ELLIPTICAL CAPACITIVE SENSOR ELECTRODE PATTERN AND SENSING THEREWITH

• US 20170192552A1
• Filed: 12/30/2015
• Published: 07/06/2017
• Est. Priority Date: 12/30/2015
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: GRAF, Arnulf B. A.
• Granted Patent: US 9,990,096 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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
• CPC Class Codes: G06F 3/0448 Details of the electrode shape, e.g. for enhancing the detection of touches, for generating specific electric field shapes, for enhancing display quality

Abstract

A capacitive sensor electrode pattern comprises a plurality of sensor electrodes. The plurality of sensor electrodes are disposed in a common layer with one another and arranged to form an ellipse. The plurality of sensor electrodes comprises first, second, and third subsets of sensor electrodes. The first subset of sensor electrodes has a first shape and a first surface area, wherein centers of mass of the first subset of sensor electrodes are substantially coincident with nodes of a coordinate system. The second subset of sensor electrodes has a second subset of sensor electrodes has a second shape and a second surface area. The third subset of sensor electrodes has a third shape and a third surface area. The first, second, and third shapes are all different. The first, second, and third surface areas are all different, and the second and third surface areas are less than the first surface area.

Claims

1. A capacitive sensor electrode pattern comprising:

a plurality of sensor electrodes disposed in a common layer with one another and arranged to form an ellipse, said plurality of sensor electrodes comprising;

a first subset of sensor electrodes having a first shape and a first surface area, wherein centers of mass of said first subset of sensor electrodes are coincident with nodes of a coordinate system;

a second subset of sensor electrodes having a second shape and a second surface area;

a third subset of sensor electrodes having a third shape and a third surface area;

wherein said first, second, and third shapes are all different; and

wherein said first, second, and third surface areas are all different, and said second and third surface areas are less than said first surface area.

2. The sensor electrode pattern of claim 1, wherein said common layer is a layer of a display.

3. The sensor electrode pattern of claim 1, wherein said ellipse is a circle.

4. The sensor electrode pattern of claim 1, wherein said first shape is one of a rectangle and a hexagon or an interdigitated electrode.

5. The sensor electrode pattern of claim 1, wherein said first shape is configured with portions which interdigitate with one or more other sensor electrodes of said first subset of sensor electrodes.

6. The sensor electrode pattern of claim 1, wherein said second and third shapes each have one curved exterior edge.

7. The sensor electrode pattern of claim 1, wherein said plurality of sensor electrodes have reflective symmetry along over a first axis and reflective symmetry over a second axis that is orthogonal to said first axis.

8. The sensor electrode pattern of claim 1, wherein said first subset of sensor electrodes are located in a central region of said sensor electrode pattern and wherein said second and third subsets of sensor electrodes are located on edge regions of said sensor electrode pattern.

9. The sensor electrode pattern of claim 1, wherein said coordinate system comprises a Cartesian coordinate system.

10. The sensor electrode pattern of claim 1, wherein centers of mass of said second and third subsets of sensor electrodes deviate from said nodes of said coordinate system.

11. A capacitive sensing input device comprising:

a capacitive sensor electrode pattern formed of a plurality of sensor electrodes disposed in a common layer with one another and arranged to form an ellipse, said plurality of sensor electrodes comprising;

a first subset of sensor electrodes having a first shape and a first surface area, wherein centers of mass of said first subset of sensor electrodes are coincident with nodes of a coordinate system;

a second subset of sensor electrodes having a second shape and a second surface area;

a third subset of sensor electrodes having a third shape and a third surface area;

wherein said first, second, and third shapes are all different; and

wherein said first, second, and third surface areas are all different and said second and third surface areas are less than said first surface area;

wherein centers of mass of said second and third subsets of sensor electrodes deviate from said nodes of said coordinate system; and

a processing system configured to;

receive capacitive resulting signals from said plurality of sensor electrodes;

scale up said capacitive resulting signals received from said second and third subsets of sensor electrodes based on a ratio of respective surface areas compared to said first surface area to achieve scaled resulting signals;

interpolate position estimates calculated from said resulting signals of said first subset of sensor electrodes and said scaled resulting signals of said second and third subsets of sensor electrodes, wherein said interpolation is based on respective deviations from said nodes of said coordinate system to achieve interpolated position estimates; and

determine a location of an input object with respect to said capacitive sensor electrode pattern based on said interpolated position estimates.

12. The capacitive sensing input device of claim 11, further comprising:

a display, wherein said common layer is layer of said display.

13. The capacitive sensing input device of claim 11, wherein said first shape is a one of a rectangle and a hexagon.

14. The capacitive sensing input device of claim 11, wherein said first shape is configured with portions which interdigitate with one or more other sensor electrodes of said first subset of sensor electrodes.

15. The capacitive sensing input device of claim 11, wherein said plurality of sensor electrodes have reflective symmetry along over a first axis and reflective symmetry over a second axis that is orthogonal to said first axis.

16. The capacitive sensing input device of claim 11, wherein said first subset of sensor electrodes are located in a central region of said sensor electrode pattern and wherein said second and third subsets of sensor electrodes are located on edge regions of said sensor electrode pattern, wherein said second shapes each have one curved exterior edge, and wherein said third shapes each have one curved exterior edge.

17. The capacitive sensing input device of claim 11, wherein said coordinate system comprises a Cartesian coordinate system.

18. The capacitive sensing input device of claim 11, wherein centers of mass of said second and third subsets of sensor electrodes deviate from said nodes of said coordinate system.

19. A processing system for a capacitive sensing input device:

said processing system communicatively configured to couple with an elliptical sensor capacitive electrode pattern comprising a first subset of sensor electrodes, a second subset of sensor electrodes, and a third subset of sensor electrodes, wherein said first subset of sensor electrodes have a first shape and a first surface area and have centers of mass coincident with nodes of a coordinate system, wherein said second subset of sensor electrodes have a second shape and a second surface area, wherein said third subset of sensor electrodes have a third shape and a third surface area, wherein said first, second, and third shapes are all different, wherein said first, second, and third surface areas are all different and said second and third surface areas are less than said first surface area, and wherein centers of mass of said second and third subsets of sensor electrodes deviate from said nodes of said coordinate system; and

said processing system configured to;

acquire capacitive resulting signals from said first subset of sensor electrodes, said second subset of sensor electrodes, and said third subset of sensor electrodes;

scale up said capacitive resulting signals received from said second and third subsets of sensor electrodes based on a ratio of respective surface areas compared to said first surface area to achieve scaled resulting signals; and

interpolate position estimates calculated from said resulting signals of said first subset of sensor electrodes and said scaled resulting signals of said second and third subsets of sensor electrodes, wherein said interpolation is based on respective deviations from said nodes of said coordinate system to achieve interpolated position estimates.

20. The processing system of claim 19, further configured to:

determine a location of an input object with respect to said elliptical capacitive sensor electrode pattern based on said interpolated position estimates.

21. The processing system of claim 19, wherein said determining a location is performed by firmware configured to operate on resulting signals received from a rectangular sensor electrode pattern.