| 摘要 |
PROBLEM TO BE SOLVED: To provide an authentication method using a code pattern capable of being analyzed easily.SOLUTION: An object provided with a code pattern is irradiated by an electromagnetic wave to be authenticated by analyzing the frequency spectrum of its transmission or reflection electromagnetic wave. The code pattern includes a first region 21 containing a plurality of regularly arranged first elements 21a. The width W1 of each of the first elements of the first region or spacing G1 between each of the first elements is at least partially smaller than the wavelength of the electromagnetic wave irradiated onto the code pattern.SELECTED DRAWING: Figure 3 |
