An optical sensor of the present disclosure detects light reflected by a transported sheet and/or light transmitted through the sheet as well as light emitted from the sheet. The optical sensor includes: a light source configured to irradiate a sheet with excitation light and detection light; a controller configured to keep the light source turned off during each of light-off periods after the emission of the excitation light; and a light receiver configured to receive light resulting from reflection of the detection light by a sheet and/or light resulting from transmission of the detection light through the sheet in each of the light-on periods and receive phosphorescence emitted from the sheet in each of the light-off periods. The controller is configured to generate data of one pixel by summing up output values based on respective phosphorescence components received by the light receiver in each of the light-off periods.

A method is provided for detecting a security thread in a value document, in which magnetic data are employed for sites on the value document. The magnetic data represents a magnetic property of the value document at the site, check sites on the value document are determined employing the sites, and from the check sites, a straight line is specified, along or on which at least some of the check sites lie and which represents a location of the security thread.

A paper sheet handling apparatus includes: a displacement amount detector that includes a pressing part intended to press a paper sheet against a transporting face of a paper sheet transporting path and having an initial position at which the pressing part is not in contact with the transporting face of the paper sheet transporting path, the displacement amount detector detecting a displacement amount of displacement of the pressing part from the initial position in a direction perpendicular to the transporting face, the pressing part being displaced according to a thickness of a paper sheet passing between the transporting face and the pressing part; a reference displacement amount storage; a paper sheet thickness storage; and a tape thickness threshold storage.

A subwavelength grating displaying a colored image exhibiting a color corresponding to a grating period of a subwavelength grating in reflection directions including a specular reflection direction. A relief surface displaying a reflection image in monochromatic reflected light in reflection directions including a direction different from the specular reflection direction. An optical element has a first state in which neither a colored image nor a reflection image is displayed, a second state in which the colored image is mainly displayed, and a third state in which the reflection image is mainly displayed. A plane in which the optical element is disposed and a plane including a line of sight of an observer form an observation angle therebetween. The optical element is observed in any of the first, second and third states according to the observation angle.

A security or identification device comprises a membrane laser structure configured to be optically pumped. The membrane laser structure comprises a flexible emission layer comprising a gain material; and one or more structures formed in or associated with the flexible emission layer and configured to provide optical feedback in the emission layer to produce a laser light output having at least one property representing an identifier.

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).

In one exemplary embodiment in accordance with the disclosure, an image processing system is configured to use a distance authentication template to execute a detection procedure that detects at least one non-linear distortion in a subject image. The distance authentication template can be generated by mapping a set of spatial coordinates of three features in a distortion-free image to a set of pixel coordinates of the three features in the distortion-free image. Addressing a non-linear distortion in the subject image can include performing remedial actions to remedy the non-linear distortion, or taking into consideration the non-linear distortion when using the distance authentication template to identify one or more features in the subject image.

A security article includes an optical component that includes a plurality of optical channels with a Fano resonance characteristic. An optical channel, of the plurality of optical channels, is configured to pass a first portion of a first set of light beams (that are associated with a first wavelength range) when the first set of light beams falls incident on at least one of a first surface or a second surface of the optical channel, reflect a second portion of the first set of light beams when the first set of light beams falls incident on the first surface of the optical channel, and reflect at least a portion of a second set of light beams (that are associated with a second wavelength range) when the second set of light beams falls incident on the second surface of the optical channel.

A method and associated system for authentication, including irradiating an item including a polymer security thread including a polymer material and a doping material within the polymer material and configured to produce a radiation spectrum in response to the irradiating, the doping material capable of absorbing, scattering, or emitting radiation, and detecting the produced radiation spectrum to confirm the presence of the polymer security thread.

The present invention is provided with: an identifying portion that reads a plurality of pieces of identification information including the same unique information provided to a division card; and a control portion that determines that the division card is usable when the unique information obtained from each of the plurality of pieces of identification information match up, and that determines that the division card is unusable when the unique information does not match up. Since whether or not the division card is usable is determined on the basis of the matching up or non-matching up of the unique information of the plurality of pieces of identification information provided to the division card, it is possible to easily determine whether or not the division card is usable.