The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 18, 2002
Filed:
Oct. 29, 1998
Jeffrey I. Robinson, New Fairfield, CT (US);
IQ Systems, Inc., Sandy Hook, CT (US);
Abstract
The apparatus of the invention (a) monitors a subscriber line for the presence of DTMF tones, (b) intercepts DTMF tones by transmitting a set of DTMF harmonics onto the subscriber line, (c) detects the intercepted DTMF tones and records them or the digits they represent, (d) analyzes the intercepted digits to determine whether a long distance number has been dialed, and (e) if a long distance call has been dialed, transmits onto the subscriber line a DTMF signal which includes the intercepted DTMF signal plus a service provider access code DTMF signal inserted before it. According to a presently preferred embodiment, the apparatus includes a voltage sensor which detects a drop in voltage whenever a phone connected to the same subscriber line as the apparatus goes off-hook. The voltage detector turns the apparatus “ON” when an off-hook condition is detected. The preferred apparatus also includes an energy sensor which rapidly detects the presence of any fixed frequency tone and triggers a harmonics tone generator which preferably generates second harmonics of each of the “row frequencies”. Thus, all DTMF tones are blocked before they are recognized.