Patent US3889288A successfully refreshed from Google Patents.
US3889288A
Expired / Lapsed
US
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Symmetrically encoded line sequential color signals
Assignee: Zenith Electronics LLC
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Filing: 1973-02-28
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Granted: 1975-06-10
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Expires: 1993-02-28
Abstract
Abstract An encoding and decoding system for color television signals wherein three color-difference signals representative of the color of a scene and a luminance signal representative of the brightness of the scene are symmetrically encoded as three-line sequential signals with relative amplitudes such that when the three sequential signals are matrixed in equal proportions a luminance signal is formed representative of the average luminance level of the picture over the preceding three lines. The symmetrical encoding of the color-difference signals eliminates the need for line identification and phase locking between the encoder and decoder switches, thereby resulting in substantial simplification.
Inventors
- 👤 John L Rennick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:19
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/80; H04N9/86; H04N11/00; H04N11/06; H04N11/20; H04N11/22
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
149 words
A system comprising a source of three primary color television signals said system comprising: encoding means coupled to said source for composing a luminance signal Y representative of the brightness of a scene and three phase and amplitude balanced color-difference signals representative of the chromaticity of the scene, said colordifference signals being equivalent to a resolution of an NTSC signal onto three equally spaced axes; switch means for changing said color-difference signals into three line sequential signals of the form Sa Y+0.877cos phi (R-Y)-0.493sin phi (B-Y), Sb Y+0.877cos(120*+ phi ) (R-Y)-0.493sin(120*+ phi ) (B-Y), Sc Y+0.877cos(240*+ phi ) (R-Y)-0.493sin(240*+ phi ) (B-Y), where phi represents the angle between one of said line sequential signals and the R-Y axis; and means responsive to the output of said switch means for converting the line sequential encoded signals into color-difference signals of a type suitable for application to a color television receiver.
Claim 2
Independent Claim
149 words
A system comprising a source of three primary color television signals said system comprising: encoding means coupled to said source for composing a luminance signal Y representative of the brightness of a scene and three phase and amplitude balanced color-difference signals representative of the chromaticity of the scene, said colordifference signals being equivalent to a resolution of an NTSC signal onto three equally spaced axes; switch means for changing said color-difference signals into three line sequential signals of the form Sa Y+0.877cos phi (R-Y)-0.493sin phi (B-Y), Sb Y+0.877cos(120*+ phi ) (R-Y)-0.493sin(120*+ phi ) (B-Y), Sc Y+0.877cos(240*+ phi ) (R-Y)-0.493sin(240*+ phi ) (B-Y), where phi represents the angle between one of said line sequential signals and the R-Y axis; and means responsive to the output of said switch means for converting the line sequential encoded signals into color-difference signals of a type suitable for application to a color television receiver.
Claim 3
Dependent Claim
11 words
A system as set forth in claim 1 where phi 0.
Claim 4
Independent Claim
103 words
A method of forming a video color signal having a plurality of color-difference signals derived from a plurality of primary color signals each representative of a different color characteristic of a scene and a luminance signal derived from selected portions of said primary color signals, which method comprises encoding said color-difference signals into three line sequential signals each being composed of said luminance signal and one of said color difference signals, each of said color difference signals having the same proportions as would be obtained from three projections of an equivalent NTSC or other chrominance signal upon three axes mutually separated by 120*.
Claim 5
Independent Claim
103 words
A method of forming a video color signal having a plurality of color-difference signals derived from a plurality of primary color signals each representative of a different color characteristic of a scene and a luminance signal derived from selected portions of said primary color signals, which method comprises encoding said color-difference signals into three line sequential signals each being composed of said luminance signal and one of said color difference signals, each of said color difference signals having the same proportions as would be obtained from three projections of an equivalent NTSC or other chrominance signal upon three axes mutually separated by 120*.
Claim 6
Dependent Claim
24 words
The method as set forth in claim 3 wherein one of said three axes is selected to coincide with a primary color-difference signal axis.
