US 12,130,455 B2
Multilayer partial mirror, backlight, and display system
Adam D. Haag, Woodbury, MN (US); Gilles J. Benoit, Minneapolis, MN (US); Stephen A. Johnson, Woodbury, MN (US); Samuel A. Minno, St. Paul, MN (US); Quinn D. Sanford, Mosinee, WI (US); Lin Zhao, Woodbury, MN (US); and Robert D. Taylor, Stacy, MN (US)
Assigned to 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
Appl. No. 18/569,302
Filed by 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
PCT Filed Jun. 28, 2022, PCT No. PCT/IB2022/056006
§ 371(c)(1), (2) Date Dec. 12, 2023,
PCT Pub. No. WO2023/281357, PCT Pub. Date Jan. 12, 2023.
Claims priority of provisional application 63/203,068, filed on Jul. 7, 2021.
Prior Publication US 2024/0264339 A1, Aug. 8, 2024
Int. Cl. G02B 5/08 (2006.01); F21V 8/00 (2006.01); G02B 5/30 (2006.01); G02B 27/28 (2006.01); G02F 1/13357 (2006.01)
CPC G02B 5/0841 (2013.01) [G02B 5/305 (2013.01); G02B 5/3066 (2013.01); G02B 5/3083 (2013.01); G02B 6/0055 (2013.01); G02B 27/281 (2013.01); G02F 1/133605 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A multilayer partial mirror comprising a plurality of alternating first and second polymeric layers numbering at least 50 in total and disposed between, and integrally formed with, opposing first and second polymeric skin layers, each of the first and second polymeric layers having an average thickness of less than about 500 nm, each of the polymeric skin layers having an average thickness of greater than about 0.5 microns, the first and second polymeric layers comprising respective indices nx1 and nx2 along a same in-plane x-direction, respective indices ny1 and ny2 along an in-plane y-direction orthogonal to the x-direction, and respective indices nz1 and nz2 along a z-direction of the polymeric layers orthogonal to the x- and y-directions, such that for at least one wavelength in a visible wavelength range extending from about 420 nm to about 680 nm:
nx1 and ny1 are within about 0.05 of each other;
nz1 is less than each of nx1 and nx2 by at least 0.06;
nx2, ny2 and nz2 are within about 0.05 of each other; and
for each of the first and second polymeric skin layers, corresponding indices of the polymeric skin layer and one of the first polymeric layers and the second polymeric layers along each of the x-, y- and z-directions are within about 0.05 of each other;
wherein, for the visible wavelength range and an incident light propagating in an incident plane that comprises the x-direction:
for an s-polarized incident light, the plurality of alternating first and second polymeric layers has an average reflectance Rs1 for a first incident angle of less than about 10 degrees, and an average reflectance Rs2 for a second incident angle of greater than about 45 degrees; and
for a p-polarized incident light, the plurality of alternating first and second polymeric layers has an average reflectance Rp1 for the first incident angle, and an average reflectance Rp2 for the second incident angle, each of Rs2/Rs1 and Rp2/Rp1 greater than about 1.15.