Power Management for Touch Controller

• US 20110061947A1
• Filed: 09/11/2009
• Published: 03/17/2011
• Est. Priority Date: 09/11/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Wilson, Thomas James, KRAH, Christoph Horst
• Granted Patent: US 8,970,506 B2
• Time in Patent Office: Days
• US Class Current: 178/18.01
• 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 lowering power consumption of a device comprising:

selecting, from a plurality of values, a value associated with a component of the device and based on an operating condition of the device; and

adjusting the component with the selected value to use less power during the operating condition of the device.

2. The method of claim 1, wherein the operating condition comprises a touch signal frequency, a device component temperature, or a touch signal noise level.

3. The method of claim 1, wherein adjusting comprises adjusting the component of the device with a bias current adjustment to use less power when the component receives a lower frequency signal.

4. The method of claim 1, wherein adjusting comprises powering down the component of the device with a bypass command when the component receives a less noisy signal.

5. The method of claim 1, wherein adjusting comprises reducing the integration time of the component of the device with a time adjustment when the component receives a less noisy signal.

6. The method of claim 1, wherein adjusting comprises adjusting the slew rate of the component of the device when the component receives a lower frequency signal.

7. The method of claim 1, wherein adjusting comprises modifying a stimulation pattern to the component of the device to reduce power to drive the device.

8. A touch controller comprising:

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

a memory configured to store a plurality of power adjustments corresponding to the sections, the adjustments based on operable conditions of the controller; and

power management logic configured to selectively apply the power adjustments to the corresponding sections in order to process the touch signal at lower power without substantially lower signal quality.

9. The touch controller of claim 8, wherein one of the plurality of sections is a receive section configured to receive the touch signal, the receive section receiving a power adjustment from the power management logic to adjust the current to one or more components in the receive section.

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

11. The touch controller of claim 8, wherein one of the plurality of sections is a demodulation section configured to demodulate the touch signal, the demodulation section receiving a power adjustment from the power management logic to reduce operating time of a component of the demodulation section.

12. The touch controller of claim 8, wherein one of the plurality of sections is a demodulation section configured to demodulate the touch signal, the demodulation section receiving a power adjustment from the power management logic to select which data to provide to a component of the demodulation section for demodulating the touch signal.

13. The touch controller of claim 8, wherein one of the plurality of sections is a transmit section configured to provide stimulation signals for generating the touch signal, the transmit section receiving a power adjustment from the power management logic to adjust a slew rate of a component of the transmit section.

14. The touch controller of claim 8, where the memory is configured to store a lookup table comprising entries, each entry including at least one of the operable conditions of the controller and the corresponding power adjustments to be made.

15. The touch controller of claim 8 incorporated into at least one of a mobile telephone, a digital media player, or a personal computer.

16. A method for selectively lowering power consumption of a device comprising:

determining an operating mode of the device;

replacing power requirements of the device in the determined operating mode with lower power requirements; and

maintaining the device at the lower power requirements until the operating mode ends.

17. The method of claim 16, wherein determining comprising determining whether the operating mode is an active mode, a ready mode, or an auto-scan mode.

18. The method of claim 16, wherein replacing comprising replacing the power requirements according to a first state during which components of the device remain active with the lower power requirements according to a second state during which the active components of the device become inactive.

19. The method of claim 16, wherein replacing comprises replacing the power requirements according to a first state during which the device powers down to a first power level and then to a second power level with the lower power requirements according to a second state during which the device directly powers down to the second power level.

20. The method of claim 16, wherein replacing comprises replacing the power requirements according to a first state having a particular time period for which the device remains idle with the lower power requirements according to a second state lengthening the particular time period for which the device remains idle.

21. The method of claim 16, further comprising alternating between the operating modes.

22. A touch controller comprising:

a plurality of operable modes comprising active periods and idle periods; and

power management logic configured to replace a power consumption level for the idle periods with a lower power consumption level at the start of the idle periods.

23. The touch controller of claim 22, wherein the plurality of operable modes includes at least one of an active mode configured to actively scan for touch events during the active periods and to wait during the idle period, a ready mode configured to actively scan for touch events during the active periods and to become inactive during the idle periods, or an auto-scan mode configured to briefly scan for touch events during the active periods and to become inactive for long periods during the idle periods.

24. The touch controller of claim 22, wherein the power management logic replaces the power consumption level in which some components are active to the lower power consumption level in which the active components are made inactive or the power management logic replaces the power consumption level in which the idle periods are a first length with the lower power consumption level in which the idles periods are a second length.

25. A touch sensitive device comprising:

a touch sensor panel configured to sense a touch or near touch and to generate touch signals based on the sensed touch or near touch; and

a touch controller configured to manage power consumption of the device, the touch controller comprising

a memory configured to store power consumption data, and

power management logic configured to selectively apply the power consumption data to the device to reduce power,

wherein the power consumption data is selectively applied to the device during processing of the touch signals to reduce power according to operable conditions of the device, and the power consumption data is selectively applied to the device during idle periods to reduce power according to operable modes of the device.