Claim 7
Dependent Claim
28 words
The method as set forth in claim 4 wherein said one axis is the R-Y primary color-difference axis and wherein said color difference signals are 0.877(R-Y) -0.438(R-Y)-0.427(B-Y) -0.438(R-Y)+0.427(B-Y).
Claim 8
Independent Claim
182 words
A system comprising a source of encoded color television signals having a luminance signal Y representative of the brightness of a scene and three phase and amplitude balanced color-difference signals representative of the chromaticity of the scene, said color-difference signals being equivalent to a resolution of an NTSC signal onto three equally spaced axes and being encoded in three line sequential signals of the form Sa Y+0.877cos phi (R-Y)-0.493sin phi (B-Y), Sb Y+0.877cos(120*+ phi ) (R-Y)-0.493sin(120*+ phi ) (B-Y), Sc Y+0.877cos(240*+ phi ) (R-Y)-0.493sin(240*+ phi ) (B-Y), where phi represents the angle between one of said line sequential signals and the R-Y axis, said system comprising: means coupled to said source for deriving three colordifference signals free of luminance signal components; decoding switch means coupled to said deriving means for converting said luminance free line-sequential color-difference signals into three simultaneous color-difference signals; and matrix means, including phase shifting means, coupled to said switch means for combining said three simultaneous color-dIfference signals in predetermined relative phases and amplitudes to produce a standard NTSC chrominance signal suitable for application to a color television receiver.
Claim 9
Independent Claim
182 words
A system comprising a source of encoded color television signals having a luminance signal Y representative of the brightness of a scene and three phase and amplitude balanced color-difference signals representative of the chromaticity of the scene, said color-difference signals being equivalent to a resolution of an NTSC signal onto three equally spaced axes and being encoded in three line sequential signals of the form Sa Y+0.877cos phi (R-Y)-0.493sin phi (B-Y), Sb Y+0.877cos(120*+ phi ) (R-Y)-0.493sin(120*+ phi ) (B-Y), Sc Y+0.877cos(240*+ phi ) (R-Y)-0.493sin(240*+ phi ) (B-Y), where phi represents the angle between one of said line sequential signals and the R-Y axis, said system comprising: means coupled to said source for deriving three colordifference signals free of luminance signal components; decoding switch means coupled to said deriving means for converting said luminance free line-sequential color-difference signals into three simultaneous color-difference signals; and matrix means, including phase shifting means, coupled to said switch means for combining said three simultaneous color-dIfference signals in predetermined relative phases and amplitudes to produce a standard NTSC chrominance signal suitable for application to a color television receiver.
Claim 10
Dependent Claim
11 words
A system as set forth in claim 6 where phi 0.
Claim 11
Independent Claim
144 words
A method of forming a video color signal having a plurality of color-difference signals derived from a plurality of primary color signals each representative of a different color characteristic of a scene and a luminance signal derived from selected portions of said primary color signals, which method comprises: matrixing said primary color signals to develop a luminance signal and three phase and amplitude balanced color-difference signals such that each of said color-difference signals is composed with the same proportions as would be obtained from three projections of an equivalent NTSC or other chrominance signal upon three axes mutually separated by 120*; and encoding said color-difference signals into three line sequential signals each consisting of the sum of said luminance signal and one of said color-difference signals, said sequential signals being constituted such that when equal parts thereof are added only said luminance signal remains.
Claim 12
Independent Claim
144 words
A method of forming a video color signal having a plurality of color-difference signals derived from a plurality of primary color signals each representative of a different color characteristic of a scene and a luminance signal derived from selected portions of said primary color signals, which method comprises: matrixing said primary color signals to develop a luminance signal and three phase and amplitude balanced color-difference signals such that each of said color-difference signals is composed with the same proportions as would be obtained from three projections of an equivalent NTSC or other chrominance signal upon three axes mutually separated by 120*; and encoding said color-difference signals into three line sequential signals each consisting of the sum of said luminance signal and one of said color-difference signals, said sequential signals being constituted such that when equal parts thereof are added only said luminance signal remains.
Claim 13
Dependent Claim
24 words
The method as set forth in claim 8 wherein one of said three axes is selected to coincide with a primary color-difference signal axis.
