Optical memory plate or panel

摘要

An optical memory plate as a data storage optical medium, particularly suitable for identification purposes or protection against forgery and counterfeiting, by providing radiation inscription of data and read-out of thus stored inscription data, as well as a method of recording (with either X-rays or ultraviolet rays) and reading out said data has been disclosed, characterised in that said optical memory comprises a europium doped alkali metal halide storage phosphor layer, substantially free of alkaline earth metals.