Multilayer reflector, authentication card, bar code label, authentication system, and authentication region forming system

摘要

Provided is a multilayer reflector about which a complicated step is not required when the molecular alignment of a retardation film is partially relaxed to form a latent image of authentication information, and about which the latent image is not made visible by the generation of unevenness in the surface. A multilayer reflector 1 has a retardation film 10 in which the phase difference &Dgr;nd1 to an observation wavelength λ is set to be m×λ/4−λ/16≦̸&Dgr;nd1≦̸m×λ/4+λ/16 wherein m is a positive odd number, and a metallic reflector 11 laminated on the rear face side of this retardation film 10, wherein an authentication region 10a where predetermined authentication information is beforehand formed in the retardation film 10 is formed to give a phase difference &Dgr;nd2 set to be n×λ/4−λ/8 ≦̸&Dgr;nd2≦̸n×λ/4+λ/8 wherein n is 0 or a positive even number provided that n