INFRARED LUMINOUS FLUORESCENT SUBSTANCE, FLUORESCENT SUBSTANCE COMPOSITION, MATERIAL CARRYING FLUORESCENT SUBSTANCE THEREON, LATENT IMAGE MARK-FORMING MEMBER, OPTICAL READER AND OPTICAL READING SYSTEM

摘要

PURPOSE: To obtain an infrared luminous fluorescent substance, containing iron and erbium as optically active elements, absorbing light in a wide region of visible to near infrared rays and excitable by exposure to exciting light and capable of emitting infrared rays. ;CONSTITUTION: This fluorescent substance contains iron (Fe) and erbium (Er) as optically active elements and preferably further at least one selected from the group of scandium (Sc), gallium (Ga), aluminum (Al), indium (In), yttrium (Y), bismuth (Bi), cerium (Ce), gadolinium (Gd), lutetium (Lu) and lanthanum (La).;COPYRIGHT: (C)1995,JPO