Postage meter having shielded keyboard to protect against electromagnetic radiation

Claim 1

In a postage meter of the type adapted to imprint postage on a mail piece, a system comprising: electronic circuit means for controlling the operation of said postage meter, said circuit means including means for accounting for postage which has been printed; a conductive housing supporting said circuit means said conductive housing having a recessed area adapted to receive a keyboard means; a keyboard means including switch means for entering data into said circuit means to effectuate operation of said postage meter, said switch means secured to said housing recessed area and including a plurality of switches electrically connected to said electronic circuit means; said keyboard means further including a conductive flexible sheet disposed above and forming a continuous conductive surface covering all of said plurality of switches, said flexible conductive sheet electrically connected to said housing and positioned above said recessed area and of size so that the margins of said conductive flexible sheet physically engage non recessed areas of said housing and operable to enable a force applied to said conductive sheet to be transmitted to actuate a selected switch to affectuate operation of said postage meter.