Telephonic communications – Supervisory or control line signaling – Signal receiver
Patent
1993-08-04
1995-06-27
Dwyer, James L.
Telephonic communications
Supervisory or control line signaling
Signal receiver
379387, 379372, 379 88, 379 89, H04M 150
Patent
active
054286808
ABSTRACT:
A DTMF signal receiving apparatus includes a DTMF signal receiver; and a DTMF signal judging circuit. The DTMF signal receiver includes an input section for receiving an input signal from an external apparatus; a plurality of first band-pass filters connected to the input section; a plurality of second band-pass filters connected to the input section; and an output section connected to the plurality of the first band-pass filters and the plurality of the second band-pass filters, for outputting a code based on a plurality of outputs from the plurality of the first band-pass filters and the plurality of the second band-pass filters. The DTMF signal judging circuit includes a first judging device connected to the plurality of the first band-pass filters, for outputting a first judgment signal based on a plurality of first outputs from the plurality of the first band-pass filters; a second judging device connected to the plurality of the second band-pass filters, for outputting a second judgment signal based on a plurality of second outputs from the plurality of the second band-pass filters; and a third judging device for judging whether the input signal is a DTMF signal or not based on the first judgment signal and the second judgment signal and for permitting the output section to output the code when judging that the input signal is a DTMF signal.
REFERENCES:
patent: 4085295 (1978-04-01), Goto et al.
patent: 4395595 (1983-07-01), Nishitani et al.
patent: 4599495 (1986-07-01), Richards
patent: 4922528 (1990-05-01), Hubert et al.
patent: 5172406 (1992-12-01), Locke
patent: 5214693 (1993-05-01), Chujo
Ikeuchi Michio
Murata Yasumoto
Yoshikawa Shuichi
Dwyer James L.
Saint-Surin Jacques M.
Sharp Kabushiki Kaisha
LandOfFree
DTMF signal receiving apparatus equipped with a DTMF signal judg does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with DTMF signal receiving apparatus equipped with a DTMF signal judg, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and DTMF signal receiving apparatus equipped with a DTMF signal judg will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-293254