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US4570193A Expired / Lapsed US ⏱️ 0.0 years remaining

Video signal processing device including emphasis and/or de-emphasis circuit

Assignee: Canon Inc
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Filing: 1982-05-04
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Granted: 1986-02-11
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Expires: 2002-05-04
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Abstract

Abstract A video signal processing device including emphasis and/or de-emphasis circuit being arranged to have a circuit to emphasize a high frequency component of a video signal which has been introduced at a time of frequency modulation in a linear phase. Further, the circuit clips an output of the emphasis circuit with a prescribed amplitude and at the same time supplies a frequency modulated video signal to a de-emphasis circuit which has a characteristic of being contrary to the frequency characteristic of the emphasis circuit.

Inventors

  • 👤 Shinichi Yamashita

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 00:09
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/92; H04N5/923

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 110 words
A video signal processing device including a de-emphasis circuit, comprising: (a) a de-emphasis circuit to de-emphasize high frequency components of a de-modulated video signal, said de-emphasis circuit including a transversal filter of a low pass type which includes analog delay elements and a coefficient imparter to impart weight to each tap output of said delay elements; and (b) a noise clipping circuit to eliminate noise components of large amplitude out of output signals of said de-emphasis circuit, said noise clipping circuit including a first subtracting circuit to obtain a difference between one of the delay outputs of each tap of said delay elements and an output of the de-emphasis circuit.
Claim 2
Dependent Claim 110 words
A video signal processing device including a de-emphasis circuit, comprising: (a) a de-emphasis circuit to de-emphasize high frequency components of a de-modulated video signal, said de-emphasis circuit including a transversal filter of a low pass type which includes analog delay elements and a coefficient imparter to impart weight to each tap output of said delay elements; and (b) a noise clipping circuit to eliminate noise components of large amplitude out of output signals of said de-emphasis circuit, said noise clipping circuit including a first subtracting circuit to obtain a difference between one of the delay outputs of each tap of said delay elements and an output of the de-emphasis circuit.
Claim 3
Dependent Claim 28 words
A device according to claim 1, wherein said noise clipping circuit further includes an amplitude limiter which limits an amplitude of an output of said first subtraction circuit.
Claim 4
Dependent Claim 35 words
A device according to claim 2, wherein said noise clipping circuit further contains a second subtraction circuit which obtains a difference between an output of said amplitude limiter and an output of the de-emphasis circuit.
Claim 5
Dependent Claim 28 words
A device according to claim 1, wherein the delay output supplied to the first subtraction circuit is the output from a center tap out of the delay elements.
Claim 6
Dependent Claim 140 words
A video signal processing device comprising: (a) an emphasis circuit including: a group of delay elements connected in series, to which a video signal which has been introduced to the emphasis circuit is supplied; a group of coefficient imparters for imparting weight to each tap output of the delay elements; and an operation circuit which operates outputs of the coefficient imparters to generate a single output, the delay time of each of said group of delay elements and the coefficient of each of said group of coefficient imparters being determined in such a manner that the output signal of the operation circuit represents the video signal introduced to said emphasis circuit and emphasized on the high frequency component in a linear phase; and (b) a clipping circuit for clipping an output signal of said emphasis circuit with a predetermined amplitude.
Claim 7
Dependent Claim 140 words
A video signal processing device comprising: (a) an emphasis circuit including: a group of delay elements connected in series, to which a video signal which has been introduced to the emphasis circuit is supplied; a group of coefficient imparters for imparting weight to each tap output of the delay elements; and an operation circuit which operates outputs of the coefficient imparters to generate a single output, the delay time of each of said group of delay elements and the coefficient of each of said group of coefficient imparters being determined in such a manner that the output signal of the operation circuit represents the video signal introduced to said emphasis circuit and emphasized on the high frequency component in a linear phase; and (b) a clipping circuit for clipping an output signal of said emphasis circuit with a predetermined amplitude.
Claim 8
Dependent Claim 19 words
A device according to claim 5, wherein said group of delay elements is formed by a charge transfer device.
Claim 9
Dependent Claim 122 words
A device according to claim 5, further comprising a de-emphasis circuit including: a group of delay elements connected in series and supplied with a video signal introduced to the de-emphasis circuit; a group of coefficient imparters for imparting weight to each tap output of said group of delay elements; and an operation circuit for operating outputs of said group of coefficient imparters to generate a single output, the delay time of each of said group of delay elements and the coefficient of each said group of coefficient imparters being determined in such a manner that the output signal of the operation circuit represents the video signal introduced to said de-emphasis circuit and de-emphasized on the high frequency component in a linear phase.

References Cited (Backward Citations)

US3288930A Cited
US3535443A Cited
US4232279A Cited
US4330769A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-02-10 1989-08-12 1990-02-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-02-10 1993-08-12 1994-02-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-02-10 1997-08-12 1998-02-11 $7700.00 Window Closed / Lapsed

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