| 摘要 |
PROBLEM TO BE SOLVED: To charge a battery efficiently without contact, using a communication antenna. SOLUTION: In a communications system comprising a reader writer 11 for performing proximate communication via a magnetic field and a portable terminal 12, the reader writer 11 sends a charge command for directing the portable terminal 12 to charge it. The portable terminal 12 transmits a response, which includes charge time information that shows the charge time required for charging an internal battery, to the reader writer 11, in response to the charge command received. The reader writer 11 increases the power of a generated field, by lowering the resistance value of output resistance, according to the charge time included in the received response. The portable terminal 12 supplies the battery with power, obtained from the magnetic field by lowering the input resistance of the antenna, according to the charge time. For example, it can be applied to, a personal computer with reader a writer functions and a portable telephone with IC card functions. COPYRIGHT: (C)2008,JPO&INPIT |
