| 摘要 |
<p>The present invention is a proximity detector for an electronic device (10). The proximity detector utilizes two capacitors (20, 22) which share a common electrode (18). The two capacitors (20, 22) are located on the housing (14) of the electronic device (10). The capacitors (20, 22) are arranged so that when the electronic device (10) is used in its normal orientation, a portion of the operator's body will occlude one of the capacitors (20, 22), but not the other. The close proximity of the operator's body will change the electric field surrouding the capacitor. Thus, the capacitance of the occluded capacitor will be different than the unencumbered capacitor. A detection circuit (24) is coupled to the capacitors (20, 22) and to the power supply (15) of the device. The circuit (24) uses very little power, and maintains the electronic device (10) in a standby or powered down mode. Only when the circuit (24) detects a difference in the capacitance generated by the two capacitors (20, 22), will it allow full power to be delivered to the electronic device (10).</p> |
