Enhanced proximity sensing

• US 8,076,949 B1
• Filed: 03/28/2008
• Issued: 12/13/2011
• Est. Priority Date: 03/30/2007
• Status: Expired due to Fees

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Best, Andrew, Birch, Robert, Bokma, Louis, Peterson, Jonathan R.
• Primary Examiner(s): NATALINI, JEFF WILLIAM
• Application Number:
  US12/057,801
• Time in Patent Office: 1,355 Days
• Field of Search: 324/663
• US Class Current: 324/663
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2217/960705 Safety of capacitive touch and proximity switches, e.g. increasing reliability, fail-safe

Abstract

An embodiment of the present invention is directed to a method for rejecting sensor information when a switch is being pressed in a system having sensors over switches. A switch in the process of being pressed may be determined based on an increase in pressure which may be determined by measuring the increase in capacitance at a plurality of capacitive sensors. The rejection of sensor information when the switch is being pressed allows the user interface to more accurately thus facilitates smooth and jitterless interface operation.

Claims

1. A method for detecting a pressing of a button comprising:

measuring an increase in capacitance of a plurality of adjacent capacitive sensors of a user input device, said user input device comprising said button and said plurality of adjacent capacitive sensors disposed adjacent to said button;

determining a number of said plurality of adjacent capacitive sensors having the increased capacitance;

using said measured increase in capacitance and said determined number of said plurality of adjacent capacitive sensors having the increased capacitance to determine whether said button is being pressed; and

provided said button has been determined to be being pressed, rejecting data from said plurality of adjacent capacitive sensors, said data corresponding to the increased capacitance.

2. The method of claim 1 further comprising:

reporting sensor data during a normal mode at a first scan rate; and

increasing said scan rate to a second rate when performing said measuring and said determining, wherein said second rate has a higher frequency than said first scan rate.

3. The method of claim 1, wherein capacitance of said measuring is based on a characteristic of material overlaying said plurality of adjacent capacitive sensors.

4. The method of claim 1, further comprising:

debouncing said button press.

5. The method of claim 1, wherein capacitance of said measuring is based on a size of said plurality of adjacent capacitive sensors.

6. A method for determining if a button is being pressed comprising:

measuring changes in a proximity of an object with a plurality of sensors of an input device comprising said plurality of sensors and said button;

determining whether a pressure of said object is increasing, wherein said pressure of said object is determined based on a change in capacitance of said plurality of sensors based on said proximity of said object; and

provided it is determined that pressure of said object is increasing, not reporting information related to said change in capacitance of said plurality of sensors to a user input detection unit.

7. The method of claim 6, wherein said plurality of sensors are adjacent.

8. The method of claim 6, wherein said plurality of sensors are adjacent to a plurality of buttons.

9. The method of claim 6, wherein said plurality of sensors comprises a plurality of capacitive sensors.

10. A system comprising:

a plurality of sensors;

a plurality of switches, wherein said plurality of switches are adjacent to said plurality of sensors; and

a control unit for communicating with an apparatus and coupled to said plurality of sensors and said plurality of switches and wherein said control unit determines a change in pressure of said plurality of sensors based on electronic signals from said plurality of sensors, and based on said pressure, said control unit operable to ignore information from said plurality of sensors during user input determination, said information corresponding to an increase in capacitance measured by said plurality of sensors.

11. The system as described in claim 10, wherein said plurality of switches are dome switches.

12. The system as described in claim 10, wherein said plurality of sensors are capacitive sensors.

13. The system as described in claim 10, wherein said plurality of switches and sensors comprises a touch pad.

14. The system as described in claim 10, wherein said plurality of switches and sensors comprises a radial slider.

15. The system as described in claim 10, wherein said plurality of switches and sensors comprises a volume control.

16. A method of detecting user input on a user input device comprising said method comprising:

measuring an increase in capacitance of a plurality of adjacent capacitive sensors of said user input device comprising said plurality of adjacent capacitive sensors and a button, wherein said plurality of adjacent capacitive sensors are disposed adjacent to said button;

determining a number of said plurality of adjacent capacitive sensors having the increased capacitance;

using said measured increase in capacitance and said determined number of said plurality of adjacent capacitive sensors having the increased capacitance to determine whether said button is in a process of being pressed; and

provided said button has been determined to be in a process of being pressed, rejecting data from said plurality of adjacent capacitive sensors in a user input determination process, said data corresponding to the increased capacitance.

17. The method as described in claim 16, wherein said plurality of sensors and button comprises a slider.

18. The method as described in claim 16, wherein said plurality of sensors and button comprises a brightness control.

19. The method as described in claim 16, wherein said plurality of sensors and button comprises a touch screen.

20. The method as described in claim 16, wherein said plurality of sensors and button comprises a portable media player.