Ungrounded user signal compensation for pixelated self-capacitance touch sensor panel

• US 10,705,658 B2
• Filed: 09/22/2014
• Issued: 07/07/2020
• Est. Priority Date: 09/22/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Li, Yingxuan, Yousefpor, Marduke, Yao, Weijun
• Primary Examiner(s): Edouard, Patrick N
• Assistant Examiner(s): Fox, Joseph P
• Application Number:
  US15/507,722
• Publication Number:
  US 20170285804A1
• Time in Patent Office: 2,115 Days
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/041662 using alternate mutual and self-capacitive scanning
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

A touch controller is disclosed. The touch controller can include sense circuitry configured to sense, during a self-capacitance portion of a touch frame, first one or more self-capacitances associated with a first plurality of touch pixels on a touch sensor panel, and sense, during a mutual capacitance portion of the touch frame, first one or more mutual capacitances associated with the first plurality of touch pixels. A touch processor can be configured to, based on the first one or more self-capacitances and the first one or more mutual capacitances, sense a single touch event associated with the touch frame.

Claims

1. A touch controller comprising:

sense circuitry configured to;

perform, during one or more self-capacitance portions of a touch frame, first one or more self-capacitance scans associated with a first plurality of touch pixels on a touch sensor panel to generate self-capacitance information associated with the first plurality of touch pixels, wherein each of the one or more first self-capacitance scans is used to generate self-capacitance information for a different respective subset of the first plurality of touch pixels, and the first one or more self-capacitance scans determine a first self-capacitance associated with a first touch pixel, a second self-capacitance associated with a second touch pixel, a third self-capacitance associated with a third touch pixel, and a fourth self-capacitance associated with a fourth touch pixel on the touch sensor panel, and

perform, during a mutual capacitance portion of the touch frame, different than the one or more self-capacitance portions of the touch frame, first one or more mutual capacitance scans associated with the first plurality of touch pixels to generate mutual capacitance information associated with the first plurality of touch pixels, wherein the first one or more mutual capacitance scans determine a first mutual-capacitance associated with the first touch pixel and the second touch pixel, and a second mutual capacitance associated with the third touch pixel and the fourth touch pixel; and

a touch processor configured to use the self-capacitance information associated with the first plurality of touch pixels and the mutual capacitance information to sense a single touch event associated with the touch frame, wherein sensing the single touch event includes adjusting the first self-capacitance based on the first, second, third and fourth self-capacitances, and the first and second mutual capacitances.

2. The touch controller of claim 1, wherein adjusting the first self-capacitance comprises scaling the first self-capacitance by a first scaling factor based on the first self-capacitance and the first mutual capacitance.

3. The touch controller of claim 1, wherein the touch processor is further configured to:

adjust the second self-capacitance based on the first, second, third and fourth self-capacitances, and the first and second mutual capacitances.

4. The touch controller of claim 3, wherein:

adjusting the first self-capacitance comprises scaling the first self-capacitance by a first scaling factor, and

adjusting the second self-capacitance comprises scaling the second self-capacitance by a second scaling factor, different from the first scaling factor.

5. The touch controller of claim 3, wherein:

adjusting the first self-capacitance comprises scaling the first self-capacitance by an average scaling factor, and

adjusting the second self-capacitance comprises scaling the second self-capacitance by the average scaling factor.

6. The touch controller of claim 1, wherein the sense circuitry is configured to concurrently perform the first one or more self-capacitance scans of the first plurality of touch pixels.

7. The touch controller of claim 1, wherein the sense circuitry is configured to sequentially perform the first one or more self-capacitance scans of the first plurality of touch pixels.

8. The touch controller of claim 1, wherein the first, second, third and fourth touch pixels are arranged in a 2×

2 configuration on the touch sensor panel.

9. The touch controller of claim 1, wherein the touch processor is further configured to adjust the second self-capacitance based on the first, second, third and fourth self-capacitances, and the first and second mutual capacitances, and the touch processor is configured to adjust the first self-capacitance differently than the second self-capacitance.

