A device includes at least one transient image having optical properties which vary depending on the angle of observation, with the image(s) consisting of a set of three-dimensional microstructures arranged in a plurality of subsets. Each subset consists of microstructures having an equivalent or identical planar angle ?. A security document can include such a device and the device can be used as a security element.

The present invention is directed to obtaining an object having an anisotropic reflection characteristic without using a lenticular lens. A print product including a print medium on which a repetitive structure of projected portions and recessed portions is formed out of image forming materials including a color material includes a first layer formed on surfaces of the projected portions out of a first color material among the image forming materials, and a second layer formed on the recessed portions out of a second color material different from the first color material, wherein the projected portions have a height to occlude part of the second layer when observed at an angle different from an angle formed by a normal to a surface of the print medium.

A security article may include a substrate. The security article may include a layer of security ink. The layer of security ink may include a set of color-shifting interference particles. The security article may include a layer of magnetic color-shifting ink. The layer of magnetic color-shifting ink may include a set of magnetically aligned magnetic particles. A color-shifting property of the layer of security ink and a color-shifting property of the layer of magnetic color-shifting ink may have a threshold level of similarity to create a color matching effect.

A substrate is printed with front side and back side markings in a first color ink. The front side when viewed with reflected light includes a first marking printed in a first saturation and a first symbol printed in the first saturation. The back side when viewed with reflected light includes: a second marking printed in a second saturation; a second symbol printed in the second saturation; a third marking printed in the first saturation; and a third symbol printed in the first saturation. The first marking, the second marking, and the third marking are printed to provide an interlocking pattern of low saturation color and high saturation color when viewed with transmitted light. The second symbol is visible, and the first symbol and the second symbol are not distinguishably visible, when viewed with transmitted light.

The present invention provides a system for forming a security pattern by magnetic and optical fields, comprising: a printing substrate having an inducible ink pattern printed on its surface; and at least one set of security pattern forming units through which the printing substrate passes sequentially. Each set of security pattern forming units comprises: a magnetic field and a light source each acting on a surface of the printing substrate, such that after the printing substrate passes through the security pattern forming unit, an inducible ink pattern on the surface thereof exhibits the effect of the dual function of the optical field and the magnetic field.

The invention relates to a security document (100) with a securing element (101) placed locally or on the entire surface of a laminated or non-laminated substrate, comprising at least a marking region composed of at least one printing ink layer containing optically variable interference pigments and fluorescent pigments and/or dyes or a printing ink layer containing optically variable interference pigments and being free of additives changing the absorption spectrum of the printing ink layer, the marking region comprising a laser marking applied by laser radiation, that is visually recognizable basing on an irreversible change of interference properties of the printing ink layer containing optically variable interference pigments and fluorescent pigments and/or dyes or printing ink layer containing optically variable interference pigments, and on a transformation, within the laser marking, of an original color demonstrating a change dependent on the observation angle into another color demonstrating no change dependent on the observation angle. Also, the invention relates to a method for producing a security document as well as the invention relates to a securing element placed on a laminated or non-laminated security document (100).

Disclosed is a security document including an image layer with in a first image area an identification image. The document has in a second image area an authentication image that is composed of a first authentication image that is a positive version of the first image and a second authentication image that is a negative version of the first image. The authentication images can be observed at different angles and form a tilt image. Mutual comparison of the positive and negative tilt images and comparison with the identification image provides improved detection of unauthorized alterations.

There is described a combined printing press (10) for the production of security documents, in particular banknotes, comprising a screen printing group (3) and a numbering group (4) adapted to process printed substrates in the form of individual sheets or successive portions of a continuous web. The screen printing group (3) is located upstream of the numbering group (4) and comprises at least one screen printing unit (32-33) designed to print a pattern of optically-variable ink, which optically-variable ink contains flakes that can be oriented by means of a magnetic field. The screen printing group further comprises a magnetic unit (36) located downstream of the screen printing unit (32-33), which magnetic unit (36) is designed to magnetically induce an optically-variable effect in the pattern of optically-variable ink applied by the screen printing unit (32-33) prior to drying/curing of the optically-variable ink. The screen printing group (3) further comprises at least one drying/curing unit (37) designed to dry/cure the pattern of optically-variable ink in which the optically-variable effect has been induced by the magnetic unit (36), prior to transfer of the printed substrates to the numbering group (4).

A security device is disclosed that has an image formed upon a substrate. The image has a first printed region and a second different printed region both printed with a same ink formulation of field alignable flakes. At least one of the printed regions has optically variable effects. One of the first and second printed regions at least partially surrounds the other. The second printed region is formed of thin parallel lines and the first printed region has substantially wider lines than are printed in the second printed region. The area density of the ink in a line in the first group of wider lines is greater than the area density of a line in the second group of narrower lines. A surprising effect of this image is that particles or flakes in the ink are field aligned so as to produce a visible kinematic dynamic effect visible in the first region and not visible in the second region when the image is tilted or rotated.

The invention relates to a transfer film (1), in particular hot-stamping film, the use of a transfer film (1), a film, a security document (2), and a method for producing a transfer film (1). Here, it is provided that the transfer film (1) comprises a transfer layer (20) detachably arranged on a carrier layer (10). The transfer layer (20) further has at least one first color layer (30) and the at least one first color layer (30) comprises at least one binder and at least first pigments, the color appearance of which changes depending on the observation angle.