US3699446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential pulse code modulator system with cyclic, dynamic decision level changing
Assignee: US Philips Corp
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Filing: 1970-12-24
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Granted: 1972-10-17
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Expires: 1990-12-24
Abstract
Abstract A device for the transmission of an information signal by means of pulse code modulation features a quantizing circuit controlled by a control circuit so that the decision levels of the quantizing circuit are cyclically changed between predetermined minimum and maximum values.
Inventors
- 👤 Philippe Sainte-Beuve
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:50
CPC Classifications
H; H03; H03M; H03M3/00; H03M3/04; H04; H04N; H04N19/00; H04N19/10; H04N19/102; H04N19/124; H04N19/50; H04N19/90
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
174 words
eA device for the transmission of an information signal by means of a pulse code, said device comprising a quantizing circuit having a plurality of decision levels, said quantizing circuit producing a quantized signal, a comparison circuit coupled to the quantized signal, said comparison circuit comprising an integrating network for integrating a signal corresponding to the quantized signal, a difference producer for producing a difference signal, means to couple the information signal to the input means of the difference producer, means to couple the comparison circuit to the input means of the difference producer, means to couple the difference signal of the difference producer to the input means of the quantizing circuit, a pulse code modulator coupled to the output means of quantizing circuit, said pulse code modulator generating code groups characterizing the magnitude and sign of the difference signal, and a control circuit coupled to the quantizing circuit for cyclically changing between predetermined minimum and maximum values the respective decision levels from which the quantizing circuit determines representative levels for the quantized signal.
Claim 2
Dependent Claim
174 words
eA device for the transmission of an information signal by means of a pulse code, said device comprising a quantizing circuit having a plurality of decision levels, said quantizing circuit producing a quantized signal, a comparison circuit coupled to the quantized signal, said comparison circuit comprising an integrating network for integrating a signal corresponding to the quantized signal, a difference producer for producing a difference signal, means to couple the information signal to the input means of the difference producer, means to couple the comparison circuit to the input means of the difference producer, means to couple the difference signal of the difference producer to the input means of the quantizing circuit, a pulse code modulator coupled to the output means of quantizing circuit, said pulse code modulator generating code groups characterizing the magnitude and sign of the difference signal, and a control circuit coupled to the quantizing circuit for cyclically changing between predetermined minimum and maximum values the respective decision levels from which the quantizing circuit determines representative levels for the quantized signal.
Claim 3
Dependent Claim
29 words
A device as claimed in claim 1, wherein the positive and negative decision levels which corresponds to a given representative level have the same absolute value at any instant.
Claim 4
Dependent Claim
29 words
A device as claimed in claim 1, wherein the positive and negative decision levels which correspond to a given representative level have a different absolute value at any instant.
Claim 5
Dependent Claim
33 words
A device as claimed in claim 1, wherein the control circuit comprises an alternating voltage source incorporated in the supply circuit of a voltage divider from which the different decision levels are derived.
Claim 6
Dependent Claim
55 words
A device as claimed in claim 1, wherein the information signal is a television video signal including line and field signals and the repetition frequency of the cycle within which the control circuit modifies the decision levels is a rational part of the line frequency or of the field frequency of the television video signal.
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) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |