US4064537A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplitude limiting circuit for frequency modulated video signals
Assignee: Victor Company of Japan Ltd
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Filing: 1976-07-13
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Granted: 1977-12-20
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Expires: 1996-07-13
Abstract
Abstract An amplitude limiting circuit comprises a high-pass filter for passing the high frequency components of a frequency modulated video signal. The centerline of a signal portion has an amplitude width which is non-linear. A first amplitude limiter both limits and amplifies the output signal from the high-pass filter. A low-pass filter passes the low frequency component of the frequency modulated video signal. An adder adds the resulting output signals of the first amplitude limiter and the low-pass filter. A second amplitude limiter limits the resulting output of the adder.
Inventors
- 👤 Yoshihiko Ota
- 👤 Akira Hirota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:41
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/93; H04N5/94; H03; H03G; H03G11/00; H03G11/06; H03G9/00; H03G9/02; H03G9/12; H03G9/18; H04N5/931; H04N5/9315
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
111 words
An amplitude limiting circuit comprising: a source of frequency modulated video signals including a signal portion having a nonlinear centerline between the amplitude crests of the waveforms; high-pass filtering means for passing the high frequency component of the frequency modulated video signal; first amplitude limiting means for limiting the amplitude of the resulting output of the high-pass filtering means; low-pass filtering means for passing the low frequency component of the frequency modulated video signal; means for adding the output signal of the first amplitude limiting means and the output of the low-pass filtering means; and second amplitude limiting means for limiting the amplitude of the resulting output of the adding means.
Claim 2
Dependent Claim
111 words
An amplitude limiting circuit comprising: a source of frequency modulated video signals including a signal portion having a nonlinear centerline between the amplitude crests of the waveforms; high-pass filtering means for passing the high frequency component of the frequency modulated video signal; first amplitude limiting means for limiting the amplitude of the resulting output of the high-pass filtering means; low-pass filtering means for passing the low frequency component of the frequency modulated video signal; means for adding the output signal of the first amplitude limiting means and the output of the low-pass filtering means; and second amplitude limiting means for limiting the amplitude of the resulting output of the adding means.
Claim 3
Dependent Claim
49 words
An amplitude limiting circuit as claimed in claim 1 wherein said source of video signals comprises means for reproducing frequency modulated video signal recorded on a recordng medium, and said video signal includes a signal waveform portion which does not cross over a straight centerline between the amplitude crests.
Claim 4
Dependent Claim
52 words
An amplitude limiting circuit as claimed in claim 1 wherein said high-pass filtering means has a filtering characteristic for passing substantially a carrier component of the frequency modulated video signal, and said low-pass filtering means has a filtering characteristic for passing a substantially lower side band of the frequency modulated video signal.
Claim 5
Dependent Claim
60 words
An amplitude limiting circuit as claimed in claim 1 wherein said high-pass filtering means and said low-pass filtering means have, respectively, decreasing characteristics with relatively gentle slopes which cross over each other, the crossing over frequency of both decreasing characteristics being selected at a frequency which is equal to a lower deviation frequency limit of the frequency modulated video signal.
Claim 6
Dependent Claim
53 words
An amplitude limiting circuit as claimed in claim 1 which further comprises means for correcting a phase of a signal passing through the high-pass filtering means thereby causing the phase of the signal passing through the high-pass filtering means to coincide with the phase of the signal passing through the low-pass filtering means.
References Cited (Backward Citations)
US3532808A
Cited
US3626087A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-19 | 1981-06-20 | 1981-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-19 | 1985-06-20 | 1985-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-19 | 1989-06-20 | 1989-12-20 | $7700.00 | Window Closed / Lapsed |