Method and apparatus for discriminating between user interactions

• US 20090225036A1
• Filed: 09/26/2007
• Published: 09/10/2009
• Est. Priority Date: 01/17/2007
• Status: Abandoned Application

• Current Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Wright, David G.
• Application Number:
  US11/904,576
• Publication Number:
  US 20090225036A1
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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

Abstract

Apparatus and methods for discriminating between a first signal from a user interface indicative of user interaction at a first location and a second signal indicative of user interaction at a second location.

Claims

1. A method, comprising:

receiving a first signal and a second signal from a user interface indicative of interaction at a first location and at a second location, respectively; and

discriminating between the first signal and the second signal corresponding to the first location and the second location, respectively.

2. The method of claim 1, wherein discriminating between the first and second signals comprises:

generating the first signal with a first frequency corresponding to the first location;

generating the second signal with a second frequency corresponding to the second location, wherein the first frequency and the second frequency are different frequencies; and

measuring the first frequency and the second frequency to discriminate between the first and second signals.

3. The method of claim 2, further comprising:

applying the generated first signal to a body of a first user at the first location, wherein the generated first signal is propagated through the body of the first user to the user interface when the first user interacts with the user interface at the first location; and

applying the generated second signal to a body of a second user at the second location, wherein the generated second signal is propagated through the body of the second user to the user interface when the second user interacts with the user interface at the second location.

4. The method of claim 1, wherein discriminating between the first and second signals comprises:

generating the first signal with a first frequency;

generating the second signal with a second frequency, wherein the first frequency is the same as the second frequency;

applying the first signal to a first user at the first location;

detecting through the first user the first signal to discriminate the first signal from the second signal;

applying the signal to a second user at the second location if no first signal is detected; and

detecting through the second user the second signal to discriminate the second signal from the first signal.

5. The method of claim 1, wherein discriminating between the first and second signals comprises:

receiving a carrier signal having a carrier frequency; and

demodulating the carrier signal to detect either the first signal or the second signal to discriminate between the first and second signals corresponding to the first location and the second location, respectively.

6. The method of claim 5, wherein discriminating between the first and second signals further comprises:

generating the carrier signal having the carrier frequency at the first and second locations;

modulating onto the carrier signal the first signal with a first frequency corresponding to the first location; and

modulating onto the carrier signal the second signal with a second frequency corresponding to the second location, wherein demodulating comprises demodulating the carrier signal to detect either the first frequency or the second frequency to discriminate between the first and second signals.

7. The method of claim 1, wherein discriminating between the first and second signals comprises:

determining a first capacitance of a first user at the first location from the first signal corresponding to the first location;

determining a second capacitance of a second user at the second location from the second signal corresponding to the second location; and

discriminating between interaction of the first user and the second user based on the determined first and second capacitances.

8. The method of claim 7, wherein discriminating between the first and second signals further comprises:

measuring a first count based on the first signal, wherein the first count is representative of the first capacitance of the first user at the first location;

measuring a second count based on the second signal, wherein the second count is representative of the second capacitance of the second user at the second location; and

discriminating between interaction of the first user and the second user based on the measured first and second counts.

9. The method of claim 1, further comprising:

providing a display configured to display a first image to a first user in the first location and a second image to a second user in the second location;

detecting a first type of interaction by the first user with the user interface at the first location;

detecting a second type of interaction by the second user with the user interface at the second location;

performing a first type of operation in response to detecting the first type of interaction at the first location; and

performing a second type of operation in response to detecting the second type of interaction at the second location.

10. The method of claim 1, further comprising detecting a presence of a conductive object on the user interface.

11. An apparatus, comprising

a detecting circuit configured to discriminate between a first signal and a second signal, wherein the first signal and the second signal are indicative of user interaction at a first location and at a second location, respectively.

12. The apparatus of claim 11, wherein the detecting circuit comprises:

a capacitance sensor configured to receive a signal representative of the interaction with the user interface at the first location or at the second location; and

a user detector circuit configured to receive the first and second signals and to discriminate between the first signal and the second signal corresponding to the first location and the second location, respectively.

13. The apparatus of claim 11, wherein the detecting circuit comprises a capacitance sensor configured to receive the first and second signals and to discriminate between the first signal and the second signal corresponding to the first location and the second location, respectively, wherein the first signal is representative of a first capacitance of a first user at the first location and the second signal is representative of a second capacitance of a second user at the second location.

14. The apparatus of claim 12, wherein the capacitance sensor comprises:

a relaxation oscillator coupled to the user interface, wherein the relaxation oscillator comprises;

a current source to provide a charge current to a plurality of sensor elements of the user interface;

a selection circuit coupled to the plurality of sensor elements and the current source, wherein the selection circuit is configured to sequentially select a sensor element of the plurality of sensor elements to provide the charge current and to measure the capacitance of each sensor element of the user interface;

a comparator coupled to the current source and the selection circuit, wherein the comparator is configured to compare a voltage on the selected sensor element and a threshold voltage; and

a reset switch coupled to the comparator, current source, and selection circuit, wherein the reset switch is configured to reset the charge current on the selected sensor element; and

a digital counter coupled to the relaxation oscillator, wherein the digital counter is configured to count at least one of a frequency or a period of a relaxation oscillator output received from the relaxation oscillator.

15. The apparatus of claim 12, wherein the user detector circuit comprises a frequency detector circuit having at least one of a phase locked loop (PLL) circuit or a tone detector.

16. The apparatus of claim 11, wherein the user interface is at least one of a capacitance sensing device or a mechanical button.

17. The apparatus of claim 11, further comprising:

the user interface coupled to the detecting circuit, wherein the detecting circuit is configured to receive the first and second signals through the user interface; and

a first drive circuit configured to generate the first signal indicative of interaction at the first location, wherein the first drive circuit is configured to apply the first signal to a body of a first user at the first location, wherein the detecting circuit is configured to receive the first signal through the body of the first user when the first user interacts with the user interface at the first location.

18. The apparatus of claim 17, further comprising a second drive circuit configured to generate the second signal indicative of interaction at the second location, wherein the second drive circuit is configured to apply the second signal to a body of a second user at the second location, wherein the detecting circuit is configured to receive the second signal through the body of the second user when the second user interacts with the user interface at the second location.

19. The apparatus of claim 17, wherein the first drive circuit is configured to generate a second signal indicative of interaction at the second location and to apply the second signal to a body of a second user at the second location, wherein the detecting circuit is configured to receive the second signal through the second user when the second user interacts with the user interface at the second location.

20. The apparatus of claim 17, wherein the first drive circuit comprises:

an oscillator;

an amplifier coupled to the amplifier; and

a coil coupled to the amplifier.

21. The apparatus of claim 17, wherein the user interface, detection circuit, and first drive circuit are installed in a car, and wherein the first drive circuit is installed in a seat of the car.

22. A method, comprising:

providing a user interface; and

discriminating between interaction with the user interface at a first location and interaction with the user interface at a second location.

23. The method of claim 22, further comprising limiting operation of the user interface at the first location while allowing interaction with the user interface at the second location.

24. The method of claim 23, wherein limiting operation of the user interface comprises preventing a first type of interaction at the first location while allowing the first type of interaction at the second location.

25. The method of claim 22, wherein the first location is a driver seat of a car and the second location is a passenger seat of the car.