Capacitive touch sensor

• US 9,696,860 B2
• Filed: 09/08/2014
• Issued: 07/04/2017
• Est. Priority Date: 09/08/2014
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Kyowski, Timothy Herbert, Pegg, Albert Murray, Huang, Li
• Primary Examiner(s): LAMB, CHRISTOPHER RAY
• Application Number:
  US14/479,609
• Publication Number:
  US 20160070379A1
• Time in Patent Office: 1,030 Days
• Field of Search: None
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/169 the I/O peripheral being an integrated pointing device, e.g. trackball in the palm rest area, mini-joystick integrated between keyboard keys, touch pads or touch stripes G06F1/1643 takes precedence; constructional details of pointing devices G06F3/033
• CPC Class Codes: G06F 3/0202 Constructional details or processes of manufacture of the input device
• 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

Abstract

The present disclosure provides a capacitive touch sensor for an electronic device. The touch sensor has a trace carrier having a sensing surface, a connecting surface, and a number of electrically conductive traces on the trace carrier. The traces form a sensing pattern on the sensing surface and pass from the sensing surface to the connecting surface. The sensor also includes a capacitive sensing circuit operable to electrically couple to the traces at the connecting surface of the trace carrier, and to sense a capacitance change. A touch position on the sensing surface is determined dependent upon the sensed capacitance change.

Claims

1. A capacitive touch sensor, comprising:

a trace carrier having a sensing surface and a connecting surface;

a plurality of electrically conductive traces on the trace carrier, each trace of the plurality of electrically conductive traces forming a sensing pattern on the sensing surface and each trace of the plurality of electrically conductive traces passing from the sensing surface to the connecting surface, where the plurality of electrically conductive traces comprises a transmitting trace and a receiving trace; and

a capacitive sensing circuit operable to;

electrically couple to the plurality of electrically conductive traces at the connecting surface of the trace carrier;

sense a capacitance change using a first trace of the plurality of electrically conductive traces, where sensing the capacitance change comprises sensing a capacitance between the transmitting and receiving traces; and

determine a touch position on the sensing surface dependent upon the sensed capacitance change.

2. The capacitive touch sensor of claim 1, further comprising a connecting structure configured to:

contact the plurality of electrically conductive traces at the connecting surface of the trace carrier; and

provide electrical connections between the capacitive sensing circuit and the plurality of electrically conductive traces.

3. The capacitive touch sensor of claim 2, where the connecting structure comprises a printed circuit and where the trace carrier is mechanically coupled to the printed circuit.

4. The capacitive touch sensor of claim 1, where the trace carrier comprises a material amenable to Laser Direct Structuring, and wherein the traces are formed by a Laser Direct Structuring process.

5. The capacitive touch sensor of claim 1, where the connecting structure comprises a flexible printed circuit.

6. The capacitive touch sensor of claim 1, wherein the trace carrier comprises a fret.

7. The capacitive touch sensor of claim 1, further comprising a cover that overlays at least the sensing surface of the trace carrier.

8. The capacitive touch sensor of claim 1, further comprising a coating that overlays at least the sensing surface of the trace carrier.

9. An input apparatus for an electronic device, comprising:

a keyboard comprising one or more keycaps;

a connecting structure underlying the keyboard;

one or more trace carriers located on the connecting structure adjacent the keycaps of the keyboard, such that a sensing surface of the one or more trace carriers projects above the connecting structure and a connecting surface of trace support element engages the connecting structure;

a plurality of electrically conductive traces on the trace carrier, each trace of the plurality of electrically conductive traces forming a sensing pattern on the sensing surface and each trace of the plurality of electrically conductive traces passing from the sensing surface to the connecting surface; and

a capacitive sensing circuit operable to;

electrically couple, via the connecting structure, to the plurality of electrically conductive traces at the connecting surface of the trace carrier;

sense a capacitance change using a first trace of the plurality of electrically conductive traces;

determine a touch position on the sensing surface dependent upon the sensed capacitance change.

10. The input apparatus of claim 9, where the trace carrier comprises a material amenable to Laser Direct Structuring, and wherein the traces are formed by a Laser Direct Structuring process.

11. The input apparatus of claim 9, where the connecting structure comprises a flexible printed circuit.

12. The input apparatus of claim 9, where the one or more keycaps comprise a plurality of keycaps arranged in rows and where at least one trace carrier of the one or more trace carriers comprises a fret sized to fit between rows of keycaps.

13. The input apparatus of claim 9, where the one or more keycaps comprise a plurality of the keycaps arranged in an array and where the trace carrier comprises a grid sized to fit between keycaps.

14. The input apparatus of claim 9, where the one or more keycaps comprise a single button and where the trace carrier surrounds the button.

15. An electronic device, comprising:

a trace carrier having a sensing surface and a connecting surface, the trace carrier located on a surface of the electronic device such that the sensing surface of the trace carrier projects from the surface of the electronic device;

a plurality of electrically conductive traces on the trace carrier, each trace of the plurality of electrically conductive traces forming a sensing pattern on the sensing surface and each trace of the plurality of electrically conductive traces passing from the sensing surface to the connecting surface, where the plurality of electrically conductive traces comprises a transmitting trace and a receiving trace; and

a capacitive sensing circuit operable to;

electrically couple to the plurality of electrically conductive traces at the connecting surface of the trace carrier;

sense a capacitance change using a first traces of the plurality of conducting traces, where sensing the capacitance change comprises sensing a capacitance between the transmitting and receiving traces; and

determine a touch position on the sensing surface dependent upon the sensed capacitance,

wherein the electronic device is responsive to the sensed capacitance.

16. The electronic device of claim 15, where the trace carrier comprises a material amenable to Laser Direct Structuring, and wherein the traces are formed by a Laser Direct Structuring process.

17. The electronic device of claim 15, where the trace carrier is located on the rear of the electronic device.

18. The electronic device of claim 15, where the trace carrier is located on a side of the electronic device.

19. The electronic device of claim 15, further comprising a mechanical keyboard have a plurality of keycaps arranged in rows, where the trace carrier comprises one or more frets located between rows of keycaps.

20. The electronic device of claim 19, further comprising a device processor responsive to the sensed capacitance and operable to determine one or more touch positions on the mechanical keyboard.