LOW POWER TOUCH DETECTION

• US 20190079576A1
• Filed: 09/11/2017
• Published: 03/14/2019
• Est. Priority Date: 09/11/2017
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: LIU, Zhao, BENBASAT, Ari Y.
• Granted Patent: US 10,444,820 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 1/3206 Monitoring of events, devices or parameters that trigger a change in power modality
• CPC Class Codes: G06F 1/3262 Power saving in digitizer or tablet
• 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 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• 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

Low-power touch detection can be beneficial for an electronic device to maintain touch detection and enable response to certain touch inputs in a low-power state (e.g., a sleep state), while consuming less power than touch detection during an awake state. For example, sensing touch during the sleep state can allow the electronic device to wake (e.g., transition from the sleep state to the awake state) in response to detecting a certain touch input (e.g., a tap or other touch input) on its touch screen while in the sleep state. Examples of the disclosure provide various ways for the electronic device to further reduce power consumption in the low-power state by simplifying the processing requirements for touch input to the touch-sensitive surface.

Claims

1. A method for touch detection in a low-power state comprising:

acquiring a touch image including measurements from a plurality of touch nodes of a touch-sensitive surface;

processing the touch image to identify whether the touch image includes one or more qualifying edge touches; and

in accordance with identifying a first qualifying edge touch;

identifying a first portion of the touch image corresponding to the first qualifying edge touch; and

processing a second portion of the touch image excluding the first portion of the touch image to identify a touch input for the touch image without segmenting the second portion of the touch image.

2. The method of claim 1, further comprising:

in accordance with identifying the first qualifying edge touch and one or more additional qualifying edge touches greater than or equal to a threshold number of qualifying edge touches;

forgoing further processing of the touch image.

3. The method of claim 1, further comprising:

in accordance with identifying no qualifying edge touch;

processing the touch image to determine the touch input for the touch image without segmenting the touch image.

4. The method of claim 1, further comprising:

in accordance with a determination that the touch input for the touch image meets one or more qualifying criteria, processing the touch input for the touch image and touch inputs from additional touch images to detect a specified gesture when one or more gesture criteria are met;

in accordance with detecting the specified gesture, performing an action associated with the specified gesture; and

in accordance with not detecting the specified gestured, forgoing performing the action associated with the specified gesture.

5. The method of claim 4, wherein the specified gesture is a tap gesture.

6. The method of claim 4, where the action associated with the specified gesture is a transition between the low-power state and an active state.

7. The method of claim 1, further comprising:

in accordance with a determination the touch input identified from processing the second portion of the touch image excluding the first portion of the touch image does not meet the one or more qualifying criteria, processing the first portion of the touch image excluding the second portion to re-identify the touch input for the touch image without segmenting the first portion of the touch image.

8. The method of claim 1, further comprising:

baselining the touch image with a baseline image;

wherein the baseline image corresponds to a previously acquired touch image without a qualifying touch input.

9. The method of claim 8, wherein the baseline image includes a plurality of qualifying edge touches of the previously acquired touch image, such that baselining filters out the plurality of qualifying edge touches.

10. The method of claim 1, wherein processing the touch image to identify whether the touch image includes the one or more qualifying edge touches comprises:

identifying one or more qualifying edge touch nodes in a first region meeting signal criteria including a first signal criterion that a respective edge touch node is greater than or equal to a first signal threshold and a second signal criterion that a respective reference touch corresponding to the respective edge touch nodes is less than a second signal threshold.

11. The method of claim 10, wherein processing the touch image to identify whether the touch image includes the one or more qualifying edge touches further comprises:

grouping the one or more qualifying edge touch nodes into one or more groups, wherein each group includes a threshold number of contiguous qualifying edge touch nodes.

12. The method of claim 11, wherein processing the touch image to identify whether the touch image includes the one or more qualifying edge touches further comprises:

evaluating one or more boundary conditions for the one or more groups, wherein a group of the one or more groups meeting the one or more boundary conditions is identified as a qualifying edge touch.

13. An electronic device comprising:

a touch-sensitive surface; and

one or more processors coupled to the touch-sensitive surface capable of;

acquiring a touch image including measurements from a plurality of touch nodes of a touch-sensitive surface;

processing the touch image to identify whether the touch image includes one or more qualifying edge touches; and

in accordance with identifying a first qualifying edge touch;

identifying a first portion of the touch image corresponding to the first qualifying edge touch; and

processing a second portion of the touch image excluding the first portion of the touch image to identify a touch input for the touch image without segmenting the second portion of the touch image.

14. The electronic device of claim 13, one or more processors further capable of:

in accordance with identifying the first qualifying edge touch and one or more additional qualifying edge touches greater than or equal to a threshold number of qualifying edge touches;

forgoing further processing of the touch image.

15. The electronic device of claim 13, one or more processors further capable of:

in accordance with a determination that the touch input for the touch image meets one or more qualifying criteria, processing the touch input for the touch image and touch inputs from additional touch images to detect a specified gesture when one or more gesture criteria are met;

in accordance with detecting the specified gesture, performing an action associated with the specified gesture; and

in accordance with not detecting the specified gestured, forgoing performing the action associated with the specified gesture.

16. The electronic device of claim 13, one or more processors further capable of:

in accordance with a determination the touch input identified from processing the second portion of the touch image excluding the first portion of the touch image does not meet the one or more qualifying criteria, processing the first portion of the touch image excluding the second portion to re-identify the touch input for the touch image without segmenting the first portion of the touch image.

17. The electronic device of claim 13, wherein processing the touch image to identify whether the touch image includes the one or more qualifying edge touches comprises:

identifying one or more qualifying edge touch nodes in a first region meeting signal criteria including a first signal criterion that a respective edge touch node is greater than or equal to a first signal threshold and a second signal criterion that a respective reference touch corresponding to the respective edge touch nodes is less than a second signal threshold.

18. The electronic device of claim 17, wherein processing the touch image to identify whether the touch image includes the one or more qualifying edge touches further comprises:

grouping the one or more qualifying edge touch nodes into one or more groups, wherein each group includes a threshold number of contiguous qualifying edge touch nodes.

19. The electronic device of claim 18, wherein processing the touch image to identify whether the touch image includes the one or more qualifying edge touches further comprises:

evaluating one or more boundary conditions for the one or more groups, wherein a group of the one or more groups meeting the one or more boundary conditions is identified as a qualifying edge touch.

20. 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:

acquiring a touch image including measurements from a plurality of touch nodes of a touch-sensitive surface;

processing the touch image to identify whether the touch image includes one or more qualifying edge touches; and

in accordance with identifying a first qualifying edge touch;

identifying a first portion of the touch image corresponding to the first qualifying edge touch; and

processing a second portion of the touch image excluding the first portion of the touch image to identify a touch input for the touch image without segmenting the second portion of the touch image.