Claim 14
Dependent Claim
27 words
The method as set forth in claim 9 wherein said one axis is the R-Y primary color-difference axis and wherein said sequential signals are Y+0.877(R-Y) Y-0.438(R-Y)-0.427(B-Y) Y-0.438(R-Y)+0.427(B-Y).
Claim 15
Independent Claim
153 words
A system for encoding and decoding color television signals in the form of color-difference signals primarily representative of the chromaticity of a scene, and a luminance signal representative of the brightness of the scene comprising: means cyclically combining said color-difference signals with said luminance signal to form line sequential encoded signals, the color-difference signals of said line sequential encoded signals being encoded with the same proportions and composition as would be obtained from projections of an equivalent NTSC or other chrominance signal upon three axes mutually separated by 120* and bearing a relationship such that when algebraically added in equal proportions only said luminance signal remains; translation means; means applying said line sequential encoded signals to said translation means; delay means coupled to said translation means rendering said line sequential encoded signals simultaneously available; and matrixing means combining equal portions of said simultaneously available line sequential encoded signals to derive said luminance signal.
Claim 16
Independent Claim
153 words
A system for encoding and decoding color television signals in the form of color-difference signals primarily representative of the chromaticity of a scene, and a luminance signal representative of the brightness of the scene comprising: means cyclically combining said color-difference signals with said luminance signal to form line sequential encoded signals, the color-difference signals of said line sequential encoded signals being encoded with the same proportions and composition as would be obtained from projections of an equivalent NTSC or other chrominance signal upon three axes mutually separated by 120* and bearing a relationship such that when algebraically added in equal proportions only said luminance signal remains; translation means; means applying said line sequential encoded signals to said translation means; delay means coupled to said translation means rendering said line sequential encoded signals simultaneously available; and matrixing means combining equal portions of said simultaneously available line sequential encoded signals to derive said luminance signal.
Claim 17
Dependent Claim
21 words
The system of claim 11 wherein one of said three axes is selected to coincide with a primary color-difference signal axis.
Claim 18
Dependent Claim
15 words
The system of claim 12 wherein said primary colordifference signal axis is the R-Y axis.
Claim 19
Dependent Claim
116 words
In a decoder for processing color signals encoded through a switch means as a plurality of line sequential signals each including a luminance signal and a phase and amplitude balanced color-difference signal, said color-difference signals being equivalent to a resolution of an NTSC signal onto three equally spaced axes; decoding switch means, including delay means for rendering said line sequential signals simultaneously available; synchronizing means for maintaining said decoding switch means in the same operating sequence as that of said encoding switch means and matrix means for combining said simultaneously available signals with equal gains and at equally displaced phase angles to produce a standard NTSC chrominance signal suitable for application to a color television receiver.
Claim 20
Dependent Claim
116 words
In a decoder for processing color signals encoded through a switch means as a plurality of line sequential signals each including a luminance signal and a phase and amplitude balanced color-difference signal, said color-difference signals being equivalent to a resolution of an NTSC signal onto three equally spaced axes; decoding switch means, including delay means for rendering said line sequential signals simultaneously available; synchronizing means for maintaining said decoding switch means in the same operating sequence as that of said encoding switch means and matrix means for combining said simultaneously available signals with equal gains and at equally displaced phase angles to produce a standard NTSC chrominance signal suitable for application to a color television receiver.
Claim 21
Dependent Claim
40 words
A decoder as set forth in claim 14 including high pass filter means in parallel with said decoding switch means and said matrix means; and means adding the output of said matrix means to the output of said filter means.
Claim 22
Dependent Claim
42 words
A decoder as set forth in claim 15 including modulation means for producing a carrier modulated with said encoded color signals for application to said decoding switch means; and detector means coupled to said decoding switch means for recovering said luminance signal.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-09 | 1978-12-09 | 1979-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-09 | 1982-12-09 | 1983-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-09 | 1986-12-09 | 1987-06-10 | $7700.00 | Window Closed / Lapsed |