US 11,945,253 B2
Use of nanoparticles to tune index of refraction of layers of a polymeric matrix to optimize microoptic (MO) focus
Nancy J. Gettens, Waban, MA (US); Jonathan D. Gosnell, Cumming, GA (US); Michael McAllister, Windham, NH (US); and Pearl N. Dickerson, New Boston, NH (US)
Assigned to Crane & Co., Inc., Dalton, MA (US)
Appl. No. 17/612,932
Filed by CRANE & CO., INC., Dalton, MA (US)
PCT Filed May 20, 2020, PCT No. PCT/US2020/070065
§ 371(c)(1), (2) Date Nov. 19, 2021,
PCT Pub. No. WO2020/237260, PCT Pub. Date Nov. 26, 2020.
Claims priority of provisional application 62/864,448, filed on Jun. 20, 2019.
Claims priority of provisional application 62/850,337, filed on May 20, 2019.
Prior Publication US 2022/0227158 A1, Jul. 21, 2022
Int. Cl. C08F 265/06 (2006.01); B42D 25/29 (2014.01); B42D 25/324 (2014.01); B42D 25/351 (2014.01); B42D 25/373 (2014.01); B82Y 30/00 (2011.01); C08F 283/06 (2006.01); C08K 3/105 (2018.01); C08K 3/22 (2006.01); C08K 3/30 (2006.01); D21H 19/58 (2006.01); D21H 21/40 (2006.01); G02B 1/04 (2006.01); G02B 3/00 (2006.01); G02B 27/16 (2006.01); B42D 25/23 (2014.01); B42D 25/24 (2014.01); B42D 25/425 (2014.01)
CPC B42D 25/324 (2014.10) [B42D 25/373 (2014.10); C08F 265/06 (2013.01); C08F 283/065 (2013.01); C08K 3/105 (2018.01); C08K 3/22 (2013.01); C08K 3/30 (2013.01); D21H 19/58 (2013.01); D21H 21/40 (2013.01); G02B 1/041 (2013.01); G02B 3/0037 (2013.01); G02B 27/16 (2013.01); B42D 25/23 (2014.10); B42D 25/24 (2014.10); B42D 25/29 (2014.10); B42D 25/351 (2014.10); B42D 25/425 (2014.10); B82Y 30/00 (2013.01); C08K 2003/2227 (2013.01); C08K 2003/2241 (2013.01); C08K 2003/2244 (2013.01); C08K 2003/3036 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A security device comprising:
an arrangement of image icon focusing elements wherein each image icon focusing element of the arrangement of image icon focusing elements has a focal path;
a first image icon layer comprising one or more image icons of a first characteristic color;
a second image icon layer disposed below the first image icon layer and comprising one or more image icons of a second characteristic color; and
one or more regions between image icons comprising a volume of substantially colorless material,
wherein, at a first viewing angle, a color is visible through each image icon focusing element, each image icon focusing element tuned to focus light of both a first wavelength of the first characteristic color and a second wavelength of the second characteristic color, and
wherein the color visible through each image icon focusing element at the first viewing angle is dependent on positions of the one or more image icons of the first characteristic color and the one or more image icons of the second characteristic color within the focal path of each image icon focusing element, and on one or a combination of the first characteristic color, the second characteristic color, and the substantially colorless material.