INPUT DEVICE BASED ON VOLTAGE GRADIENTS

• US 20110062974A1
• Filed: 09/10/2010
• Published: 03/17/2011
• Est. Priority Date: 09/11/2009
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Day, Shawn P., Worfolk, Patrick
• Granted Patent: US 8,638,112 B2
• Time in Patent Office: Days
• US Class Current: 324/713
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer

Abstract

An input device is disclosed, including a first drive electrode comprising a resistive material and a first sense electrode disposed proximate to the first drive electrode. The input device further includes a processing system which is coupled with the first drive electrode and the first sense electrode. In one embodiment, the processing system is configured for electrically driving a first end of the first drive electrode and electrically driving a second end of the first drive electrode to cause a change in a voltage gradient along a length of the first drive electrode. In such an embodiment, the change in the voltage gradient generates a first electrical signal in the first sense electrode. The processing system also acquires a first measurement of the first electrical signal and determines positional information along the length of the first drive electrode based upon the first measurement, wherein the positional information is related to an input object.

Claims

1. An input device comprising:

a first drive electrode;

a first sense electrode disposed proximate to said first drive electrode; and

a processing system coupled with said first drive electrode and said first sense electrode, said processing system configured for;

electrically driving a first end of said first drive electrode and electrically driving a second end of said first drive electrode to cause a change in a voltage gradient along a length of said first drive electrode, wherein said change in said voltage gradient generates a first electrical signal on said first sense electrode;

acquiring a first measurement of said first electrical signal; and

determining positional information along said length of said first drive electrode based upon said first measurement, said positional information related to an input object.

2. The input device of claim 1, further comprising:

a second drive electrode, said second drive electrode disposed in parallel with said first drive electrode such that said first sense electrode is arranged between said first drive electrode and said second drive electrode.

3. The input device of claim 2, further comprising a conductive element electrically coupling together one end of said first drive electrode with one end of said second drive electrode.

4. The input device of claim 1, wherein said processing system is further configured for:

electrically driving said first drive electrode to generate a second electrical signal on said first sense electrode; and

acquiring a second measurement, said second measurement being of said second electrical signal.

5. The input device of claim 4, wherein said processing system is further configured for determining said positional information based also upon said second measurement.

6. The input device of claim 4, wherein said processing system is further configured for:

determining two-dimensional positional information for said input object based upon said first and said second measurements.

7. The input device of claim 4, wherein said electrically driving said first drive electrode to generate a second electrical signal on said first sense electrode causes a second change in said voltage gradient.

8. The input device of claim 1, wherein said first drive electrode and said first sense electrode are disposed in a single layer on a common substrate.

9. A method of sensing, said method comprising:

electrically driving a first end of a first drive electrode and electrically driving a second end of said first drive electrode to cause a change in a voltage gradient along a length of said first drive electrode, wherein said change in said voltage gradient generates a first electrical signal on a first sense electrode;

acquiring a first measurement of said first electrical signal; and

determining positional information along said length of said first drive electrode based upon said first measurement, said positional information related to an input object.

10. The method as recited in claim 9, further comprising:

electrically driving said first drive electrode to generate a second electrical signal on said first sense electrode; and

acquiring a second measurement, said second measurement being of said second electrical signal.

11. The method as recited in claim 10, further comprising:

determining said positional information based at least in part upon said second measurement.

12. The method as recited in claim 10, further comprising:

determining two-dimensional positional information for said input object based upon said first and said second measurements.

13. The method as recited in claim 10 wherein said electrically driving said first drive electrode to generate a second electrical signal on said first sense electrode causes a second change in said voltage gradient.

14. A sensor component comprising:

a sensor substrate;

a plurality of drive electrodes wherein each drive electrode of said plurality of drive electrodes is substantially parallel with a first axis and elongated along said first axis;

a conductive element coupling together a first end of each drive electrode of said plurality of drive electrodes;

a plurality of conductive routing traces, each conductive routing trace of said plurality of conductive routing traces coupled to a second end of an associated drive electrode of said plurality of drive electrodes; and

a plurality of sense electrodes, wherein each sense electrode of said plurality of sense electrodes is substantially parallel with said first axis, and wherein each sense electrode of said plurality of sense electrodes is disposed proximate to at least one drive electrodes of said plurality of drive electrodes.

15. The sensor component of claim 14, wherein said plurality of drive electrodes and said plurality of sense electrodes are disposed in a single layer on a common substrate.

16. The sensor component of claim 14 further comprising:

a communicative coupling between said sensor component and a processing system, said processing system configured for;

electrically driving said first end of each drive electrode of said plurality of drive electrodes and electrically driving said second end of each drive electrode of said plurality of drive electrodes to cause a change in a plurality of voltage gradients, each voltage gradient of said plurality of voltage gradients being along one of said drive electrodes of said plurality of drive electrodes, wherein said change in said plurality of voltage gradients generates a first plurality of electrical signals on said plurality of sense electrodes;

acquiring a first plurality of measurements, each measurement of said first plurality of measurements being of one of said electrical signals of said first plurality of electrical signals; and

determining positional information along said first axis based upon said first plurality of measurements, said positional information related to an input object.

17. The sensor component of claim 16, wherein said processing system is further configured for:

electrically driving each drive electrode of said plurality of drive electrodes to generate a second plurality of electrical signals on said plurality of sense electrodes; and

acquiring a second plurality of measurements, each measurement of said second plurality of measurements being of one of said second plurality of electrical signals.

18. The sensor component of claim 17, wherein said processing system is further configured for determining said positional information based upon said second plurality of measurements.

19. The sensor component of claim 17, wherein said processing system is further configured for determining two-dimensional positional information for said input object.

20. The sensor component of claim 17, wherein said electrically driving each drive electrode of said plurality of drive electrodes to generate a second plurality of electrical signals on said plurality of sense electrodes causes a second change in said plurality of voltage gradients.

21. The sensor component of claim 14 further comprising:

a communicative coupling between said sensor component and a processing system, said processing system configured for;

electrically driving said second end of each drive electrode of said plurality of drive electrodes to cause a change in a plurality of voltage gradients, each voltage gradient of said plurality of voltage gradients being along one of said drive electrodes of said plurality of drive electrodes, wherein said change in said plurality of voltage gradients generates a first plurality of electrical signals on said plurality of sense electrodes;

acquiring a first plurality of measurements, each measurement of said first plurality of measurements being of one of said electrical signals of said first plurality of electrical signals; and

determining positional information along said first axis based upon said first plurality of measurements, said positional information related to an input object.

22. The sensor component of claim 14, wherein, for a drive electrode of said plurality of drive electrodes, application of different voltages to different ends of said drive electrode creates a voltage gradient along said drive electrode.

23. A processing system configured to:

electrically drive a first end of a drive electrode and electrically drive a second end of said drive electrode to cause a change in a voltage gradient along a length of said drive electrode, wherein said change in said voltage gradient generates a first electrical signal on a sense electrode;

acquire a first measurement of said first electrical signal; and

determine positional information along said length of said drive electrode based upon said first measurement, said positional information related to an input object.

24. The processing system of claim 23 further configured to:

electrically drive said drive electrode to generate a second electrical signal on said sense electrode; and

acquire a second measurement, said second measurement being of said second electrical signal.

25. The processing system of claim 23 further configured to:

determine said positional information based at least in part upon said second measurement.

26. The processing system of claim 23 further configured to:

determine two-dimensional positional information for said input object based upon said first and said second measurements.

27. The processing system of claim 23, wherein said electrically driving said drive electrode to generate a second electrical signal on said sense electrode causes a second change in said voltage gradient.