US3610816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods for converting color television standards
Assignee: Robert Bosch Fernsehanlagen GmbH
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Filing: 1969-07-28
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Granted: 1971-10-05
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Expires: 1989-07-28
Abstract
Abstract A method for color standard conversion for color television, in which the color television signal to be converted is separated into luminance and chrominance components. The chrominance component from the separating step is converted in an auxiliary chrominance signal of lower carrier frequency. The lower carrier frequency signal is an integral multiple of the line frequency of the color television signal to be converted. The auxiliary chrominance signal is reproduced on the screen of a black-white picture tube which is then scanned corresponding to the synchronizing standard to which the television signal is to be converted. The signal resulting from this scanning step is then converted to a chrominance signal having the color carrier frequency of the new standard, and this converted chrominance signal is then combined with the luminance signal which has been converted to conform to the new standard.
Inventors
- 👤 Fritz Jaeschke
- 👤 Hartmut Wendt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:27
CPC Classifications
H; H04; H04N; H04N11/00; H04N11/06; H04N11/20
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
161 words
A method for color standard conversion in color television for convertIng from a first standard having a color carrier to a second standard, comprising the steps of separating the color television signal to be converted into luminance and chrominance components; mixing the chrominance component from said separating step with a predetermined frequency for generating an auxiliary chrominance signal on a color carrier of which the frequency is an integral multiple of the line frequency of the color television signal to be converted and is lower than the color carrier frequency of the first standard; reproducing said auxiliary chrominance signal on a black-white picture screen; scanning said picture screen corresponding to the synchronizing standard to which said color television signal is to be converted; converting the signal from said scanning step to a chrominance signal of the desired frequency of the second standard; converting the luminance signal to said second standard; and combining said converted chrominance signal with the converted luminance signal.
Claim 2
Independent Claim
161 words
A method for color standard conversion in color television for convertIng from a first standard having a color carrier to a second standard, comprising the steps of separating the color television signal to be converted into luminance and chrominance components; mixing the chrominance component from said separating step with a predetermined frequency for generating an auxiliary chrominance signal on a color carrier of which the frequency is an integral multiple of the line frequency of the color television signal to be converted and is lower than the color carrier frequency of the first standard; reproducing said auxiliary chrominance signal on a black-white picture screen; scanning said picture screen corresponding to the synchronizing standard to which said color television signal is to be converted; converting the signal from said scanning step to a chrominance signal of the desired frequency of the second standard; converting the luminance signal to said second standard; and combining said converted chrominance signal with the converted luminance signal.
Claim 3
Dependent Claim
154 words
The method as defined in claim 1, including the steps of combining said auxiliary chrominance signal with a pilot frequency being a multiple of the horizontal frequency, said pilot frequency lying outside of the frequency band used for said auxiliary chrominance signal; converting said combined pilot frequency and auxiliary chrominance signal in a first black-white standards converter; modifying the frequency of the converted pilot frequency to the frequency of the carrier of the converted auxiliary signal; demodulating said converted auxiliary signal for producing a first color difference signal; shifting the phase of said modified pilot frequency by 90*; demodulating the converted auxiliary signal for producing a second color difference signal, said modified pilot frequency in said demodulating steps being a reference frequency; delaying said luminance signal for time compensating; and processing said time compensated luminance signal together with said color difference signals in an encoder for converting said television signal to said second standard.
Claim 4
Dependent Claim
33 words
The method as defined in claim 2, wherein the pilot frequency signal combined with said auxiliary chrominance signal has a frequency double the frequency of said color carrier of said auxiliary chrominance signal.
Claim 5
Dependent Claim
20 words
The method as defined in claim 3, wherein the frequency of said color carrier is 260 times the horizontal frequency.
Claim 6
Dependent Claim
25 words
The method as defined in claim 4, wherein said luminance signal has a carrier, and said pilot frequency is the carrier of said luminance signal.
Claim 7
Dependent Claim
37 words
The method as defined in claim 1, including the step of controlling a start-stop oscillator with the horizontal frequency of said first standard; and generating said color carrier of the auxiliary chrominance signal through said start-stop oscillator.
