US4612654A
Expired / Lapsed
US
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Digital encoding circuitry
Assignee: ROSEN GERALD D FOR BENEFIT CREDITORS OF DELTALAB RESEARCH Inc
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Filing: 1984-08-27
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Granted: 1986-09-16
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Expires: 2004-08-27
Abstract
Abstract Delta encoding circuitry of the type in which a digitally-encoded signal is determined by the difference between a present value of an input signal and a reconstructed signal representative of a past value of said input signal. The occurrence of a high or a low state in the digitally-encoded signal corresponds to an incremental change in the input signal of an amount dependent upon a reference signal determined from said digitally-encoded signal. The reference signal is increased by a positive-feedback circuit upon detection of one or more consecutive repetitions of the same digital state in the digitally-encoded signal.
Inventors
- 👤 Richard E. DeFreitas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:37
CPC Classifications
H; H03; H03M; H03M3/00; H03M3/02; H03M3/022
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
176 words
An electrical system comprising means for generating a digitally-encoded signal with high and low states, wherein said digitally-encoded signal is determined at least in part by the difference between a present value of an input signal and a reconstructed signal representative of a past value of said input signal, and wherein the state of said digitally-encoded signal is redetermined at a clock frequency, increment-adjusting means for providing that the occurrence of a high or a low state in said digitally-encoded signal corresponds to an incremental change in said input signal of an amount dependent upon a reference signal determined from said digitally-encoded signal, and reference-signal-generating means including means for increasing the value of said reference signal upon detection of one or more consecutive repetitions of the same digital state in said digitally-encoded signal and decreasing said value upon detection of an end to said repetitions, wherein said increases in said reference signal are provided primarily by a clock-independent circuit, said circuit including means for increasing said reference signal at a rate independent of said clock frequency.
Claim 2
Dependent Claim
176 words
An electrical system comprising means for generating a digitally-encoded signal with high and low states, wherein said digitally-encoded signal is determined at least in part by the difference between a present value of an input signal and a reconstructed signal representative of a past value of said input signal, and wherein the state of said digitally-encoded signal is redetermined at a clock frequency, increment-adjusting means for providing that the occurrence of a high or a low state in said digitally-encoded signal corresponds to an incremental change in said input signal of an amount dependent upon a reference signal determined from said digitally-encoded signal, and reference-signal-generating means including means for increasing the value of said reference signal upon detection of one or more consecutive repetitions of the same digital state in said digitally-encoded signal and decreasing said value upon detection of an end to said repetitions, wherein said increases in said reference signal are provided primarily by a clock-independent circuit, said circuit including means for increasing said reference signal at a rate independent of said clock frequency.
Claim 3
Dependent Claim
41 words
The system of claim 1 wherein said clock-independent circuit comprises a positive-feedback circuit comprising an amplifier, the output of which provides said reference signal, and wherein a positive feedback path is provided from said output to the input of said amplifier.
Claim 4
Dependent Claim
23 words
The system of claim 2 wherein said increment-adjusting means comprises an integrator in which the integration slope is determined from said reference signal.
Claim 5
Dependent Claim
30 words
The system of claim 2 wherein said increment-adjusting means comprises a variable gain amplifier operating on said input signal, the gain of said amplifier being determined from said reference signal.
Claim 6
Dependent Claim
47 words
The system of claim 2 wherein said reference-signal-generating means generates a coincidence signal when there has been detection of said one or more consecutive repetitions and wherein said positive-feedback circuit further comprises a switch adapted to complete said positive feedback path when activated by said coincidence signal.
Claim 7
Dependent Claim
33 words
The system of claim 4 wherein said positive-feedback circuit further comprises a charge-storage device such as a capacitor so connected that it charges when said positive feedback path is completed by said switch.
Claim 8
Dependent Claim
39 words
The system of claim 6 wherein said positive-feedback circuit further comprises a discharge circuit path from said charge-storage device to ground and wherein said switch is adapted to complete said circuit path when not activated by said coincidence signal.
Claim 9
Dependent Claim
30 words
The system of claim 7 wherein the time constant of charging when said switch is activated is less than the time constant of decay when said switch is not activated.
Claim 10
Dependent Claim
26 words
The system of claim 2 wherein said positive-feedback circuit includes means to cause said reference signal to rise with the transient characteristic of a rising exponential.
Claim 11
Dependent Claim
46 words
The system of claim 9 wherein the shape of said transient characteristic can be represented as V ref =(V/k)(e kt/ τ -1), where V Ref is the voltage of said reference signal, V is constant voltage, τ is a time constant, and k is a constant.
Claim 12
Dependent Claim
13 words
The system of claim 2 wherein said detection is of three said repetitions.
Claim 13
Dependent Claim
30 words
The system of claim 2 wherein said reference-signal-generating means comprises means for activating said positive-feedback circuit before or simultaneous with activation of any other circuit for generating said reference signal.
Claim 14
Dependent Claim
18 words
The system of claim 12 wherein said activation of said positive-feedback circuit is before any other said activation.
Claim 15
Dependent Claim
32 words
The system of claim 2 wherein said reference-signal-generating means is adapted so that increases in said reference signal due to said positive-feedback circuit are greater than any increases due to other circuitry.
Claim 16
Dependent Claim
26 words
The system of claim 2 wherein said reference-signal-generating means is adapted so that all said increases in said reference signal are provided by said positive-feedback circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-15 | 1990-03-17 | 1990-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-15 | 1994-03-17 | 1994-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-15 | 1998-03-17 | 1998-09-16 | $7700.00 | Window Closed / Lapsed |