US4605954A
Expired / Lapsed
US
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Method of and arrangement for adjusting color saturation in a video printer
Assignee: Agfa Gevaert AG
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Filing: 1984-04-30
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Granted: 1986-08-12
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Expires: 2004-04-30
Abstract
Abstract An image to be printed in a CRT or video color printer is sensed to generate red, blue and green signals respectively representing a characteristic of the image in red, blue and green. The signals are processed in a matrix circuit to generate a luminance signal. The red and blue signals are subtracted from the luminance signal in operational amplifiers to obtain unadjusted difference signals. Each of the unadjusted difference signals is multiplied by an adjusting factor which is established using variable resistors and functions to provide level adjustment. The adjusted difference signals obtained in this manner are subtracted from the luminnce signal in respective operational amplifiers to yield modified red and blue signals. The modified red and blue signals are processed together with the luminanace signal in a second matrix circuit to generate a modified green signal. Control of color saturation may be achieved simply and inexpensively by adjusting the variable resistors and thereby changing the adjusting factor which determines color saturation.
Inventors
- 👤 Friedrich Bestenreiner
- 👤 Immo Boie
- 👤 Josef Helmberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:34
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6027; H04N9/00; H04N9/64; H04N9/68
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
148 words
A method of adjusting color saturation in a color printer, particularly a video printer, comprising the steps of: (a) generating a luminance signal for an image to be printed by processing a first blue signal representing a characteristic of the image in blue together with a first red signal and a first green signal respectively representing the characteristic in red and green; (b) forming a pair of unadjusted difference signals by subtraction of said luminance signal and two selected ones of said first signals; (c) adjusting each of said unadjusted difference signals to obtain a pair of adjusted difference signals; (d) deriving a pair of modified signals for the two colors corresponding to said selected signals by subtraction of said luminance signal and said adjusted difference signals; and (e) calculating a modified signal for the third color by combining said luminance signal with said pair of modified signals.
Claim 2
Independent Claim
148 words
A method of adjusting color saturation in a color printer, particularly a video printer, comprising the steps of: (a) generating a luminance signal for an image to be printed by processing a first blue signal representing a characteristic of the image in blue together with a first red signal and a first green signal respectively representing the characteristic in red and green; (b) forming a pair of unadjusted difference signals by subtraction of said luminance signal and two selected ones of said first signals; (c) adjusting each of said unadjusted difference signals to obtain a pair of adjusted difference signals; (d) deriving a pair of modified signals for the two colors corresponding to said selected signals by subtraction of said luminance signal and said adjusted difference signals; and (e) calculating a modified signal for the third color by combining said luminance signal with said pair of modified signals.
Claim 3
Dependent Claim
11 words
The method of claim 1, wherein said third color is green.
Claim 4
Dependent Claim
15 words
The method of claim 1, wherein the generating step is performed by a matrix circuit.
Claim 5
Dependent Claim
15 words
The method of claim 1, wherein the calculating step is performed by a matrix circuit.
Claim 6
Dependent Claim
21 words
The method of claim 1, wherein the adjusting step comprises multiplying each of said unadjusted difference signals by an adjusting factor.
Claim 7
Dependent Claim
19 words
The method of claim 5, wherein both of said unadjusted difference signals are multiplied by the same adjusting factor.
Claim 8
Dependent Claim
28 words
The method of claim 5, wherein the adjusting factor for both of said unadjusted difference signals is 1/k where k is greater than 0 and less than 1.
Claim 9
Dependent Claim
245 words
An arrangement for adjusting color saturation in a color printer, particularly a video printer, comprising: (a) conductor means for the transmission of a first blue signal representing a characteristic of an image to be printed in blue, a first red signal representing the characteristic in red and a first green signal representing the characteristic in green; (b) first calculating means arranged to receive the first signals and to generate a luminance signal therefrom; (c) subtracting and adjusting means arranged to receive the luminance signal and two selected ones of the first signals, said subtracting and adjusting means being designed to form a pair of unadjusted difference signals by subtraction of the luminance signal and the selected first signals, and said subtracting and adjusting means also being designed to adjust each of the unadjusted difference signals so as to generate a pair of adjusted difference signals; (d) subtracting means arranged to receive the luminance signal and the adjusted difference signals, said subtracting means being designed to generate a pair of modified signals for the two colors corresponding to the selected first signals by subtraction of the luminance signal and the adjusted difference signals; and (e) second calculating means arranged to receive the luminance signal and the modified signals for the two colors corresponding to the selected first signals, said second calculating means being designed to derive a modified signal for the third color from the luminance signal and the modified signals generated by said subtracting means.
