US4543598A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color television systems
Assignee: British Broadcasting Corp
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Filing: 1982-07-07
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Granted: 1985-09-24
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Expires: 2002-07-07
Abstract
Abstract In a color television system the luminance signal is split into high and low frequency components, and the high-frequency luminance components are frequency shifted to above the conventional television bandwidth. A conventional receiver uses the low-frequency luminance components (Y 1 ) and the chrominance component (C), with no cross effects between them. A high-quality receiver can be constructed to recombine the low-frequency and high-frequency luminance components (Y 1 and Y 2 ') giving improved luminance detail, again without cross effects with the chrominance signal. The sound signal (S) is carried between the chrominance and high-frequency luminance. A transmitter (FIG. 4) and receiver (FIG. 5) are described. The system has particular applicability to satellite and cable television.
Inventors
- 👤 Andrew Oliphant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:31
CPC Classifications
H; H04; H04N; H04N11/00; H04N11/06; H04N11/12; H04N11/14; H04N11/16
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
111 words
A colour television encoder, comprising: input means for receiving luminance and chrominance input signals; means for separating out high-frequency luminance components of the luminance signal; means for modulating the chrominance signal onto a subcarrier so that the modulated chrominance components fall in the frequency range of the high-frequency luminance components; and means for frequency shifting the separated high frequency luminance components to above the frequency band of the modulated chrominance components, said frequency shifting means comprising means for multiplying said separated high frequency luminance components by a constant frequency signal to generate sum and difference frequency signals, and means for selecting the sum signal as the frequency-shifted high frequency luminance component.
Claim 2
Dependent Claim
111 words
A colour television encoder, comprising: input means for receiving luminance and chrominance input signals; means for separating out high-frequency luminance components of the luminance signal; means for modulating the chrominance signal onto a subcarrier so that the modulated chrominance components fall in the frequency range of the high-frequency luminance components; and means for frequency shifting the separated high frequency luminance components to above the frequency band of the modulated chrominance components, said frequency shifting means comprising means for multiplying said separated high frequency luminance components by a constant frequency signal to generate sum and difference frequency signals, and means for selecting the sum signal as the frequency-shifted high frequency luminance component.
Claim 3
Dependent Claim
19 words
An encoder according to claim 1, including high-pass filtering means for removing low-frequency components from the modulated chrominance signal.
Claim 4
Dependent Claim
27 words
An encoder according to claim 1, in which the separating means cancels out all high-frequency luminance components from the high-frequency luminance frequency band in the luminance signal.
Claim 5
Dependent Claim
32 words
An encoder according to claim 1, in which the frequency shifting means shifts the high-frequency luminance components by an amount substantially equal to the colour subcarrier frequency or a frequency related thereto.
Claim 6
Dependent Claim
41 words
An encoder according to claim 4, in which said separating means comprises band pass filter means providing a first separated output and subtractor means for subtracting the first separated output from the luminance input signal to provide a second separated output.
Claim 7
Dependent Claim
120 words
A colour television decoder, comprising means for receiving an input signal and for separating out three successive frequency bands of which the first is the lowest and the third is the highest; means for frequency-shifting the signals in the third band into the frequency range of the second band and for combining the resultant with the signal in the first band to produce a luminance signal, said frequency-shifting means comprising means for multiplying the third band by a constant frequency signal of frequency below said third band to generate sum and difference frequency signals, and means for selecting the difference signal as said resultant; and means for demodulating the received signal in the second band to provide a chrominance signal.
Claim 8
Dependent Claim
120 words
A colour television decoder, comprising means for receiving an input signal and for separating out three successive frequency bands of which the first is the lowest and the third is the highest; means for frequency-shifting the signals in the third band into the frequency range of the second band and for combining the resultant with the signal in the first band to produce a luminance signal, said frequency-shifting means comprising means for multiplying the third band by a constant frequency signal of frequency below said third band to generate sum and difference frequency signals, and means for selecting the difference signal as said resultant; and means for demodulating the received signal in the second band to provide a chrominance signal.
Claim 9
Dependent Claim
25 words
A decoder according to claim 6, in which the frequency-shifting means shifts the third signal by an amount substantially equal to the colour subcarrier frequency.
Claim 10
Dependent Claim
61 words
A colour television signal comprising low frequency luminance components in a first frequency band, at least modulated chrominance components in a second frequency band above the low frequency luminance components, and frequency-shifted high-frequency luminance components in a third frequency band above the modulated chrominance components, the highest frequency luminance frequency components being at the high frequency end of the third band.
Claim 11
Dependent Claim
61 words
A colour television signal comprising low frequency luminance components in a first frequency band, at least modulated chrominance components in a second frequency band above the low frequency luminance components, and frequency-shifted high-frequency luminance components in a third frequency band above the modulated chrominance components, the highest frequency luminance frequency components being at the high frequency end of the third band.
