TOUCH CONTROLLER ARCHITECTURE

• US 20150035768A1
• Filed: 07/16/2014
• Published: 02/05/2015
• Est. Priority Date: 07/31/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: SHAHPARNIA, Shahrooz, YOUSEFPOR, Marduke
• Granted Patent: US 10,845,901 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware
• CPC Class Codes: G06F 3/041661 using detection at multiple resolutions, e.g. coarse and fine scanning; using detection within a limited area, e.g. object tracking window
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0441 using active external devices, e.g. active pens, for receiving changes in electrical potential transmitted by the digitiser, e.g. tablet driving signals
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A touch controller that can configure touch circuitry according to a scan plan, which can define a sequence of scan events to be performed on a touch panel is disclosed. The touch controller can include a configurable transmit section to generate stimulation signals to drive the panel, a configurable receive section to receive and process touch signals from the panel, and a configurable memory to store the touch signals. The touch controller can also include a programmable scan engine to configure the transmit section, the receive section, and the memory according to the scan plan. The touch controller advantageously provides more robust and flexible touch circuitry to handle various types of touch events at the panel. An active stylus that can generate stimulation signals that can be detected by the touch controller during various touch events at the panel is also disclosed.

Claims

1. A touch controller comprising:

a configurable transmit section capable of generating one or more stimulation signals having one or more phases and one or more frequencies to drive a touch sensor panel;

a configurable receive section capable of receiving and processing one or more touch signals; and

a programmable scan engine capable of configuring at least one of the transmit section or the receive section according to a scan plan, the scan plan defining a sequence of scan events to be performed at the touch sensor panel, each scan event defining at least one of first settings for first components of the transmit section or second settings for second components of the receive section.

2. The controller of claim 1, further comprising a configurable memory capable of storing the one or more touch signals, wherein the programmable scan engine is capable of configuring the memory according to the scan plan and a scan event defines storage allocations in the memory.

3. The controller of claim 1, wherein the transmit section comprises:

one or more oscillators capable of generating the stimulation signals at one or more frequencies;

one or more digital-to-analog converters (DACs) coupled to the oscillators and capable of generating the stimulation signals at one or more phases; and

one or more channels coupled to the DAC converters, each channel including a first multiplexer capable of selecting one of the stimulation signals having one of the phases and one of the frequencies;

wherein the scan engine is capable of configuring the first settings for the oscillators, the DAC converters, and the first multiplexers of the one or more channels.

4. The controller of claim 3, wherein the transmit section further comprises:

a second multiplexer capable of routing the selected stimulation signal outputted from the first multiplexer to a row or column trace of the touch sensor panel;

wherein the scan engine is capable of configuring the first settings for the second multiplexers of the one or more channels.

5. The controller of claim 4, wherein the second multiplexer is capable of coupling the row or column trace of the touch sensor panel to at least one of the selected stimulation signal outputted from the first multiplexer, the receive section, or ground.

6. The controller of claim 1, wherein the receive section comprises:

one or more channels coupled to the touch sensor panel, each channel including;

a sense amplifier capable of receiving at least one touch signal from the touch sensor panel; and

one or more demodulators capable of demodulating the at least one touch signal to output at least one of an in-phase (I) component, a quadrature (Q) component, or an in-phase-quadrature (IQ) component;

wherein the scan engine is capable of configuring the second settings for the sense amplifiers and the demodulators of the channels.

7. The controller of claim 6, wherein each demodulator is capable of demodulating the at least one touch signal at a phase and frequency of interest corresponding to the phase and frequency of at least one stimulation signal or at least one stylus stimulation signal.

8. The controller of claim 2, wherein the memory comprises:

a pointer bank including one or more pointers, each pointer capable of pointing to locations allocated in the memory to store the touch signal;

wherein the scan engine is capable of configuring the pointer bank and the locations allocated in the memory.

9. The controller of claim 1, wherein the scan events include at least one of a mutual capacitance scan, a self-capacitance scan, or a stylus scan.

10. The controller of claim 1, wherein the scan engine is capable of executing the scan plan so as to cause the sequence of scan events to be performed at the configurations for the scan events.

11. The controller of claim 1, wherein the scan engine is capable of dynamically changing the scan plan during execution.

