SHIFTING CARRIER FREQUENCY TO AVOID INTERFERENCE

• US 20110210940A1
• Filed: 02/24/2011
• Published: 09/01/2011
• Est. Priority Date: 02/26/2010
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Reynolds, Joseph Kurth
• Granted Patent: US 9,922,622 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G09G 5/18 Timing circuits for raster scan displays specially adapted for television H04N ; synchronisation between the display unit and other display units, videodisc player G09G5/12

Abstract

In a method of avoiding interference in an integrated capacitive sensor device and display device, a first transmitter signal having a first frequency is transmitted with a combination electrode of the integrated capacitive sensor device and display device. The combination electrode is configured for both capacitive sensing and display updating. A shift is made from transmitting the first transmitter signal with the combination electrode to transmitting a second transmitter signal with the combination electrode. The shift is made by changing a duration of at least one non-display update time period of the display device. The second transmitter signal has a second frequency, and the shifting occurs based at least in part upon an amount of interference.

Claims

1. A method of avoiding interference in an integrated capacitive sensor device and display device, said method comprising:

transmitting a first transmitter signal having a first frequency with a combination electrode of said integrated capacitive sensor device and display device, wherein said combination electrode is configured for both capacitive sensing and display updating; and

shifting from transmitting said first transmitter signal with said combination electrode to transmitting a second transmitter signal with said combination electrode by changing a duration of at least one non-display update time period of said display device, wherein said second transmitter signal has a second frequency, and wherein said shifting occurs based at least in part upon an amount of interference.

2. The method as recited in claim 1, further comprising:

using said first transmitter signal to update said display device.

3. The method as recited in claim 1, further comprising:

receiving a resulting signal with a receiver electrode, said resulting signal corresponds to said first transmitter signal;

determining a first measurement of a change in a transcapacitive coupling between said combination electrode and said receiver electrode based on said resulting signal; and

determining positional information based on said first measurement.

4. The method as recited in claim 1, wherein said changing the duration of at least one non-display update time period comprises:

increasing duration of a non-display update time period associated with updating a row of said display device.

5. The method as recited in claim 1, wherein said changing a duration of at least one non-display update time period comprises:

decreasing duration of a non-display update time period associated with updating a row of said display device.

6. The method as recited in claim 1, wherein said shifting from transmitting said first transmitter signal with said combination electrode to transmitting a second transmitter signal with said combination electrode does not change a refresh rate of said display device.

7. The method as recited in claim 1, wherein said first transmitter signal comprises at least two transitions that occur during a non-display update time period associated with updating a row of said display device.

8. A processing system communicatively coupled with a capacitive sensor device and a display device, said processing system comprising:

transmitter circuitry configured for transmitting a first transmitter signal having a first frequency using a combination electrode, said combination electrode configured for both display updating and touch sensing;

receiver circuitry configured for receiving a resulting signal using a receiver electrode of said capacitive sensor device, said resulting signal corresponds to said first transmitter signal; and

a duration changer configured for changing a duration of at least one non-display update time period of said display device, wherein said change in duration causes a shift from transmitting said first transmitter signal with said combination electrode to transmitting a second transmitter signal with said combination electrode, wherein said second transmitter signal has a second frequency, wherein said change does not substantially change a refresh rate of said display device, and wherein said change occurs based at least in part upon an amount of interference.

9. The processing system of claim 8, further comprising:

display update circuitry configured for performing a display updating function of said display device with said combination electrode.

10. The processing system of claim 9, wherein said display update circuitry is configured for performing said display updating function by using said first transmitter signal as a display update signal for updating said display device.

11. The processing system of claim 8, wherein said duration changer is configured to change said duration of said at least one non-display update time period by increasing duration of a non-display update time period associated with updating a row of said display device.

12. The processing system of claim 8, wherein said duration changer is configured to change said duration of said at least one non-display update time period by decreasing duration of a non-display update time period associated with updating a row of said display device.

13. The processing system of claim 8, wherein said first transmitter signal comprises at least two transitions that occur during at least one non-display update time period associated with updating a row of said display device.

14. The processing system of claim 8, wherein said processing system is configured to:

determine a first measurement of a change in a transcapacitive coupling between said combination electrode and said receiver electrode based on said resulting signal; and

determine positional information based on said first measurement.

15. A touch screen device comprising:

a display device, said display device comprising a combination electrode configured for both display updating and touch sensing;

a receiver electrode proximate said combination electrode, said receiver electrode configured for touch sensing; and

a processing system communicatively coupled with said combination electrode and said receiver electrode, said processing system configured to;

transmit a first transmitter signal having a first frequency using said combination electrode;

receive a resulting signal using said receiver electrode, said resulting signal corresponds to said first transmitter signal; and

change a duration of at least one non-display update time period of said display device, wherein said change in duration causes a shift from transmitting said first transmitter signal with said combination electrode to transmitting a second transmitter signal with said combination electrode, wherein said second transmitter signal has a second frequency, wherein said change does not substantially change a refresh rate of said display device, and wherein said change occurs based at least in part upon an amount of interference.

16. The touch screen device of claim 15, wherein said processing system is configured to perform a display updating function of said display device with said combination electrode.

17. The touch screen device of claim 16, wherein said processing system is configured to perform said display updating function of said display device with said combination electrode by using said first transmitter signal as a display update signal for updating said display device.

18. The touch screen device of claim 15, wherein said processing system is configured to change said duration of said at least one non-display update time period by increasing duration of a non-display update time period associated with updating a row of said display device.

19. The touch screen device of claim 15, wherein said processing system is configured to change said duration of said at least one non-display update time period by decreasing duration of a non-display update time period associated with updating a row of said display device.

20. The touch screen device of claim 15, wherein said transmitter signal comprises at least two transitions that occur during at least one non-display update time period associated with updating a row of said display device.