Touch sensitive switch pads

• US 5,403,980 A
• Filed: 08/06/1993
• Issued: 04/04/1995
• Est. Priority Date: 08/06/1993
• Status: Expired due to Fees

• Current Assignee: Iowa State University Research Foundation Incorporated (Iowa State University)
• Original Assignee: Iowa State University Research Foundation Incorporated (Iowa State University)
• Inventors: Eckrich, Karl M.
• Primary Examiner(s): SCOTT, JAMES R
• Application Number:
  US08/103,345
• Time in Patent Office: 606 Days
• Field of Search: 200/5 A, 200/52 R, 200/61.05, 200/512-517, 200/314, 200/315, 200/292, 174/250-264, 361/748-751
• US Class Current: 200/52.00R
• CPC Class Codes: H01H 13/02 Details
• CPC Class Codes: H01H 2223/022 Adhesive
• CPC Class Codes: H03K 17/96 Touch switches specially adapted for electronic time-pieces with no moving parts G04G21/08
• CPC Class Codes: H03K 17/9645 Resistive touch switches
• CPC Class Codes: H03K 2017/9602 characterised by the type or shape of the sensing electrodes
• CPC Class Codes: Y10S 200/02 Body attached switches

Abstract

A touch sensitive switch pad. The switch pad includes a flexible film with a two conductive ink patterns on one side and an adhesive on the other. The adhesive backing can be of the peel off type such that a user simply peels off a protective backing to reveal the adhesive. The conductive ink patterns are disposed sufficiently close to each other such that there is a high probability that when a user touches the pad, a closed circuit occurs between the two patterns. Each conductive ink pattern is connected to an electrical contact which in turn can be connected to switching circuitry which is sensitive enough to sense the high resistance closed circuit. An extra adhesive-backed flap connected to the film and disposed in close proximity to the electrical contacts can be used to help protect the electrical contacts.

Claims

1. A touch sensitive switch pad actuated by operator resistive bridging, such as skin comprising:

a flexible film, said film having a first surface and a second surface;

an adhesive backing distributed on said first surface;

a first conductive ink pattern disposed on said second surface;

a second conductive ink pattern disposed on said second surface;

wherein said first conductive ink pattern and said second conductive ink pattern are separate with respect to each other; and

means disposed on said film for electrically connecting to said first and said second conductive ink patterns.

2. The touch sensitive switch pad of claim 1 wherein said film is transparent.

3. The touch sensitive switch pad of claim 1 wherein said film is a polyester film.

4. The touch sensitive switch pad of claim 1 wherein said film has a thickness of approximately 5 millimeters.

5. The touch sensitive switch pad of claim 1 wherein said film is of rectangular shape.

6. The touch sensitive switch pad of claim 5 wherein said first surface and said second surface of said film is approximately two (2) inches by four (4) inches.

7. The touch sensitive switch pad of claim 5 wherein said first surface and said second surface of said film is approximately three (3) inches by five (5) inches.

8. The touch sensitive switch pad of claim 5 wherein said first surface and said second surface of said film is approximately one tenth (0.1) of an inch by twenty-four (24) inches.

9. The touch sensitive switch pad of claim 1 wherein the length of said film is significantly greater than the width of said film.

10. The touch sensitive switch pad of claim 1 wherein said film is of arcuate shape.

11. The touch sensitive switch pad of claim 1 wherein the conductive ink used in said first conductive ink pattern and said second conductive ink pattern comprises a silver ink and carbon ink composite.

12. The touch sensitive switch pad of claim 1 wherein the conductive ink used in said first conductive ink pattern and said second conductive ink pattern is highly resistant to corrosion.

13. The touch sensitive switch pad of claim 1 wherein the conductive ink used in said first conductive ink pattern and said second conductive ink pattern is sufficiently resilient to withstand application to non-planer devices.

14. The touch sensitive switch pad of claim 1 wherein the conductive ink used in said first conductive ink pattern and said second conductive ink pattern is transparent.

15. The touch sensitive switch pad of claim 1 wherein said connecting means includes solder tabs.

16. The touch sensitive switch pad of claim 1 wherein said film includes a flap positioned in close proximity to said connecting means whereby said flap can be wrapped around said connecting means to provide protection for said connecting means.

17. The touch sensitive switch pad of claim 1 including:

a cable wherein one end of said cable is connected to said connecting means; and

a plug connected to the other end of said cable.

18. A touch sensitive switch pad actuated by operator resistive bridging, such as skin, comprising:

a flexible film, said film having a first surface and a second surface;

an adhesive backing distributed on said first surface;

a first conductive ink pattern disposed on said second surface;

a second conductive ink pattern disposed on said second surface;

wherein said first conductive ink pattern and said second conductive ink pattern are separate with respect to each other;

means disposed on said film for electrically connecting to said first and said second conductive ink patterns;

wherein said film is transparent;

wherein said film is a polyester film;

wherein said film has a thickness of approximately 5 millimeters;

wherein the conductive ink used in said first conductive ink pattern and said second conductive ink pattern comprises a silver and carbon composite;

wherein said connecting means includes solder tabs; and

wherein said film includes a flap positioned in close proximity to said connecting means whereby said flap can be wrapped around said connecting means to provide protection for said connecting means.

19. A touch sensitive switch pad actuated by operator resistive bridging, comprising:

a flexible film, said film having a first surface and a second surface;

an adhesive backing distributed on said first surface;

resistive bridging switching means for creating a closed circuit upon skin contact by an operator, said switching means including a first conductive ink pattern disposed on said second surface and a second conductive ink pattern disposed on said second surface;

wherein said first conductive ink pattern and said second conductive ink pattern are separate with respect to each other; and

means disposed on said film for electrically connecting to said first and said second conductive ink patterns.