Identification medium, article, and identification medium use method

Abstract

An identification medium including a light reflection layer and a patterned phase difference layer, wherein the light reflection layer is a layer that reflects incident light as circularly polarized light or linearly polarized light, and the patterned phase difference layer is a layer that includes an area having a phase difference, and is a layer provided in the identification medium so that the area having a phase difference occupies a partial area of a display surface of the identification medium. Also provided are an article including the identification medium, and a method for using the identification medium wherein, in observation of the reflected light, a linear polarization component or a circular polarization component of the reflected light is selectively observed, or linearly polarized light, circularly polarized light, or elliptically polarized light is made incident as the incident light.

Dependencies are inferred from the claim text.