Piezoelectric key board switch
US3935485A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1974 |
| Grant date | Jan 27, 1976 |
| Priority date | — |
| Expiry date | Sep 17, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S310/80
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A key board switch comprising a multi-piezoelectric polymer film element A having, in the surface of the polymer film, a plurality of piezoelectric unit elements satisfying the following criteria: (a) the unit elements have electrodes on both surfaces thereof, (b) the portions of the polymer film of the piezoelectric unit elements held between the electrodes on both surfaces have piezoelectric properties and (c) any two piezoelectric unit elements are electrically independent of each other at least with respect to electrodes on one of the surfaces; and a substrate sheet B on which the polymer film element A is laid over and having windows or recesses in the positions corresponding to each of the piezoelectric unit elements of the polymer film element A. The key board switch is adapted so that those portions of the polymer film between each of the piezoelectric unit elements in the element A are secured to the substrate B at intermediate positions between the windows or recesses in the substrate B, whereby the stress applied to one of the piezoelectric unit elements is not transmitted to other adjacent elements so that the changes in the electric field generated from each of the pie…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.