PURPOSE: To provide the titled invisible ink containing a fluorescent material, capable of printing both visible information for man and invisible information for machine reading to the same paper, giving easily readable information for machine reading, utilizable for the correction of data, and ascertainable with the naked eyes.
CONSTITUTION: An invisible ink for ink-jet printer, contaning a fluorescent material. The fluorescent material is e.g. those having no absorption band in the visible range (e.g. fluorescent bleaching agent, material for scincillator, etc.) or having an absorption band in the visible range (e.g. a fluorescent dye). In the latter case, its content is preferably selected to give a recorded density on the printing paper of ≤0.1 in terms of optical density.
SUKEGAWA TAKESHI
SHIWA SHINICHI
TAKANO RIKUO
KOBAYASHI MASATO
TAKAHASHI TAKAO
