CAPACITIVE TOUCH SENSOR

• US 20090260897A1
• Filed: 04/16/2009
• Published: 10/22/2009
• Est. Priority Date: 04/16/2008
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: InFocus Corporation (Lap-Shun Hui, MBA)
• Inventors: Kruse, Ross
• Application Number:
  US12/425,131
• Publication Number:
  US 20090260897A1
• Time in Patent Office: Days
• US Class Current: 178/18.10
• 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

Abstract

A capacitive touch sensor is provided. The capacitive touch sensor may include a printed circuit board coupled to one or more electronic components, a sensing pad coupled to the circuit board, the sensing pad configured to detect touch input, a touch surface positioned in a cooperative position with the circuit board and the sensing pad, and a dielectric material interposed by the sensing pad and the touch surface, the dielectric material having a dielectric constant greater than air at a substantially equivalent temperature and pressure.

Claims

1. A capacitive touch sensor comprising:

a printed circuit board coupled to one or more electronic components;

a sensing pad coupled to the circuit board, the sensing pad configured to detect touch input;

a touch surface positioned in a cooperative position with the circuit board and the sensing pad; and

a dielectric material interposed by the sensing pad and the touch surface, the dielectric material having a dielectric constant greater than air at a substantially equivalent temperature and pressure.

2. The capacitive touch sensor of claim 1, wherein the dielectric material is compressible.

3. The capacitive touch sensor of claim 2, wherein the dielectric material is a polymeric foam.

4. The capacitive touch sensor of claim 2, wherein the dielectric material is an elastomeric material.

5. The capacitive touch sensor of claim 1, wherein the dielectric material is configured to substantially surround the electronic components included in the circuit board.

6. The capacitive touch sensor of claim 1, wherein the sensing pad includes a layer of indium tin oxide configured to conduct a continuous electric current across the sensing pad during operation of the touch sensor.

7. The capacitive touch sensor of claim 1, wherein the dielectric material substantially spans the longitudinal and lateral lengths of one or more of the sensing pad and the touch surface.

8. The capacitive touch sensor of claim 1, wherein the dielectric material substantially spans a length between the circuit board and the touch surface.

9. The capacitive touch sensor of claim 1, wherein a thickness of the dielectric material is selected based on one or more of the following parameters:

a thickness of the touch surface, a thickness of the printed circuit board, and a dielectric constant of the dielectric material and/or the touch surface.

10. The capacitive touch sensor of claim 1, wherein the sensing pad is integrated into at least a portion of the printed circuit board.

11. An electronic device having touch sensitive capabilities comprising:

a capacitive touch sensor including a touch surface positioned in a cooperative position with a printed circuit board, one or more electronic components protruding from and coupled to the printed circuit board, a sensing pad coupled to the printed circuit board, the sensing pad configured to conduct an electric current during operation of the electronic device, and a dielectric material interposed by the sensing pad and the touch surface; and

a control system configured to receive inputs from the capacitive touch sensor.

12. The electronic device of claim 11, wherein the dielectric constant of the dielectric material at a standard temperature and pressure is greater than the dielectric constant of air at the standard temperature and pressure.

13. The electronic device of claim 11, wherein the dielectric material is compressible.

14. The electronic device of claim 13, wherein the dielectric material is configured to conform to the shape of the electronic components.

15. The electronic device of claim 11, wherein the dielectric material substantially spans a length between the substrate of the printed circuit board and the touch surface.

16. An electronic device having touch sensitive capabilities comprising:

a capacitive touch sensor including a touch surface positioned in as cooperative position with a printed circuit board, one or more electronic components protruding from and coupled to the printed circuit board, a sensing pad coupled to the printed circuit board, the sensing pad including a layer of indium tin oxide, and a compressible dielectric foam interposed by the printed circuit board and the touch surface and substantially spanning a length between the touch surface and the sensing pad, the dielectric foam having a dielectric constant greater than air at a substantially equivalent temperature and pressure; and

a control system configured to receive inputs from the capacitive touch sensor.

17. The electronic device of claim 16, wherein the sensing pad is integrated into the printed circuit board.

18. The electronic device of claim 16, wherein the electronic components have varying thicknesses.

19. The electronic device of claim 18, wherein the dielectric material extends beyond the electronic components in a direction towards the touch surface.