Patent ID: 7492583
Filing Date: 2009-02-17
Classification: H03K

Abstract:
1. A portable computer having a display part and a main part, the display part having a back light module, the portable computer comprising: a magnetic piece installed in the display part of the portable computer; and a control circuit installed in the portable computer, the control circuit comprising: a Hall sensor installed in the main part of the portable computer corresponding to the magnetic piece, the Hall sensor comprising a power pin connected to a first direct current (DC) power supply of the portable computer via a first resistor, an output pin, and a ground pin connected to ground; a switch circuit; and a control terminal configured for connecting to a power supply of the back light module of the display part, the output pin of the Hall sensor connected to the control terminal and a second DC power supply of the portable computer via the switch circuit, when the display part is in a closed position, the Hall sensor entering and sensing the magnetic field of the magnetic piece and outputting a control signal to the switch circuit, the switch circuit receiving the control signal to turn off the power supply of the back light module of the display part via the control terminal.