Patent US5070398A successfully refreshed from Google Patents.
US5070398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contour compensator for carrier chrominance signal
Assignee: Mitsubishi Electric Corp
•
Filing: 1991-04-19
•
Granted: 1991-12-03
•
Expires: 2011-04-19
Abstract
Abstract A contour compensator according to the present invention contour-enhances first and second demodulated signals, which are obtained by temporarily demodulating a carrier chrominance signal by first and second demodulators, instead of directly contour-enhancing the carrier chrominance signal itself since contour enhancement of the carrier chrominance signal itself is difficult. The first and second demodulated signals are low-frequency components and have only amplitude information, and hence contour enhancement thereof is relatively easy. Thereafter the contour-enhanced first and second demodulated signals are modulated by first and second modulators under the same condition as that in demodulation and composed by an adder, thereby to generate a contour-enhanced carrier chrominance signal. Thus, the newly generated carrier chrominance signal is reliably contour-enhanced, with no hue change or saturation change.
Inventors
- 👤 Junji Suzuki
- 👤 Tsutomu Kawano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:54
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/646; H04N9/79; H04N9/793
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
289 words
A contour compensator for a carrier chrominance signal for generating a second carrier chrominance signal by contour-enhancing a first carrier chrominance signal, said contour compensator comprising: reference subcarrier generating means for generating a first reference subcarrier and a second reference subcarrier being out of phase with said first reference subcarrier by an angle other than 90° and 180°; carrier chrominance signal generating means for generating said first carrier chrominance signal; a first demodulator connected to said reference subcarrier generating means and said carrier chrominance signal generating means for demodulating said first carrier chrominance signal through said first reference subcarrier to output a first demodulated signal; a second demodulator connected to said reference subcarrier generating means and said carrier chrominance signal generating means for demodulating said first carrier chrominance signal through said second reference subcarrier to output a second demodulated signal; a first contour enhancer connected to said first demodulator for detecting abrupt waveform portions of said first demodulated signal and enhancing abruptness thereof, thereby to output a first contour-enhanced signal; a second contour enhancer connected to said second demodulator for detecting abrupt waveform portions of said second demodulated signal and enhancing abruptness thereof, thereby to output a second contour-enhanced signal; a first modulator connected to said reference subcarrier generating means and said first contour enhancer for modulating said first reference subcarrier through said first contour-enhanced signal to output a first modulated signal; a second modulator connected to said reference subcarrier generating means and said second contour enhancer for modulating said second reference subcarrier through said second contour-enhanced signal to output a second modulated signal; and an adder connected to said first and second modulators for composing said first and second modulated signals to generate said second carrier chrominance signal.
Claim 2
Dependent Claim
289 words
A contour compensator for a carrier chrominance signal for generating a second carrier chrominance signal by contour-enhancing a first carrier chrominance signal, said contour compensator comprising: reference subcarrier generating means for generating a first reference subcarrier and a second reference subcarrier being out of phase with said first reference subcarrier by an angle other than 90° and 180°; carrier chrominance signal generating means for generating said first carrier chrominance signal; a first demodulator connected to said reference subcarrier generating means and said carrier chrominance signal generating means for demodulating said first carrier chrominance signal through said first reference subcarrier to output a first demodulated signal; a second demodulator connected to said reference subcarrier generating means and said carrier chrominance signal generating means for demodulating said first carrier chrominance signal through said second reference subcarrier to output a second demodulated signal; a first contour enhancer connected to said first demodulator for detecting abrupt waveform portions of said first demodulated signal and enhancing abruptness thereof, thereby to output a first contour-enhanced signal; a second contour enhancer connected to said second demodulator for detecting abrupt waveform portions of said second demodulated signal and enhancing abruptness thereof, thereby to output a second contour-enhanced signal; a first modulator connected to said reference subcarrier generating means and said first contour enhancer for modulating said first reference subcarrier through said first contour-enhanced signal to output a first modulated signal; a second modulator connected to said reference subcarrier generating means and said second contour enhancer for modulating said second reference subcarrier through said second contour-enhanced signal to output a second modulated signal; and an adder connected to said first and second modulators for composing said first and second modulated signals to generate said second carrier chrominance signal.
Claim 3
Dependent Claim
56 words
A contour compensator for a carrier chrominance signal in accordance with claim 1, wherein said reference subcarrier generating means comprises: a crystal oscillator for generating said first reference subcarrier, and a phase shifter for shifting a phase of said first reference subcarrier by an angle other than 90° and 180°, to output said second reference subcarrier.
Claim 4
Dependent Claim
26 words
A contour compensator for a carrier chrominance signal in accordance with claim 2, wherein said crystal oscillator is shared with said carrier chrominance signal generating means.
Claim 5
Dependent Claim
27 words
A contour compensator for a carrier chrominance signal in accordance with claim 1, wherein said carrier chrominance signal generating means includes a reproduction system of a VTR.
References Cited (Backward Citations)
US2830112A
Cited
GB806391A
Cited
US3711635A
Cited
US3825673A
Cited
GB1507386A
Cited
US4459613A
Cited
DE3136217A1
Cited
DE3239308A1
Cited
DE3241736A1
Cited
JPS61590A
Cited
JPS61589A
Cited
JPS61274490A
Cited
JPS63292777A
Cited
US4918528A
Cited
DE3829965A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-02 | 1995-06-03 | 1995-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-02 | 1999-06-03 | 1999-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-02 | 2003-06-03 | 2003-12-03 | $7700.00 | Window Closed / Lapsed |