Input Device for and Method of Communication with Capacitive Devices Through Frequency Variation

• US 20140028576A1
• 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: Shahparnia, Shahrooz
• Granted Patent: US 9,557,845 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• 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;

a touch filter in communication with the touch interface; and

a peripheral filter in communication with the touch interface;

wherein

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.

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

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

a plurality of drive lines in communication with the processor; and

a plurality of sense lines in communication with the processor, the touch filter, and the peripheral filter;

wherein

the peripheral signal and the touch signal are provided to the peripheral filter and the touch filter, respectively, by the sense lines.

3. The computing device of claim 2, further comprising a drive peripheral filter in communication with the drive lines and configured to detect the peripheral signal of the peripheral device along the drive 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 peripheral filter.

5. The computing device of claim 1, wherein the touch filter and the 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 to 10000 kHz.

8. The computing device of claim 1, wherein the peripheral filter is a band pass filter 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 peripheral filter ranges between 100 to 2000 kHz.

10. A method for receiving digital data through a touch screen comprising:

scanning a plurality of sense lines;

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

filtering the first signal by a peripheral filter; and

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

11. The method of claim 10, further wherein if the first signal is an input device signal, scanning a plurality of drive lines.

12. The method of claim 10, wherein after scanning the plurality of drive lines, filtering by the peripheral filter a second signal received through one or more of the drive lines.

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

14. The method of claim 13, wherein the input device is a stylus.

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

16. The method of claim 15, wherein a pass band of the peripheral filter is different from a pass band of the touch filter.

17. The method of claim 16, wherein the peripheral filter is configured to reject a bandwidth of frequencies falling within the pass band of the touch filter.