Keypad system and keypad with enhanced security
US8288672B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 30, 2010 |
| Grant date | Oct 16, 2012 |
| Priority date | — |
| Expiry date | May 4, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/960745
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In one form, a keypad includes a substrate and a flexible membrane disposed above a top surface of the substrate. The substrate has the top surface, a first conductor below the top surface, an insulator layer separating the first conductor from the top surface, and a second conductor disposed in proximity to the first conductor and to the top surface and coupled to a voltage terminal. The flexible membrane is disposed above the top surface of the substrate and has a third conductor forming a key. The third conductor is movable relative to the top surface. In another form, a keypad system includes such a keypad and a capacitive sensing circuit coupled to the first conductor for sensing a change in capacitance between the first conductor and the voltage terminal when the third conductor moves relative to the top surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.