Solid state keyswitch arrangement
US4203093A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1978 |
| Grant date | May 13, 1980 |
| Priority date | — |
| Expiry date | Sep 19, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/972
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A solid state keyboard comprised of a base module, a plurality of key members each having a plunger member comprised of a uniform mixture of a magnetic material such as barium ferrite and a binder such as nylon, and a respective plurality of improved Hall Effect generators, provides a significant improvement in performance and cost effectiveness. Actuation of a key member moves its plunger member, which has a preselected magnetic field, in rectilinear fashion relative to an improved Hall Effect generator, in which offset voltage has been substantially eliminated. This movement exposes the generator to a change in the direction of the magnetic field thus causing a corresponding change in the output voltage of the generator from a first predetermined voltage to a second predetermined voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.