PRESSURE-SENSITIVE TRACKPAD

• US 20140085254A1
• Filed: 03/15/2013
• Published: 03/27/2014
• Est. Priority Date: 09/27/2012
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Leiba, Aaron, Tenuta, Matthew D.
• Granted Patent: US 9,250,754 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells

Abstract

Trackpad apparatus and computing devices including trackpad apparatus are disclosed. In an example implementation, a trackpad apparatus includes a capacitive touch-sensing pattern disposed on a top surface of the trackpad apparatus and a capacitive pressure-sensing pattern disposed below the capacitive touch-sensing pattern. The trackpad apparatus also includes at least one controller. The at least one controller and the capacitive touch-sensing pattern are collectively configured to detect location-specific reductions in charge coupling in the capacitive touch-sensing pattern resulting from charge being shunted out of the capacitive touch-sensing pattern by one or more electrically conductive objects being placed in electrical contact with the top surface of the trackpad apparatus. In the example trackpad apparatus, the at least one controller and the capacitive pressure-sensing pattern are collectively configured to detect location-specific changes in charge coupling in the capacitive pressure-sensing pattern resulting from pressure being applied to the top surface of the trackpad apparatus.

Claims

1. A trackpad apparatus comprising:

a capacitive touch-sensing pattern disposed on a top surface of the trackpad apparatus;

a capacitive pressure-sensing pattern disposed below the capacitive touch-sensing pattern;

a compressible membrane disposed below the capacitive pressure-sensing pattern; and

at least one controller,

wherein;

the at least one controller and the capacitive touch-sensing pattern are collectively configured to detect location-specific reductions in charge coupling in the capacitive touch-sensing pattern resulting from charge being shunted out of the capacitive touch-sensing pattern by one or more electrically conductive objects being placed in electrical contact with the top surface of the trackpad apparatus; and

the at least one controller, the capacitive pressure-sensing pattern and the compressible membrane are collectively configured to detect location-specific changes in charge coupling in the capacitive pressure-sensing pattern resulting from pressure being applied to the top surface of the trackpad apparatus, wherein the location-specific changes in charge coupling in the capacitive pressure-sensing pattern are due at least in part to displacement of the compressible membrane.

2. The trackpad apparatus of claim 1, wherein the at least one controller and the capacitive pressure-sensing pattern are collectively further configured to detect, for one or more corresponding locations on the top surface of the trackpad apparatus, a respective amount of pressure applied to the top surface of the trackpad apparatus.

3. The trackpad apparatus of claim 1, further comprising an insulating layer disposed between the capacitive touch-sensing pattern and the capacitive pressure-sensing pattern.

4. The trackpad apparatus of claim 1, further comprising a printed circuit board (PCB) substrate disposed between the capacitive touch-sensing pattern and the capacitive pressure-sensing pattern.

5. The trackpad apparatus of claim 4, wherein the PCB substrate comprises a glass-reinforced epoxy laminate PCB substrate.

6. The trackpad apparatus of claim 1, wherein the location-specific changes in charge coupling in the capacitive pressure-sensing pattern comprise respective decreases in location-specific charge coupling in the capacitive pressure-sensing pattern resulting from corresponding increases in location-specific charge coupling to an electrical ground due to displacement of the compressible membrane.

7. The trackpad apparatus of claim 6, wherein the compressible membrane includes at least one of silicone, polyethylene terephthalate and air.

8. The trackpad apparatus of claim 1, wherein the compressible membrane is disposed between a first layer of the capacitive pressure-sensing pattern and a second layer of the capacitive pressure-sensing pattern, wherein the location-specific changes in charge coupling in the capacitive pressure-sensing pattern comprise respective location-specific increases in charge coupling between the first layer of the capacitive pressure-sensing pattern and the second layer of the capacitive pressure-sensing pattern due to displacement of the compressible membrane.

9. The trackpad apparatus of claim 8, wherein the compressible membrane includes at least one of silicone, polyethylene terephthalate and air.

10. The trackpad apparatus of claim 1, wherein the at least one controller is further configured to:

resolve one or more geometric patterns corresponding with the detected location-specific reductions in charge coupling in the capacitive touch-sensing pattern; and

filter the resolved one or more geometric patterns based on one or more pattern filtering criteria.

11. The trackpad apparatus of claim 10, wherein the one or more pattern filtering criteria comprise at least one of a finger ellipse pattern matching criteria and a palm pattern rejection criteria.

12. The trackpad apparatus of claim 10, wherein the at least one controller is further configured to filter the detected location-specific changes in charge coupling in the capacitive pressure-sensing pattern based on the one or more resolved geometric patterns and the pattern filtering criteria.

13. The trackpad apparatus of claim 1, wherein the at least one controller is further configured to detect movement of the one or more electrically conductive objects across the top surface of the trackpad apparatus based on movement of the detected location-specific reductions in charge coupling in the capacitive touch-sensing pattern.

14. The trackpad apparatus of claim 1, wherein the at least one controller is further configured to detect movement of the one or more electrically conductive objects across the top surface of the trackpad apparatus based on movement of the detected location-specific changes in charge coupling in the capacitive pressure-sensing pattern.

