Hand temperature compensation
Systems and methods for calibrating presence and gesture detection thermal sensors in a mobile electronic communications device entail sensing an ambient temperature and designating the sensed ambient temperature as room temperature, and determining that a user appendage has touched, or is close to but not touching, the thermal sensor. If the user appendage has touched a lens of the thermal sensor, a sensed temperature just prior to that event is used as hand temperature. If the user appendage is close to but not touching the lens of the thermal sensor, the temperature during that event is used as hand temperature. A difference between the hand temperature and the room temperature is then determined and the presence and gesture detection functions for the device are calibrated based on the determined difference.
1. A method of calibrating presence and gesture detection in a mobile electronic communications device having a thermal sensor, the method comprising:
sensing a background temperature via the thermal sensor and designating the sensed background temperature as room temperature;
detecting via a secondary sensor located adjacent to the thermal sensor that a user has touched the thermal sensor;
setting a temperature detected at the thermal sensor just prior to the detected touch as hand temperature;
determining a difference between the hand temperature and the room temperature; and
calibrating presence and gesture detection for the device based on the determined difference.
2. The method in accordance with claim 1 , wherein the secondary sensor comprise a capacitive sensor.
3. The method in accordance with claim 2 , wherein the capacitive sensor comprises a capacitive ring surrounding a lens of the thermal sensor.
4. The method in accordance with claim 1 , wherein the secondary sensor comprises an IR (infrared) proximity sensor.
5. The method in accordance with claim 1 , wherein the thermal sensor comprises a thermopile.
6. The method in accordance with claim 1 , wherein the secondary sensor comprises at least one of an ultrasonic sensor, a RADAR sensor, a light sensor, and a camera.
7. The method in accordance with claim 1 , wherein the thermal sensor includes a lens and wherein touching the thermal sensor comprises touching the lens of the thermal sensor.
8. A method of calibrating presence and gesture detection in a mobile electronic communications device having a thermal sensor, the device comprising:
sensing a background temperature via the thermal sensor and designating the sensed background temperature as room temperature;
determining via a secondary sensor that a user appendage is close to but not touching the thermal sensor;
setting a temperature detected while the user appendage is close to but not touching the thermal sensor as hand temperature;
determining a difference between the hand temperature and the room temperature; and
calibrating presence and gesture detection for the device based on the determined difference.
9. The method in accordance with claim 8 , wherein the secondary sensor comprises a capacitive sensor.
10. The method in accordance with claim 9 , wherein the capacitive sensor comprises a capacitive ring surrounding a lens of the thermal sensor.
11. The method in accordance with claim 8 , wherein the secondary sensor comprises an IR (infrared) proximity sensor.
12. The method in accordance with claim 8 , wherein the thermal sensor comprises a thermopile.
13. The method in accordance with claim 8 , wherein the secondary sensor comprises at least one of an ultrasonic sensor, a RADAR sensor, a light sensor, and a camera.
14. The method in accordance with claim 8 , wherein the thermal sensor includes a lens and wherein touching the thermal sensor comprises touching the lens of the thermal sensor.
15. A method of calibrating presence and gesture detection in a mobile electronic communications device having a thermal sensor, the device comprising:
sensing a background temperature via the thermal sensor and designating the sensed background temperature as room temperature;
determining that a user appendage is touching the thermal sensor by detecting a start of a thermal transfer at the thermal sensor that is indicative of contact between the user and a lens of the thermal sensor;
setting a temperature detected immediately prior to the start of the thermal transfer as hand temperature;
determining a difference between the hand temperature and the room temperature; and
calibrating presence and gesture detection for the device based on the determined difference.
16. The method in accordance with claim 15 , wherein the thermal sensor comprises a thermopile.