Input device with floating electrodes having at least one aperture

• US 8,653,834 B2
• Filed: 01/13/2011
• Issued: 02/18/2014
• Est. Priority Date: 01/15/2010
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Reynolds, Joseph Kurth
• Primary Examiner(s): Koval, Melissa
• Assistant Examiner(s): MILLER, DANIEL R
• Application Number:
  US13/006,019
• Publication Number:
  US 20110175671A1
• Time in Patent Office: 1,132 Days
• Field of Search: 324658-690, 178/18.06, 178/19.03, 341/33, 345/173, 345/174
• US Class Current: 324/658
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• 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: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2017/9602 characterised by the type or shape of the sensing electrodes
• CPC Class Codes: H03K 2217/96077 comprising an electrode which is floating
• CPC Class Codes: H03K 2217/960775 Emitter-receiver or "fringe" type detection, i.e. one or more field emitting electrodes and corresponding one or more receiving electrodes
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

Devices and methods are provided that facilitate improved input device performance. The devices and methods utilize a transmitter sensor electrode and a receiver sensor electrode that are capacitively coupled to form a transcapacitance for capacitively sensing input objects in a sensing region. A measure of the transcapacitance may be used to determine positional information for the input objects in the sensing region. In accordance with the various embodiments, the devices and methods include a floating electrode that is ohmically insulated from other electrical elements during operation. A first portion of the floating electrode overlaps a portion of the transmitter sensor electrode and a second portion of the floating electrode overlaps a portion of the receiver sensor electrode. The floating electrode additionally includes at least one aperture within the first portion of the floating electrode, where the at least one aperture at least in part overlaps the transmitter sensor electrode.

Claims

1. An input device for capacitively sensing an input object in a sensing region, comprising:

a transmitter sensor electrode;

a receiver sensor electrode; and

a floating electrode, the floating electrode configured to be electrically floating during operation, wherein a first portion of the floating electrode overlaps a portion of the transmitter sensor electrode and a second portion of the floating electrode overlaps a portion of the receiver sensor electrode, wherein the floating electrode comprises at least one aperture within the first portion of the floating electrode at least in part overlapping the transmitter sensor electrode, and wherein the at least one aperture overlaps the transmitter sensor electrode by a first area, the at least one aperture overlaps the receiver sensor electrode by a second area, and the first area is greater than the second area.

2. The input device of claim 1, wherein the at least one aperture comprises at least one of a hole within the first portion of the floating electrode and a slot within the first portion of the floating electrode.

3. The input device of claim 1, wherein the at least one aperture includes a first aperture and a second aperture within the first portion of the floating electrode, each at least in part overlapping the transmitter sensor electrode.

4. The input device of claim 1, further comprising a filling structure in the at least one aperture.

5. The input device of claim 1 wherein the transmitter sensor electrode and the receiver sensor electrode are disposed on a same layer.

6. The input device of claim 5 further comprising a shield electrode disposed between the transmitter sensor electrode and the receiver sensor electrode.

7. An input device for capacitively sensing an input object in a sensing region, comprising:

a transmitter sensor electrode;

a receiver sensor electrode; and

a floating electrode, the floating electrode configured to be electrically floating during operation, wherein a first portion of the floating electrode overlaps a portion of the transmitter sensor electrode and a second portion of the floating electrode overlaps a portion of the receiver sensor electrode, and wherein the floating electrode comprises a first aperture within the first portion of the floating electrode and at least in part overlapping the transmitter sensor electrode;

where the transmitter sensor electrode comprises a jumper, wherein the jumper and the floating electrode are disposed on a same layer, and wherein the jumper crosses over the receiver sensor electrode and is electrically insulated from the receiver sensor electrode.

8. An input device for capacitively sensing input objects in a sensing region, comprising:

a set of transmitter sensor electrodes;

a set of receiver sensor electrodes; and

a set of floating electrodes, each floating electrode of the set of floating electrodes configured to be electrically floating in operation, wherein a first portion of a first floating electrode of the set of floating electrodes overlaps a first portion of a first transmitter sensor electrode of the set of transmitter sensor electrode and a second portion of the first floating electrode of the set of floating electrodes overlaps a first portion of a first receiver sensor electrode of the set of receiver sensor electrodes, the first floating electrode of the set of floating electrodes comprising at least one aperture within the first portion of the first floating electrode and at least in part overlapping the first transmitter sensor electrode, wherein the at least one aperture overlaps the first transmitter sensor electrode by a first area, the at least one aperture overlaps a first receiver sensor electrode by a second area, and the first area is greater than the second area.

