Glass membrane keyboard switch assembly for domestic appliance
US4901074A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1987 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Dec 31, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2239/018
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A keyboard switch assembly includes a thin, flexible, glass top layer forming a membrane. Disposed on an inner surface of the glass membrane is a first conductive layer forming an electrode. Disposed beneath the first conductive layer is an insulating layer or spacer having an aperture therein that defines a switch contact area. Beneath the spacer a rigid portion of the keyboard switch assembly is provided. The rigid portion of the keyboard switch assembly includes a rigid substrate with a conductive coating formed thereon to provide a second conductive layer or electrode disposed beneath the spacer. A flexible polymer layer may further be disposed between the rigid substrate and the second conductive layer to reduce point contact degradation in the keyboard switch assembly. Decorative paint layers may be formed on the inner surface of the glass membrane between the glass membrane and the first conductive layer. Alternatively, where the layers forming the keyboard switch assembly are transparent, a decorative paint layer may be disposed on an outer surface of the rigid substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.