130, PCT Pub. Date May 14, 2021.
Claims priority of provisional application 62/932,578, filed on Nov. 8, 2019.
Prior Publication US 2024/0142673 A1, May 2, 2024
Int. Cl. G02B 3/08 (2006.01); G02B 1/10 (2015.01)
CPC G02B 3/08 (2013.01) [G02B 1/10 (2013.01)] 11 Claims
OG exemplary drawing
 
1. An optical film comprising a polymeric layer comprising a microstructured surface conformally coated with an inorganic optically transparent layer, the conformally coated microstructured surface comprising a plurality of microstructures, each microstructure comprising an optical facet and a sidewall meeting the optical facet at a ridge of the microstructure, the optical facet and the sidewall defining an oblique angle therebetween, wherein for each microstructure in at least a majority of the microstructures:
an optically absorptive layer is disposed on and substantially covers the sidewall, the optically absorptive layer comprising a first polyelectrolyte; and
the optical facet has a mean deviation surface roughness Ra<50 nm.