The present invention refers to a safety device (1) for authorizing an operation, comprising: a supporting structure (2); a color-shift structure (5) coupled to the supporting structure (2) on a side or face of this latter; a first safety string (6) made in the supporting structure (2) and disposed on said side or face of the supporting structure (2) so that the first safety string (6) and color-shift structure (5) are overlapped on each other; a second safety string (7) made in the supporting structure (2) and disposed on said side or face of the supporting structure (2) so that the second safety string (7) and color-shift structure (5) are overlapped on each other. The present invention refers also to a safety method and system for authorizing an operation exploiting such safety device.

Security documents often incorporate security devices to prevent or hinder counterfeiters. Disclosed herein are security devices that include a fluid or fluids within the devices. Such devices, and security documents that include them, afford new techniques to check whether a security document is a legitimate or counterfeit copy.

Security documents often incorporate security devices to prevent or hinder counterfeiters. Disclosed herein are security devices that include a fluid or fluids within the devices. Such devices, and security documents that include them, afford new techniques to check whether a security document is a legitimate or counterfeit copy.

A security device and method of making thereof. The security device includes a colour shifting element that exhibits different colours dependent on the angle of incidence of light impinging upon the colour shifting element, and; an at least partially transparent light control layer covering at least a part of the colour shifting element and including a surface relief adapted to modify the angle of light incident upon the light control layer, wherein; the light control layer includes at least first and second functional regions having different refractive indices such that light incident upon the first functional region impinges upon the colour shifting element at a first angle of incidence, and light incident upon the second functional region impinges upon the colour shifting element at a second, different, angle of incidence.

Processes can produce strongly adherent, particularly embossed, films on flexible substrates. Security elements may be obtained by such processes as may be security documents, e.g., comprising the security elements. By coating a flexible substrate first with a primer layer and then with an embossed film, the adherence of the embossed film to the substrate may be improved while keeping the optical performance of the embossed film.

Processes can produce strongly adherent, particularly embossed, films on flexible substrates. Security elements may be obtained by such processes as may be security documents, e.g., comprising the security elements. By coating a flexible substrate first with a primer layer and then with an embossed film, the adherence of the embossed film to the substrate may be improved while keeping the optical performance of the embossed film.

An optical marking device including at least a first layer and a second layer disposed at least partially opposite each other, at least one of the first and second layers having an optically variable element being able to change colour between a first colour and a second colour, the first and second colours contrasting from a colour of the other layer in such a way that when the optically variable element displays the first colour, the first layer is visible and when the optically variable element displays the second colour, the second colour is visible, or when the optically variable element displays the first colour, the second layer is visible and when the optically variable element displays the second colour, the first layer is visible.

An optical marking device including at least a first layer and a second layer disposed at least partially opposite each other, at least one of the first and second layers having an optically variable element being able to change colour between a first colour and a second colour, the first and second colours contrasting from a colour of the other layer in such a way that when the optically variable element displays the first colour, the first layer is visible and when the optically variable element displays the second colour, the second colour is visible, or when the optically variable element displays the first colour, the second layer is visible and when the optically variable element displays the second colour, the first layer is visible.

A security element includes a transparent film, a first layer and a second layer. The first layer includes a first metal arranged on the transparent film in a first pattern. The second layer includes a second metal being a baser metal than the first metal arranged over the first layer in a second pattern. Each of the first and second patterns is composed of metallic regions and metal-free regions. The metal-free regions of the second pattern overlap with the metal-free regions of the first pattern. The metallic regions of the first pattern overlap with the metal-free regions of the second pattern.

A reflective security element for checking the authenticity with polarized light, has a retroreflective layer and a birefringent layer arranged in a structured manner on the retroreflective layer.