Coarse scan and targeted active mode scan for touch and stylus

• US 10,664,113 B2
• Filed: 08/27/2018
• Issued: 05/26/2020
• Est. Priority Date: 12/04/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Shahparnia, Shahrooz, Pant, Vivek, Yousefpor, Marduke, Krah, Christoph H.
• Primary Examiner(s): Nguyen, Jennifer T
• Application Number:
  US16/114,023
• Publication Number:
  US 20190095006A1
• Time in Patent Office: 638 Days
• Field of Search: 345174-178
• CPC Class Codes: G06F 1/3215 Monitoring of peripheral devices
• CPC Class Codes: G06F 1/3262 Power saving in digitizer or tablet
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware
• CPC Class Codes: G06F 3/041661 using detection at multiple resolutions, e.g. coarse and fine scanning; using detection within a limited area, e.g. object tracking window
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• 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

Abstract

Power consumption of touch sensing operations for touch sensitive devices can be reduced by implementing a coarse scan (e.g., banked common mode scan) to coarsely detect the presence or absence of an object touching or proximate to a touch sensor panel and the results of the coarse scan can be used to dynamically adjust the operation of the touch sensitive device to perform or not perform a fine scan (e.g., targeted active mode scan). In some examples, the results of the coarse scan can be used to program a touch controller for the next touch sensing frame to idle when no touch event is detected or to perform a fine scan when one or more touch events are detected. In some examples, the results of the coarse scan can be used to abort a scheduled fine scan during the current touch sensing frame when no touch event is detected.

Claims

1. An apparatus comprising:

a touch sensor panel comprising touch electrodes, the touch sensor panel including a plurality of first regions, each of the plurality of first regions including a plurality of the touch electrodes; and

processing circuitry configured to;

perform a first detection scan of the touch sensor panel, the first detection scan comprising generating a touch value representative of an amount of touch at each of the plurality of first regions;

identify, based on the first detection scan, a coarse location of an object touching or proximate to the touch sensor panel, the coarse location corresponding to a second region smaller than one of the plurality of first regions; and

perform a second detection scan, the second detection scan of a portion of the touch sensor panel corresponding to the second region; and

identify, based on the second detection scan, a fine location of the object touching or proximate to the touch sensor panel.

2. The apparatus of claim 1, wherein the plurality of touch electrodes corresponding to one of the plurality of first regions is coupled to one corresponding sense channel during the first detection scan.

3. The apparatus of claim 1, where the first detection scan comprises a self-capacitance scan in which the plurality of first regions are simultaneously sensed.

4. The apparatus of claim 1, the processing circuitry further configured to:

reconfigure a connection between the touch electrodes of the touch sensor panel and sense channels between the first detection scan and the second detection scan, wherein reconfiguring the connection comprises connecting one of the sense channels to a second number of the touch electrodes for the second detection scan, the second number of the touch electrodes less than a first number of the touch electrodes connected to the one of the sense channels for the first detection scan.

5. The apparatus of claim 1, wherein identifying the coarse location of the object comprises:

identifying one of the plurality of first regions having a maximum touch value generated during the first detection scan.

6. The apparatus of claim 5, wherein identifying the coarse location of the object further comprises:

computing a centroid using the maximum touch value and touch values of one or more of the plurality of first regions adjacent to the one of the plurality of first regions having the maximum touch value generated during the first detection scan.

7. The apparatus of claim 5, wherein identifying the coarse location of the object further comprises:

computing a first centroid using the maximum touch value and touch values of two of the plurality of first regions adjacent to, and on opposite sides in a first dimension of, the one of the plurality of first regions having the maximum touch value generated during the first detection scan; and

computing a second centroid using the maximum touch value and touch values of two of the plurality of first regions adjacent to, and on opposite sides in a second dimension of, the one of the plurality of first regions having the maximum touch value generated during the first detection scan.

8. The apparatus of claim 5, wherein identifying the coarse location of the object further comprises:

comparing touch values of two of the plurality of first regions adjacent to, and on opposite sides in a first dimension of, the one of the plurality of first regions having the maximum touch value generated during the first detection scan.

9. The apparatus of claim 1, wherein the second detection scan of the portion of the touch sensor panel corresponding to the second region includes a portion of the plurality of touch electrodes of the one of the plurality of first regions having a maximum touch value generated during the first detection scan and a portion of the plurality of touch electrodes of one or more of the plurality of first regions adjacent to the one of the plurality of first regions having the maximum touch value generated during the first detection scan.

10. The apparatus of claim 1, wherein the object comprises a stylus and wherein the portion of the touch sensor panel corresponding to the second region is determined based on a size of the stylus.

