Patent US4508937A successfully refreshed from Google Patents.
US4508937A
Expired / Lapsed
US
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Method and circuitry for encoding telephone ringing signals
Assignee: AMERICAN BELL INCORPORATED A CORP OF DE
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Filing: 1983-02-28
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Granted: 1985-04-02
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Expires: 2003-02-28
Abstract
Abstract In the disclosed coded telephone ringing signal method and circuitry, audibly distinguishable ringing codes are generated by alternately shifting between at least a pair of single frequency tones at different modulation rates. Other distinguishable ringing codes are generated by changing both the modulation rates and tone frequencies utilized.
Inventors
- 👤 William A. Burger
- 👤 David M. Embree
- 👤 Martin H. Singer
- 👤 David R. Vogelpohl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:20
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/02; H04M19/00; H04M19/02; H04M19/04; H04M1/00; H04M1/66; H04M1/663; H04M1/665; H04M9/00; Y; Y10; Y10S; Y10S379/00; Y10S379/911
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
110 words
A circuit responsive to a ringing signal received over a communication line for providing a user with encoded telephone ringing signals from a plurality of tones comprising: ring detector means for detecting the existence of said ringing signal and generating an enable signal during the existence of said ringing signal, modulating means responsive to said enable signal for generating an encoded ringing signal for the user during the existence of said enable signal by modulating between at least two of said plurality of tones and means for controlling the modulation rate of said modulating means at one of a plurality of fixed rates with each rate representing a different code.
Claim 2
Dependent Claim
110 words
A circuit responsive to a ringing signal received over a communication line for providing a user with encoded telephone ringing signals from a plurality of tones comprising: ring detector means for detecting the existence of said ringing signal and generating an enable signal during the existence of said ringing signal, modulating means responsive to said enable signal for generating an encoded ringing signal for the user during the existence of said enable signal by modulating between at least two of said plurality of tones and means for controlling the modulation rate of said modulating means at one of a plurality of fixed rates with each rate representing a different code.
Claim 3
Dependent Claim
49 words
The circuit of claim 1 wherein said modulation rate controlling means includes first control signal for selecting a first modulation rate for a first group of said plurality of tones, and second control signal for selecting a second modulation rate for a second group of said plurality of tones.
Claim 4
Dependent Claim
52 words
The circuit of claim 2 wherein the frequencies of said first group of tones are not easily humanly distinguishable from the frequencies of said second group of tones and wherein the modulation rate of said first modulation rate is not easily humanly distinguishable from the modulation rate of said second modulation rate.
Claim 5
Dependent Claim
45 words
The circuit of claim 3 wherein the respective frequencies of said first and second group of tones have a frequency ratio in the range 1.6-2.0 to 1 and wherein said first and second modulation rates have a modulation ratio in the range 2.6-3.0 to 1.
Claim 6
Dependent Claim
38 words
The circuit of claim 1 wherein said circuit further includes means for binarily encoding the amplitude of encoded signals generated by said modulating means into one of a plurality of codes in response to an amplitude control signal.
Claim 7
Dependent Claim
25 words
The circuit of claim 5 wherein said circuit further includes means for generating said amplitude control signal from the detected envelope of said ring signal.
Claim 8
Dependent Claim
23 words
The circuit of claim 5 wherein the encoded signals of said modulation means and said amplitude encoding means represent different types of information.
Claim 9
Independent Claim
96 words
A method of providing encoded telephone ringing signals from a plurality of tones in response to a ringing signal received over a communication line comprising the steps of: detecting the existence of said ringing signal and generating an enable signal during the existence of said ringing signal, modulating between at least two of said plurality of tones to generate an encoded ringing signal for the user during the existence of said enable signal and controlling the modulation rate of said modulating step at one of a plurality of fixed rates with each representing a different code.
Claim 10
Independent Claim
96 words
A method of providing encoded telephone ringing signals from a plurality of tones in response to a ringing signal received over a communication line comprising the steps of: detecting the existence of said ringing signal and generating an enable signal during the existence of said ringing signal, modulating between at least two of said plurality of tones to generate an encoded ringing signal for the user during the existence of said enable signal and controlling the modulation rate of said modulating step at one of a plurality of fixed rates with each representing a different code.
Claim 11
Dependent Claim
42 words
The method of claim 8 wherein said controlling step includes the steps of: selecting a first modulation rate for a first group of said plurality of tones, and selecting a second modulation rate for a second group of said plurality of tones.
Claim 12
Dependent Claim
52 words
The method of claim 9 wherein the frequencies of said first group of tones are not easily humanly distinguishable from the frequencies of said second group of tones and wherein the modulation rate of said first modulation rate is not easily humanly distinguishable from the modulation rate of said second modulation rate.
Claim 13
Dependent Claim
45 words
The method of claim 10 wherein the respective frequencies of said first and second group of tones have a frequency ratio in the range 1.6-2.0 to 1 and wherein said first and second modulation rates have a modulation ratio in the range 2.6-3.0 to 1.
Claim 14
Dependent Claim
34 words
The method of claim 8 further including the step of: binarily encoding the amplitude of encoded signals generated during said modulating step into a plurality of codes in response to an amplitude control signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-01 | 1988-10-01 | 1989-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-01 | 1992-10-01 | 1993-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-01 | 1996-10-01 | 1997-04-02 | $7700.00 | Window Closed / Lapsed |