US3751581A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color television standard system converting equipment
Assignee: Japan Broadcasting Corp
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Filing: 1971-10-18
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Granted: 1973-08-07
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Expires: 1991-10-18
Abstract
Abstract A system for converting color television signals from one standard system having a certain number of scanning lines and fields to a second standard system having a different number scanning lines and of fields, comprising the steps in a sequence of; line interpolation, line length compensation, line number conversion, field setting, field number conversion, time error compensation, interlace interpolation and field interpolation or in a sequence reverse thereto while using the SECAM type signal. Most of the equipment used in each of the above steps are so constructed that the SECAM type composite color signal may be processed without modifying the signal in order to simplify the system. The respective equipment comprises delay lines as the main constructive elements to stabilize the operation. In order to effectively utilize the delay element the desired interpolated signal is formed in the frequency domain by a combining means by using a frequency modulated signal, and by means of the same the discontinuity of the picture which will be or has been accompanied with the conversion of the number of lines or number of fields is compensated.
Inventors
- 👤 H Sakata
- 👤 H Tanimura
- 👤 R Kaneko
- 👤 T Kubo
- 👤 H Kusaka
- 👤 E Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:14
CPC Classifications
H; H04; H04N; H04N11/00; H04N11/06; H04N11/20; H04N11/22
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
590 words
A color television standard system converting equipment comprising a line interpolator, a line length difference compensator, a line converter, a field setter, a field converter and a field interpolator arranged in the above-mentioned sequence or reverse thereto between at least two sets of terminaLs, wherein; a. the line interpolator comprises a luminance-chrominance separator for separating a luminance signal and an FM color difference signal from a SECAM type input first color television signal, a frequency modulator for modulating the luminance signal derived from said luminance-chrominance separator to obtain an FM signal in a frequency band suitable to transmit it through delay lines with desired transmission efficiency, a luminance line interpolator for making weighted addition at a desired ratio in the frequency domain between co-related two adjacent lines of the FM luminance signal obtained from said frequency modulator so as to obtain an interpolated luminance signal, a chrominance line interpolator for making weighted addition at a desired ratio in the frequency domain between two adjacent lines of the FM color difference signal of the same kind of color so as to obtain an interpolated chrominance signal, and a frequency adder for making frequency addition of the derived output signals from both interpolators to form an FM-SECAM type signal suitably transmitted through delay lines with high efficiency; b. the line length difference compensator comprises a plurality of delay lines and is so arranged as to switch delay time with at least a delay time pitch corresponding to the difference between the line length (H'') of the input first color television signal which is to be converted and the line length (H) of an output second color television signal; c. the line converter comprises a plurality of delay lines each having a minimum delay unit having an amount of delay corresponding to H''+5(H''-H), wherein H'' is the line period of the first color television signal and H is the line period of the second color television signal, and a switching circuit to switch the delay lines to obtain a desired delay time in a pitch of the minimum delay time by combining the delay lines in a various manner; d. the field setter comprises at least a H/2 delay line and a switcher for the setting field of in input signal to the field converter so as to obtain an interlaced scanning in the output signal from the field converter; e. the field converter comprises a plurality of cascade connected delay lines having delay time corresponding to the difference between the field period of the incoming first color television signal and that of the desired second color television signal, and is so constructed as to vary the delay time corresponding to the field period of the second color television signal with pitches each corresponding to said difference between both field periods; f. the field interpolator comprises delay means to alternately provide delay times corresponding to 1F + OR - H/2, wherein F is a field period of the second color television signal; a luminance field interpolator for making weighted addition at the desired weight ratio of a delayed signal from the delay means and a non-delayed signal, a chrominance field interpolator for making weighted addition at the desired ratio of said delayed signal and non-delayed signal after the FM color difference signals are removed, and an adding circuit including means for demodulating an output signal from the luminance field interpolator to obtain a luminance signal thereafter to add the FM color difference signal thereto to form a SECAM type second color television signal.
