Touch controller with improved diagnostics calibration and communications support

• US 8,664,548 B2
• Filed: 09/11/2009
• Issued: 03/04/2014
• Est. Priority Date: 09/11/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Wilson, Thomas James, Krah, Christoph Horst
• Primary Examiner(s): Haley, Joseph
• Assistant Examiner(s): FRANK, EMILY J
• Application Number:
  US12/558,140
• Publication Number:
  US 20110061948A1
• Time in Patent Office: 1,635 Days
• Field of Search: None
• US Class Current: 178/18.01
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

A touch controller with improved diagnostics calibration and communication support includes a data capture register configured to sample data from one or a plurality of touch panel sense channels at an output of an analog to digital (A/D) converter. The sampled data is bit packed, and a demodulation waveform is captured, correlated with the sampled data. The contents of the data capture register, including the sampled data and the demodulation waveform, are transferred to a memory configured to create one or more records from the transferred contents. A processor can be used to extract the one or more records captured in the memory to display to a user for diagnostics or calibration.

Claims

1. A method, comprising;

sampling data from one or a plurality of touch panel sense channels prior to demodulation;

capturing a demodulation waveform, correlated with the sampled data, to form a record;

storing one or a plurality of records; and

accessing the one or a plurality of records to extract diagnostics information.

2. The method of claim 1, further comprising:

displaying at least part of the one or a plurality of records.

3. The method of claim 1, further comprising:

automatically calibrating a gain of the one or a plurality of sense channels based at least in part on one or more captured records.

4. The method of claim 3, further comprising capturing minimum and maximum amplitude data to compute the gain of the one or a plurality of sense channels.

5. The method of claim 1, further comprising:

determining a relative phase shift between the sampled data and the demodulation waveform.

6. The method of claim 5, further comprising:

automatically calibrating a phase of the one or a plurality of sense channels, based at least in part on one or more captured records.

7. The method of claim 1, wherein the one or a plurality of records are captured when a start bit is stored in a start register.

8. The method of claim 1, wherein N records are captured, wherein N is an integer greater than or equal to 1, and depends on a programmable integration period.

9. The method of claim 8, wherein each record includes a predetermined number of sense channel outputs and a correlating demodulation waveform.

10. The method of claim 1, wherein the sampled data is composite touch data.

11. The method of claim 1, wherein the touch panel sense channel is incorporated within a computing system.

12. A touch controller, comprising;

a data capture register configured to sample data from one or a plurality of touch panel sense channels prior to demodulation, and to capture a demodulation waveform correlated with the sampled data;

a memory configured to form a record, including the sampled data and the demodulation waveform, and to store one or a plurality of records; and

a processor configured to access the one or a plurality records to extract diagnostics information.

13. The touch controller of claim 12, wherein the processor is further configured to automatically calibrate a gain of the one or a plurality of sense channels, based on at least part of the one or more records captured in the memory.

14. The touch controller of claim 13, further comprising a min/max register configured to capture minimum and maximum amplitude data to compute the gain of the one or a plurality of sense channels.

15. The touch controller of claim 12, wherein the processor is further configured to determine a relative phase shift between the sampled data and the demodulation waveform.

16. The touch controller of claim 15, wherein the processor is further configured to automatically calibrate a phase of the one or a plurality of sense channels, based on at least part of the one or more records captured in the memory.

17. The touch controller of claim 12, wherein the memory is coupled to a start register, and the memory is configured to capture the one or a plurality of records when a start bit is stored in the start register.

18. The touch controller of claim 12, wherein the memory is configured to capture N records, wherein N is an integer greater than or equal to 1, and depends on a programmable integration period.

19. The touch controller of claim 18, wherein each record includes a predetermined number of sense channel outputs and a correlating demodulation waveform.

20. The touch controller of claim 12, wherein the sampled data is composite touch data.

21. The touch controller of claim 12, wherein the plurality of touch panel sense channels are within a touch sensor panel.

22. The touch controller of claim 21, wherein the touch sensor panel is incorporated within a computing system.

23. A system, comprising:

means for sampling data from one or a plurality of touch panel sense channels prior to demodulation;

means for capturing a demodulation waveform, correlated with the sampled data, to form a record;

means for storing one or a plurality of records; and

means for accessing the one or a plurality of records to extract diagnostics information.