NEW BANK OF JAPAN NOTE DETERMINING METHOD

摘要

PPROBLEM TO BE SOLVED: To provide a new method for determining authenticity of a banknote issued by the Bank of Japan from patterns on front and rear surfaces of the bill visually and safely even in outdoors and in a dark room at night. PSOLUTION: Several to dozens of thin and round patterns having diameter of 2 to 3 mm are irregularly provided on front and rear surfaces of the bill, and an indistinct, pale, and yellow ring having diameter of 1 mm which cannot be visually determined in daylight is printed in these patterns. The ring having diameter of about 1 mm is printed by ink which does not react for ultraviolet rays at all. However, this ring printed by ink can be visually determined in the darkness at night and in a place without lighting facility when light in a region of wavelength of blue color of about 430 to 490 nm is applied. Since irradiation light having wavelength (467 to 483 nm) in a specific range can emphasize contrast of the patterns, the ring in the pattern, and color of the background of the pattern, they can be visually and very easily confirmed. PCOPYRIGHT: (C)2006,JPO&NCIPI