| 摘要 |
<p>PURPOSE:To prevent the forgery of an information recording paper by displaying a detection mark like a timing mark, etc., on the upper or rear surface of the information recording paper with use of the detection ink containing a near infrared ray absorbent except the carbon black that has the absorbing force to a specific wavelength of at least 700 - 1500nm. CONSTITUTION:A detection mark like an end mark, a position mark, a counter mark, a timing mark, etc., is displayed on the upper or rear surface of an information recording paper with the display ink containing a near infrared ray absorbent except the carbon black that has the absorbing force to a specific wavelength of at least 700 - 1500nm. Thus the application of a color mark is facilitated with use of such an almost colorless detection mark that has the detection sensitivity equivalent to a black mark using the conventional India ink and can be used with other coloring matters as necessary. However the satisfactory detection sensitivity is not obtained even with use of a closely resemble hue only. Thus the forgery of the recording paper can be prevented.</p> |
