US 11,953,709 B2
Optical camouflage filter
Guanglei Du, Woodbury, MN (US); John A. Wheatley, Lake Elmo, MN (US); William B. Kolb, Stillwater, MN (US); John C. Schultz, Afton, MN (US); Daoyun Song, Woodbury, MN (US); and Luke D. Riveness, Hastings, MN (US)
Assigned to 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
Filed by 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
Filed on Nov. 16, 2021, as Appl. No. 17/527,837.
Application 17/527,837 is a continuation of application No. 16/071,573, granted, now 11,204,456, previously published as PCT/US2017/014031, filed on Jan. 19, 2017.
Claims priority of provisional application 62/281,643, filed on Jan. 21, 2016.
Prior Publication US 2022/0075107 A1, Mar. 10, 2022
Int. Cl. G02B 5/26 (2006.01); G02B 5/20 (2006.01); G02B 5/22 (2006.01); G02B 5/28 (2006.01)
CPC G02B 5/26 (2013.01) [G02B 5/206 (2013.01); G02B 5/208 (2013.01); G02B 5/22 (2013.01); G02B 5/223 (2013.01); G02B 5/281 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A system comprising:
one or both of a light emitter or a light receiver;
a reflective layer, the reflective layer including a multilayer optical film; and
a wavelength selective scattering layer, the wavelength selective scattering layer including a plurality of interconnected voids, wherein the wavelength selective scattering layer has a near-infrared scattering ratio of less than about 0.9, the near-infrared scattering ratio being a ratio of an average near-infrared scattering to an average visible scattering, and wherein the wavelength selective scattering layer has a visible reflective haze ratio of greater than about 0.5, the visible reflective haze ratio being a ratio of an average visible diffusive reflectance to an average visible total reflectance, wherein light between the wavelength selective scattering layer and one or both of the light emitter and the light receiver follows an indirect path.