Claim 2
Dependent Claim
590 words
A color television standard system converting equipment comprising a line interpolator, a line length difference compensator, a line converter, a field setter, a field converter and a field interpolator arranged in the above-mentioned sequence or reverse thereto between at least two sets of terminaLs, wherein; a. the line interpolator comprises a luminance-chrominance separator for separating a luminance signal and an FM color difference signal from a SECAM type input first color television signal, a frequency modulator for modulating the luminance signal derived from said luminance-chrominance separator to obtain an FM signal in a frequency band suitable to transmit it through delay lines with desired transmission efficiency, a luminance line interpolator for making weighted addition at a desired ratio in the frequency domain between co-related two adjacent lines of the FM luminance signal obtained from said frequency modulator so as to obtain an interpolated luminance signal, a chrominance line interpolator for making weighted addition at a desired ratio in the frequency domain between two adjacent lines of the FM color difference signal of the same kind of color so as to obtain an interpolated chrominance signal, and a frequency adder for making frequency addition of the derived output signals from both interpolators to form an FM-SECAM type signal suitably transmitted through delay lines with high efficiency; b. the line length difference compensator comprises a plurality of delay lines and is so arranged as to switch delay time with at least a delay time pitch corresponding to the difference between the line length (H'') of the input first color television signal which is to be converted and the line length (H) of an output second color television signal; c. the line converter comprises a plurality of delay lines each having a minimum delay unit having an amount of delay corresponding to H''+5(H''-H), wherein H'' is the line period of the first color television signal and H is the line period of the second color television signal, and a switching circuit to switch the delay lines to obtain a desired delay time in a pitch of the minimum delay time by combining the delay lines in a various manner; d. the field setter comprises at least a H/2 delay line and a switcher for the setting field of in input signal to the field converter so as to obtain an interlaced scanning in the output signal from the field converter; e. the field converter comprises a plurality of cascade connected delay lines having delay time corresponding to the difference between the field period of the incoming first color television signal and that of the desired second color television signal, and is so constructed as to vary the delay time corresponding to the field period of the second color television signal with pitches each corresponding to said difference between both field periods; f. the field interpolator comprises delay means to alternately provide delay times corresponding to 1F + OR - H/2, wherein F is a field period of the second color television signal; a luminance field interpolator for making weighted addition at the desired weight ratio of a delayed signal from the delay means and a non-delayed signal, a chrominance field interpolator for making weighted addition at the desired ratio of said delayed signal and non-delayed signal after the FM color difference signals are removed, and an adding circuit including means for demodulating an output signal from the luminance field interpolator to obtain a luminance signal thereafter to add the FM color difference signal thereto to form a SECAM type second color television signal.
Claim 3
Dependent Claim
393 words
A color television standard system converting equipment as claimed in claim 1, said converting equipment being suitable for converting a first color television standard system having a larger number of horizontal scanning lines into a second color television standard system having a smaller number of horizontal scanning lines, said converting equipment further comprising a time error compensator included between said field converter and said field interpolator and an interlace interpolator connected between said time error compensator and said field interpolator, wherein said time error compensator comprises a digital type variable delay circuit comprising a first tapped variable delay circuit having a long delay time for deriving separately two delayed signals having delay times of O - NT (where N is positive integer) at a step of a long delay time T, two sets of tapped variable delay circuit having a fine delay time for deriving separately two delayed signals by delaying said two delayed signals derived from said first tapped variable delay circuit by delay times of O - nt (wherein n is positive integer) at a step of a fine delay time t and a switcher for deriving either one of said delayed signals derived from said two sets of tapped variable delay circuits; and wherein said interlace interpolator comprises an FM demodulator for demodulating in input FM signal applied thereto, a luminance-chrominance separator for deriving separately a luminance signal and FM color difference signals from said demodulated signal, a luminance signal interlace interpolator for deriving a signal by adding with weighting at a suitable ratio two adjacent lines in a frequency domain, after converting the luminance signal from said luminance-chrominance separator into an FM signal having a frequency band suitable for transmission through delay lines, said weight addition signal and non-weight addition signal being derived alternately at a desired rate, a chrominance signal interlace interpolator for deriving alternately a weight addition signal and non-weight addition FM color difference signals at a desired rate, said weight addition signal being derived by adding with weighting at a given ratio two adjacent lines of the same kind of the FM color difference signals supplied from said luminance-chrominance separator, and a frequency adder for adding in a frequency domain output signals from said both interlace interpolators so as to convert them into an FM signal having a frequency band suitable for transmission through delay lines.
Claim 4
Dependent Claim
130 words
A color television standard system converting equipment as claimed in claim 2, wherein said luminance signal interlace interpolator is so composed that two FM luminance signals are added in a frequency domain after the frequency of said two FM luminance signals are stepped down by 2 so as to obtain a weight addition signal having a weighting ratio of 0.5/0.5, and said chrominance signal interlace interpolator is so composed that a weight addition signal having a weighting ratio of 0.25/0.75 is obtained by adding two FM color difference signals in a frequency domain, stepping down the frequency of the resulted addition signal by 2, adding the resulting signal with one of said two FM color difference signals and then stepping down the frequency of the signal thus obtained by two.
