Patent · US Expired

Keyboard, especially for electronic data-processing apparatuses

US5359166A · kind A · utility

3Cited by

9References

30Claims

0Family size

Assignee

MARQUARDT GMBH · DE

Inventors

Heinz Elsaesser · Spaichingen, DE
Kurt Klaiber · Spaichingen, DE
Ralf Sauer · Overpelt, BE

Key dates

Filing date	Oct 29, 1992
Grant date	Oct 25, 1994
Priority date	—
Expiry date	Oct 29, 2012

Classification

Technology area (CPC H)Electricity
CPC primaryH01H2239/032
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A keyboard for electronic equipment screens off RF radiation by using a conductive housing (2), preferably made of extruded aluminum, which is closed off at its two ends by conductive end pieces (25) and which is closed off underneath by a conductive base plate (30). Key switches (9) extend through openings in a conductive frame (15) that is mounted inside the housing (2), which itself has openings (5, 6) for passage of the key switches (9). The elements are configured to reduce the level of any RF radiation that escapes from inside the keyboard. Among other advantages, this reduction of escaping RF radiation prevents illicit detection and decoding of information which is being entered via the keyboard.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.