9 Currency authentication apparatus and equipment, namely, optical reading machines which detect printed security devices and electronic and magnetic coded document readers; detectors and sensing apparatus and equipment for use in authenticating currency, credit cards, identity cards, passports and other security and identification documents, namely, optical reading machines which detect printed security devices and electronic and magnetic coded document readers; apparatus and equipment for detecting security documents, namely, passports, identity cards, driver licenses, securities, share certificates, deeds of title, travel documents, airline tickets, entrance cards and tickets, birth, death and marriage certificates, academic transcripts, namely, optical reading machines which detect printed security devices and electronic and magnetic coded document readers; optical detection apparatus and equipment, namely, optical reading machines which detect printed security devices and electronic and magnetic coded document readers; optical diffraction gratings; optically variable devices, namely, diffractive optical elements being lenses, hologram apparatus, optical interference filters, holographic optical filters, optical polarization filters, security embossings provided on films, exposed optical thin films, multilayer printing films, iridescent layers and reflective layers for use as security features in bank notes and security documents and liquid crystal displays; security devices in the nature of optically variable devices for bank notes, bank cheques, encoded credit cards and other security documents, namely, passports, identity cards, driver licenses, securities, share certificates, deeds of title, travel documents, airline tickets, entrance cards and tickets, birth, death and marriage certificates and academic transcripts; goods incorporating optically variable devices, security inks or other security devices, namely, magnetically encoded credit cards; computer hardware and software for use in currency authentication equipment and apparatus; and computer hardware and software for producing optically variable devices and other security devices, namely, metallic, phosphorescent and fluorescent security threads, diffractive optical elements, holograms, interference filters, holographic filters, polarization filters, embossings, optical thin films, multilayer films, iridescent layers, reflective layers and liquid crystals