Claim 12
Dependent Claim
18 words
A signal according to claim 8, in which the second frequency band contains no high frequency luminance components.
Claim 13
Dependent Claim
123 words
A colour television receiver, comprising means for receiving a colour television signal comprising low frequency luminance components and high frequency luminance components in a frequency band spaced above the low-frequency luminance components; means for frequency shifting high-frequency luminance components in said signal down in frequency such as to be contiguous in frequency with the low frequency luminance components, said frequency shifting means comprising means for multiplying said high frequency components by a constant frequency signal of frequency below the frequency of said high frequency components in said received colour television signal to generate sum and difference signals, and means for selecting the difference signal; and means for recombining said shifted components with the low-frequency luminance components to provide a luminance signal for display.
Claim 14
Dependent Claim
123 words
A colour television receiver, comprising means for receiving a colour television signal comprising low frequency luminance components and high frequency luminance components in a frequency band spaced above the low-frequency luminance components; means for frequency shifting high-frequency luminance components in said signal down in frequency such as to be contiguous in frequency with the low frequency luminance components, said frequency shifting means comprising means for multiplying said high frequency components by a constant frequency signal of frequency below the frequency of said high frequency components in said received colour television signal to generate sum and difference signals, and means for selecting the difference signal; and means for recombining said shifted components with the low-frequency luminance components to provide a luminance signal for display.
Claim 15
Dependent Claim
90 words
A colour television encoder, comprising: input means for receiving luminance and chrominance input signals; means for separating out high-frequency luminance components of the luminance signal; means for modulating the chrominance signal onto a subcarrier so that the modulated chrominance components fall in the frequency range of the high-frequency luminance components; and means for frequency shifting the separated high frequency luminance components to above the frequency band of the modulated chrominance components, said frequency shifting means shifting the high-frequency luminance components by an amount substantially equal to the colour subcarrier frequency.
Claim 16
Dependent Claim
90 words
A colour television encoder, comprising: input means for receiving luminance and chrominance input signals; means for separating out high-frequency luminance components of the luminance signal; means for modulating the chrominance signal onto a subcarrier so that the modulated chrominance components fall in the frequency range of the high-frequency luminance components; and means for frequency shifting the separated high frequency luminance components to above the frequency band of the modulated chrominance components, said frequency shifting means shifting the high-frequency luminance components by an amount substantially equal to the colour subcarrier frequency.
Claim 17
Dependent Claim
19 words
An encoder according to claim 11, including high-pass filtering means for removing low-frequency components from the modulated chrominance signal.
Claim 18
Dependent Claim
27 words
An encoder according to claim 11, in which the separating means cancels out all high-frequency luminance components from the high-frequency luminance frequency band in the luminance signal.
Claim 19
Dependent Claim
99 words
A colour television decoder, comprising: means for receiving an input signal and for separating out three successive frequency bands of which the first is the lowest and the third is the highest; means for frequency-shifting the signals in the third band into the frequency range of the second band and for combining the resultant with the signal in the first band to produce a luminance signal, said frequency-shifting means shifting the third signal by an amount substantially equal to the colour subcarrier frequency; and means for demodulating the received signal in the second band to provide a chrominance signal.
Claim 20
Dependent Claim
99 words
A colour television decoder, comprising: means for receiving an input signal and for separating out three successive frequency bands of which the first is the lowest and the third is the highest; means for frequency-shifting the signals in the third band into the frequency range of the second band and for combining the resultant with the signal in the first band to produce a luminance signal, said frequency-shifting means shifting the third signal by an amount substantially equal to the colour subcarrier frequency; and means for demodulating the received signal in the second band to provide a chrominance signal.
Claim 21
Dependent Claim
56 words
A colour television signal comprising low frequency luminance components in a first frequency band, at least modulated chrominance components in a second frequency band above the low frequency luminance components, and frequency-shifted high-frequency luminance components in a third frequency band shifted above the modulated chrominance components by an amount substantially equal to the chrominance subcarrier frequency.
Claim 22
Dependent Claim
56 words
A colour television signal comprising low frequency luminance components in a first frequency band, at least modulated chrominance components in a second frequency band above the low frequency luminance components, and frequency-shifted high-frequency luminance components in a third frequency band shifted above the modulated chrominance components by an amount substantially equal to the chrominance subcarrier frequency.
Claim 23
Dependent Claim
18 words
A signal according to claim 15, in which the second frequency band contains no high frequency luminance components.
Claim 24
Dependent Claim
87 words
A colour television receiver, comprising: means for receiving a colour television signal comprising low frequency luminance components and high frequency luminance components in a frequency band spaced above the low-frequency luminance components; means for frequency shifting high-frequency luminance components in said signal down in frequency by an amount substantially equal to the chromiunance sub-carrier frequency such as to be contiguous in frequency with the low frequency luminance components; and means for recombining said shifted components with the low-frequency luminance components to provide a luminance signal for display.
