Don and Doff Sensing Using Capacitive Sensors

• US 20130249849A1
• Filed: 03/21/2012
• Published: 09/26/2013
• Est. Priority Date: 03/21/2012
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Wong, Adrian, Hebenstreit, Joseph John, Mirov, Russell Norman
• Granted Patent: US 8,907,867 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G06F 1/3231 Monitoring the presence, absence or movement of users
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Methods and devices for determining whether a head-mountable computing device is donned or doffed are disclosed. In one embodiment, a method is disclosed that includes receiving from at least one capacitive sensor data indicating a rate of change of capacitance, making a comparison of the rate of change of capacitance to a threshold rate of change of capacitance and, based on the comparison, determining whether the head-mountable computing device is donned or doffed. The method further includes, if the head-mountable computing device is donned, causing the head-mountable computing device to operate in a first state, and if the head-mountable computing device is doffed, causing the head-mountable computing device to operate in a second state, where the head-mountable computing device consumes less power in the second state than in the first state.

Claims

1. A method comprising:

receiving from at least one capacitive sensor data indicating a rate of change of capacitance;

making a comparison of the rate of change of capacitance and a threshold rate of change of capacitance;

based on the comparison, determining whether a head-mountable computing device is donned or doffed;

if the head-mountable computing device is donned, causing the head-mountable computing device to operate in a first state; and

if the head-mountable computing device is doffed, causing the head-mountable computing device to operate in a second state, wherein the head-mountable computing device consumes less power in the second state than in the first state.

2. The method of claim 1, wherein the threshold rate of change of capacitance is greater than a typical rate of change of capacitance due to changes in environmental conditions.

3. The method of claim 1, wherein the threshold rate of change of capacitance is determined based on a measured rate of change of capacitance measured while the head-mountable computing device moved from being donned to being doffed or moved from being doffed to being donned.

4. The method of claim 1, wherein:

the head-mountable computing device being donned comprises the head-mountable computing device being proximate to a head of a user; and

the head-mountable computing device being doffed comprises the head-mountable computing device not being proximate to a head of a user.

5. The method of claim 1, wherein a display of the head-mountable computing device is on in the first state and off in the second state.

6. The method of claim 1, wherein determining whether the head-mountable computing device is donned or doffed comprises:

based on the data, determining whether the capacitance is increasing or decreasing;

if the rate of change in capacitance is greater than the threshold rate of change in capacitance and if the capacitance is increasing, determining that the head-mountable computing device is donned; and

if the rate of change in capacitance is greater than the threshold rate of change in capacitance and if the capacitance is decreasing, determining that the head-mountable computing device is doffed.

7. A method comprising:

receiving from at least one capacitive sensor data indicating a change of capacitance;

making a comparison of the change of capacitance and a threshold change of capacitance;

based on the comparison, determining whether a head-mountable computing device is donned or doffed;

if the head-mountable computing device is donned, causing the head-mountable computing device to operate in a first state; and

if the head-mountable computing device is doffed, causing the head-mountable computing device to operate in a second state, wherein the head-mountable computing device consumes less power in the second state than in the first state.

8. The method of claim 7, wherein the threshold change of capacitance is greater than a typical change of capacitance due to changes in environmental conditions.

9. The method of claim 7, wherein the threshold change of capacitance is determined based on a measured change of capacitance measured while the head-mountable computing device moved from being donned to being doffed or moved from being doffed to being donned.

10. The method of claim 7, wherein a display of the head-mountable computing device is on in the first state and off in the second state.

11. The method of claim 7, wherein determining whether the head-mountable computing device is donned or doffed comprises:

based on the data, determining whether the capacitance is increasing or decreasing;

if the change in capacitance is greater than the threshold change in capacitance and if the capacitance is increasing, determining that the head-mountable computing device is donned; and

if the change in capacitance is greater than the threshold change in capacitance and if the capacitance is decreasing, determining that the head-mountable computing device is doffed.

12. A head-mountable computing device comprising:

at least one capacitive sensor;

at least one processor; and

data storage comprising instructions executable by the at least one processor to;

receive from the at least one capacitive sensor data indicating a rate of change of capacitance;

make a comparison of the rate of change of capacitance and a threshold rate of change of capacitance;

based on the comparison, determine whether the head-mountable computing device is donned or doffed;

if the head-mountable computing device is donned, cause the head-mountable computing device to operate in a first state; and

if the head-mountable computing device is doffed, cause the head-mountable computing device to operate in a second state, wherein the head-mountable computing device consumes less power in the second state than in the first state.

13. The head-mountable computing device of claim 12, wherein the at least one capacitive sensor comprises two capacitive sensors.

14. The head-mountable computing device of claim 12, wherein:

the head-mountable device comprises a sidearm; and

the at least one capacitive sensor is positioned on the sidearm.

15. The head-mountable computing device of claim 12, wherein:

the head-mountable device comprises a first sidearm and a second sidearm;

the at least one capacitive sensor comprises a first capacitive sensor and a second capacitive sensor;

the first capacitive sensor is positioned on the first sidearm; and

the second capacitive sensor is positioned on the second sidearm.

16. The head-mountable computing device of claim 12, further comprising a display.

17. The head-mountable computing device of claim 16, wherein the display is on in the first state and off in the second state.

18. The head-mountable computing device of claim 12, wherein:

the head-mountable computing device being donned comprises the head-mountable computing device being proximate to a head of a user; and

the head-mountable computing device being doffed comprises the head-mountable computing device not being proximate to a head of a user.

19. The head-mountable computing device of claim 12, wherein the instructions are further executable by the at least one processor to:

receive data from the at least one capacitive sensor indicating an input; and

in response to receiving the data indicating the input, cause the head-mountable computing device to operate in a third state, wherein the head-mountable computing device consumes less power in the second state than in the third state.

20. The head-mountable computing device of claim 19, wherein:

the head-mountable computing device consumes more power in the third state than in the second state; and

the head-mountable computing device consumes less power in the third state than in the first state.