| 摘要 |
<p>PROBLEM TO BE SOLVED: To read out information at a high S/N without causing any problem in the reading of code information or the discrimination of characters by heating a base, on which a light transmissive pattern is formed while containing a material for absorbing the infrared rays of any specified wavelength, or irradiating the base with infrared rays. SOLUTION: On a base 1, a pattern 2 containing an infrared absorber having cyano group is formed. The pattern area of this base 1 is irradiated with infrared rays from an infrared lamp 11 through a filter 13. By using the filter 13 for transmitting the infrared rays of wavelength from 4μm to 5μm, the pattern 2 containing the infrared absorber having cyano group is preferentially heated but the base 1 is not heated so much. After the lapse of time for generating enough temperature difference between the pattern 2 and the base 1, the base 1 is conveyed and infrared rays generated from the pattern 2 are detected by an infrared detector 12 so that the pattern can be read out.</p> |
