| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a new and improved portable terminal that can charge a secondary battery even at a place where it is difficult to obtain a power supply by using solar cells and that can easily change over power supply sources between the secondary battery and the solar cells according to power generation quantity from the solar cells. <P>SOLUTION: The portable terminal includes the solar cells, in which a photoelectromotive force is generated by receiving the irradiation of light; the secondary battery, which accumulates electric charge with the photoelectromotive force of the solar cells; a first switch, which controls the start and stop of the secondary battery; and a voltage detection portion, which detects a voltage of the secondary battery and outputs signals for changing over conduction and non-conduction of the first switch according to the detected voltage. <P>COPYRIGHT: (C)2008,JPO&INPIT |