Claim 8
Dependent Claim
60 words
The method as defined in claim 6, including the step of regenerating the color carrier of the first standard; mixing the regenerated color carrier with said color carrier of said auxiliary chrominance signal; combining the mixed signal with the chrominance signal of said first standard for producing a difference frequency signal, said difference frequency signal being the auxiliary chrominance signal.
Claim 9
Dependent Claim
36 words
The method as defined in claim 7, including the step of adding to said auxiliary chrominance signal two pilot frequency signals being integral multiples of the frequency of said color carrier of said auxiliary chrominance signal.
Claim 10
Dependent Claim
43 words
The method as defined in claim 8, wherein one pilot frequency is triple the frequency of the color carrier of said auxiliary chrominance signal, and the other pilot frequency is five times the frequency of said color carrier of said auxiliary chrominance signal.
Claim 11
Dependent Claim
56 words
The method as defined in claim 9 including the step of doubling one pilot frequency; mixing the doubled pilot frequency with the other pilot frequency and producing thereby a difference frequency signal; demodulating said auxiliary chrominance signal with said difference frequency signal being the reference carrier for generating the video frequency components of the chrominance signal.
Claim 12
Dependent Claim
77 words
The method as defined in claim 10 including the step of amplitude limiting one of said pilot frequencies with the color carrier of said auxiliary chrominance signal with frequency multiplied by a factor of 3; adding said amplitude limited pilot frequency to said reference carrier; limiting the signal sum resulting from the addition of said reference carrier and said amplitude limited pilot frequency; and filtering said signal sum for producing the reference carrier for said demodulation step.
Claim 13
Dependent Claim
66 words
The method as defined in claim 11, including the step of amplitude limiting one of said pilot frequencies with the frequency of the color carrier of said auxiliary chrominance signal with frequency multiplied by a factor of 5 to thereby produce a second amplitude limited pilot frequency; and adding said second amplitude limited pilot frequency to said reference carrier and the first amplitude limited pilot frequency.
Claim 14
Dependent Claim
31 words
The method as defined in claim 6, wherein said pilot frequency comprises pulse-shaped signals with pulse repetition frequency equal to the frequency of the color carrier of said auxiliary chrominance signal.
Claim 15
Dependent Claim
60 words
The method as defined in claim 13, including the step of compensating the fundamental wave components in said pulse-shaped signals with a signal opposite in phase to said fundamental wave components and with frequency equal to the frequency of the color carrier of said auxiliary chrominance signal, said compensating signal of opposite phase being of predetermined amplitude and phase relationship.
Claim 16
Dependent Claim
28 words
The method as defined in claim 13, wherein the waveform of said pulse-shaped signal comprises two adjacently connected spike-shaped pulses situated in opposite directions and being double pulses.
Claim 17
Dependent Claim
23 words
The method as defined in claim 15, wherein the duration of said pulse-shaped signals is within the range of 100 to 400 nsec.
Claim 18
Dependent Claim
118 words
The method as defined in claim 15, including the step of delaying said auxiliary chrominance signal; adding the delayed chrominance signal with the undelayed chrominance signal; delaying the television signal by half the delay; subtracting the delayed television signal from the sum of said delayed and undelayed chrominance signals to produce a difference signal; exciting an oscillating circuit with the frequency of the color carrier of said auxiliary chrominance signal through the pulse-shaped signal in said difference signal; adding said pulse-shaped signal in said difference signal to the color carrier of said auxiliary chrominance signal to form a combined signal; and synchronizing a synchronizable oscillator for producing the reference carrier for the demodulation of said auxiliary chrominance signal.
Claim 19
Dependent Claim
15 words
The method as defined in claim 17, wherein said synchronizable oscillator comprises a blocking oscillator.
References Cited (Backward Citations)
US3475549A
Cited
US3475548A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-04 | 1975-04-05 | 1975-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-04 | 1979-04-05 | 1979-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-04 | 1983-04-05 | 1983-10-05 | $7700.00 | Window Closed / Lapsed |