USING NANOPARTICLES TO ADJUST REFRACTIVE INDEX OF POLYMER MATRIX LAYERS TO OPTIMIZE MICROOPTICAL (MO) FOCUSING Russian patent published in 2023 - IPC G02B27/16 

FIELD: security devices.

SUBSTANCE: invention is related to improving the characteristics of security devices, such as micro-optical strips. The security device includes a pictogram focusing element means, wherein each pictogram focusing element of the pictogram focusing element means is associated with a focal path. The device further comprises a layer of pictograms with one or more pictograms associated with a first characteristic colour and one or more pictograms associated with a second characteristic colour, and one or more areas between the pictograms containing a volume of substantially colourless material. At a first viewing angle, the colour is visible through each pictogram focusing element, and the colour visible through each pictogram focusing element at the first viewing angle is based on one or more colours of a first characteristic colour, a characteristic colour, or a substantially colourless material.

EFFECT: invention provides expanded functionality of the protective device.

20 cl, 26 dwg