US 11,840,112 B2
Optical structures providing dichroic effects
Roger Winston Phillips, Santa Rosa, CA (US); Christopher Chapman Rich, Rancho Palos Verdes, CA (US); and Joel Mikael Petersen, Valley Village, CA (US)
Assigned to WAVEFRONT TECHNOLOGY, INC., Paramount, CA (US)
Filed by WAVEFRONT TECHNOLOGY, INC., Paramount, CA (US)
Filed on Aug. 26, 2021, as Appl. No. 17/445,996.
Application 17/445,996 is a continuation of application No. 16/780,777, filed on Feb. 3, 2020, granted, now 11,198,316.
Claims priority of provisional application 62/829,572, filed on Apr. 4, 2019.
Prior Publication US 2022/0227159 A1, Jul. 21, 2022
Int. Cl. B42D 25/373 (2014.01); B42D 25/29 (2014.01); B42D 25/351 (2014.01); B42D 25/355 (2014.01); B42D 25/378 (2014.01); B42D 25/45 (2014.01)
CPC B42D 25/373 (2014.10) [B42D 25/29 (2014.10); B42D 25/351 (2014.10); B42D 25/355 (2014.10); B42D 25/378 (2014.10); B42D 25/45 (2014.10)] 27 Claims
OG exemplary drawing
 
1. A document having a security feature, the document comprising:
a main body of the document; and
a pigment disposed on the main body, the pigment comprising:
an optical structure comprising at least three metal layers and at least two dielectric layers,
wherein the at least two dielectric layers are disposed on opposite sides of a first metal layer of the at least three metal layers such that each of said dielectric layers has a first side facing said first metal layer and a second side opposite said first side,
wherein remaining metal layers of the at least three metal layers are disposed on said second side of the at least two dielectric layers opposite the first side facing the first metal layer, and
wherein the pigment produces a first color in a reflection view and a second color different from the first color in a transmission view.