10. The touch controller of claim 1, wherein:

the sense circuitry is further configured to;

perform second one or more self-capacitance scans associated with a second plurality of touch pixels, different than the first plurality of touch pixels, on the touch sensor panel to generate self-capacitance information associated with the second plurality of touch pixels, wherein each of the one or more second self-capacitance scans is used to generate self-capacitance information for a different respective subset of the second plurality of touch pixels; and

perform second one or more mutual capacitance scans associated with the second plurality of touch pixels to generate mutual capacitance information associated with the second plurality of touch pixels; and

the touch processor is configured to use the self-capacitance information associated with the first and second plurality of touch pixels and the mutual capacitance information associated with the first and second plurality of touch pixels to sense the single touch event, wherein sensing the single touch event includes adjusting one or more self-capacitances associated with the second plurality of touch pixels based on the self-capacitance information and the mutual capacitance information associated with the second plurality of touch pixels, but not the self-capacitance information and the mutual capacitance information associated with the first plurality of touch pixels.

11. A method comprising:

performing, during one or more self-capacitance portions of a touch frame, first one or more self-capacitance scans associated with a first plurality of touch pixels on a touch sensor panel to generate self-capacitance information associated with the first plurality of touch pixels, wherein each of the one or more first self-capacitance scans is used to generate self-capacitance information for a different respective subset of the first plurality of touch pixels, and the first one or more self-capacitance scans determine a first self-capacitance associated with a first touch pixel, a second self-capacitance associated with a second touch pixel, a third self-capacitance associated with a third touch pixel, and a fourth self-capacitance associated with a fourth touch pixel on the touch sensor panel;

performing, during a mutual capacitance portion of the touch frame, different than the one or more self-capacitance portions of the touch frame, first one or more mutual capacitance scans associated with the first plurality of touch pixels to generate mutual capacitance information associated with the first plurality of touch pixels, wherein the first one or more mutual capacitance scans determine a first mutual-capacitance associated with the first touch pixel and the second touch pixel, and a second mutual capacitance associated with the third touch pixel and the fourth touch pixel; and

using the self-capacitance information associated with the first plurality of touch pixels and the mutual capacitance information, sensing a single touch event associated with the touch frame, wherein sensing the single touch event includes adjusting the first self-capacitance based on the first, second, third and fourth self-capacitances, and the first and second mutual capacitances.

12. The method of claim 11, wherein adjusting the first self-capacitance comprises scaling the first self-capacitance by a first scaling factor based on the first self-capacitance and the first mutual capacitance.

13. The method of claim 11, further comprising adjusting the second self-capacitance based on the first, second, third and fourth self-capacitances, and the first and second mutual capacitances.

14. The method of claim 13, wherein:

adjusting the first self-capacitance comprises scaling the first self-capacitance by a first scaling factor, and

adjusting the second self-capacitance comprises scaling the second self-capacitance by a second scaling factor, different from the first scaling factor.

15. The method of claim 13, wherein:

adjusting the first self-capacitance comprises scaling the first self-capacitance by an average scaling factor, and

adjusting the second self-capacitance comprises scaling the second self-capacitance by the average scaling factor.

16. The method of claim 11, wherein the self-capacitance scans of the first plurality of touch pixels are performed concurrently.

17. The method of claim 11, wherein the self-capacitance scans of the first plurality of touch pixels are performed sequentially.

18. The method of claim 11, wherein the first, second, third and fourth touch pixels are arranged in a 2×

2 configuration on the touch sensor panel.

19. The method of claim 11, further comprising adjusting the second self-capacitance based on the first, second, third and fourth self-capacitances, and the first and second mutual capacitances, wherein the first self-capacitance is adjusted differently than the second self-capacitance.

20. The method of claim 11, further comprising:

performing second one or more self-capacitance scans associated with a second plurality of touch pixels, different than the first plurality of touch pixels, on the touch sensor panel to generate self-capacitance information associated with the second plurality of touch pixels, wherein each of the one or more second self-capacitance scans is used to generate self-capacitance information for a different respective subset of the second plurality of touch pixels;

performing second one or more mutual capacitance scans associated with the second plurality of touch pixels to generate mutual capacitance information associated with the second plurality of touch pixels; and

using the self-capacitance information associated with the first and second plurality of touch pixels and the mutual capacitance information associated with the first and second plurality of touch pixels to sense the single touch event, wherein sensing the single touch event includes adjusting one or more self-capacitances associated with the second plurality of touch pixels based on the self-capacitance information and the mutual capacitance information associated with the second plurality of touch pixels, but not the self-capacitance information and the mutual capacitance information associated with the first plurality of touch pixels.