Electronic device with sensing assembly and method for detecting gestures of geometric shapes

1. 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.

2. The method of claim 1 , wherein the geometric shape is one of a circle, a triangle, and a quadrilateral.

3. The method of claim 1 , wherein the evaluating further includes

determining whether an initial point location in the group of point locations is approximately the same as a final point location in the group of point locations.

4. The method of claim 3 , wherein the evaluating further includes:

forming at least one subgroup of point locations based on slope calculations of adjacent point locations, and wherein the geometric shape is determined by a number of subgroups.

5. The method of claim 4 , wherein adjacent point locations in each subgroup have similar corresponding slopes.

6. The method of claim 4 , wherein if the number of subgroups is three, then the geometric shape is a triangle; and if the number of subgroups is four, then the geometric shape is a quadrilateral.

7. The method of claim 3 , wherein the evaluating further includes:

determining a line segment for each subgroup by curve fitting;

calculating angles between each pair of adjacent line segments;

adding together the calculated angles to produce a sum; and

determining the geometric shape based on the sum.

8. The method of claim 7 , wherein if the sum is approximately 180 degrees, then the geometric shape is a triangle, and wherein if the sum is approximately 360 degrees, then the geometric shape is a quadrilateral.

9. The method of claim 1 , wherein the evaluating comprises:

determining if the measured signals indicate the geometric shape is in a plane.

10. 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 phototransmitter and a plurality of photoreceivers, wherein the at least one phototransmitter is positioned to emit infrared light away from the electronic device about a central transmission axis, and each photoreceiver is positioned so as to receive infrared light about a corresponding central receiving axis, wherein each central receiving axis is oriented in a different direction with respect to the others;

controlling emission of infrared light by the at least one phototransmitter during each of a plurality of sequential time periods during movement of the external object in the geometric shape relative to the electronic device;

for each of the plurality of photoreceivers and for each of the plurality of sequential time periods, generating a corresponding measured signal indicative of a respective amount of infrared light which originated from the at least one phototransmitter during the corresponding time period and was reflected by the external object prior to being received by the corresponding photoreceiver; and

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 plurality of photoreceivers; 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.

11. The method of claim 10 , wherein the geometric shape is one of a circle, a triangle, and a quadrilateral.

12. The method of claim 10 wherein the evaluating further includes:

determining whether an initial point location in the group of point locations is approximately the same as a final point location in the group of point locations.

13. The method of claim 12 , wherein the evaluating further includes:

forming at least one subgroup of point locations based on slope calculations of adjacent point locations, and wherein the geometric shape is determined by a number of subgroups.

14. The method of claim 13 , wherein adjacent point locations in each subgroup have similar corresponding slopes.

15. The method of claim 13 , wherein if the number of subgroups is on three, the geometric shape is a triangle, and if the number of subgroups is four, then the geometric shape is a quadrilateral.

16. The method of claim 12 , wherein the evaluating further includes:

determining a line segment for each subgroup by curve fitting;

calculating angles between each pair of adjacent line segments;

adding together the calculated angles to produce a sum; and

determining the geometric shape based on the sum.

17. The method of claim 16 , wherein if the sum is between 150 degrees and 210degrees, then the geometric shape is a triangle, and wherein if the sum is between 330 degrees and 390 degrees, then the geometric shape is a quadrilateral.

18. The method of claim 10 , wherein the controlling includes one of an activation command, a deactivation command, a mode switching command, a toggle command, and a select mode command.