Patent ID: 8595514

Claim:
A data entry device comprising: a housing formed of at least two portions; data entry circuitry including circuitry located on a substrate within said housing; at least one case-open switch assembly operative to sense when said housing is opened; and tamper indication circuitry operative to receive an input from said at least one case-open switch assembly and to provide an output indication of possible tampering with said data entry circuitry located within said housing, said at least one case-open switch assembly including an arrangement of electrical contacts located on said substrate, said electrical contacts including at least first, second and third contacts and a displaceable conductive element, which defines a short circuit between said first and second contacts only when said housing is closed, said third contact being arranged between said first and second contacts and said displaceable conductive element so as to normally not be short circuited to said first and second contacts when said housing is closed, said tamper indication circuitry and said third contact together being operative such that when said third contact is short circuited to at least one of said first contact, said second contact and another contact, an output indication of possible tampering is provided.