Patricia D Croxell

US Patent:

56362714, Jun 3, 1997

Filed:

Jun 14, 1995

Appl. No.:

8/490448

Inventors:

Gregory J. Paterno - Plano TX
Patricia D. Croxell - Plano TX

Assignee:

MCI Corporation - Washington DC

International Classification:

H04M 100

US Classification:

379355

Abstract:

A card for tonal entry of PIN codes into a telephone is provided. The keys of a key entry device are contacted in a proscribed sequence to enter a number into the card with each use of the card. The keyed in number is compared with a number stored in the card. If the numbers are the same, an acknowledgement tone is sent. Upon obtaining of the acknowledgement tone, the annunciator in the card is held to the telephone mouthpiece and activated by the user to produce a tonal representation of the PIN number. If an improper number sequence is keyed in by the user, the card produces a warning signal requiring reentry of a number. After three or four successive failures of the user to enter the correct number, the card is disabled and a new one has to be obtained by the cardholder.