A secure multilayer structure, in particular for a secure document, including a base layer, at least one masking layer including a window opened in the masking layer, the window having an edge, a security element including a photoluminescent agent positioned between the base layer and the masking layer, adjacent to the window edge, such that the presence of the agent can be checked by illuminating the edge of the window and viewing the re-radiated luminescent light emerging from the masking layer through the window edge.

An information recording medium is formed by laminating a transparent protective layer and a base material having laser color-developing properties. The information recording medium includes an intermediate layer that is disposed between the transparent protective layer and the base material. In the information recording medium, the intermediate layer includes a diffraction structure layer that has a diffraction structure, and a first reflective layer that reflects visible light and is destroyed when irradiated with a laser beam. Light, when incident from a transparent protective layer side, causes a diffracted light pattern to appear in the diffraction structure layer so as to be observable from the transparent protective layer side. A laser beam, when applied from the transparent protective layer side, passes through the diffraction structure layer, destroys the first reflective layer, and develops color in the base material.

An information recording medium is formed by laminating a transparent protective layer and a base material having laser color-developing properties. The information recording medium includes an intermediate layer that is disposed between the transparent protective layer and the base material. In the information recording medium, the intermediate layer includes a diffraction structure layer that has a diffraction structure, and a first reflective layer that reflects visible light and is destroyed when irradiated with a laser beam. Light, when incident from a transparent protective layer side, causes a diffracted light pattern to appear in the diffraction structure layer so as to be observable from the transparent protective layer side. A laser beam, when applied from the transparent protective layer side, passes through the diffraction structure layer, destroys the first reflective layer, and develops color in the base material.

A security device is disclosed, comprising: a first ink (21) and a second ink (22) each arranged in respective laterally offset first and second regions of the security device, the first and second inks each comprising a respective luminescent material which both luminesce in response to irradiation at at least one excitation wavelength in the ultra-violet spectrum, the first and second inks each exhibiting substantially the same non-luminescent visible colour as one another when illuminated with visible light in the absence of the at least one excitation wavelength, and the first and second inks each exhibiting visible colours which are different from the non-luminescent visible colour and from one another when illuminated with a combination of visible light and the at least one excitation wavelength; a third ink (23) arranged in a third region of the device laterally offset from the first and second regions of the device, the third ink not luminescing in response to the at least one excitation wavelength, and the third ink exhibiting substantially the same non-luminescent visible colour as the first and second inks when illuminated with visible light in the absence of the at least one excitation wavelength; and a fourth ink (24) arranged in a masking pattern which partially overlaps one or more portions of the first ink in the first region and/or of the second ink in the second region, the fourth ink not luminescing in response to the at least one excitation wavelength, and the fourth ink exhibiting a different visible colour from the non-luminescent visible colour of the first, second and third inks when illuminated with visible light in the absence of the at least one excitation wavelength. When the security device is illuminated with visible light in the absence of the at least one excitation wavelength, the first, second and third regions together appear as one continuous pattern in the non-luminescent visible colour, the fourth ink obscuring the presence of more than one ink forming the continuous pattern, and when the security device is illuminated with a combination of visible light and the at least one excitation wavelength, the first and second regions become visibly distinct from each other and from the remainder of the continuous pattern.

