Channel scan logic

• US 8,390,588 B2
• Filed: 03/17/2010
• Issued: 03/05/2013
• 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:
  US12/726,126
• Publication Number:
  US 20100188356A1
• Time in Patent Office: 1,084 Days
• Field of Search: 345173-179, 345/204, 455/556.1, 178 1801- 1804, 340/825.44, 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 digital audio player comprising:

an event-sensitive panel having a plurality of sensors for providing an output signal indicative of an event or no-event condition on the panel; and

channel scan logic configured to generate timing sequences and sensor address information for autonomously scanning at least some of the plurality of sensors substantially free of intervention from a processor.

2. The digital audio player of claim 1, the channel scan logic comprising a channel timing generator for generating an analog-to-digital converter control signal.

3. The digital audio player of claim 1, wherein the channel timing generator is a state machine.

4. The digital audio player of claim 1, the channel scan logic comprising an address generator for generating a sensor address signal, the sensor address signal enabling at least some of the plurality of sensors to be scanned.

5. The digital audio player of claim 1, the channel scan logic comprising a clock generator and a clock divider configured to generate a stimulus signal that is to be applied to at least some of the plurality of sensors.

6. The digital audio player of claim 1, the channel scan logic comprising a demodulator look up table containing a number of demodulation values used to form a demodulation waveform.

7. The digital audio player of claim 6, the channel scan logic further comprising a counter capable of generating an incremented value corresponding to one of the demodulation values stored in the demodulator look up table.

8. The digital audio player of claim 1, the channel scan logic comprising delay logic configured to delay a demodulated waveform that is to be applied to an analog channel so that the demodulated waveform is applied to the analog channel at about the same time feedback from a corresponding stimulus signal reaches the analog channel.

9. The digital audio player of claim 1, the channel scan logic comprising delay logic configured to delay an analog to digital converter control signal to account for delay associated with a stimulus signal'"'"'s feedback reaching an analog channel associated with the analog to digital converter.

10. The digital audio player of claim 1, further comprising a processor operatively connected to the channel scan logic and configured to program channel scan logic control parameters into memory units, the channel scan control parameters configured to control one or more functions of the channel scan logic.

11. The digital audio player of claim 1, further comprising a computing system that incorporates the channel scan logic, the computing system comprising:

a multi-event subsystem operatively connected to the plurality of sensors and incorporating the channel scan logic;

a multi-event panel processor operatively connected to the multi-event subsystem; and

a host processor operatively connected to the multi-event panel processor.