Portable electronic device and method for waking up the same from sleep mode through touch screen

A portable electronic device, comprising:

• a central processor, capable of operating in a sleep mode and a normal operation mode;
• a display, having a display area for displaying information;
• a touch screen, overlaid on the display and having a first touch area overlaid on the display area of the display, a second touch area extending to outside of the display area, and at least one electrode, wherein when the central processor operates in the sleep mode and one of the first and the second touch areas senses a touch, the at least one electrode generates a touch signal;
• and
• a micro processing unit, electrically connected to the at least one electrode, for determining whether the touch is sensed by the first or the second touch area according to the touch signal, wherein when the touch is sensed by the second touch area, the micro processing unit outputs a wake-up signal to the central processor, so as to switch the central processor from the sleep mode to the normal operation mode.