US4480267A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Line standard conversion circuit
Assignee: US Philips Corp
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Filing: 1982-09-13
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Granted: 1984-10-30
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Expires: 2002-09-13
Abstract
Abstract The use of a field interpolation circuit which interpolates by means of equal amplitudes of the information from two successive fields results in a television line standard doubler capable of furnishing a very good picture quality.
Inventors
- 👤 Pieter M. Van Den Avoort
- 👤 Marinus C. W. van Buul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:06
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/01; H04N7/0135
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
242 words
A line standard conversion circuit for converting an interlaced television signal having a given number of lines per picture into a converted television signal having substantially double the number of lines per picture while maintaining the field frequency, said conversion circuit having a converter and a field interpolation circuit coupled to the converter for obtaining practically equal amplitudes of the information from each of two successive fields of the television signal to be converted into each of the lines of the converted television signal, wherein said field interpolation circuit includes a line averaging circuit which comprises a circuit for combining the sum of the amplitudes of the information from consecutive lines in one field with the sum of the amplitudes of the information from consecutive lines in a successive field which lines would interlace with said lines from said one field, the summed amplitude of the information from said one field being substantially equal to the summed amplitude of the information from said successive field, wherein the amplitude values of the signals of different lines in a first field are made to contribute to the sum in a first fixed ratio while the amplitude values of the signals of different lines in a second field are made to contribute to the sum in a second and different fixed ratio, the sum of the coefficients in said first fixed ratio being equal to the sum of the coefficients in said second fixed ratio.
Claim 2
Dependent Claim
242 words
A line standard conversion circuit for converting an interlaced television signal having a given number of lines per picture into a converted television signal having substantially double the number of lines per picture while maintaining the field frequency, said conversion circuit having a converter and a field interpolation circuit coupled to the converter for obtaining practically equal amplitudes of the information from each of two successive fields of the television signal to be converted into each of the lines of the converted television signal, wherein said field interpolation circuit includes a line averaging circuit which comprises a circuit for combining the sum of the amplitudes of the information from consecutive lines in one field with the sum of the amplitudes of the information from consecutive lines in a successive field which lines would interlace with said lines from said one field, the summed amplitude of the information from said one field being substantially equal to the summed amplitude of the information from said successive field, wherein the amplitude values of the signals of different lines in a first field are made to contribute to the sum in a first fixed ratio while the amplitude values of the signals of different lines in a second field are made to contribute to the sum in a second and different fixed ratio, the sum of the coefficients in said first fixed ratio being equal to the sum of the coefficients in said second fixed ratio.
Claim 3
Dependent Claim
95 words
A line standard conversion circuit as claimed in claim 1 wherein in a first field period, a first, third and fifth line from said first field contribute in said first fixed ratio and a second and fourth line of said second field contribute in said second fixed ratio and wherein in a next field period, a first, third and fifth line of the second field contribute in a reverse sequence of the first fixed ratio while a second and fourth line of a third field contribute in a reverse sequence of the second fixed ratio.
Claim 4
Dependent Claim
24 words
A line standard conversion circuit as claimed in claim 2, wherein said first fixed ratio is (-1):(12):(-3) and said second fixed ratio is (0):(8).
Claim 5
Dependent Claim
76 words
A line standard conversion circuit as claimed in claims 2 or 3 wherein said field interpolation circuit further comprises a field delay circuit, a line delay circuit and a combining circuit, an output and an input of the field delay circuit along with an output of the line delay circuit each being coupled to an input of the combining circuit, an output of the combining circuit being coupled to an input of the line averaging circuit.
References Cited (Backward Citations)
GB1019811A
Cited
GB1326386A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-30 | 1988-04-30 | 1988-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-30 | 1992-04-30 | 1992-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-30 | 1996-04-30 | 1996-10-30 | $7700.00 | Window Closed / Lapsed |