A security device is disclosed, comprising: a first ink (21) and a second ink (22) each arranged in respective laterally offset first and second regions of the security device, the first and second inks each comprising a respective luminescent material which both luminesce in response to irradiation at at least one excitation wavelength in the ultra-violet spectrum, the first and second inks each exhibiting substantially the same non-luminescent visible colour as one another when illuminated with visible light in the absence of the at least one excitation wavelength, and the first and second inks each exhibiting visible colours which are different from the non-luminescent visible colour and from one another when illuminated with a combination of visible light and the at least one excitation wavelength; a third ink (23) arranged in a third region of the device laterally offset from the first and second regions of the device, the third ink not luminescing in response to the at least one excitation wavelength, and the third ink exhibiting substantially the same non-luminescent visible colour as the first and second inks when illuminated with visible light in the absence of the at least one excitation wavelength; and a fourth ink (24) arranged in a masking pattern which partially overlaps one or more portions of the first ink in the first region and/or of the second ink in the second region, the fourth ink not luminescing in response to the at least one excitation wavelength, and the fourth ink exhibiting a different visible colour from the non-luminescent visible colour of the first, second and third inks when illuminated with visible light in the absence of the at least one excitation wavelength. When the security device is illuminated with visible light in the absence of the at least one excitation wavelength, the first, second and third regions together appear as one continuous pattern in the non-luminescent visible colour, the fourth ink obscuring the presence of more than one ink forming the continuous pattern, and when the security device is illuminated with a combination of visible light and the at least one excitation wavelength, the first and second regions become visibly distinct from each other and from the remainder of the continuous pattern.

The present disclosure relates to signal processing such as digital watermarking and other encoded signals. One claim recites a method of offsetting color casting for a printed object associated with a retail product. The method includes: providing a first additive that absorbs light energy at or around a center wavelength of an illumination source; providing a second additive that absorbs in the ultra-violet spectrum, yet fluoresces at or around the center wavelength of the illumination source, wherein a combination of spectral responses of the first additive and the second additive offset color casting; printing the first additive, second additive and a color on the printed object, wherein the printing conveys an encoded plural bit signal. Of course, other claims and combinations are provided in the specification with reference to specific implementations and related examples.

An improved data bearing card includes a card body, personalization data unique to the data bearing card, and non-visible production indicia, separate from the personalization data, disposed on the card body and indicative of production-related information not otherwise provided on the data bearing card. The non-visible production indicia may be indicative of a corresponding piece of production equipment and/or an operator thereof utilized in connection with the data bearing card, or of a location of a corresponding region of a sheet assembly from which the corresponding card body was separated during production, or of other production-related information. The non-visible production indicia facilitates remedial action in the event that a defect or near-defect is found in the card body or other components of the data bearing card, and may otherwise facilitate card tracking during the production process.

An improved data bearing card includes a card body, personalization data unique to the data bearing card, and non-visible production indicia, separate from the personalization data, disposed on the card body and indicative of production-related information not otherwise provided on the data bearing card. The non-visible production indicia may be indicative of a corresponding piece of production equipment and/or an operator thereof utilized in connection with the data bearing card, or of a location of a corresponding region of a sheet assembly from which the corresponding card body was separated during production, or of other production-related information. The non-visible production indicia facilitates remedial action in the event that a defect or near-defect is found in the card body or other components of the data bearing card, and may otherwise facilitate card tracking during the production process.

A value document having a security element in the form of a strip with a first polymer layer which comprises at least one embossed diffraction structure, having at least one reflection layer which visually interacts with the diffraction structure in order to form a reflection hologram as the first visually recognisable security feature, and having at least one imprint which is luminescent under UV radiation and which forms a second security feature that is visually recognisable under UV light, wherein the reflection hologram comprises at least one see-through region on the second security feature. In order to increase the level of protection against forgery of the security element, the luminescent imprint comprises a halftone print image, and the see-through region is formed by at least one recess in the reflection layer and by the polymer layer which is free in this region of the recess from the diffraction structure at least above the halftone print image of the imprint.

A value document having a security element in the form of a strip with a first polymer layer which comprises at least one embossed diffraction structure, having at least one reflection layer which visually interacts with the diffraction structure in order to form a reflection hologram as the first visually recognisable security feature, and having at least one imprint which is luminescent under UV radiation and which forms a second security feature that is visually recognisable under UV light, wherein the reflection hologram comprises at least one see-through region on the second security feature. In order to increase the level of protection against forgery of the security element, the luminescent imprint comprises a halftone print image, and the see-through region is formed by at least one recess in the reflection layer and by the polymer layer which is free in this region of the recess from the diffraction structure at least above the halftone print image of the imprint.