US 12,427,802 B2
Optical anti-counterfeiting element and optical anti-counterfeiting product
Weiwei Zhang, Beijing (CN); Kai Sun, Beijing (CN); and Chunhua Hu, Beijing (CN)
Assigned to Zhongchao Special Security Technology Co., Ltd, Beijing (CN); and China Banknote Printing and Minting Corp., Beijing (CN)
Appl. No. 17/633,165
Filed by Zhongchao Special Security Technology Co., Ltd, Beijing (CN); and China Banknote Printing and Minting Corp., Beijing (CN)
PCT Filed Aug. 7, 2020, PCT No. PCT/CN2020/107721
§ 371(c)(1), (2) Date Feb. 4, 2022,
PCT Pub. No. WO2021/027708, PCT Pub. Date Feb. 18, 2021.
Claims priority of application No. 201910734492.X (CN), filed on Aug. 9, 2019.
Prior Publication US 2022/0297465 A1, Sep. 22, 2022
Int. Cl. G02B 5/08 (2006.01); B42D 25/324 (2014.01); B42D 25/351 (2014.01); B42D 25/373 (2014.01)
CPC B42D 25/373 (2014.10) [B42D 25/324 (2014.10); B42D 25/351 (2014.10); G02B 5/0816 (2013.01)] 11 Claims
OG exemplary drawing
 
1. An optical anti-counterfeiting element, comprising:
a substrate having a first surface and a second surface opposite each other, at least a partial region of the substrate is transparent;
a microstructure formation layer formed on the first surface, the microstructure formation layer has at least a first region and a second region, the first region comprises a first surface micro relief structure, the second region comprises a second surface micro relief structure, and a specific volume of the first surface micro relief structure is less than a specific volume of the second surface micro relief structure; and
a reflective layer, a protective layer, a first transflective coating, a dielectric layer and a second transflective coating which sequentially and homomorphically cover on the first region, the first transflective coating, the dielectric layer and the second transflective coating also sequentially and homomorphically cover on the second region, wherein a ratio of a refractive index of the first transflective coating to an extinction coefficient of the first transflective coating is different from a ratio of a refractive index of the second transflective coating to an extinction coefficient of the second transflective coating;
the first transflective coating, the dielectric layer and the second transflective coating covering on the second region from a first multi-layer optically variable coating, and the reflective layer, the protective layer, the first transflective coating, the dielectric layer and the second transflective coating, covering on the first region form a second multi-layer optically variable coating, and the first multi-layer optically variable coating on the second region and the second multi-layer optically variable coating on the first region are strictly positioned on the two regions respectively.