Patent ID: 6703599
Filing Date: 2004-03-09
Classification: G06F,H03K,Y02D

Abstract:
A system for sensing the presence of a body part or other object in close proximity to a device, comprising:an electromagnetic energy source which can be selectively activated and deactivated; a receptor which generates an output that varies over time in response to exposure to electromagnetic energy; and a processor in communication with the source and the receptor, and configured to: activate and deactivate the source, sample output of the receptor, store a first indicator for receptor output samples bearing a first relation to a threshold value of receptor output, store a second indicator for receptor output samples bearing a second relation to the threshold value, compare a first set of indicators stored during an interval when the source is deactivated with a second set of indicators stored during an interval when the source is activated, and recognize an object-near condition if the comparison identifies a triggering level of difference between the first and second sets.