Power management for touch controller

• US 9,529,415 B2
• Filed: 06/24/2015
• Issued: 12/27/2016
• Est. Priority Date: 09/11/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Krah, Christoph H., Wilson, Thomas James
• Primary Examiner(s): Haley, Joseph
• Assistant Examiner(s): FRANK, EMILY J
• Application Number:
  US14/749,524
• Publication Number:
  US 20150293583A1
• Time in Patent Office: 552 Days
• Field of Search: None
• US Class Current: 1/1
• 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 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: G06F 1/3296 by lowering the supply or operating voltage
• 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: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Power management for a touch controller is disclosed. The touch controller can include a transmit section for transmitting stimulation signals to an associated touch sensor panel to drive the panel, where the touch controller can selectively adjust the transmit section to reduce power during the transmission. The touch controller can also include a receive section for receiving touch signals resulting from the driving of the panel, where the touch controller can selectively adjust the receive section to reduce power during the receipt of the touch signals. The touch controller can also include a demodulation section for demodulating the received touch signals to obtain touch event results, where the touch controller can selectively adjust the demodulation section to reduce power during the demodulation of the touch signals. The touch controller can also selectively reduce power below present low levels during idle periods. The touch controller can be incorporated into a touch sensitive device.

Claims

1. A method for selectively adjusting power consumption of a touch controller device for a touch screen, the touch screen configured for applying a stimulation signal to capacitive sensing nodes of the touch screen, the method comprising:

determining an operating condition of the touch controller device;

selecting at least one component of the touch controller device, and for each selected component, selecting from a plurality of values, a value associated with the component of the device, wherein the at least one component and corresponding value selected is based on the determined operating condition of the touch controller device;

adjusting the at least one component with the corresponding selected value so as to adjust power consumption during the determined operating condition of the touch controller device; and

wherein the operating condition comprises a frequency of the stimulation signal.

2. The method of claim 1,

wherein determining the operating condition comprises determining a first and a second value of the operating condition of the touch controller device, wherein the first value of the operating condition corresponds to a first amount of power consumed for the touch controller and the second value of the operating condition corresponds to a second amount of power consumed for the touch controller, the first amount of power being less than the second amount of power;

and

wherein the at least one selected component and corresponding selected value is based on the determined first value of the operating condition of the touch controller device.

3. The method of claim 2, wherein adjusting comprises powering down the component of the device.

4. The method of claim 2, wherein adjusting comprises reducing an integration time of the component of the device.

5. The method of claim 2, wherein adjusting comprises modifying a stimulation pattern to the component of the touch controller device.

6. A touch controller for a touch screen, the touch screen configured for applying a stimulation signal to capacitive sensing nodes of the touch screen, the touch controller comprising:

a plurality of sections configured to process a touch signal, each section having adjustable power;

a memory configured to store at least a first and second power adjustment corresponding to at least one of the plurality of sections, the first power adjustment resulting in a lower power operating mode for the corresponding at least one of the plurality of sections than the second power adjustment; and

power management logic configured to detect an operating condition of a device, select the first power adjustment, and apply the selected first power adjustments to the corresponding at least one of the plurality of sections, wherein the at least first and second power adjustments is based on the detected operating condition of the device, and wherein the operating condition comprises a frequency of the stimulation signal.

7. The touch controller of claim 6, wherein one of the plurality of sections is a receive section configured to receive the touch signal, the receive section receiving the first power adjustment from the power management logic to adjust a current to one or more components in the receive section.

8. The touch controller of claim 6, wherein the at least one of the plurality of sections is a receive section configured to receive the touch signal, the receive section receiving the first power adjustment from the power management logic to power down one or more components in the receive section.

9. The touch controller of claim 6, wherein the at least one of the plurality of sections is a demodulation section configured to demodulate the touch signal, the demodulation section receiving the first power adjustment from the power management logic corresponding to an operating time of a component of the demodulation section.

10. The touch controller of claim 6, wherein the at least one of the plurality of sections is a demodulation section configured to demodulate the touch signal, the demodulation section receiving the first power adjustment from the power management logic to select data to provide to a component of the demodulation section for demodulating the touch signal.

11. The touch controller of claim 6, wherein the at least one of the plurality of sections is a transmit section configured to provide the stimulation signal for generating the touch signal, the transmit section receiving the first power adjustment from the power management logic to adjust a slew rate of a component of the transmit section.

12. The touch controller of claim 6, where the memory is configured to store a lookup table comprising entries, each entry including at least one of the operating conditions of the controller and the corresponding first and second power adjustments.

13. The touch controller of claim 6 incorporated into at least one of a mobile telephone, a digital media player, or a personal computer.