| 摘要 |
<p>PURPOSE:To enhance the difficulty of the confirmation of a data mark part at least in a case based on observation with the naked eye, in the preparation of a data concealing card, especially, a card wherein discriminable inherent writing data is subjected to concealing treatment by a card reader, by devising the concealing treatment while keeping the reading function of the data mark part. CONSTITUTION:A process forming a data mark part BD absorbing infrared rays L and a space part WD reflecting infrared rays L in the data writing region 11A of a card substrate 11 and a process performing the concealing treatment of the data writing region 11A by a concealing substance 12 pervious to infrared rays L are provided and, when the data mark part BD and the space part WD are formed, the density adjusting treatment of the printing substance BL of the data mark part BD and the printing substance BL of the space part WD is performed.</p> |
