Device and method for force and proximity sensing employing an intermediate shield electrode layer

• US 9,632,638 B2
• Filed: 09/10/2014
• Issued: 04/25/2017
• Est. Priority Date: 09/10/2014
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Worfolk, Patrick
• Primary Examiner(s): Mehmood, Jennifer
• Assistant Examiner(s): SUBEDI, DEEPROSE D
• Application Number:
  US14/482,121
• Publication Number:
  US 20160070398A1
• Time in Patent Office: 958 Days
• Field of Search: 345174
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• 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
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

Methods, systems and devices are described for use with an electronic system. The device includes a pliable component having an input surface and a first plurality of sensor electrodes; a support substrate spaced apart from the pliable component; a second plurality of sensor electrodes disposed on a second substrate; a spacing layer disposed between the pliable component and the support substrate, the spacing layer configured to locally deform in response to a force applied to the input surface; and a shield electrode layer disposed between the first plurality and the second plurality of sensor electrodes.

Claims

1. An input device for an electronic system, comprising:

a pliable component having an input surface and a first plurality of sensor electrodes, the first plurality of sensor electrodes comprising a first subset characterized by a first geometric pattern and a second subset characterized by a second geometric pattern;

a support substrate spaced apart from the pliable component;

a second plurality of sensor electrodes disposed on a second substrate;

a spacing layer disposed between the pliable component and the support substrate, the spacing layer configured to locally deform in response to a force applied to the input surface; and

a shield electrode layer;

disposed between the first plurality of sensor electrodes and the second plurality of sensor electrodes;

comprising an array of conductive segments overlaying the first geometric pattern and an array of voids overlaying the second geometric pattern; and

configured to electrically shield the first plurality of sensor electrodes from the second plurality of sensor electrodes so that a touch image measured is substantially independent of the force applied to the input surface.

2. The input device of claim 1, wherein the second plurality of sensor electrodes is characterized by a third geometric pattern which substantially overlaps the array of voids.

3. The input device of claim 1, wherein the array of conductive segments comprises a common voltage node.

4. The input device of claim 3, wherein the shield electrode layer is ohmically coupled to a source of constant electrical potential.

5. The input device of claim 1, wherein, in response to a force applied to the input surface, a distance between at least one electrode of the second subset of the first plurality of sensor electrodes and an electrode from the second plurality of sensor electrodes is reduced.

6. The input device of claim 1, wherein the first subset and the second subset are arranged in a single layer including jumpers configured to ohmically isolate the first subset from the second subset.

7. The input device of claim 1, wherein the first subset and the second subset arranged in a single layer without the use of jumpers.

8. The input device of claim 1, further comprising a flexible printed circuit board (PCB) electrically connected to the first plurality of sensor electrodes and the second plurality of sensor electrodes, and not electrically connected to the shield electrode layer.

9. The input device of claim 1, wherein the first plurality of sensor electrodes is configured to detect positional information for input objects in a sensing region of the input device.

10. The input device of claim 1, wherein the first subset and the second subset disposed on one of:

opposite sides of a first substrate; and

the same side of the first substrate.

11. The input device of claim 10, wherein the second plurality of sensor electrodes and the second subset of the first plurality of sensor electrodes are configured to detect force imparted to the input surface.

12. A processing system for use with an input device of the type including

a pliable component having an input surface and a first plurality of sensor electrodes, the first plurality of sensor electrodes comprising a first subset characterized by a first geometric pattern and a second subset characterized by a second geometric pattern;

a support substrate spaced apart from the pliable component;

a second plurality of sensor electrodes disposed on a second substrate;

a spacing layer disposed between the pliable component and the support substrate, the spacing layer configured to locally deform in response to a force applied to the input surface; and

a shield electrode layer;

disposed between the first plurality of sensor electrodes and the second plurality of sensor electrodes;

comprising an array of conductive segments overlaying the first geometric pattern and an array of voids overlaying the second geometric pattern; and

configured to electrically shield the first plurality of sensor electrodes from the second plurality of sensor electrodes so that a touch image measured is substantially independent of the force applied to the input surface;

the processing system configured to be communicatively coupled to the first plurality of sensor electrodes and to the second plurality of sensor electrodes and configured to;

determine a first type of resulting signal from a first subset of the first plurality of sensor electrodes, and a second type of resulting signal from the second plurality of sensor electrodes,

wherein the first type of resulting signal comprises effects of input objects proximate the input surface, and further wherein the second type of resulting signal comprises effects of a force applied to the input surface.

13. The processing system of claim 12, further configured to:

determine a proximity image and a force image from the first and second types of resulting signals; and

determine a user interface action based on at least one of the proximity image and the force image.

14. The processing system of claim 12, further configured to maintain the shield electrode layer at a constant electrical potential.

15. The processing system of claim 12, further configured to:

drive a sensing signal onto the second subset of the first plurality of sensor electrodes;

receive a first type of resulting signal from the first subset of the first plurality of sensor electrodes; and

receive a second type of resulting signal from the second plurality of sensor electrodes;

wherein the processing system is configured to determine positional and force information for an input object based on the first and second type of resulting signals.

16. The processing system of claim 15, wherein the first type of resulting signal includes effects of an input object in the sensing region, and the second type of resulting signal includes effects of force applied to the input surface.

17. The processing system of claim 15, wherein the first resulting signal remains substantially constant in response to force applied to the input surface, and the second resulting signal remains substantially constant in response to input object presence in the sensing region.

18. An input device, comprising:

a pliable component having an input surface and a first plurality of sensor electrodes;

a second plurality of sensor electrodes disposed on a second substrate, the first plurality of sensor electrodes comprising a first subset characterized by a first geometric pattern and a second subset characterized by a second geometric pattern;

a spacing layer including a shield electrode layer disposed between first and second pluralities of sensor electrodes, the spacing layer configured to locally deform in response to a force applied to the input surface,

wherein the shield electrode layer is configured to electrically shield the first plurality of sensor electrodes from the second plurality of sensor electrodes so that a touch image measured is substantially independent of the force applied to the input surface, and

wherein the shield layer comprises an array of conductive segments overlaying the first geometric pattern and an array of voids overlaying the second geometric pattern; and

a processing system communicatively coupled to the first plurality of sensor electrodes and to the second plurality of sensor electrodes and configured to determine a first type of resulting signal from a first subset of the first plurality of sensor electrodes, and a second type of resulting signal from the second plurality of sensor electrodes, wherein the first type of resulting signal comprises effects of input objects proximate the input surface, and the second type of resulting signal comprises effects of a force applied to the input surface.