Touch switch

• US 4,123,631 A
• Filed: 02/16/1977
• Issued: 10/31/1978
• Est. Priority Date: 02/16/1977
• Status: Expired due to Term

• Current Assignee: Owens-Illinois Glass Container, Inc. (O-I Glass, Inc.)
• Original Assignee: Owens-Illinois Incorporated (O-I Glass, Inc.)
• Inventors: Lewis, Albert D.
• Primary Examiner(s): Scott, James R.
• Application Number:
  US05/769,260
• Time in Patent Office: 622 Days
• Field of Search: 200/52 R, 200/DIG. 1, 361/278, 361/280, 361/281, 361/283, 361/287, 361/288, 361/300, 361/301, 361/303, 361/306, 361/292, 361/329, 340/365 C, 340/337
• US Class Current: 200/600
• CPC Class Codes: H03K 17/962 Capacitive touch switches

Abstract

An improved touch actuated capacitance switch. A series of conductive touch pads are formed on one face of a dielectric material substrate plate. The touch pads are deposited by techniques which result in metallic films that are quite sensitive to damage by abrasion. To protect these pads, a protective overcoat is put over each touch pad, the overcoat obscuring no more than about seventy-percent of the total area of the touch pad. On the other face of the substrate plate are adhered a series of conductive sites, each site being in alignment across the thickness of the substrate plate with one of the touch pads. The conductive sites are then interconnected by a conductor network to give a predefined logic pattern.

Claims

1. A touch actuated capacitance type switch which comprises, in combination:

a substrate plate, made of a dielectric material, having opposing faces;

a plurality of separated conductive touch pads formed on and adhered to one face of said plate, each of said pads being a relatively thin metallic area possessing little resistance to abrasive wear and having a touch surface parallel to said plate;

a protective overcoat of a relatively abrasion resistant material overlying each of said touch pads in an open pattern which obscures no more than about seventy-percent of the total available area of said touch surface of said touch pads;

a plurality of separated and discrete conductive pads formed on and adhered to the other face of said substrate plate, said conductive pads being positioned in general alignment with said touch pads across the thickness of said substrate plate to thereby define capacitors; and

a conductor network intrconnecting said conductive pads in a predetermined logic configuration to thereby define a switch.

2. The switch of claim 1 which further includes:

a coating of a dielectric material completely covering said other face of said substrate plate and positioned between said other face and said conductive pads; and

wherein said conductive pads are adhered to said coating of dielectric material.

3. The switch of claim 1 wherein said protective overcoat comprises a half tone dot pattern of said abrasion resistant material.

4. The switch of claim 1 wherein said protective overcoat comprises a basket weave type pattern of said abrasion resistant material.

5. The switch of claim 3 wherein said abrasion resistant material is a form of organopolysiloxane resin.

6. The switch of claim 3 wherein said abrasion resistant material is vitreous type ink and said half tone dot pattern is screen printed over said touch pads and fired.

7. A touch actuated capacitance switch which comprises, in combination:

a substrate plate, made of a dielectric material, having opposing faces;

a plurality of separated conductive touch pads formed on and adhered to one face of said plate, each of said pads being a relatively thin metallic area possessing little resistance to abrasive wear;

a protective overcoat of a relatively abrasion resistant material overlying the top surface of each of said touch pads and obscuring no more than about seventy-percent of the total available surface area of said touch pads;

a plurality of separated conductive pads formed on and adhered to the other face of said substrate plate, said conductive pads being positioned in general alignment with said touch pads across the thickness of said substrate plate to thereby define capacitors;

a printed circuit conductor network interconnecting said conductive pads in a predetermined logic configuration to thereby define a switch; and

a coating of a dielectric material completely covering said other face of said substrate plate and positioned between said other face and said conductive pads; and

wherein said conductive pads are adhered to said coating of dielectric material.