US4511916A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for correcting chrominance signal
Assignee: Canon Inc
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Filing: 1983-03-25
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Granted: 1985-04-16
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Expires: 2003-03-25
Abstract
Abstract A method and a device for correcting a chrominance signal is arranged such that, in obtaining a carrier chrominance signal by modulating a subcarrier with an input chrominance signal, a first hue component which has a phase about plus 90° relative to the phase of the subcarrier of a specific hue component of the input chrominance signal and a second hue component which has a phase about minus 90° relative thereto are taken out; when the first and second hue components are sufficiently small, the carrier chrominance signal is corrected to correct the color of the specific hue component without affecting other colors.
Inventors
- 👤 Ryo Fujimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:28
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/643
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
114 words
A method for correcting a chrominance signal, comprising steps of: (a) obtaining a carrier chrominance signal by modulating a carrier with an input chrominance signal; (b) taking out from said input signal a first hue component which is of a phase differing about plus 90° from the phase of a specific color relative to the carrier and a second hue component which is of a phase differing about minus 90° from the phase of the specific color; (c) determining the magnitudes of said first and second hue components; and (d) correcting said carrier chrominance signal when the magnitudes of said first and second hue components are determined to be less than a prescribed value.
Claim 2
Independent Claim
114 words
A method for correcting a chrominance signal, comprising steps of: (a) obtaining a carrier chrominance signal by modulating a carrier with an input chrominance signal; (b) taking out from said input signal a first hue component which is of a phase differing about plus 90° from the phase of a specific color relative to the carrier and a second hue component which is of a phase differing about minus 90° from the phase of the specific color; (c) determining the magnitudes of said first and second hue components; and (d) correcting said carrier chrominance signal when the magnitudes of said first and second hue components are determined to be less than a prescribed value.
Claim 3
Dependent Claim
37 words
A method according to claim 1, wherein said carrier chrominance signal is corrected when the ratio of said first and second hue components to the phase component of said specific color is less than a prescribed ratio.
Claim 4
Dependent Claim
20 words
A method according to claim 1, wherein the level of said carrier chrominance signal is corrected in said correcting step.
Claim 5
Dependent Claim
12 words
A method according to claim 2, wherein said prescribed ratio is variable.
Claim 6
Dependent Claim
40 words
A method according to claim 2, wherein said carrier chrominance signal is corrected when the magnitude of the phase component of said specific color is at least 5 times as much as those of said first and second hue components.
Claim 7
Dependent Claim
17 words
A method according to claim 3, wherein the correcting degree of said level is variable or alterable.
Claim 8
Independent Claim
138 words
A device for correcting a chrominance signal, comprising: (a) a modulation circuit which is arranged to modulate a carrier with an input chrominance signal to give a carrier chrominance signal thereby; (b) a detection circuit which takes out from said input chrominance signal a phase component of a specific color, a first hue component of phase differing about plus 90° from the phase component of said specific color and a second hue component which is of a phase differing about minus 90° from the phase of said specific color about the said carrier; (c) a comparison circuit which compares and determines the ratio of said first and second hue components to said phase component of said specific color; and (d) a correction circuit which corrects said carrier chrominance signal by means of the output of said comparison circuit.
Claim 9
Independent Claim
138 words
A device for correcting a chrominance signal, comprising: (a) a modulation circuit which is arranged to modulate a carrier with an input chrominance signal to give a carrier chrominance signal thereby; (b) a detection circuit which takes out from said input chrominance signal a phase component of a specific color, a first hue component of phase differing about plus 90° from the phase component of said specific color and a second hue component which is of a phase differing about minus 90° from the phase of said specific color about the said carrier; (c) a comparison circuit which compares and determines the ratio of said first and second hue components to said phase component of said specific color; and (d) a correction circuit which corrects said carrier chrominance signal by means of the output of said comparison circuit.
Claim 10
Dependent Claim
44 words
A device according to claim 7, further including an amplifier circuit which supplies said phase component of the specific color to said comparison circuit by amplifying the phase component at an amplification constant differing from amplification constants for said first and second hue components.
Claim 11
Dependent Claim
39 words
A device according to claim 8, wherein the amplification constant of said amplifier circuit for said first and second hue components is variable or alterable relative to the amplification constant thereof for the phase component of said specific color.
Claim 12
Dependent Claim
44 words
A device according to claim 7, wherein said comparison circuit comprises transistors which are arranged to have the outputs of said phase component of said specific color, said first and second hue components supplied to the bases thereof and to have a common emitter.
References Cited (Backward Citations)
US4296432A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-15 | 1988-10-15 | 1989-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-15 | 1992-10-15 | 1993-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-15 | 1996-10-15 | 1997-04-16 | $7700.00 | Window Closed / Lapsed |