Patent ID: 7774031

Claim:
A portable electronic device with a plurality of operation modes determined in accordance with power consumption, comprising: a digital still camera (DSC) module; a mobile communication module; a battery cell unit for providing a voltage for operation of said DSC module and said mobile communication module; a first voltage detection unit coupled between said battery cell unit and said DSC module, said first voltage detection unit detecting a voltage provided by said battery cell unit and selectively shutting off said DSC module, independent of said mobile communication module operation mode, when said voltage provided by said battery cell unit is lower than a first reference voltage, wherein said first reference voltage is a predetermined minimum threshold voltage sufficient for operation of said DSC module; and a second voltage detection unit coupled between said battery cell unit and said mobile communication module, said second voltage detection unit detecting the voltage provided by said battery cell unit and selectively shutting off said mobile communication module, independent of said DSC module operation mode, when said voltage provided by said battery cell unit is lower than a second reference voltage, wherein said second reference voltage is a predetermined minimum threshold voltage sufficient for operation of said mobile communication module, and wherein said second reference voltage is lower than said first reference voltage; wherein, when said voltage provided by said battery cell unit is higher than said first reference voltage, both of said DSC module and said mobile communication module are maintained operative, wherein, when said voltage provided by said battery cell unit is between said first reference voltage and said second reference voltage, only the mobile communication module is maintained operative, and wherein, when said voltage provided by said battery cell unit is lower than said second reference voltage, both of said DSC module and said mobile communication module are deactivated.