Patent ID: 8269175

Claim:
A method for detecting movement of an external object in a geometric shape and controlling an electronic device, the method comprising: providing a sensing assembly including at least one photoreceiver and a plurality of phototransmitters, wherein each phototransmitter emits infrared light away from the electronic device about a corresponding central transmission axis, wherein each central transmission axis is oriented in a different direction with respect to the others; controlling emission of infrared light by each of the phototransmitters during each of a plurality of time periods during movement of the external object in the geometric shape relative to the electronic device; for each of the plurality of phototransmitters and for each of the plurality of time periods, generating a corresponding measured signal indicative of a respective amount of infrared light which originated from that phototransmitter during that time period and was reflected by the external object prior to being received by the at least one photoreceiver; evaluating the measured signals over time to identify the geometric shape by: dividing the measured signals into measured signal sets, with each measured signal set corresponding to a respective one of the phototransmitters, and calculating a group of point locations of the external object using comparisons between measured signal sets; and controlling the electronic device in response to the identification of the geometric shape.