12. The controller of claim 1, wherein the scan events include at least one mutual capacitance scan, wherein the scan engine is capable of:

configuring the transmit section to stimulate a plurality of row traces and configuring the receive section to receive touch signals from a plurality of column traces, the touch signals indicative of a mutual capacitance between the row and column traces;

configuring the transmit section to stimulate the plurality of column traces and configuring the receive section to receive touch signals from the plurality of row traces, the touch signals indicative of a mutual capacitance between the row and column traces;

configuring the transmit section to stimulate a first set of the plurality of row traces and configuring the receive section to receive touch signals from a second set of the plurality of row traces, the touch signals indicative of a mutual capacitance between row traces in the first and second sets of the row traces;

or

configuring the transmit section to stimulate a first set of the plurality of column traces and configuring the receive section to receive touch signals from a second set of the plurality of column traces, the touch signals indicative of a mutual capacitance between column traces in the first and second sets of the column traces.

13. The controller of claim 1, wherein the scan events include at least one self-capacitance scan, wherein the scan engine is capable of:

configuring the transmit section to stimulate a non-inverting input of sense amplifiers in the receive section and configuring the receive section to receive touch signals from a plurality of row traces, the plurality of row traces coupled to the inverting input of the sense amplifiers, the touch signal indicating a self-capacitance between the row traces and an object proximate to the panel;

or

configuring the transmit section to stimulate a non-inverting input of sense amplifiers in the receive section and configuring the receive section to receive touch signals from a plurality of column traces, the plurality of column traces coupled to the inverting input of the sense amplifiers, the touch signal indicating a self-capacitance between the column traces and the object proximate to the panel.

14. The controller of claim 13, wherein the scan engine is further capable of configuring the transmit section to apply a guard signal to unused row or column traces to block interference with the touch signals.

15. The controller of claim 1, wherein the scan events include at least one of a touch spectral analysis scan, a stylus spectral analysis scan or a stylus scan, wherein the scan engine is capable of:

configuring the receive section to receive touch signals from one or more of row and column traces when the controller is not generating any stimulation signals.

16. The controller of claim 1, wherein the configurable transmit and receive sections are implemented in a master-slave configuration, such that a first portion of the configurable transmit section and a first portion of the configurable receive section are implemented in a master touch controller, and a second portion of the configurable transmit section and a second portion of the configurable receive section are implemented in a slave touch controller.

17. The controller of claim 1, wherein the transmit section is capable of driving a first portion of the touch sensor panel with first stimulation signals having a first frequency and simultaneously driving a second portion of the touch sensor panel with second stimulation signals having a second frequency.

18. A non-transitory computer readable storage medium having stored thereon a scan plan for configuring a touch controller in a touch sensitive device that when executed by a scan engine causes the scan engine to:

configure a portion of the touch controller to be a transmit section, the transmit section capable of driving a touch sensor panel to detect a touch or hover event;

configure another portion of the touch controller to be a receive section, the receive section capable of processing the detected touch or hover event; and

direct a scan sequence at the touch sensitive device according to the scan plan, the scan plan defining the scan sequence.

19. The non-transitory computer readable storage medium of claim 18, wherein the scan engine directs the scan sequence including one or more scan events at predefined times, each scan event having associated therewith specific configurations of the transmit section and the receive section.

20. The non-transitory computer readable storage medium of claim 19, wherein the scan engine is capable of dynamically changing the scan sequence.

21. The non-transitory computer readable storage medium of claim 18, wherein the transmit section is capable of driving a first portion of the touch sensor panel with first stimulation signals having a first frequency and simultaneously driving a second portion of the touch sensor panel with second stimulation signals having a second frequency.

22. A method for configuring a touch controller in a touch sensitive device, the method comprising:

configuring portions of the touch controller to be a transmit section or a receive section, the transmit section capable of driving a touch sensor panel to detect a touch or hover event and the receive section capable of processing the detected touch or hover event; and

performing the one or more scan events according to a scan plan, the scan plan defining the scan sequence, and each scan event defining a transmit configuration and a receive configuration for that particular scan event.

23. The method of claim 22, wherein the scan engine performs the one or more scan events at predefined times, each scan event having associated therewith specific configurations of the transmit section and the receive section.

24. The method of claim 23, wherein the scan engine is capable of dynamically changing the scan sequence.

25. The method of claim 22, wherein the transmit section is capable of driving a first portion of the touch sensor panel with first stimulation signals having a first frequency and simultaneously driving a second portion of the touch sensor panel with second stimulation signals having a second frequency.