Channel Scan Logic

• US 20100164898A1
• Filed: 03/12/2010
• Published: 07/01/2010
• Est. Priority Date: 01/03/2007
• Status: Active Grant

• Current Assignee: Christoph Horst Krah, Minh-Dieu Thi Vu, Thomas James Wilson
• Original Assignee: Christoph Horst Krah, Minh-Dieu Thi Vu, Thomas James Wilson
• Inventors: Wilson, Thomas James, Krah, Christoph Horst, Vu, Minh-Dieu Thi
• Granted Patent: US 8,471,837 B2
• Time in Patent Office: Days
• 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. Channel scan logic for controlling scanning functions of a sensor panel, comprising:

a clock generator configured to generate a clock signal based on one of a plurality timing parameters inputted into the clock generator;

a stimulus signal divider operatively connected to the clock generator, the stimulus frequency divider configured to output a stimulus signal by dividing a the clock signal by a stimulus divide parameter;

a count divider operatively connected to the clock generator, the count divider configured to divide the clock signal by a count divide parameter to produce a count clock signal;

a counter operatively connected to the count divider, the counter configured to generate a plurality of incremented signals in response to the count clock signal;

a demodulation look up table operatively connected to the counter, the demodulation look up table outputting a demodulation value corresponding to each of the plurality of incremented signals;

a channel timing generator configured receive channel timing parameters and generate an analog channel control signal based on the channel timing parameters;

a sensor address generator configured to receive sensor address parameters and generate a sensor address control signal based on the sensor address parameters; and

delay logic operatively connected to the channel timing generator and the demodulation lookup table, the delay logic configured to generate delayed demodulation waveform signals and delayed analog to digital control signals.

2. The channel scan logic of claim 1, wherein the counter is configured to receive a value corresponding to a total number of demodulation values and rest upon counting up to the value corresponding to the total number of demodulation values.

3. The channel scan logic of claim 1, wherein the channel timing generator is a state machine.

4. The channel scan logic of claim 1, wherein the sensor address generator is a state machine.

5. The channel scan logic of claim 1, wherein the sensor address parameters include row mask parameters, scan pattern parameters, timing sequence parameters and high and low address parameters.

6. The channel scan logic of claim 1, wherein the sensor address parameters control which sensors are scanned.

7. The channel scan logic of claim 1, wherein the delay logic comprises a shift register and a multiplexer.

8. The channel scan logic of claim 1, further comprising a computing system that incorporates the channel scan logic, the computing system comprising:

a multi-event sensor panel comprising a plurality of sensors;

a multi-event subsystem operatively connected to the plurality of sensors;

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

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

9. The channel scan logic of claim 8, further comprising a mobile telephone that incorporates the computing system.

10. The channel scan logic of claim 8, further comprising a digital audio player that incorporates the computing system.

11. The channel scan logic of claim 8, wherein the plurality of sensors form one or more sensor rows located in distinct and non-overlapping areas.

12. The channel scan logic of claim 8, wherein the plurality of sensors are arranged in rows and columns in the sensor panel, each column operatively connected to a different analog channel.