| 摘要 |
PROBLEM TO BE SOLVED: To attain accurate data communication with electromagnetically coupled IC cards by optimizing matching with the IC cards regardless of the scale of distances with the IC cards or the kinds and the number of the IC cards. SOLUTION: When an IC card 2 is electromagnetically coupled with an antenna pattern, the voltage level of a matching circuit 14 is detected by a matching state monitoring part 17, and outputted to a gate array 12. At the time of inputting the detection level from the matching state monitoring part 17, the gate array 12 compares the voltage level with a preset voltage level, and when they are mismatched, the gate array 12 drives a switch control part 18 to operate the loop closing and opening of the circular pattern of the antenna part 15. Thus, an optimal matching state with the IC card 2 can be obtained. |
