Shield electrode overlying portions of capacitive sensor electrodes

• US 9,411,474 B2
• Filed: 11/15/2012
• Issued: 08/09/2016
• Est. Priority Date: 11/15/2012
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Rauhala, Jyri Kalervo, Turunen, Seppo Tapio
• Primary Examiner(s): Chang, Kent
• Assistant Examiner(s): BRITTINGHAM, NATHANIEL P
• Application Number:
  US13/677,399
• Publication Number:
  US 20140132335A1
• Time in Patent Office: 1,363 Days
• Field of Search: 345156-178
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2017/9602 characterised by the type or shape of the sensing electrodes
• CPC Class Codes: H03K 2217/960765 Details of shielding arrangements

Abstract

An apparatus including: an array of capacitive sensor electrodes including a plurality of distinct capacitive sensor electrodes distributed over a sensing area; conductive traces connected to respective ones of the plurality of distinct capacitive sensor electrodes; and a shield electrode overlying, in the sensing area, conductive traces.

Claims

1. An apparatus comprising:

an array of capacitive sensor electrodes comprising a plurality of distinct capacitive sensor electrodes distributed over a sensing area;

conductive traces connected to respective ones of the plurality of distinct capacitive sensor electrodes; and

a shield electrode overlying, in the sensing area, conductive traces and portions of at least some of the sensor electrodes;

wherein the shield electrode overlies, in the sensing area, and covers all of the conductive traces;

wherein the shield electrode overlying portions of at least some of the sensor electrodes defines uncovered portions of the sensor electrodes as operational sensor electrodes of equal operational size; and

wherein the shield electrode extends across the whole sensing area as a strip except at openings through the shield electrode to the underlying capacitive sensor electrodes, the openings defining multiple parallel shielding strips, each parallel strip associated with each row of capacitive sensor electrodes, the portions of the sensor electrodes that are uncovered defining operational sensor electrodes of equal operational size.

2. An apparatus as claimed in claim 1, wherein the shield electrode overlies, in the sensing area, more than 80% of the area occupied by the conductive traces.

3. An apparatus as claimed in claim 1, wherein the sensor electrodes have different sizes.

4. An apparatus as claimed in claim 1, wherein the sensor electrodes are larger towards a center region of the sensing area and smaller towards a perimeter of the sensing area.

5. An apparatus as claimed in claim 1, wherein the sensor electrodes and the conductive traces are arranged within a common plane.

6. An apparatus as claimed in claim 1, wherein the sensor electrodes and the conductive traces are transparent.

7. An apparatus as claimed in claim 1, wherein the shield electrode overlying at least portions of at least some of the sensor electrodes defines operational sensor electrodes of equal operational capacitance.

8. An apparatus as claimed in claim 1, wherein the shield electrode overlying the sensor electrodes comprises openings of equal size to the sensor electrodes.

9. An apparatus as claimed in claim 1, further comprising a second further shield electrode underlying, in the sensing area, the conductive traces and the sensing electrodes.

10. An apparatus as claimed in claim 9, wherein the further shield electrode is a continuous uninterrupted electrode.

11. An apparatus as claimed in claim 9, comprising circuitry configured to provide a time-varying reference voltage signal to the further shield electrode.

12. An apparatus as claimed in claim 1, comprising circuitry configured to provide a time-varying reference voltage signal to the shield electrode.

13. An apparatus as claimed in claim 9, comprising detection circuitry connected between the further shield electrode and the array of capacitive sensor electrodes.

14. An apparatus as claimed in claim 13 comprising a multiplexer connected between the detection circuitry and the array of capacitive sensor electrodes, wherein the multiplexer is configured to isolate, for detection, each of the plurality of capacitive sensor electrodes of the array.

16. An apparatus as claimed in claim 1 embodied as device selected from the group comprising:

a touch panel module;

a touch sensitive display module; and

an electronic device.

15. An apparatus comprising:

a sensing arrangement comprising a plurality of capacitive sensor electrodes distributed over a sensing area and conductive traces at least partially distributed over the sensing area; and

a shield electrode partially overlying, in the sensing area, the sensing arrangement and portions of at least some of the sensor electrodes;

wherein the shield electrode overlies, in the sensing area, and covers all of the conductive traces;

wherein the shield electrode overlying at least portions of some of the sensor electrodes defines uncovered portions of the sensor electrodes as operational sensor electrodes of equal operational size; and

wherein the shield electrode extends across the whole sensing area as a strip except at openings through the shield electrode to the underlying capacitive sensor electrodes, the openings defining multiple parallel shielding strips, each parallel strip associated with each row of capacitive sensor electrodes, the portions of the sensor electrodes that are uncovered defining operational sensor electrodes of equal operational size.