9. The input device of claim 8 wherein each transmitter sensor electrode in the set of transmitter sensor electrodes is capacitively coupled to at least one receiver sensor electrode in the set of receiver sensor electrodes to form a set of transcapacitances.

10. The input device of claim 8 further comprising a processing system coupled to the set of transmitter sensor electrodes and the set of receiver sensor electrodes, the processing system configured to:

transmit with the first transmitter sensor electrode of the set of transmitter sensor electrodes;

receive a resulting signal with the first receiver sensor electrode of the set of receiver sensor electrodes while transmitting with the first transmitter sensor electrode; and

determine positional information for an input object in the sensing region based at least in part on a first measurement of the resulting signal.

11. The input device of claim 8, wherein a first portion of a second floating electrode of the set of floating electrodes overlaps a first portion of a second transmitter sensor electrode of the set of transmitter sensor electrode and a second portion of the second floating electrode of the set of floating electrodes overlaps a first portion of a second receiver sensor electrode of the set of receiver sensor electrodes, the second floating electrode of the set of floating electrodes comprising at least one aperture within the first portion of the second floating electrode of the set of floating electrodes and at least in part overlapping the second transmitter sensor electrode.

12. The input device of claim 8, wherein the set of transmitter sensor electrodes and the set of receiver sensor electrodes are disposed on a same layer.

13. The input device of claim 8, wherein the first floating electrode is interdigitated with a second floating electrode of the set of floating electrodes.

14. An input device for capacitively sensing input objects in a sensing region, comprising:

a set of transmitter sensor electrodes;

a set of receiver sensor electrodes; and

a set of floating electrodes, each floating electrode of the set of floating electrodes configured to be electrically floating in operation, wherein a first portion of a first floating electrode of the set of floating electrodes overlaps a first portion of a first transmitter sensor electrode of the set of transmitter sensor electrode and a second portion of the first floating electrode of the set of floating electrodes overlaps a first portion of a first receiver sensor electrode of the set of receiver sensor electrodes, the first floating electrode of the set of floating electrodes comprising at least one aperture within the first portion of the first floating electrode and at least in part overlapping the first transmitter sensor electrode;

wherein the first transmitter sensor electrode of the set of transmitter sensor electrodes comprises at least one jumper, wherein the at least one jumper and the set of floating electrodes are disposed on the same layer and wherein the at least one jumper crosses over at least one of the set of receiver sensor electrodes.

15. The input device of claim 14 wherein the at least one jumper is encompassed by the first floating electrode.

16. The input device of claim 14 wherein the at least one jumper crosses over two receiver sensor electrodes of the set of receiver sensor electrodes.

17. A method for forming an input device for capacitively sensing an input object in a sensing region, comprising:

forming a transmitter sensor electrode;

forming a receiver sensor electrode; and

forming a floating electrode, the floating electrode configured to be electrically floating during operation, wherein a first portion of the floating electrode overlaps a portion of the transmitter sensor electrode and a second portion of the floating electrode overlaps at least a portion of the receiver sensor electrode, and wherein the floating electrode comprises at least one aperture within the first portion of the floating electrode and at least in part overlapping the transmitter sensor electrode, wherein the at least one aperture overlaps the transmitter sensor electrode by a first area, the at least one aperture overlaps the receiver sensor electrode by a second area, and the first area is greater than the second area.

18. The method of claim 17, wherein the at least one aperture comprises at least one of a hole within the floating electrode and a slot within the floating electrode.

19. The method of claim 17, wherein the floating electrode further comprises a first aperture and a second aperture within the first portion of the floating electrode and at least in part overlapping the transmitter sensor electrode.

20. The method of claim 17 further comprising forming a jumper coupled to the transmitter sensor electrode, wherein the jumper and floating electrode are formed on a same layer, and wherein the jumper crosses over the receiver sensor electrode and is electrically insulated from the receiver sensor electrode.