Device for Digital Communication Through Capacitive Coupling

• US 20140028607A1
• Filed: 07/27/2012
• Published: 01/30/2014
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Tan, Liquan, Harley, Jonah A., Yu, Feiqiao Brian
• Granted Patent: US 9,652,090 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• 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 an input 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; and

a receiving unit in communication with the processor and the touch interface and configured to receive through the touch interface at least one input signal from the input device;

wherein

the receiving unit amplifies the at least one input signal creating at least one amplified input signal; and

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.

2. The computing device of claim 1, wherein the receiving unit includes a high pass filter.

3. The computing device of claim 1, wherein the receiving unit further comprises a comparator, and the comparator analyzes the at least one amplified input signal and creates the at least one output digital 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;

a plurality of sense lines configured to cross at least a portion of the plurality of drive 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 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. A method for transmitting digital data to a computing device through a touch interface comprising:

transmitting an activation signal to at least one drive line of the touch interface;

receiving by a receiving unit a digital input signal from an input device through at least one sense line of the touch interface;

amplifying by the receiving unit the digital input signal; and

creating an output digital signal corresponding to the digital input signal.

10. The method of claim 9, wherein creating the output digital signal comprises analyzing an amplified digital input signal to determine at least one peak and at least one valley.

11. The method of claim 9, wherein the input device is a stylus.

12. The method of claim 9, wherein the output digital signal is created by a comparator or a converter.

13. The method of claim 9, wherein the receiving unit includes a high pass filter that amplifies the digital input signal.

14. The method of claim 9, wherein the touch interface is configured to detect changes in capacitance in order to detect an object approaching or touching a surface.

15. The method of claim 9, wherein the computing device is a smart phone.