Input device for and method of communication with capacitive devices through frequency variation

• US 9,557,845 B2
• Filed: 07/27/2012
• Issued: 01/31/2017
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Shahparnia, Shahrooz
• Primary Examiner(s): Kumar, Srilakshmi K
• Assistant Examiner(s): Reed, Stephen T
• Application Number:
  US13/560,958
• Publication Number:
  US 20140028576A1
• Time in Patent Office: 1,649 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 3/033 Pointing devices displaced or positioned by the user , e.g. mice, trackballs, pens or joysticks; Accessories therefor digitisers characterised by the transducing means G06F3/041
• 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 3/0443 using a single layer of sensing electrodes

Abstract

A computing device configured to receive data from a peripheral device, such as a stylus. The computing device includes a processor, a touch interface, such as a touch screen, in communication with the processor and configured to detect an input corresponding to an object approaching or contacting a surface. The computing device further includes a touch filter in communication with the touch interface and a peripheral filter in communication with the touch interface. The touch filter is configured to reject a peripheral frequency corresponding to a peripheral signal of the peripheral device and the peripheral filter is configured to reject a touch frequency component corresponding to a touch signal corresponding to a touch input.

Claims

1. A computing device configured to receive data from a peripheral device, comprising:

a processor;

a touch interface in communication with the processor and configured to detect an input corresponding to an object approaching or contacting a surface, the touch interface comprising a plurality of drive lines coupled via a multiplexer to drive circuitry and a plurality of sense lines coupled to sense circuitry;

a touch filter in the sense circuitry in communication with at least one of the plurality of sense lines and configured to reject a peripheral frequency corresponding to a peripheral signal of the peripheral device;

a first peripheral filter in the sense circuitry in communication with the at least one of the plurality of sense lines and configured to reject a touch frequency component corresponding to a touch signal corresponding to a touch input; and

a second peripheral filter in the drive circuitry in communication with at least one of the plurality of drive lines and configured to detect the peripheral signal of the peripheral device along the drive lines;

wherein the multiplexer is configurable to;

couple the drive lines to a stimulation signal in the drive circuitry when scanning the sense lines for the touch and peripheral signals; and

couple the drive lines to the second peripheral filter in the drive circuitry when scanning the drive lines for the peripheral signal when the peripheral signal is detected by the sense circuitry in response to the stimulation signal.

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

a display screen in communication with the processor and configured to provide a visual output for the computing device.

3. The computing device of claim 1, wherein the peripheral signal and the touch signal are provided to the first peripheral filter and the touch filter, respectively, by the at least one of the plurality of sense lines.

4. The computing device of claim 1, wherein the touch interface further comprises one or more analog to digital converters, wherein the analog to digital converters are in communication with the touch filter and the first peripheral filter.

5. The computing device of claim 1, wherein the touch filter and the first peripheral filter receive the input from the touch interface substantially simultaneously.

6. The computing device of claim 1, wherein the touch filter is a band pass filter having a pass band set to a frequency corresponding to a frequency of the touch signal.

7. The computing device of claim 6, wherein the pass band of the touch filter ranges between 100 kHz to 10000 kHz.

8. The computing device of claim 1, wherein the first peripheral filter and the second peripheral filter are band pass filters having a pass band set to a frequency corresponding to a frequency of the peripheral signal.

9. The computing device of claim 8, wherein the pass band of the first and second peripheral filters ranges between 100 kHz to 2000 kHz.

10. A method for receiving digital data from a peripheral input device at a touch screen including a plurality of drive lines and a plurality of sense lines, the method comprising:

scanning the plurality of sense lines, wherein the plurality of drive lines are coupled via a multiplexer to a stimulation signal when scanning the plurality of sense lines;

filtering a first signal received through one or more of the plurality of sense lines by a touch filter coupled to the one or more of the plurality of sense lines;

filtering the first signal by a first peripheral filter coupled to the one or more of the plurality of sense lines;

analyzing a touch output from the touch filter and a peripheral output from the first peripheral filter to determine whether the first signal is a touch signal or an input device signal; and

when the first signal is determined to be the input device signal;

coupling, via the multiplexer, a second peripheral filter to one or more of the plurality of drive lines;

scanning the plurality of drive lines; and

filtering a second signal received through the one or more of the plurality of drive lines by the second peripheral filter.

11. The method of claim 10, wherein the input device signal is a modulated analog signal including digital data corresponding to the input device.

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

13. The method of claim 10, wherein the first peripheral filter and the touch filter are band pass filters.

14. The method of claim 13, wherein a pass band of the first peripheral filter is different from a pass band of the touch filter.

15. The method of claim 14, wherein the first peripheral filter is configured to reject a bandwidth of frequencies falling within the pass band of the touch filter.