FORGERY PREVENTION MEDIUM AND PRODUCTION METHOD OF THE SAME, AND METHOD FOR DETERMINING AUTHENTICITY OF FORGERY PREVENTION MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a structure of a forgery prevention medium and a production method of the medium which makes it difficult to imitate a forgery prevention medium having the same visual effects as an authentic product and makes it difficult to determine an imitation level or target details of imitation, considering that the principal of a polarized latent image and its visual effects are well-known and the image is easily imitated or forged.SOLUTION: The forgery prevention medium 1 includes a reflection layer 12 formed on a substrate 11, and an intermediate layer 13 thereon, which is laid in a pattern of mountain range having the same height, the same inclination of slopes and ridgelines parallel to one another at the same pitch. A predetermined polarized latent image pattern is formed on slopes of one side in the mountain range-like intermediate layer 13, and a polarized latent image pattern different from the first pattern is formed on slopes in the other side. These polarized latent image patterns are formed of liquid crystal retardation layers having different retardation values from each other.