Optically variable anti-counterfeiting element

Abstract

The invention provides an optically variable anti-counterfeiting element first, which at least has a first liquid crystal layer and a dark background layer, wherein the first liquid crystal layer is made of at least one cholesteric liquid crystal material, the dark background layer contains an anti-counterfeiting material which can be identified by machine reading, and at least part of dark background layer is overlapped with at least part of the first liquid crystal layer up and down to form an overlapped area; and when the overlapped area is observed at two set angles, the reflected light changes between a colorless state and a colored state. The optically variable anti-counterfeiting element provided by the invention has a primary anti-counterfeiting characteristic that reflected light of at least part of areas changes between a colorless state and a colored state with the change in an observation angle and secondary machine-reading anti-counterfeiting characteristics of infrared rays, magnetism, fluorescence, information hiding and the like, thereby allowing people to identify counterfeit easily and combining multi-stage anti-counterfeiting factors different to counterfeit. The invention also provides product with the optically variable anti-counterfeiting element.

Description

technical field [0001] The invention relates to an optically variable anti-counterfeiting element for protecting valuable items, in particular to an optically variable anti-counterfeiting element, which is viewed from different angles, and the color of at least some areas is interchangeable between colorless and colored and combined with machine-readable anti-counterfeiting features. Optical variable anti-counterfeiting element. Background technique [0002] With the development of modern duplication technology, counterfeiting crimes against all kinds of brand-name goods, financial instruments and securities are becoming more and more rampant. , some counterfeit securities have even reached the point where it is difficult to distinguish the real from the fake for the public, causing unnecessary confusion. The sophistication and extensiveness of counterfeiting technology have put forward higher requirements for anti-counterfeiting technology. [0003] At present, a variety ...

AI Technical Summary

Problems solved by technology

However, in this application, when the lighting conditions are poor, it is difficult for the naked eye to accurately identify this color change effect, which affects the anti-counterfeiting effect of the anti-counterfeiting element containing this liquid crystal material to a large extent.

[0009] To sum up, anti-counterfeiting using the angle-dependent color-changing effect of optical components or optically variable pigments has been widely used, and has played a very good role in anti-counterfeiting for a long period of time, but currently Optically variable pigments (OVP) and liquid crystal pigments for making such optically variable anti-counterfeiting elements can be easily obtained in the market. Moreover, many optically variable anti-counterfeiting elements that already exist have the same or similar angle-dependent color changing effect, which is easy to confuse the public. , providing opportunities for counterfeiters

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