| 摘要 |
<P>PROBLEM TO BE SOLVED: To allow a user to receive a store position retrieval service that utilizes positional information, even when the user has not taken notice of battery exhaustion. <P>SOLUTION: A portable terminal device includes: a battery residual amount detecting device 19 for detecting the residual voltage of the battery 18; a positional information detecting device 14 for detecting position information; and a radio communication apparatus 13 for performing data communication with an information service center which provides map information. The portable terminal device acquires the map information of a place for charging the battery 18, at a location close to the position of the terminal device, and displays the information on a display device 15. When the residual voltage of the battery 18 is small in the terminal device and is unable to display map information, the map information can be referred to by another information terminal which is to be connected to a network. <P>COPYRIGHT: (C)2010,JPO&INPIT |
