| 摘要 |
PROBLEM TO BE SOLVED: To increase the communication distance with an IC card even while preventing an operation abnormality or the like of the IC card. SOLUTION: An antenna for communication assembled in a card reader main body for performing the communication with the IC card is arranged separately from a communication surface of an outer surface part of the main body to an inner side and the output of the antenna is made sufficiently larger than the conventional one (B). At this time, electromagnetic field strength generated from the antenna for the communication has properties of being highest on a surface of the antenna and being attenuated inversely proportionally to the cube of a distance as separating from there. The output of the antenna for the communication is set so as to make the electromagnetic field strength on the surface of the antenna for the communication exceed (Hrw) an operation guarantee range of the IC card and to make the electromagnetic field strength on the communication surface be in the operation guarantee range, the maximum value (Hmax) of the operation guarantee range in this case, as indicated by A. |