15. A computing device comprising:

a display device, the computing device being configured to render a graphical user interface (GUI) on the display device;

a trackpad apparatus configured to facilitate user interaction with the GUI, the trackpad apparatus comprising;

a capacitive touch-sensing pattern disposed on a top surface of the trackpad apparatus;

a capacitive pressure-sensing pattern disposed below the capacitive touch-sensing pattern;

a compressible membrane disposed below the capacitive pressure-sensing pattern; and

at least one controller,

wherein;

the at least one controller and the capacitive touch-sensing pattern are collectively configured to detect location-specific reductions in charge coupling in the capacitive touch-sensing pattern resulting from charge being shunted out of the capacitive touch-sensing pattern by one or more electrically conductive objects being placed in electrical contact with the top surface of the trackpad apparatus;

the at least one controller, the capacitive pressure-sensing pattern and the compressible membrane are collectively configured to detect location-specific changes in charge coupling in the capacitive pressure-sensing pattern resulting from pressure being applied to the top surface of the trackpad apparatus, wherein the location-specific changes in charge coupling in the capacitive pressure-sensing pattern are due at least in part to displacement of the compressible membrane; and

user interaction with the GUI is based on the detected location-specific reductions in charge coupling in the capacitive touch-sensing pattern and the detected location-specific changes in charge coupling in the capacitive pressure-sensing pattern.

16. The computing device of claim 15, wherein:

the at least one controller and the capacitive pressure-sensing pattern are collectively further configured to, for one or more corresponding locations on the top surface of the trackpad apparatus, detect a respective amount of pressure applied to the top surface of the trackpad apparatus; and

user interaction with the GUI is further based on the detected respective amounts of pressure for the one or more corresponding locations on the top surface of the trackpad apparatus.

17. The computing device of claim 15, wherein the trackpad apparatus further comprises an insulating layer disposed between the capacitive touch-sensing pattern and the capacitive pressure-sensing pattern.

18. The computing device of claim 15, wherein the location-specific changes in charge coupling in the capacitive pressure-sensing pattern comprise respective decreases in location-specific charge coupling in the capacitive pressure-sensing pattern resulting from corresponding increases in location-specific charge coupling to an electrical ground due to displacement of the compressible membrane.

19. The computing device of claim 15, wherein the compressible membrane is disposed between a first layer of the capacitive pressure-sensing pattern and a second layer of the capacitive pressure-sensing pattern, wherein the location-specific changes in charge coupling in the capacitive pressure-sensing pattern comprise respective location-specific increases in charge coupling between the first layer of the capacitive pressure-sensing pattern and the second layer of the capacitive pressure-sensing pattern due to displacement of the compressible membrane.

20. The computing device of claim 15, wherein:

the at least one controller is further configured to;

resolve one or more geometric patterns corresponding with the detected location-specific reductions in charge coupling in the capacitive touch-sensing pattern;

filter the resolved one or more geometric patterns based on one or more pattern filtering criteria; and

filter the detected location-specific changes in charge coupling in the capacitive pressure-sensing pattern based on the one or more resolved geometric patterns and the pattern filtering criteria; and

user interaction with the GUI is further based on the filtered one or more geometric patterns and the filtered location-specific changes in charge coupling in the capacitive pressure-sensing pattern.

21. A trackpad apparatus comprising:

a capacitive touch-sensing pattern disposed on a top surface of the trackpad apparatus;

a capacitive pressure-sensing pattern disposed below the capacitive touch-sensing pattern;

a compressible membrane disposed below the capacitive pressure-sensing pattern; and

at least one controller,

wherein;

the at least one controller and the capacitive touch-sensing pattern are collectively configured to detect location-specific reductions in charge coupling in the capacitive touch-sensing pattern resulting from charge being shunted out of the capacitive touch-sensing pattern by one or more electrically conductive objects being placed in electrical contact with the top surface of the trackpad apparatus;

the at least one controller, the capacitive pressure-sensing pattern and the compressible membrane are collectively configured to detect location-specific changes in charge coupling in the capacitive pressure-sensing pattern resulting from pressure being applied to the top surface of the trackpad apparatus, wherein the location-specific changes in charge coupling in the capacitive pressure-sensing pattern are due at least in part to displacement of the compressible membrane; and

the at least one controller is further configured to;

resolve one or more geometric patterns corresponding with the detected location-specific reductions in charge coupling in the capacitive touch-sensing pattern;

filter the resolved one or more geometric patterns based on one or more pattern filtering criteria; and

filter the detected location-specific changes in charge coupling in the capacitive pressure-sensing pattern based on the one or more resolved geometric patterns and the pattern filtering criteria.

22. The trackpad apparatus of claim 21, wherein the location-specific changes in charge coupling in the capacitive pressure-sensing pattern comprise respective decreases in location-specific charge coupling in the capacitive pressure-sensing pattern resulting from corresponding increases in location-specific charge coupling to an electrical ground due to displacement of the compressible membrane.

23. The trackpad apparatus of claim 22, wherein the compressible membrane includes at least one of silicone, polyethylene terephthalate and air.

24. The trackpad apparatus of claim 21, wherein the compressible membrane is disposed between a first layer of the capacitive pressure-sensing pattern and a second layer of the capacitive pressure-sensing pattern, wherein the location-specific changes in charge coupling in the capacitive pressure-sensing pattern comprise respective location-specific increases in charge coupling between the first layer of the capacitive pressure-sensing pattern and the second layer of the capacitive pressure-sensing pattern due to displacement of the compressible membrane.

25. The trackpad apparatus of claim 24, wherein the compressible membrane includes at least one of silicone, polyethylene terephthalate and air.