Claim 25
Dependent Claim
87 words
A colour television receiver, comprising: means for receiving a colour television signal comprising low frequency luminance components and high frequency luminance components in a frequency band spaced above the low-frequency luminance components; means for frequency shifting high-frequency luminance components in said signal down in frequency by an amount substantially equal to the chromiunance sub-carrier frequency such as to be contiguous in frequency with the low frequency luminance components; and means for recombining said shifted components with the low-frequency luminance components to provide a luminance signal for display.
Claim 26
Dependent Claim
104 words
A colour television encoder, comprising: input means for receiving luminance and chrominance input signals; means for separating out high-frequency luminance components of the luminance signal, said separating means comprising band pass filter means providing a first separated output, and subtractor means for subtracting the first separated output from the luminance input signal to provide a second separated output; means for modulating the chrominance signal onto a subcarrier so that the modulated chrominance components fall in the frequency range of the high-frequency luminance components; and means for frequency shifting the separated high frequency luminance components to above the frequency band of the modulated chrominance components.
Claim 27
Dependent Claim
104 words
A colour television encoder, comprising: input means for receiving luminance and chrominance input signals; means for separating out high-frequency luminance components of the luminance signal, said separating means comprising band pass filter means providing a first separated output, and subtractor means for subtracting the first separated output from the luminance input signal to provide a second separated output; means for modulating the chrominance signal onto a subcarrier so that the modulated chrominance components fall in the frequency range of the high-frequency luminance components; and means for frequency shifting the separated high frequency luminance components to above the frequency band of the modulated chrominance components.
Claim 28
Dependent Claim
19 words
An encoder according to claim 18, including high-pass filtering means for removing low-frequency components from the modulated chrominance signal.
Claim 29
Dependent Claim
32 words
An encoder according to claim 18, in which the frequency shifting means shifts the high-frequency luminance components by an amount substantially equal to the colour subcarrier frequency or a frequency related thereto.
Claim 30
Dependent Claim
150 words
A colour television decoder, comprising: means for receiving an input signal; means coupled to the input means for separating out three successive frequency bands of which the first is the lowest and the third is the highest; means for frequency shifting the signals in the third band into the frequency range of the second band; means for combining the resultant with the signal in the first band to produce a luminance signal, said combining means comprising first and second input terminals, a subtractor having its non-inverting input connected to said first input terminal and its inverting input connected to said input terminal, band-pass filter means connected to the output of said subtractor, and adder means connected to the output of said band-pass filter means and said second input terminal to provide said luminance signal; and means for demodulating the received signal in the second band to provide a chrominance signal.
Claim 31
Dependent Claim
150 words
A colour television decoder, comprising: means for receiving an input signal; means coupled to the input means for separating out three successive frequency bands of which the first is the lowest and the third is the highest; means for frequency shifting the signals in the third band into the frequency range of the second band; means for combining the resultant with the signal in the first band to produce a luminance signal, said combining means comprising first and second input terminals, a subtractor having its non-inverting input connected to said first input terminal and its inverting input connected to said input terminal, band-pass filter means connected to the output of said subtractor, and adder means connected to the output of said band-pass filter means and said second input terminal to provide said luminance signal; and means for demodulating the received signal in the second band to provide a chrominance signal.
Claim 32
Dependent Claim
25 words
A decoder according to claim 21, in which the frequency-shifting means shifts the third signal by an amount substantially equal to the colour subcarrier frequency.
Claim 33
Dependent Claim
139 words
A colour television receiver, comprising: means for receiving a colour television signal comprising low frequency luminance components and high frequency luminance components in a frequency band spaced above the low-frequency luminance components; means for frequency shifting high-frequency luminance components in said signal down in frequence such as to be contiguous in frequency with the low frequency luminance components; and means for recombining said shifted components with the low-frequency luminance components to provide a luminance signal for display, said recombining means comprising first and second input terminals, a subtractor having its non-inverting input connected to said first input terminal and its inverting input connected to said input terminal, band-pass filter means connected to the output of said subtractor and adder means connected to the output of said band-pass filter means and said second input terminal to provide said luminance signal.
Claim 34
Dependent Claim
139 words
A colour television receiver, comprising: means for receiving a colour television signal comprising low frequency luminance components and high frequency luminance components in a frequency band spaced above the low-frequency luminance components; means for frequency shifting high-frequency luminance components in said signal down in frequence such as to be contiguous in frequency with the low frequency luminance components; and means for recombining said shifted components with the low-frequency luminance components to provide a luminance signal for display, said recombining means comprising first and second input terminals, a subtractor having its non-inverting input connected to said first input terminal and its inverting input connected to said input terminal, band-pass filter means connected to the output of said subtractor and adder means connected to the output of said band-pass filter means and said second input terminal to provide said luminance signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-23 | 1989-03-25 | 1989-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-23 | 1993-03-25 | 1993-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-23 | 1997-03-25 | 1997-09-24 | $7700.00 | Window Closed / Lapsed |