Patent EP0206746A2 successfully refreshed from Google Patents.
EP0206746A2
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EP
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Circuit arrangements for modifying dynamic range using series and parallel circuit techniques
Assignee: Dolby Laboratories Licensing Corp
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Filing: 1986-06-17
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Granted: —
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Expires: 2006-06-17
Abstract
Abstract The circuit arrangements for modifying the dynamic range of signals, particularly compressors and expanders for use in noise reduction compander systems, have the advantages of fixed band characteristics (variable attenuation throughout all or part of the frequency band) and sliding band characteristics (variable attenuation through part of the frequency band achieved by a variable pass filter), without the disadvantages normally inherent in each characteristic. Fixed band and sliding band compressors (54, 56) are operated in parallel, as are complementary expanders (60, 62), the compressors and expanders operating in generally the same level range and at least a partial overlapping in frequency range. The transfer characteristics of the parallel circuits add. Alternatively the circuits are operated in series and their characteristics multiply.
Inventors
- 👤 Ray Milton Dolby
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 15:51
CPC Classifications
H; H03; H03G; H03G7/00; H03G9/00; H03G9/02; H03G9/025
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
64 words
A circuit for modifying the dynamic range of an input signal, comprising variable gain circuit means, variable pass filter circuit means, means for connecting said circuit means in series or parallel, means for coupling the input signal to the series or parallel arrangement of said circuit means, and means for deriving an output signal from the series or parallel arrangement of said circuit means.
Claim 2
Dependent Claim
64 words
A circuit for modifying the dynamic range of an input signal, comprising variable gain circuit means, variable pass filter circuit means, means for connecting said circuit means in series or parallel, means for coupling the input signal to the series or parallel arrangement of said circuit means, and means for deriving an output signal from the series or parallel arrangement of said circuit means.
Claim 3
Dependent Claim
35 words
A circuit according to claim 1 wherein at least one of said circuit means operates in a restricted frequency band, the circuit means operating within at least a substantially overlapping frequency range during quiescent conditions.
Claim 4
Dependent Claim
16 words
A circuit according to claim 1 wherein the circuit means are arranged in parallel circuit paths.
Claim 5
Dependent Claim
16 words
A circuit according to claim 1 wherein the circuit means are arranged in series circuit paths.
Claim 6
Dependent Claim
195 words
A circuit according to claim 1 wherein said variable gain circuit means includes first and second variable gain circuits, each having a band defining filter, the filters having a substantially identical cutoff frequency, the band defining filter included with said first variable gain circuit defining a band in the lower portion of the frequency spectrum of the input signal and the band defining filter included with said second vatiable gain circuit defining a band in the upper portion of the frequency spectrum of the input signal, and wherein said variable pass filter circuit means includes first and second variable pass filter circuits, the quiescent filter characteristic of said first variable pass filter circuit defining a band substantially the same as that defined by the band defining filter of said first variable gain circuit, the quiescent filter characteristic of said second variable pass filter circuit defining a band substantially the same as that defined by the band defining filter of said second variable gain circuit, the first variable pass filter circuit having a cutoff frequency that shifts downward in frequency, and the second variable pass filter circuit having a cutoff frequency that shifts upward in frequency.
Claim 7
Independent Claim
97 words
A method for modifying the dynamic range of input signal components within a frequency band, comprising selecting two circuit characteristic actions represented by the voltage transfer functions t (s) and t 2 (s), wherein one of the transfer function represents a fixed band characteristic and the other transfer function represents a sliding band characteristic, the characteristic actions operating at least partially within substantially the same frequency and level region, and operating the circuit characteristics such that when input signal components are applied, represented by the voltage V in , the output voltage V out is represented by
Claim 8
Independent Claim
97 words
A method for modifying the dynamic range of input signal components within a frequency band, comprising selecting two circuit characteristic actions represented by the voltage transfer functions t (s) and t 2 (s), wherein one of the transfer function represents a fixed band characteristic and the other transfer function represents a sliding band characteristic, the characteristic actions operating at least partially within substantially the same frequency and level region, and operating the circuit characteristics such that when input signal components are applied, represented by the voltage V in , the output voltage V out is represented by
Claim 9
Independent Claim
99 words
A method for modifying the dynamic range of input signal components within a frequency band, comprising selecting two circuit characteristic actions represented by the voltage transfer functions t 1 (s) and t 2 (s), wherein one of the transfer function represents a fixed band characteristic and the other transfer function represents a sliding band characteristic, the characteristic actions operating at least partially within substantially the same frequency and level region, and operating the circuit characteristics such that when input signal components are applied, represented by the voltage V. , the output voltage V out is in out represented by
Claim 10
Independent Claim
99 words
A method for modifying the dynamic range of input signal components within a frequency band, comprising selecting two circuit characteristic actions represented by the voltage transfer functions t 1 (s) and t 2 (s), wherein one of the transfer function represents a fixed band characteristic and the other transfer function represents a sliding band characteristic, the characteristic actions operating at least partially within substantially the same frequency and level region, and operating the circuit characteristics such that when input signal components are applied, represented by the voltage V. , the output voltage V out is in out represented by
Claim 11
Dependent Claim
103 words
A circuit for modifying the dynamic range of input signal components within a frequency band, comprising two circuit elements, each having its own characteristic action represented by the voltage transfer functions t 1 (s) and t 2 (s), respectively, wherein one of the transfer function represents a fixed band characteristic and the other transfer function represents a sliding band characteristic, the characteristic actions operating at least partially within substantially the same frequency and level region, and means for interconnecting the circuit elements such that when input signal components are applied, represented by the voltage V the output voltage V out is represented by
Claim 12
Dependent Claim
103 words
A circuit for modifying the dynamic range of input signal components within a frequency band, comprising two circuit elements, each having its own characteristic action represented by the voltage transfer functions t 1 (s) and t 2 (s), respectively, wherein one of the transfer function represents a fixed band characteristic and the other transfer function represents a sliding band characteristic, the characteristic actions operating at least partially within substantially the same frequency and level region, and means for interconnecting the circuit elements such that when input signal components are applied, represented by the voltage V the output voltage V out is represented by
Claim 13
Dependent Claim
105 words
A circuit for modifying the dynamic range of input signal components within a frequency band, comprising two circuit elements, each having its own characteristic action represented by the voltage transfer functions t 1 (s) and t 2 (s), respectively, wherein one of the transfer function represents a fixed band characteristic and the other transfer function represents a sliding band characteristic, the characteristic actions operating at least partially within substantially the same frequency and level region, and means for interconnecting the circuit elements such that when input signal components are applied, represented by the voltage V in , the output voltage V out is represented by
Claim 14
Dependent Claim
105 words
A circuit for modifying the dynamic range of input signal components within a frequency band, comprising two circuit elements, each having its own characteristic action represented by the voltage transfer functions t 1 (s) and t 2 (s), respectively, wherein one of the transfer function represents a fixed band characteristic and the other transfer function represents a sliding band characteristic, the characteristic actions operating at least partially within substantially the same frequency and level region, and means for interconnecting the circuit elements such that when input signal components are applied, represented by the voltage V in , the output voltage V out is represented by
References Cited (Backward Citations)
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