Claim 10
Dependent Claim
245 words
An arrangement for adjusting color saturation in a color printer, particularly a video printer, comprising: (a) conductor means for the transmission of a first blue signal representing a characteristic of an image to be printed in blue, a first red signal representing the characteristic in red and a first green signal representing the characteristic in green; (b) first calculating means arranged to receive the first signals and to generate a luminance signal therefrom; (c) subtracting and adjusting means arranged to receive the luminance signal and two selected ones of the first signals, said subtracting and adjusting means being designed to form a pair of unadjusted difference signals by subtraction of the luminance signal and the selected first signals, and said subtracting and adjusting means also being designed to adjust each of the unadjusted difference signals so as to generate a pair of adjusted difference signals; (d) subtracting means arranged to receive the luminance signal and the adjusted difference signals, said subtracting means being designed to generate a pair of modified signals for the two colors corresponding to the selected first signals by subtraction of the luminance signal and the adjusted difference signals; and (e) second calculating means arranged to receive the luminance signal and the modified signals for the two colors corresponding to the selected first signals, said second calculating means being designed to derive a modified signal for the third color from the luminance signal and the modified signals generated by said subtracting means.
Claim 11
Dependent Claim
22 words
The arrangement of claim 8, wherein said subtracting and adjusting means is arranged to receive the first blue and first red signals.
Claim 12
Dependent Claim
14 words
The arrangement of claim 8, wherein said first calculating means comprises a matrix circuit.
Claim 13
Dependent Claim
14 words
The arrangement of claim 8, wherein said second calculating means comprises a matrix circuit.
Claim 14
Dependent Claim
25 words
The arrangement of claim 8, wherein said subtracting and adjusting means is designed to multiply each of the unadjusted difference signals by an adjusting factor.
Claim 15
Dependent Claim
26 words
The arrangement of claim 12, wherein said subtracting and adjusting means is designed to multiply each of the unadjusted difference signals by the same adjusting factor.
Claim 16
Dependent Claim
36 words
The arrangement of claim 12, wherein said subtracting and adjusting means is designed to multiply each of the unadjusted difference signals by an adjusting factor 1/k where k is greater than 0 and less than 1.
Claim 17
Dependent Claim
15 words
The arrangement of claim 12, wherein said subtracting and adjusting means comprises operational amplifier means.
Claim 18
Dependent Claim
34 words
The arrangement of claim 15, wherein said subtracting and adjusting means comprises adjustable resistor means for varying the adjusting factor, said resistor means including at least one feedback resistor for said operational amplifier means.
Claim 19
Dependent Claim
31 words
The arrangement of claim 16, wherein said subtracting and adjusting means comprises voltage divider means, said resistor means including at least one resistor which constitutes part of said voltage divider means.
Claim 20
Dependent Claim
15 words
The arrangement of claim 12, wherein said subtracting and adjusting means comprises voltage divider means.
Claim 21
Dependent Claim
36 words
The arrangement of claim 18, wherein said subtracting and adjusting means comprises adjustable resistor means for varying the adjusting factor, said resistor means including at least one resistor which constitutes part of said voltage divider means.
Claim 22
Dependent Claim
20 words
The arrangement of claim 12, wherein said subtracting and adjusting means comprises adjustable resistor means for varying the adjusting factor.
Claim 23
Dependent Claim
57 words
The arrangement of claim 12, comprising a pair of signal-transmitting channels for the two colors corresponding to the selected first signals, each of said channels comprising a conductor constituting part of said conductor means, a subtracting and adjusting unit constituting part of said subtracting and adjusting means, and a subtracting unit constituting part of said subtracting means.
Claim 24
Dependent Claim
32 words
The arrangement of claim 21, wherein each of said subtracting and adjusting units comprises an adjustable resistor for varying the adjusting factor; and further comprising a common adjusting device for said resistors.
References Cited (Backward Citations)
US4418358A
Cited
US4556900A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-08-11 | 1990-02-10 | 1990-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-11 | 1994-02-10 | 1994-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-11 | 1998-02-10 | 1998-08-12 | $7700.00 | Window Closed / Lapsed |