| 摘要 |
<P>PROBLEM TO BE SOLVED: To secure a sufficient communication distance to an external reader/writer even when an antenna coil on a non-contact IC card side and an antenna coil on the reader/writer side are disposed close to each other. <P>SOLUTION: This data communication device has: a non-contact IC card circuit 21 written or read with data by the external reader/writer 100 electromagnetically coupled through the first antenna coil 24; a reader/writer circuit 22 written or read with the data to the external non-contact IC card 102 electromagnetically coupled through the second antenna coil 27; a filter circuit 30 suppressing a signal emitted from the second antenna coil 27 to a prescribed signal level; and a changeover switch 34 switching the filter circuit 30 such that load impedance of the filter circuit 30 in a view from the second antenna coil 27 side is larger than in non-operation, so as to suppress the operation of the filter circuit 30 when communication between the external reader/writer 100 and the non-contact IC card circuit 21 is performed. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
