Device for digital communication through capacitive coupling

• US 9,652,090 B2
• Filed: 07/27/2012
• Issued: 05/16/2017
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Harley, Jonah A., Yu, Feiqiao Brian, Tan, Liquan
• Primary Examiner(s): Mehmood, Jennifer
• Assistant Examiner(s): Reed, Stephen T
• Application Number:
  US13/560,963
• Publication Number:
  US 20140028607A1
• Time in Patent Office: 1,754 Days
• Field of Search: None
• CPC Class Codes: G06F 3/03545 Pens or stylus
• 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 3/0441 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 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A computing device configured to communicate with an input device. The computing device includes a processor, a touch interface, such as a touch screen, and a receiving unit. The touch interface is configured to detect an input signal corresponding to an object approaching or contacting a surface. The receiving unit is configured to receive, through the touch interface, at least one input signal from the input device, and the receiving unit amplifies the at least one input signal creating at least one amplified input signal. Additionally, at least one of the processor or the receiving unit analyzes the at least one amplified input signal and creates at least one output digital signal corresponding to the at least one input signal.

Claims

1. A computing device configured to communicate with a peripheral input device, the computing device comprising:

a processor;

a touch interface in communication with the processor and configured to detect an input signal corresponding to an object approaching or contacting a surface;

a digital data receiver in communication with the processor and the touch interface and configured to receive through the touch interface at least one input signal transmitted from the peripheral input device, wherein the at least one input signal transmitted from the peripheral input device includes an excitation signal with a first amplitude and digital data with a second amplitude, wherein the second amplitude is smaller than the first amplitude; and

a plurality of switches configured to couple, in response to receiving the excitation signal, the digital data receiver to a plurality of sense lines of the touch interface to receive the digital data during transmission periods of the peripheral input device, and decouple, in response to receiving a termination signal from the peripheral input device, the digital data receiver from the plurality of sense lines of the touch interface;

wherein

the digital data receiver amplifies the at least one input signal creating at least one amplified input signal; and

one of the processor or the digital data receiver analyzes the at least one amplified input signal and creates at least one digital output signal corresponding to the at least one input signal.

2. The computing device of claim 1, wherein the digital data receiver includes a high pass filter amplifier.

3. The computing device of claim 2, wherein the digital data receiver further comprises a comparator coupled to the high pass filter amplifier, and the comparator generates the at least one digital output signal based on the at least one amplified input signal.

4. The computing device of claim 3, wherein the comparator is a Schmitt trigger.

5. The computing device of claim 1, wherein the computing device further comprises a display screen in communication with the processor and positioned to at least partially overlap with the touch interface.

6. The computing device of claim 1, wherein the touch interface further comprises

a plurality of driving electrodes in communication drive lines, the plurality of drive lines configured to cross at least a portion of the plurality of sense lines;

a transmission medium positioned between the plurality of drive lines and the plurality of sense lines; and

a sensing circuit in communication with the plurality of sense lines and configured to detect a signal change on the plurality of sense lines.

7. The computing device of claim 1, wherein the at least one input signal includes digital data corresponding to at least one sensor within the peripheral input device.

8. The computing device of claim 7, wherein the at least one sensor is one of an accelerometer, a gyroscope, a force sensor, a pressure sensor, or a temperature sensor.

9. The computing device of claim 1, wherein one of the processor, a sensing circuit, or the digital data receiver can determine the location of the based on the excitation signal.

10. A method for transmitting digital data to a computing device through a touch interface comprising:

receiving an activation signal transmitted from a peripheral input device to at least one electrode of the touch interface;

receiving at a digital data receiver a digital input signal transmitted from the peripheral input device through at least one electrode of the touch interface;

coupling, in response to receiving the activation signal, via a plurality of switches, a digital data receiver to a plurality of sense lines of the touch interface to receive the digital data during transmission periods of the peripheral input device;

decoupling, via the plurality of switches, the digital data receiver from the plurality of sense lines of the touch interface in response to receiving a termination signal from the peripheral input device;

amplifying at the digital data receiver the transmitted digital input signal; and

generating a digital output signal based on the amplified digital input signal.

11. The method of claim 10, wherein generating the output digital signal comprises analyzing an amplified digital input signal to determine at least one peak and at least one valley.

12. The method of claim 10, wherein the peripheral input device is a stylus.

13. The method of claim 10, wherein the digital output signal is generated by a comparator or a converter.

14. The method of claim 10, wherein the digital data receiver includes a high pass filter that amplifies high-frequency components of the input signal.

15. The method of claim 10, wherein the touch interface is configured to detect changes in capacitance in order to detect an object approaching or touching a surface.

16. The method of claim 10, wherein the computing device is a smart phone.

17. The method of claim 10, the method further comprising:

configuring the digital data receiver to receive the digital input signal in response to receiving the activation signal.

18. The method of claim 10, further comprising:

in response to receiving the activation signal, entering a peripheral input device mode.

19. The method of claim 18, further comprising:

generating the digital output signal based on the amplified input signal in response to receiving the termination signal.

20. The method of claim 19, further comprising:

in response to receiving the termination signal, exiting the peripheral input device mode.

21. The method of claim 18, wherein the termination signal is embedded within the digital input signal.

22. The method of claim 10, wherein the activation signal and the digital input signal are received by a common electrode.

23. A non-transitory computer readable storage medium having stored thereon a set of instructions for transmitting digital data to a computing device through a touch interface that when executed by a processor causes the processor to:

receive an activation signal transmitted from a peripheral input device to at least one electrode of the touch interface;

receive at a digital data receiver a digital input signal transmitted from the peripheral input device through at least one electrode of the touch interface;

couple, in response to receiving the activation signal, via a plurality of switches, a digital data receiver to a plurality of sense lines of the touch interface to receive the digital data during transmission periods of the peripheral input device;

decouple, via the plurality of switches, the digital data receiver from the plurality of sense lines of the touch interface in response to receiving a termination signal from the peripheral input device;

amplify at the digital data receiver the transmitted digital input signal; and

generate a digital output signal based on the amplified digital input signal.