The present invention relates to a security device comprising a colloidal crystal which exhibits excellent visibility and is also easily manufactured. The security device, according to the present invention, comprises: a substrate; a groove part formed on the substrate; a colloidal crystal positioned in the groove part; and an aging film. The security device, according to the present invention, exhibits excellent security and visibility, and thus may be used for securities, credit cards, security cards, anti-forgery products, etc.

Provided is an information display medium that can enhance a forgery prevention effect. An information display medium (100) includes a light reflection layer (20) made of a metal or a metallic oxide and partially or fully placed on one surface of a substrate, and the light reflection layer (20) includes a first region (30) where first information is displayed by either of or a combination of an outline shape and a shape of an uneven region, and a second information display region (21a) where identification information formed by partial material removal of the light reflection layer (20), the second information display region being set to partially or fully overlap with the light reflection layer (20) where the first information is displayed in the first region (30).

A manufacturing process that allows for the transfer of labels formed from polarizer film to end-use products. The polarizer film is covered by a masking layer that is typically die cut to create the labels from the continuous sheet of film. Here, an additional covering layer (or layers) of a relatively stiff material is disposed over the masking layer. The addition of the covering layer results in the processed polarizer film being less susceptible to damage (related to unwanted bending) during further processing and/or shipment. Advantageously, the covering layer improves the ability to remove individual labels from the film, particularly with respect to attempting to peel off the thin masking layer.

A display medium comprises a substrate having first and second surfaces, and a reflective layer on at least one of the first and second surfaces. The substrate includes a polarized light separation layer capable of reflecting circularly polarized light having one rotation direction DA and transmitting circularly polarized light having an opposite rotation direction to the rotation direction DA therethrough. The reflective layer contains first and second reflective pigments capable of reflecting circularly polarized light having rotation directions DBR and DBL, respectively, and transmitting circularly polarized light having opposite rotation directions to the rotation directions DBR and DBL, respectively, therethrough. The rotation directions DBR and DBL of the circularly polarized light that the first and second reflective pigments, respectively, can reflect are opposite to each other. Hues of the circularly polarized light that the first and second reflective pigments can reflect are differ from each other.

A flat security element with optical security features includes at least one first surface region with a first sub-wavelength structure. The structure elements that define the first sub-wavelength structure periodically repeat in the plane of the security element. In order to be able to convey a motif with increased forgery protection using at least two different color impressions, which motif is easy to produce, the first sub-wavelength structure of at least one partial region of the first surface region is additionally provided with an interference coating for producing a color-shifting effect.

A method for producing flakes of a resin thin film including: a step (1) of forming a resin thin film on a substrate film to obtain a multilayer film; a step (2) of pressing the multilayer film by a member having a concavo-convex shape to form cracks in the resin thin film; and a step (3) of stripping the resin thin film from the substrate film to obtain flakes. The step (2) is preferably performed with a pressing pressure of 100 MPa or less. The resin thin film is preferably formed of a cured product of a photocurable liquid crystal composition. The resin thin film is preferably a cholesteric resin layer.

A method for producing flakes of a resin thin film including: a step (1) of forming a resin thin film on a substrate film to obtain a multilayer film; a step (2) of pressing the multilayer film by a member having a concavo-convex shape to form cracks in the resin thin film; and a step (3) of stripping the resin thin film from the substrate film to obtain flakes. The step (2) is preferably performed with a pressing pressure of 100 MPa or less. The resin thin film is preferably formed of a cured product of a photocurable liquid crystal composition. The resin thin film is preferably a cholesteric resin layer.

A security element includes a first transparent film, on which a holographic layer is formed having a holographic surface structure, a reflective layer arranged in contact with the holographic layer having a pattern of non-transparent regions and transparent regions, a color changing layer, and a photoactive layer having dark regions and transparent regions. In first regions, parts of the non-transparent regions of the reflective layer are not overlapped by the dark regions of the photoactive layer. In second regions, the color changing layer is backed by the dark regions of the photoactive layer. In third regions, the transparent regions of the photoactive layer are at least partly in register with the transparent regions of the reflective layer so that the third regions are continuous when passing from patterns outside the non-transparent regions of the reflective layer to patterns outside the dark regions of the photoactive layer.

A security element includes a first transparent film, on which a holographic layer is formed having a holographic surface structure, a reflective layer arranged in contact with the holographic layer having a pattern of non-transparent regions and transparent regions, a color changing layer, and a photoactive layer having dark regions and transparent regions. In first regions, parts of the non-transparent regions of the reflective layer are not overlapped by the dark regions of the photoactive layer. In second regions, the color changing layer is backed by the dark regions of the photoactive layer. In third regions, the transparent regions of the photoactive layer are at least partly in register with the transparent regions of the reflective layer so that the third regions are continuous when passing from patterns outside the non-transparent regions of the reflective layer to patterns outside the dark regions of the photoactive layer.

A see-through security element (2), a security document (1) and a method for producing a see-through security element (2). The see-through security element has a first element with one or more transparent first partial areas and at least one reflective second partial area. The see-through security element has a second element with one or more first partial areas, which in each case in transmission form a color filter matched to a respectively assigned color, and has at least one second partial area, which is formed colorless, in particular colorless transparent, or in transmission and/or reflection forms a color filter which is matched to a color which is not assigned to any of the one or more first partial area of the second element. The first partial areas of the first element and the first partial areas of the second element at least partially overlap.