Claim 5
Dependent Claim
268 words
A color television standard system converting equipment as claimed in claim 3, wherein said luminance signal line interpolator of said line interpolator and said luminance signal field interpolator of said field interpolator are so composed that weight addition signals having weighted ratios of 1/0, 0.75/0.25, 0.5/0.5, 0.25/0.75 and 0/1 are obtained by selectively deriving by means of a selecting switcher first and second FM signals, a third FM signal obtained by adding said first and second FM signals after the frequency of these FM signals is stepped down by 2, fourth and fifth FM signals obtained by adding in a frequency domain said third FM signal after its frequency is stepped down by 2 and said first and second FM signals after their frequency is stepped down by 2, said chrominance signal line interpolator and said chrominance signal field interpolator are so composed that weighted addition signals having weighting ratios of 1/0, 0.75/0.25, 0.5/0.5, 0.25/0.75 and 0/1 of first and second FM chrominance sigNals to be added are obtained selectively by selectively deriving by means of a selecting switcher said first and second FM color difference signals, a third FM color difference signal obtained by adding in a frequency domain said first and second FM color difference signals and then the frequency of the FM signal thus added being stepped down by 2, fourth and fifth FM color difference signals obtained by adding in a frequency domain said third FM color difference signal and said first and second FM color difference signals, respectively and then the frequency of thus added FM color signals being stepped down by 2.
Claim 6
Dependent Claim
135 words
A color television standard system converting equipment as claimed in claim 3, wherein said line length difference compensator comprises a plurality of delay lines having delay times equal to 0.5 Delta , 1 Delta , 2 Delta , 4 Delta , 8 Delta and 16 Delta , wherein Delta is equal to a difference in a horizontal scanning line length between the input first color television signal to be converted and the output second color television signal, these delay lines being connected in cascade with desired combination so as to decrease a composite delay time successively in such a manner that each input line signal applied to said line length difference compensator arrives at an output terminal thereof at a timing faster than a former input line signal by an amount of 0.5 Delta .
Claim 7
Dependent Claim
219 words
A color television standard system converting equipment as claimed in claim 2 for converting a first color television standard system of 625 lines per frame and 50 fields per second into a second color television standard system of 525 lines per frame and 60 fields per second, wherein said line converter comprises a plurality of delay lines having delay times equal to (H''+5 Delta ), 2(H''+5 Delta ), 3(H''+5 Delta ), 6(H''+5 Delta ), 10(H''+5 Delta ), 20(H''+5 Delta ) and 34(H''+5 Delta ), wherein H'' is a horizontal scanning line period of the input first color television signal and Delta is a line length difference between the first and second color television signals, these delay lines being connected into circuit in cascade with desired combination so that a delay time is reduced successively from 50H''+250 Delta to 0 Delta at a step of 1H''+5 Delta so as to decrease a composite delay time successively in such a manner that each input line signal supplied to said line converter arrives at the output terminal thereof at a timing faster than a former input line signal by an amount of H''+5 Delta and the output signal being composed of a 50H''+262.5 Delta blank period and 262.5 lines each having 1H for each field period of the first color television signal.
Claim 8
Dependent Claim
81 words
A color television standard system converting equipment as claimed in claim 6, said field converter comprising five delay lines each having a delay time equal to 50H''+262.5 Delta , these five delay lines being so connected that delay times of from 0 to 5(50H''+262.5 Delta ) are obtained at a step of 50H''+262.5 Delta , the same field signal being derived twice with non-delay and 5(50H''+262.5 Delta ) delay so as to convert each successive five fields into six successive fields.
Claim 9
Dependent Claim
36 words
A color television standard system converting equipment as claimed in claim 1, said converting equipment further comprising a plurality of co-operated switchers, wherein by driving these switchers, the coupling sequence of a constructive element is severed.
Claim 10
Dependent Claim
68 words
A color television standard system converting equipment as claimed in claim 8, wherein said field interpolator comprises an FM modulator and the input color television signal to be converted is applied to said FM modulator and is converted intO an FM signal having a frequency band suitable for transmission through delay lines and then being further supplied through delay means, a luminance field interpolator and an FM modulator.
Claim 11
Dependent Claim
169 words
A color television standard system converting equipment as claimed in claim 9, wherein said switchers are so composed that a time error compensator is inserted between said line length difference compensator and the line interpolator in response to the switching operation of said switcher, wherein said time error compensator comprises a digital type variable delay circuit comprising a first tapped variable delay circuit having a long delay time for deriving separately two delayed signals having delay times of 0 D NT (where N is positive integer) at a step of a long delay time T, two sets of tapped variable delay circuits having a fine delay time for deriving separately two delayed signals by delaying said two delayed signals derived from said first tapped variable delay circuit by delay times of 0 D nt (wherein n is positive integer) at a step of a fine delay time t and a switcher for deriving either one of said delayed signals derived from said two sets of tapped variable delay circuits.
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) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |