| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a personal digital assistant which can sufficiently secure power during use by mounting a secondary cell and a fuel cell and performing charge and discharge effectively. <P>SOLUTION: The personal digital assistant 50 mounts two sets of secondary cells and fuel cells for charging the secondary cells. When a visitor brings a personal digital assistant 50 close to an exhibit 52a in an exposition, the information about the exhibit 52a is regenerated in the personal digital assistant 50. At this time, a pair of secondary cells perform power supply, working as power supply side. Residual secondary cells in a pair are charged with electricity by the fuel cells. When the visitor returns the personal digital assistant 50, a person in charge holds up the personal digital assistant 50 over an RFID chip 53 so as to read in information. For the personal digital assistant 50 that has read in the information, the power is switched off. At this point, the secondary cell on power supply side and the secondary cell on charge side are switched, and the secondary cell lying on the power supply side in operation is charged by the fuel cell. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
