User Interface Device Having Capacitive Trackball Assembly

• US 20140002362A1
• Filed: 06/29/2012
• Published: 01/02/2014
• Est. Priority Date: 06/29/2012
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Inventors: Srivastava, Apoorv
• Granted Patent: US 8,994,661 B2
• Time in Patent Office: Days
• US Class Current: 345/167
• CPC Class Codes: G06F 3/03549 Trackballs G06F3/03541 takes precedence
• CPC Class Codes: G06F 3/0362 with detection of 1D translations or rotations of an operating part of the device, e.g. scroll wheels, sliders, knobs, rollers or belts

Abstract

A user interface device (100) includes a capacitive trackball assembly (108) having a conductive trackball (110) and one or more conductive plates (210, 310, 410, 510, 610) proximate to a surface of the conductive trackball (110), thereby enabling the conductive trackball assembly (108) to operate as a capacitive touch sensor. Each user contact point with the conductive trackball (110) modifies the effective capacitance of the conductive trackball assembly (108). The user interface device (100) senses the effective capacitance of the conductive trackball assembly (108) to discern the number of user contact points on the conductive trackball (110) and uses this information, along with other parameters, such as a concurrent sensed rotation vector of the conductive trackball (110), to identify a user command intended by the user. The identified user command may be transmitted to a controlled system (740) to effectuate or modify an operation at the controlled system (740).

Claims

1. A system comprising:

a user interface device comprising a capacitive trackball assembly having;

a conductive trackball; and

a conductive plate proximate to a surface of the conductive trackball;

wherein the user interface device is to transmit a user command responsive to an effective capacitance of the capacitive trackball assembly resulting from a user contact with the conductive trackball.

2. The system of claim 1, wherein the user interface device further comprises:

a rotation sensor to detect a rotation vector of the conductive trackball concurrent with the user contact; and

wherein the user interface device is to transmit the user command further responsive to the rotation vector.

3. The system of claim 1, wherein the user interface device comprises:

a housing having a first opening at a first surface, wherein a first hemispherical portion of the conductive trackball is accessible via the first opening.

4. The system of claim 3, wherein the housing comprises:

a second opening at a second surface, wherein a second hemispherical portion of the conductive trackball is accessible via the second opening.

5. The system of claim 1, wherein the user interface device is to determine the user command based on a relationship between the effective capacitance of the capacitive trackball assembly and a plurality of threshold levels, each threshold level representing a corresponding number of user contact points with the capacitive trackball assembly.

6. The system of claim 5, wherein:

the plurality of threshold levels comprises a first threshold level and a second threshold level greater than the first threshold level;

the user interface device is to select the user command from a first set of one or more user commands responsive to the effective capacitance falling between the first threshold level and the second threshold level; and

the user interface device is to select the user command from a second set of one or more user commands responsive to the effective capacitance exceeding the second threshold level.

7. The system of claim 1, further comprising:

a display system to receive the user command, the display system to modify an operation of the display system responsive to the user command.

8. The system of claim 7, further comprising:

an intermediary device wirelessly coupled to the user interface device and wirelessly coupled to the display system; and

wherein the user interface device is to wirelessly transmit the user command to the intermediary device and the intermediary device is to wirelessly transmit the user command to the display system.

9. A user interface device comprising:

a capacitive trackball assembly having;

a conductive trackball; and

a conductive plate proximate to a surface of the conductive trackball; and

a capacitive sense circuit coupled to the capacitive trackball assembly, the capacitive sense circuit to detect an effective capacitance of the capacitive trackball assembly.

10. The user interface device of claim 9, further comprising:

a command controller coupled to the capacitive sense circuit, the command controller to determine a user command based on a relationship between the effective capacitance and a plurality of threshold levels.

11. The user interface device of claim 10, further comprising:

a rotation sensor coupled to the command controller, the rotation sensor to detect a rotation vector of the conductive trackball; and

wherein the command controller is to provide the user command further based on the rotation vector.

12. The user interface device of claim 10, wherein:

the command controller is to select the user command from a first set of one or more user commands responsive to the effective capacitance falling below a threshold level of the plurality of threshold levels; and

the command controller is to select the user command from a second set of one or more user commands responsive to the effective capacitance exceeding the threshold level.

13. The user interface device of claim 10, wherein the plurality of threshold levels are adjustable.

14. The user interface device of claim 13, wherein the command controller is to dynamically adjust the plurality of threshold levels based on a noise calibration of the capacitive trackball assembly.

15. The user interface device of claim 9, wherein the conductive plate substantially encircles the conductive trackball.

16. The user interface device of claim 9, wherein the capacitive trackball assembly comprises a plurality of conductive plates including the conductive plate.

17. The user interface device of claim 16, wherein the plurality of conductive plates comprises:

a first conductive plate coupled to an input of the capacitive sense circuit; and

a second conductive plate physically separate from the first conductive plate and coupled to a ground potential.

18. The user interface device of claim 9, wherein the conductive plate is coupled to an input of the capacitive sense circuit.

19. The user interface device of claim 9, wherein the conductive plate is coupled to a ground potential and the conductive trackball is coupled to an input of the capacitive sense circuit.

20. The user interface device of claim 9, wherein the user interface device comprises a portable user device having:

a housing containing the capacitive trackball assembly and the capacitive sense circuit, the housing comprising;

a first surface having a first opening, wherein a first hemispherical portion of the conductive trackball is accessible via the first opening; and

a second surface opposite the first surface.

21. The user interface device of claim 20, wherein the housing further comprises:

a second opening at the second surface, wherein a second hemispherical portion of the conductive trackball is accessible via the second opening.

22. A method comprising:

determining an effective capacitance of a capacitive trackball assembly of a user interface device resulting from a user contact with a conductive trackball, the capacitive trackball assembly comprising the conductive trackball and a conductive plate proximate to a surface of the conductive trackball; and

determining a number of user contact points in contact with the conductive trackball based on the effective capacitance.

23. The method of claim 22, further comprising:

determining a user command for transmission from the user interface device based on the number of user contact points.

24. The method of claim 23, further comprising:

detecting a rotation vector of the conductive trackball concurrent with detecting the number of user contact points; and

wherein determining the user command for transmission comprises determining the user command further based on the rotation vector.

25. The method of claim 23, further comprising:

transmitting the user command from the user interface device to a display system; and

modifying an operation of the display system based on the user command.

26. The method of claim 25, wherein transmitting the user command comprises:

wirelessly transmitting the user command from the user interface device to an intermediary device; and

wirelessly transmitting the user command from the intermediary device to the display system.

27. The method of claim 22, wherein determining the number of user contact points comprises:

determining the number of user contact points based on a relationship between the effective capacitance and a plurality of threshold levels, each threshold level associated with a different number of user contact points.