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US4498099A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for frame-to-frame comb filtering composite TV signal

Assignee: RCA Licensing Corp
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Filing: 1982-11-26
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Granted: 1985-02-05
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Expires: 2002-11-26
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Abstract

Abstract A frame-to-frame comb filter for separating chrominance and luminance signals from composite video signals produces objectionable double images around the edges of moving objects. The double images are substantially removed by low pass filtering the combed chrominance signal and combining the low pass filtered chrominamce signal with the combed luminance signal.

Inventors

  • 👤 Dalton H. Pritchard

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 17:21
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/77; H04N9/78

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 148 words
A comb filter for processing TV signals comprising: a delay means for delaying said TV signal by one image period; first means for combining said TV signal and delayed TV signal from said delay means to produce the sum thereof corresponding substantially to a first component from said TV signal; second means for combining said TV signal and delayed TV signal from said delay means to produce the difference thereof corresponding substantially to a second component from said TV signal; filter means having an input terminal coupled to said second means, and having an output terminal, said filter means having a transfer characteristic for substantially rejecting said second component of said TV signal; and third means for combining the first component of signal with filtered signal from the output terminal of said filter means to correct the first component of signal for errors therein due to interimage motion.
Claim 2
Dependent Claim 148 words
A comb filter for processing TV signals comprising: a delay means for delaying said TV signal by one image period; first means for combining said TV signal and delayed TV signal from said delay means to produce the sum thereof corresponding substantially to a first component from said TV signal; second means for combining said TV signal and delayed TV signal from said delay means to produce the difference thereof corresponding substantially to a second component from said TV signal; filter means having an input terminal coupled to said second means, and having an output terminal, said filter means having a transfer characteristic for substantially rejecting said second component of said TV signal; and third means for combining the first component of signal with filtered signal from the output terminal of said filter means to correct the first component of signal for errors therein due to interimage motion.
Claim 3
Dependent Claim 173 words
A comb filter for processing a composite TV signal including chrominance and luminance components, comprising: a delay means for delaying said TV signal by at least one frame period; first means for combining said TV signal and delayed TV signal from said delay means to produce the sum thereof corresponding substantially to said luminance component from said TV signal; second means for combining said TV signal and delayed TV signal from said delay means to produce the difference thereof corresponding substantially to said chrominance component from said TV signal; a linear phase low pass filter coupled to said second means for applying said chrominance component of the TV signal to an input terminal thereof, and having an output terminal, said low pass filter substantially rejecting the frequency spectrum normally occupied by said chrominance component; and third means for combining the luminance component of signal with the low passed filtered signal at the output terminal of said low pass filter to correct the luminance component of signal for errors therein due to interimage motion.
Claim 4
Dependent Claim 173 words
A comb filter for processing a composite TV signal including chrominance and luminance components, comprising: a delay means for delaying said TV signal by at least one frame period; first means for combining said TV signal and delayed TV signal from said delay means to produce the sum thereof corresponding substantially to said luminance component from said TV signal; second means for combining said TV signal and delayed TV signal from said delay means to produce the difference thereof corresponding substantially to said chrominance component from said TV signal; a linear phase low pass filter coupled to said second means for applying said chrominance component of the TV signal to an input terminal thereof, and having an output terminal, said low pass filter substantially rejecting the frequency spectrum normally occupied by said chrominance component; and third means for combining the luminance component of signal with the low passed filtered signal at the output terminal of said low pass filter to correct the luminance component of signal for errors therein due to interimage motion.
Claim 5
Dependent Claim 17 words
The comb filter set forth in claim 2 wherein the third means comrprises a linear addition circuit.
Claim 6
Dependent Claim 17 words
The comb filter set forth in claim 2 wherein the third means comprises a linear subtraction circuit.
Claim 7
Independent Claim 108 words
A method of comb filtering TV signals to separate chrominance and luminance components thereof comprising: delaying the TV signal by the duration of one frame of information; subtractively combining delayed and non-delayed TV signal to produce a comb filtered chrominance component; additively combining delayed and non-delayed TV signal to produce a comb filtered luminance signal; low pass filtering the combed chrominance component with a linear phase filter to substantially eliminate the chrominance signal therefrom; and combining the low pass filtered combed chrominance signal with the combed luminance signal during periods of interframe motion to produce a combed luminance signal substantially free of distortion due to interframe scene motion.
Claim 8
Independent Claim 108 words
A method of comb filtering TV signals to separate chrominance and luminance components thereof comprising: delaying the TV signal by the duration of one frame of information; subtractively combining delayed and non-delayed TV signal to produce a comb filtered chrominance component; additively combining delayed and non-delayed TV signal to produce a comb filtered luminance signal; low pass filtering the combed chrominance component with a linear phase filter to substantially eliminate the chrominance signal therefrom; and combining the low pass filtered combed chrominance signal with the combed luminance signal during periods of interframe motion to produce a combed luminance signal substantially free of distortion due to interframe scene motion.

References Cited (Backward Citations)

US4232330A Cited
US4241363A Cited
US4296436A Cited
DE3007520A1 Cited
GB2078054A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-02-05 1988-08-06 1989-02-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-02-05 1992-08-06 1993-02-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-02-05 1996-08-06 1997-02-05 $7700.00 Window Closed / Lapsed

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