Switch with at least one flexible conductive member

• US 6,469,267 B1
• Filed: 07/12/2000
• Issued: 10/22/2002
• Est. Priority Date: 07/12/2000
• Status: Expired due to Fees

• Current Assignee: Agfa-Gevaert N.V., Elo Touch Solutions, Inc.
• Original Assignee: Elo Touchsystems Incorporated (Elo Touch Solutions, Inc.)
• Inventors: Cloots, Tom J. A. M., Willaert, Peter J. M., Radzilowski, Leonard H., Muys, Bavo A. A., Welsh, Laurence M.
• Primary Examiner(s): Luebke, Renee
• Application Number:
  US09/614,290
• Time in Patent Office: 832 Days
• Field of Search: 345/173, 200/512, 200/262
• US Class Current: 200/512
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 13/785 characterised by the material of the contacts, e.g. conductive polymers
• CPC Class Codes: H01H 2201/032 Conductive polymer; Rubber
• CPC Class Codes: H01H 2209/082 transparent

Abstract

A switch comprises two substrates coated with conductive elements opposed to each other across a gap. At least one of the conductive elements comprises an intrinsically conductive polymer. The switch completes an electrical circuit when one of substrates is pressed toward the other of the substrates and the two conductive elements touch. The polarity applied to the intrinsically conductive polymer coating is, preferably, negative. The voltage applied to the electrical circuit, is, preferably, less than five volts; more preferably, the voltage applied to the electrical circuit is less than three volts; even more preferably, the voltage applied to the electrical circuit is less than one volt.

Claims

1. A switch comprising:

a coversheet comprising an intrinsically conductive polymer, and

a substrate comprising a conductive surface, the substrate spaced apart from the coversheet,

wherein movement of the coversheet into contact with the conductive surface of the substrate generates a signal indicative of said contact and wherein said coversheet has a polarity that is negative relative to the conductive surface of said substrate.

2. The switch of claim 1, wherein:

a first terminal extends from the coversheet, and

a second terminal extends from the conductive surface of the substrate,

the first terminal, the coversheet, the conductive surface of the substrate, and the second terminal forming an electrical circuit such that the circuit is completed when movement of the coversheet brings the coversheet into contact with the conductive surface of the substrate.

3. The switch of claim 2, wherein an electrical potential of less than five volts is applied to the electrical circuit.

4. The switch of claim 2, wherein an electrical potential of less than one volt is applied to the electrical circuit.

5. The switch of claim 2, wherein an electrical potential of less than three volts is applied to the electrical circuit.

6. The switch of claim 5, wherein the electrical potential applied is direct current.

7. The switch of claim 5, wherein the electrical potential applied is alternating current.

8. The switch of claim 1, wherein the coversheet and the substrate are substantially transparent.

9. The switch of claim 1, wherein the intrinsically conductive polymer is poly(ethylenedioxythiophene).

10. A switch comprising:

a coversheet comprising a first substrate and a first conductive coating applied to a first surface of the first substrate, the first conductive coating comprising an intrinsically conductive polymer; and

a second substrate comprising a second conductive coating applied to a first surface of the second substrate,

wherein the first and second substrates are positioned such that the first and second conductive coatings face each other and an electric potential of less than five volts is applied across the first and second conductive coatings and wherein the polarity of the first conductive coating is negative relative to the second conductive coating.

11. The switch of claim 10, wherein the intrinsically conductive polymer is poly(ethylenedioxythiophene).

12. A touchscreen comprising:

a coversheet comprising a first substrate, the first substrate comprising a plastic;

a second substrate spaced apart from the first substrate;

a first conductive coating on the first substrate, the first conductive coating having opposed surfaces, one of the opposed surfaces of the first conductive coating facing the first substrate, the other of the opposed surfaces of the first conductive coating facing the second substrate, the first conductive coating comprising an intrinsically conductive polymer;

a second conductive coating on the second substrate, the second conductive coating spaced apart from the first conductive coating, the second conductive coating having a surface facing the first conductive coating and spaced apart therefrom wherein the first conductive coating has a polarity that is negative relative to the second conductive coating; and

a plurality of spacer dots,

wherein;

the plurality of spacer dots are disposed on the first conductive coating or the second conductive coating on the surface thereof facing the other of the conductive coatings, the spacer dots spaced apart from the other of the conductive coatings;

a first terminal extends from the first conductive coating;

a second terminal extends from the second conductive coating; and

the first terminal, the first conductive coating, the second conductive coating, and the second terminal form an electrical circuit such that the electrical circuit is completed for transmission of an electrical signal to a receiving medium when the first conductive coating and the second conductive coating are pressed together.

13. The touchscreen of claim 12, wherein an electrical potential of less than three volts is applied to the electrical circuit.

14. The touchscreen of claim 12, wherein an electrical potential of less than one volt is applied to the electrical circuit.

15. The touchscreen of claim 12, wherein the first substrate, the second substrate, the first conductive coating, and the second conductive coating are substantially transparent.

16. The touchscreen of claim 12, wherein the intrinsically conductive polymer is poly(ethylenedioxythiophene).

17. The touchscreen of claim 12, wherein the second conductive coating comprises an intrinsically conductive polymer.

18. The touchscreen of claim 12, wherein an electrical potential of less than five volts is applied to the electrical circuit.

19. The touchscreen of claim 18, wherein the electrical potential applied is direct current.

20. The touchscreen of claim 18, wherein the electrical potential applied is alternating current.