US3641468A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Time-modulating apparatus
Assignee: Bell and Howell Co
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Filing: 1970-02-09
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Granted: 1972-02-08
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Expires: 1990-02-09
Abstract
Abstract An apparatus with error signal precorrection for time-modulating an information signal, which upon demodulation tends to be accompanied by an unwanted component, comprises a time modulator and auxiliary circuits. The auxiliary circuits include a network for providing an error signal having a frequency equal to the difference between the average sampling frequency of the timemodulation and the frequency of the unwanted component, and a network for combining the error signal with the information and for applying these combined signals to the time modulator for simultaneous modulation, whereby the error signal precorrects the information signal for the above mentioned unwanted component.
Inventors
- 👤 Wayne K Hodder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:56
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/32; H03F1/3241; H03F1/3276; H03C; H03C3/00; H03C3/02; H03F1/3252
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
90 words
Apparatus for time-modulating at an average sampling rate of fs an information signal which upon demodulation tends to be accompanied by an unwanted component of a frequency of fx, comprising in combination: first means for providing an error signal having a frequency of fs minus fx; second means connected to said first means for combining said error signal with said information signal; and third means connected to said second means for time-modulating said combined error and information signals at said sampling rate whereby said error signal precorrects said unwanted component.
Claim 2
Dependent Claim
90 words
Apparatus for time-modulating at an average sampling rate of fs an information signal which upon demodulation tends to be accompanied by an unwanted component of a frequency of fx, comprising in combination: first means for providing an error signal having a frequency of fs minus fx; second means connected to said first means for combining said error signal with said information signal; and third means connected to said second means for time-modulating said combined error and information signals at said sampling rate whereby said error signal precorrects said unwanted component.
Claim 3
Dependent Claim
21 words
Apparatus as claimed in claim 1, wherein: said first means include means for deriving said error signal from said information signal.
Claim 4
Dependent Claim
22 words
Apparatus as claimed in claim 1, wherein: said first means include diode means for deriving said error signal from said information signal.
Claim 5
Dependent Claim
56 words
Apparatus as claimed in claim 1, wherein: said frequency fx of said unwanted component is variable; and said first means include means for limiting said error signal of fs minus f x to frequencies above one-half of said average sampling rate of fs for a precorrection of unwanted components below one-half of said average sampling rate.
Claim 6
Dependent Claim
100 words
Apparatus for time-modulating at an average sampling rate of fs an information signal having a frequency of fm which upon demodulation tends to be accompanied by unwanted components of frequencies equal to fs minus nfm, where n represents integers greater than one, comprising in combination: first means for providing error signals having frequencies equal to nfm; second means connected to said first means for combining said error signals with said information signal; and third means connected to said second means for time-modulating said combined error and information signals at said sampling rate whereby said error signals precorrect said unwanted components.
Claim 7
Dependent Claim
100 words
Apparatus for time-modulating at an average sampling rate of fs an information signal having a frequency of fm which upon demodulation tends to be accompanied by unwanted components of frequencies equal to fs minus nfm, where n represents integers greater than one, comprising in combination: first means for providing error signals having frequencies equal to nfm; second means connected to said first means for combining said error signals with said information signal; and third means connected to said second means for time-modulating said combined error and information signals at said sampling rate whereby said error signals precorrect said unwanted components.
Claim 8
Dependent Claim
21 words
Apparatus as claimed in claim 5, wherein: said first means include means for deriving said error signals from said information signal.
Claim 9
Dependent Claim
22 words
Apparatus as claimed in claim 5, wherein: said first means include diode means for deriving said error signals from said information signal.
Claim 10
Dependent Claim
46 words
Apparatus as claimed in claim 5, wherein: said first means include means for limiting said error signals to frequencies above one-half of said average sampling rate of fs for an at least partial precorrection of unwanted components having frequencies below one-half of said average sampling rate.
Claim 11
Dependent Claim
104 words
Apparatus for time-modulating at an average sampling frequency of fs an information signal including components of frequencies of fm'' and fm'''' which upon demodulation tend to be accompanied by unwanted components of frequencies of (fs-2fm''), (fs-2fm'''') and (fs-fm''-fm''''), comprising in combination: first means for providing error signals having frequencies of 2fm'', 2fm'''', and (fm''+fm''''); second means connected to said first means for combining said error signals with said information signal including said fm'' and fm'''' components; and third means connected to said second means for time-modulating said combined error and information signals at said sampling rate whereby said error signals precorrect said unwanted components.
Claim 12
Dependent Claim
104 words
Apparatus for time-modulating at an average sampling frequency of fs an information signal including components of frequencies of fm'' and fm'''' which upon demodulation tend to be accompanied by unwanted components of frequencies of (fs-2fm''), (fs-2fm'''') and (fs-fm''-fm''''), comprising in combination: first means for providing error signals having frequencies of 2fm'', 2fm'''', and (fm''+fm''''); second means connected to said first means for combining said error signals with said information signal including said fm'' and fm'''' components; and third means connected to said second means for time-modulating said combined error and information signals at said sampling rate whereby said error signals precorrect said unwanted components.
Claim 13
Dependent Claim
21 words
Apparatus as claimed in claim 9, wherein: said first means include means for deriving said error signals from said information signal.
Claim 14
Dependent Claim
22 words
Apparatus as claimed in claim 9, wherein: said first means include diode means for deriving said error signals from said information signal.
Claim 15
Dependent Claim
46 words
Apparatus as claimed in claim 9, wherein: said first means include means for limiting said error signals to frequencies above one-half of said average sampling rate of fs for an at least partial precorrection of unwanted components having frequencies below one-half of said average sampling rate.
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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |