US3612772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for adding codes resulting from nonlinear coding
Assignee: International Standard Electric Corp
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Filing: 1969-04-09
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Granted: 1971-10-12
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Expires: 1989-04-09
Abstract
Abstract A PCM circuit adds the speech codes of subscribers who are participating in a conference call. A decoding circuit decodes two PCM codes, and the resulting analog voltages are added together. The sum of the analog voltages are reencoded and sent out to the other subscribers.
Inventors
- 👤 Claude Paul Henri Lerouge
- 👤 Jean Perrault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:49
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/42; H04M3/56; H04M3/561
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
90 words
A circuit for adding signals in PCM code resulting from nonlinear coding comprising: decoding means for converting two code words into analog signals provided by said decoding means, coding means for encoding the sum of said analog voltages, means for transferring a third code word and the encoded sum into said decoding means, gating means for sending out from said coding means a code word which represents the sum of codes, and clock means for providing signals for controlling the coding means and said transferring means and said gating means.
Claim 2
Dependent Claim
90 words
A circuit for adding signals in PCM code resulting from nonlinear coding comprising: decoding means for converting two code words into analog signals provided by said decoding means, coding means for encoding the sum of said analog voltages, means for transferring a third code word and the encoded sum into said decoding means, gating means for sending out from said coding means a code word which represents the sum of codes, and clock means for providing signals for controlling the coding means and said transferring means and said gating means.
Claim 3
Dependent Claim
43 words
An adder circuit according to claim 1 and at least one ladder attenuator said decoding means comprising current generators for supplying said ladder attenuator, and said coding means is a feedback coder, said ladder attenuator being common to said decoding and coding means.
Claim 4
Dependent Claim
89 words
A circuit for adding speech signals in PCM code from subscribers who are participating in a conference call connection comprising: means for decoding first and second PCM code words including respective first and second decoders, means for adding the analog voltages resulting from the first and second decoders, means for encoding the sum of the voltages, electronic gate means for selectively coupling the encoding means to said conference connection and to said second decoder, and means comprising a clock circuit for supplying control signals to the electronic gate means.
Claim 5
Dependent Claim
89 words
A circuit for adding speech signals in PCM code from subscribers who are participating in a conference call connection comprising: means for decoding first and second PCM code words including respective first and second decoders, means for adding the analog voltages resulting from the first and second decoders, means for encoding the sum of the voltages, electronic gate means for selectively coupling the encoding means to said conference connection and to said second decoder, and means comprising a clock circuit for supplying control signals to the electronic gate means.
Claim 6
Dependent Claim
25 words
The circuit of claim 3 and a feedback coder having ladder attenuator means, the ladder means being common to two decoders of the decoding means.
Claim 7
Dependent Claim
68 words
The circuit of claim 4 wherein the number of subscribers participating in the conference call is equal to a maximum number n, each represented by an address comprising part of a code word, and wherein there are means for introducing code words in the decoding circuit means according to a sequence comprising the group of n code words ranged in the same order, each word including (n-1) addresses.
Claim 8
Dependent Claim
71 words
The circuit of claim 5, wherein the number n1 of subscribers participating in a conference is less than the maximum n for which the conference call circuit is designed, and the means for introducing the sequence of the addresses in code words is in an order which is identical to the order for n subscribers except that (n-n1) addresses of the group of n code words are constituted by zero digits.
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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) | 1974-10-11 | 1975-04-12 | 1975-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-11 | 1979-04-12 | 1979-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-11 | 1983-04-12 | 1983-10-12 | $7700.00 | Window Closed / Lapsed |