Proximity activated gesture
View Patent ↗A proximity-activated gesture circuit includes an activation receiver electrode, a transmitter electrode, additional receiver electrodes, a control circuit, and a signal processor circuit. The control circuit is configured to activate the transmitter electrode and additional receiver electrodes when a capacitance measurement by the activation receiver electrode reaches a threshold. The signal processor circuit is configured to interpret measurements from the additional receiver electrodes as a gesture.
1. A proximity-activated gesture circuit, comprising:
a feedback circuit formed by:
a first activation receiver electrode coupled with an associated receiver circuit;
a driver circuit having an input coupled with an output of the receiver circuit;
a transmitter electrode coupled with an output of the driver circuit;
a plurality of second receiver electrodes and associated receiver circuits;
wherein the feedback circuit is configured to only oscillate when a first capacitance between the transmitter electrode and the first activation receiver electrode reaches a threshold; and
a signal processor circuit configured to receive signals from the second receiver electrodes while said feedback circuit oscillates to determine a gesture.
2. The proximity-activated gesture circuit of claim 1 , further comprising a second capacitance between the first activation receiver electrode and the transmitter electrode, wherein the second capacitance is coupled in parallel with the first capacitance.
3. The proximity-activated gesture circuit of claim 2 , wherein the second capacitance has a controllable value.
4. The proximity-activated gesture circuit of claim 1 , wherein one of the plurality of second receiver electrodes is configured as a second activation receiver electrode, wherein the feedback circuit is further configured to only oscillate when the first capacitance reaches a threshold or when a third capacitance between the transmitter electrode and the second activation receiver electrode reaches another threshold.
5. The proximity-activated gesture circuit of claim 4 , wherein the plurality of second receiver electrodes is arranged to detect gestures in a virtual keyboard.
6. The proximity-activated gesture circuit of claim 1 , wherein one of the plurality of second receiver electrodes is configured as a second activation receiver electrode, wherein the feedback circuit is further configured to oscillate when both:
the first capacitance reaches a threshold; and
a third capacitance between the transmitter electrode and the second activation receiver electrode reaches another threshold.
7. The proximity-activated gesture circuit of claim 6 , wherein the first activation receiver electrode is placed at one edge of a space for detection, and the second activation receiver electrode is placed at an opposite edge of the space for detection.
8. The proximity-activated gesture circuit of claim 7 , wherein the first activation receiver electrode and the second activation receiver electrode are placed at edges of a space representing a space bar of a virtual keyboard.
9. The proximity-activated gesture circuit of claim 6 , further comprising an envelope detector coupled with the first and second activation receiver electrodes and said signal processing circuit.
10. The proximity-activated gesture circuit of claim 1 , wherein the plurality of second receiver electrodes is arranged in a linear manner to capture a multi-dimensional movement.
11. The proximity-activated gesture circuit of claim 1 , wherein the plurality of second receiver electrodes is arranged in a linear manner to capture a multi-dimensional movement adjacent to the circuit.
12. The proximity-activated gesture circuit of claim 1 , wherein the signal processor circuit is configured to interpret the gesture from amplitude or phase data from the plurality of second receiver electrodes and from frequency data from the first activation receiver electrode, wherein:
the first activation receiver electrode is adjacent to the transmitter electrode; and
the plurality of second receiver electrodes are arranged to define a space to be monitored.
13. The proximity-activated gesture circuit of claim 1 , further comprising a summation node receiving and summing output signals form the receiver circuits and feeding a summation signal into the driver circuit.
14. A method for proximity-activated gesture detection, comprising the steps of:
providing a feedback circuit formed by:
a first activation receiver electrode coupled with an associated receiver circuit;
a driver circuit having an input coupled with an output of the receiver circuit;
a transmitter electrode coupled with an output of the driver circuit;
a plurality of second receiver electrodes and associated receiver circuits;
configuring the feedback circuit to only oscillate when a first capacitance between the transmitter electrode and the first activation receiver electrode reaches a threshold; and
processing signals received from the second receiver electrodes when the feedback circuit oscillates to determine a gesture.
15. The method of claim 14 , further comprising a second capacitance between the first activation receiver electrode and the transmitter electrode.
16. The method of claim 15 , wherein the second capacitance is controllable.
17. The method of claim 16 , wherein the plurality of second receiver electrodes is arranged to detect gestures in a virtual keyboard.
18. The method of claim 14 , further comprising a summation node receiving and summing output signals form the receiver circuits and feeding a summation signal into the driver circuit.
19. The method of claim 18 , further comprising an envelope detector coupled with the first activation receiver electrode and the plurality of second receiver electrodes and said signal processing circuit.
20. The method of claim 14 , further comprising a second activation receiver electrode, wherein the feedback circuit oscillates when the first capacitance reaches a threshold or when a third capacitance between the transmitter electrode and the second activation receiver electrode reaches another threshold.
21. The method of claim 14 , further comprising a second activation receiver electrode, wherein the feedback circuit oscillates when both:
the first capacitance reaches a threshold; and
a third capacitance between the transmitter electrode and the second activation receiver electrode reaches another threshold.
22. The method of claim 21 , wherein the first activation receiver electrode is placed at one edge of a space for detection, and the second activation receiver electrode is placed at an opposite edge of the space for detection.
23. The method of claim 22 , wherein the first activation receiver electrode and the second activation receiver electrode are placed at edges of a space representing a space bar of a virtual keyboard.
24. The method of claim 14 , wherein the plurality of second receiver electrodes is arranged in a linear manner to capture a multi-dimensional movement.
25. The method of claim 14 , wherein the plurality of second receiver electrodes is arranged in a linear manner to capture a multi-dimensional movement adjacent to the circuit.
26. The method of claim 14 , further comprising interpreting the gesture from amplitude or phase data from the plurality of second receiver electrodes and from frequency data from the first activation receiver electrode, wherein:
the first activation receiver electrode is adjacent to the transmitter electrode; and
the plurality of second receiver electrodes are arranged to define a space to be monitored.