| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a portable electronic device for effectively utilizing a battery capacity without a waste and used for a long time even if the battery capacity of a sub battery is not large, and a method for charging the battery in the portable electronic device. <P>SOLUTION: A control section 105 switches from a main battery 103 to the sub battery 108, operates it in a power saving mode when an output from the main battery 103 is a first preset voltage in the vicinity of a lower limit for operating the portable electronic device or less, boosts the output from the main battery, and charges the sub battery when an output from the sub battery 108 is a second preset voltage for operating the portable electronic device or less. In the power saving mode, the control section reduces its operating clock frequency, restricts a camera function, activates an off-line mode for inhibiting a call, deactivates a back light function, and uses a voltage boosting circuit of a back light as a circuit for boosting the output from the main battery. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
