DIFRACTION PROTECTIVE ELEMENT WITH A GREY-SCALE IMAGE Russian patent published in 2008 - IPC B42D15/10 G02B5/18 G06K19/16 

FIELD: machine building.

SUBSTANCE: diffraction element has a grey-scale image from diffraction structures in the reflection layer, which are placed between a transparent layer and a protective layer of lacquer. The grey-scale image is divided into image elements, with at least one dimension less than 1 mm. The section of each image element is divided into a background image and the sample of the image element. At least through part of the surface of the grey-scale image pass streaks of the sample with a linear sample of thickness ranging from 15 mcm to 300 mcm and partially cover the background field and samples of the image elements. The linear sample is made from a band of the surface with structures of the sample and with thickness of the line in the range from 5 mcm to 50 mcm. The linear samples consist of letters, words, linear elements and pictograms. The structure of the sample differs from the first and second surfaces of the structure, at least, on one parameter of the structure. Thickness of the lines of the band of the surface in background fields is constant. Surface brightness of the image elements through the thickness of the lines of the surface streaks on the image element is controlled in such a way that, part of the area of the sample of the image element, not covered by the linear sample, is determined respectively by the surface brightness of the image of the grey-scale image in the location of the image element and with consideration of surface brightness of adjacent image elements.

EFFECT: provides for making a diffraction protective element, which demonstrates a grey-scale image and which is difficult to imitate or copy.

17 cl, 3 tbl, 10 dwg