11. A method comprising:

at an electronic device with a touch sensor panel, the touch sensor panel including a plurality of first regions, each of the plurality of first regions including a plurality of the touch electrodes;

performing a first detection scan of the touch sensor panel, the first detection scan comprising generating a touch value representative of an amount of touch at each of the plurality of first regions;

identifying, based on the first detection scan, a coarse location of an object touching or proximate to the touch sensor panel, the coarse location corresponding to a second region smaller than one of the plurality of first regions; and

performing a second detection scan, the second detection scan of a portion of the touch sensor panel corresponding to the second region; and

identifying, based on the second detection scan, a fine location of the object touching or proximate to the touch sensor panel.

12. The method of claim 11, further comprising:

reconfiguring a connection between the touch electrodes of the touch sensor panel and sense channels between the first detection scan and the second detection scan, wherein reconfiguring the connection comprises connecting one of the sense channels to a second number of the touch electrodes for the second detection scan, the second number of the touch electrodes less than a first number of the touch electrodes connected to the one of the sense channels for the first detection scan.

13. The method of claim 11, wherein identifying the coarse location of the object comprises:

identifying one of the plurality of first regions having a maximum touch value generated during the first detection scan; and

computing a centroid using the maximum touch value and touch values of one or more of the plurality of first regions adjacent to the one of the plurality of first regions having the maximum touch value generated during the first detection scan.

14. The method of claim 11, wherein identifying the coarse location of the object comprises:

identifying one of the plurality of first regions having a maximum touch value generated during the first detection scan; and

computing a first centroid using the maximum touch value and touch values of two of the plurality of first regions adjacent to, and on opposite sides in a first dimension of, the one of the plurality of first regions having the maximum touch value generated during the first detection scan; and

computing a second centroid using the maximum touch value and touch values of two of the plurality of first regions adjacent to, and on opposite sides in a second dimension of, the one of the plurality of first regions having the maximum touch value generated during the first detection scan.

15. The method of claim 11, wherein identifying the coarse location of the object comprises:

identifying one of the plurality of first regions having a maximum touch value generated during the first detection scan; and

comparing touch values of two of the plurality of first regions adjacent to, and on opposite sides in a first dimension of, the one of the plurality of first regions having the maximum touch value generated during the first detection scan.

16. A non-transitory computer readable storage medium storing instructions, which when executed by one or more processors, cause the one or more processors to perform a method, the method comprising:

at an electronic device with a touch sensor panel, the touch sensor panel including a plurality of first regions, each of the plurality of first regions including a plurality of the touch electrodes;

performing a first detection scan of the touch sensor panel, the first detection scan comprising generating a touch value representative of an amount of touch at each of the plurality of first regions;

identifying, based on the first detection scan, a coarse location of an object touching or proximate to the touch sensor panel, the coarse location corresponding to a second region smaller than one of the plurality of first regions; and

performing a second detection scan, the second detection scan of a portion of the touch sensor panel corresponding to the second region; and

identifying, based on the second detection scan, a fine location of the object touching or proximate to the touch sensor panel.

17. The non-transitory computer readable storage medium of claim 16, the method further comprising:

reconfiguring a connection between the touch electrodes of the touch sensor panel and sense channels between the first detection scan and the second detection scan, wherein reconfiguring the connection comprises connecting one of the sense channels to a second number of the touch electrodes for the second detection scan, the second number of the touch electrodes less than a first number of the touch electrodes connected to the one of the sense channels for the first detection scan.

18. The non-transitory computer readable storage medium of claim 16, wherein identifying the coarse location of the object comprises:

identifying one of the plurality of first regions having a maximum touch value generated during the first detection scan; and

computing a centroid using the maximum touch value and touch values of one or more of the plurality of first regions adjacent to the one of the plurality of first regions having the maximum touch value generated during the first detection scan.

19. The non-transitory computer readable storage medium of claim 16, wherein identifying the coarse location of the object comprises:

identifying one of the plurality of first regions having a maximum touch value generated during the first detection scan; and

computing a first centroid using the maximum touch value and touch values of two of the plurality of first regions adjacent to, and on opposite sides in a first dimension of, the one of the plurality of first regions having the maximum touch value generated during the first detection scan; and

computing a second centroid using the maximum touch value and touch values of two of the plurality of first regions adjacent to, and on opposite sides in a second dimension of, the one of the plurality of first regions having the maximum touch value generated during the first detection scan.

20. The non-transitory computer readable storage medium of claim 16, wherein identifying the coarse location of the object comprises:

identifying one of the plurality of first regions having a maximum touch value generated during the first detection scan; and

comparing touch values of two of the plurality of first regions adjacent to, and on opposite sides in a first dimension of, the one of the plurality of first regions having the maximum touch value generated during the first detection scan.