| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a portable equipment, of which a user can easily grab residue of fuel liquid of a fuel cell. <P>SOLUTION: A CPU of portable music reproducing device determines whether the device is in a vertical state by a gravity sensor (S401). If in a vertical state (S401, Yes), a liquid level position of a fuel tank is detected by a liquid level sensor, whereby, a residue of the fuel liquid is measured (S402), which is stored in an HDD as a measured value of the residue of the fuel liquid (S403). If the device is not in a vertical state (S401, No), a consumption volume of the fuel liquid at the previous measurement or since prediction time is predicted to predict a current residue of the liquid fuel from the previous measurement value or the predicted value (S405). <P>COPYRIGHT: (C)2007,JPO&INPIT |
