Channel scan logic

• US 8,836,656 B2
• Filed: 01/04/2012
• Issued: 09/16/2014
• Est. Priority Date: 01/03/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Vu, Minh-Dieu Thi, Wilson, Thomas James, Krah, Christoph Horst
• Primary Examiner(s): NGUYEN, KIMNHUNG T
• Application Number:
  US13/343,604
• Publication Number:
  US 20120098778A1
• Time in Patent Office: 986 Days
• Field of Search: 345173-179, 345/204, 178 1801- 1804, 710/14, 713/2
• US Class Current: 345/173
• 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 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• 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 3/044 by capacitive means
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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

A device that can autonomously scan a sensor panel is disclosed. Autonomous scanning can be performed by implementing channel scan logic. In one embodiment, channel scan logic carries out many of the functions that a processor would normally undertake, including generating timing sequences and obtaining result data; comparing scan result data against a threshold value (e.g., in an auto-scan mode); generating row count; selecting one or more scanning frequency bands; power management control; and performing an auto-scan routine in a low power mode.

Claims

1. A method for detecting an object touching or hovering near a touch sensor panel, comprising:

continuously and autonomously scanning the touch sensor panel substantially free of intervention from a processor and storing scan data in a first memory unit until a first event is detected;

moving the stored scan data to a second memory unit when the first event is detected; and

resuming the scanning of the touch sensor panel when a second event is detected.

2. The method of claim 1, wherein the first event comprises a notification that the first memory unit is full.

3. The method of claim 1, wherein the first event comprises a request from the processor to stop scanning.

4. The method of claim 1, wherein the second event comprises a notification that the first memory is not full.

5. The method of claim 1, wherein the second event comprises a request from the processor to resume scanning.

6. An apparatus for detecting an object touching or hovering near a touch sensor panel, comprising:

a touch sensor panel;

first and second memory units; and

scan logic communicatively coupled to the touch sensor panel and the first memory unit and configured for

continuously and autonomously scanning the touch sensor panel substantially free of intervention from a processor and storing scan data in the first memory unit until a first event is detected,

moving the stored scan data to the second memory unit when the first event is detected, and

resuming the scanning of the touch sensor panel when a second event is detected.

7. The apparatus of claim 6, wherein the first event comprises a notification that the first memory unit is full.

8. The apparatus of claim 6, further comprising:

a processor communicatively coupled to the scan logic and the first memory unit;

wherein the first event comprises a first request from the processor to stop scanning.

9. The apparatus of claim 8, wherein the second event comprises a second request from the processor to resume scanning.

10. The apparatus of claim 6, wherein the second event comprises a notification that the first memory is not full.

11. A method for detecting an object touching or hovering near a touch sensor panel, comprising:

scanning a first portion of the touch sensor panel substantially free of intervention from a processor;

processing data obtained from the scan of the first portion while waiting for permission to scan a second portion of the touch sensor panel; and

scanning the second portion after receiving permission to scan the second portion.

12. The method of claim 11, wherein the first portion is a first frame of the touch sensor panel and the second portion is another frame of the touch sensor panel.

13. The method of claim 11, wherein the first portion is a first row of the touch sensor panel and the second portion is another row of the touch sensor panel.

14. The method of claim 11, further comprising powering down receive channel circuitry while waiting for permission to scan the second portion.

15. An apparatus for detecting an object touching or hovering near a touch sensor panel, comprising:

a touch sensor panel;

scan logic communicatively coupled to the touch sensor panel and configured for

scanning a first portion of the touch sensor panel substantially free of intervention from a processor,

processing data obtained from the scan of the first portion while waiting for permission to scan a second portion of the touch sensor panel, and

scanning the second portion after receiving permission to scan the second portion.

16. The apparatus of claim 15, wherein the first portion is a first frame of the touch sensor panel and the second portion is another frame of the touch sensor panel.

17. The apparatus of claim 15, wherein the first portion is a first row of the touch sensor panel and the second portion is another row of the touch sensor panel.

18. The apparatus of claim 15, further comprising:

a processor communicatively coupled to the scan logic;

wherein the scan logic is further configured for powering down receive channel circuitry while waiting for permission to scan the second portion.