Electret stylus for touch-sensor device

• US 20120043142A1
• Filed: 05/09/2008
• Published: 02/23/2012
• Est. Priority Date: 05/09/2007
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Wacom Co Limited (Wacom)
• Inventors: Grivna, Edward L.
• Granted Patent: US 9,285,930 B2
• Time in Patent Office: Days
• US Class Current: 178/19.03
• CPC Class Codes: G06F 3/03545 Pens or stylus

Abstract

A method and apparatus to couple a piece of electret material to a touch-sensor device stylus, where the electret material emits an electrostatic field to be sensed by a touch-sensor device.

Claims

1. A touch-sensor device stylus, comprising:

a body having a first end and a second end; and

a piece of electret material coupled to the first end of the body, wherein the electret material emits an electrostatic field to be sensed by a touch-sensor device.

2. The touch-sensor device stylus of claim 1, wherein the electret material at the first end of the body tapers to a point.

3. The touch-sensor device stylus of claim 1, wherein the second end of the body comprises a handle.

4. An apparatus comprising the touch-sensor device stylus of claim 1, further comprising:

a socket within the touch-sensor device, the socket to receive the first end of the stylus, wherein an interior surface of the socket is lined with a conductive material.

5. The apparatus of claim 4, wherein the conductive material is disposed within the socket to contact substantially an entire surface of the electret material.

6. An apparatus comprising the touch-sensor device stylus of claim 1, further comprising:

a stylus cap to receive the first end of the body, wherein an interior surface of the cap is lined with a conductive material.

7. The apparatus of claim 1, wherein the electret material comprises a fluoropolymer.

8. The apparatus of claim 1, wherein the electret material comprises a wax.

9. The apparatus of claim 1, wherein the electret material comprises a resin.

10. The apparatus of claim 1, wherein the electret material comprises polypropylene.

11. The apparatus of claim 1, wherein the electret material comprises a synthetic polymer.

12. A method, comprising

providing a touch-sensor device stylus having a piece of electret material coupled to a first end of the stylus;

and

emitting an electrostatic field from the piece of electret material to be sensed by a touch-sensor device.

13. The method of claim 12, further comprising:

sensing the electrostatic field from the piece of electret material and determining the location of the stylus in relation to the touch-sensor device.

14. The method of claim 13, wherein determining the location of the stylus comprises comparing an electrostatic field produced by the touch-sensor device to a combined electrostatic field produced by the touch-sensor device and the electret material.

15. The method of claim 12, wherein the touch-sensor device is a touchpad device.

16. The method of claim 12, wherein the touch-sensor device is a touch screen device.

17. A method, comprising:

providing a body of a touch-sensor device stylus having a first end and a second end; and

coupling a piece of electret material to the first end of the body.

18. The method of claim 17, wherein coupling the electret material to the first end of the body comprises coupling a metallic probe, internal to the electret material, to the first end of the body.

19. The method of claim 17, wherein coupling the electret material to the first end of the body comprises affixing the electret material to the first end of the body.

20. The method of claim 17, wherein the electret material comprises a fluoropolymer.