US3716670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Comb effect elimination
Assignee: DIGITAL LASER TRANSFORM Ltd
•
Filing: 1971-12-20
•
Granted: 1973-02-13
•
Expires: 1991-12-20
Abstract
Abstract The so-called ''''comb effect'''' in the recording of video pictures on film, caused by the lateral displacement of a moving object against a contrasting background during the time interval between an odd-field scan and the corresponding even-field scan interlaced with the odd-field scan to form a frame of the video picture, is eliminated by comparing each line of the even-field scan (the prime line) with the preceding even-field line and with the preceding odd-field line, and comparing the preceding oddfield line with the following odd-field line. If the comparisons show identity between the pair of even-field lines and between the pair of odd-field lines, but a difference between the prime line and the odd-field line, the circuit substitutes adjacent odd-field information for the prime line information; otherwise the circuit transmits the prime line unchanged. During the oddfield scan, all lines are transmitted without change.
Inventors
- 👤 J Lowry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:30
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/84
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
61 words
A method for eliminating the comb effect in interlaced-scan video pictures recorded on motion picture film, comprising the steps of: a. selecting one of said interlaced scans as the primary-parity scan; b. detecting differences between adjacent scan lines of opposite parity; and c. substituting for the secondary-parity line a line derived from adjacent primary-parity line information whenever a difference is detected.
Claim 2
Independent Claim
61 words
A method for eliminating the comb effect in interlaced-scan video pictures recorded on motion picture film, comprising the steps of: a. selecting one of said interlaced scans as the primary-parity scan; b. detecting differences between adjacent scan lines of opposite parity; and c. substituting for the secondary-parity line a line derived from adjacent primary-parity line information whenever a difference is detected.
Claim 3
Independent Claim
61 words
A method for eliminating the comb effect in interlaced-scan video pictures recorded on motion picture film, comprising the steps of: a. selecting one of said interlaced scans as the primary-parity scan; b. detecting differences between adjacent scan lines of opposite parity; and c. substituting for the secondary-parity line a line derived from adjacent primary-parity line information whenever a difference is detected.
Claim 4
Independent Claim
61 words
A method for eliminating the comb effect in interlaced-scan video pictures recorded on motion picture film, comprising the steps of: a. selecting one of said interlaced scans as the primary-parity scan; b. detecting differences between adjacent scan lines of opposite parity; and c. substituting for the secondary-parity line a line derived from adjacent primary-parity line information whenever a difference is detected.
Claim 5
Dependent Claim
12 words
The method of claim 1, in which said differences are relative motion.
Claim 6
Independent Claim
110 words
A method for eliminating the comb effect in interlaced-scan video pictures recorded on motion picture film, comprising the steps of: a. selecting one of said interlaced scans as the primary-parity scan, the other scan being the secondary-parity scan; b. detecting substantial similarity between a secondary-parity prime line being scanned and an adjacent secondary-parity line; c. detecting substantial similarity betweeN the two primary-parity lines adjacent to said prime line; d. detecting substantial dissimilarity between said prime line and an adjacent primary-parity line; and e. substituting picture information derived from at least one of said primary-parity lines for corresponding prime-line picture information when and only when said similarities and dissimilarity are detected.
Claim 7
Independent Claim
110 words
A method for eliminating the comb effect in interlaced-scan video pictures recorded on motion picture film, comprising the steps of: a. selecting one of said interlaced scans as the primary-parity scan, the other scan being the secondary-parity scan; b. detecting substantial similarity between a secondary-parity prime line being scanned and an adjacent secondary-parity line; c. detecting substantial similarity betweeN the two primary-parity lines adjacent to said prime line; d. detecting substantial dissimilarity between said prime line and an adjacent primary-parity line; and e. substituting picture information derived from at least one of said primary-parity lines for corresponding prime-line picture information when and only when said similarities and dissimilarity are detected.
Claim 8
Dependent Claim
169 words
A comb effect elimination circuit, comprising: a. a source of video signals; b. first, second and third delay means for delaying said video signals by one line interval, one field interval, and one field interval minus one line interval, respectively; c. first comparator means for comparing said video signals and the output of said first delay means, and for producing a first control signal in response to a difference therebetween; d. second comparator means for comparing the outputs of said second and third delay means, and for producing a second control signal in response to a difference therebetween; e. third comparator means for comparing said video signal and the output of said third delay means, and for producing a third control signal in response to a difference therebetween; f. output means; and g. selector means operatively responsive to said control signals for selectively conveying to said output means said video signal or a signal derived from the output of at least one of said second and third delay means.
Claim 9
Dependent Claim
169 words
A comb effect elimination circuit, comprising: a. a source of video signals; b. first, second and third delay means for delaying said video signals by one line interval, one field interval, and one field interval minus one line interval, respectively; c. first comparator means for comparing said video signals and the output of said first delay means, and for producing a first control signal in response to a difference therebetween; d. second comparator means for comparing the outputs of said second and third delay means, and for producing a second control signal in response to a difference therebetween; e. third comparator means for comparing said video signal and the output of said third delay means, and for producing a third control signal in response to a difference therebetween; f. output means; and g. selector means operatively responsive to said control signals for selectively conveying to said output means said video signal or a signal derived from the output of at least one of said second and third delay means.
Claim 10
Dependent Claim
31 words
The circuit of claim 4, in which said selector means is operatively responsive to the presence of said third control signal and the absence of said first and second control signals.
Claim 11
Dependent Claim
33 words
The circuit of claim 5, further comprising gate means responsive to the presence of said first and second control signals, respectively, to block transmission of said third control signal to said selector means.
Claim 12
Dependent Claim
28 words
The circuit of claim 4, in which said selector means selectively conveys said video signal or a combination of the outputs of said second and third delay means.
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) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |