Patent US3814850A successfully refreshed from Google Patents.
US3814850A
Expired / Lapsed
US
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Flying spot film scanner providing increased time for film pull-down
Assignee: Rank Cintel Ltd
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Filing: 1972-10-27
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Granted: 1974-06-04
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Expires: 1992-10-27
Abstract
Abstract A flying spot scanner for producing a television video signal from a motion picture film in which a period of time longer than the blanking interval between successive fields is available for film pull-down. The longer interval for film pull down is provided by delaying the production of the first field scan of each frame via a delay line, by an amount no greater than the field blanking interval, initiating the second field scan of each frame during a time interval immediately following the first field scan and of a duration less than the normal blanking interval between frames. The pulling down or advancing of the film one frame is done during the longer than blanking interval period of time between the second field scan of one frame and the first field scan of an immediately following frame. The delay can be provided by a delay line which delays the field scan signal for the first field scan of a frame. The resulting video signal is retimed so the picture information containing portions are separated by the normal field blanking interval. The retiming can be accomplished by the same delay line used to provide the double blanking interval, via electronic switching which alternately switches the delay line into the outputs of a field scan generator and a video processor.
Inventors
- 👤 R Matchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:30
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/36; H04N3/40
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
69 words
In a flying spot film scanner, the combination of intermittent motion film pull-down means for pulling film down during a period of time between successive field scans which is longer than the field blanking interval and substantially shorter than a field interval, and means for providing said longer period by delaying the first field scan of each film frame by an amount no greater than a field blanking interval.
Claim 2
Dependent Claim
69 words
In a flying spot film scanner, the combination of intermittent motion film pull-down means for pulling film down during a period of time between successive field scans which is longer than the field blanking interval and substantially shorter than a field interval, and means for providing said longer period by delaying the first field scan of each film frame by an amount no greater than a field blanking interval.
Claim 3
Dependent Claim
41 words
A flying spot film scanner according to claim 1, in which the means for delaying the first field scan of each film frame comprises means for delaying corresponding ones of a series of field frequency signals which initiate said field scans.
Claim 4
Dependent Claim
139 words
A flying spot film scanner comprising an intermittent motion film pull-down mechanism, a cathode ray tube for producing a raster for scanning the film a plurality of times per second, means for generating a field scan waveform to control the cathode ray tube, means for delaying the first field scan of each film frame by no more than one field blanking interval, whereby an extended interval greater than a single field blanking interval is produced between each said first field scan and the preceding field scan during which extended interval the film pull-down mechanism is arranged to operate, and means to retime a picture information bearing signal derived from the scanning into a form in which the portions of the signal corresponding to the field scans applied to the cathode ray tube are separated by the field blanking interval.
Claim 5
Dependent Claim
139 words
A flying spot film scanner comprising an intermittent motion film pull-down mechanism, a cathode ray tube for producing a raster for scanning the film a plurality of times per second, means for generating a field scan waveform to control the cathode ray tube, means for delaying the first field scan of each film frame by no more than one field blanking interval, whereby an extended interval greater than a single field blanking interval is produced between each said first field scan and the preceding field scan during which extended interval the film pull-down mechanism is arranged to operate, and means to retime a picture information bearing signal derived from the scanning into a form in which the portions of the signal corresponding to the field scans applied to the cathode ray tube are separated by the field blanking interval.
Claim 6
Dependent Claim
41 words
A flying spot film scanner according to claim 3, in which the means for delaying the first field scan of each film frame comprises means for delaying corresponding ones of a series of field frequency signals which initiate said field scans.
Claim 7
Dependent Claim
24 words
A flying spot film scanner according to claim 3, in which the picture information bearing signal is a video signal resulting from the scanning.
Claim 8
Dependent Claim
22 words
A flying spot film scanner according to claim 3, in which the picture information bearing signal is an encoded coloUr television signal.
Claim 9
Dependent Claim
44 words
A flying spot film scanner according to claim 3, in which the retiming means comprises means for delaying those portions of the picture information bearing signal corresponding to all but the first field scans by an amount equal to the delay of the latter.
Claim 10
Dependent Claim
41 words
A flying spot film scanner according to claim 7, in which means for delaying the first field scan of each film frame and the means for delaying the said portions of the picture information bearing signal comprise a single delay line.
Claim 11
Dependent Claim
44 words
A flying spot film scanner according to claim 4, in which the retiming means comprises means for delaying those portions of the picture information bearing signal corresponding to all but the first field scans by an amount equal to the delay of the latter.
Claim 12
Dependent Claim
42 words
A flying spot film scanner according to claim 9, in which the means for delaying the first field scan of each film frame and the means for delaying the said portions of the picture information bearing signal comprise a single delay line.
Claim 13
Independent Claim
262 words
A method of producing a television video signal from a motion pciture film comprising the steps of: scanning a first frame of the film with a flying spot scanner to produce first and second successive fields, said scanning including delaying the initiation of the first field scan by an amount not greater than a normal blanking interval between fields, and causing initiation of a second field scan during a time interval following the first scan which is less than a normal blanking interval, whereby the first and second fields are separated by a time interval shorter than the normal blanking interval, scanning a second frame of the film with the flying spot scanner to produce first and second fields, said scanning of the second frame including delaying the initiation of the first field scan of the second frame by an amount not greater than a normal blanking interval, and causing initiation of the second field scan of the second frame during a time interval following the first frame which is less than a normal blanking interval, so that there is a time interval between the second field scan of the first frame and the first field scan of the second frame which is no longer than a normal blanking interval, moving the film one frame during the longer time interval between the second field scan of the first frame and the first field scan of the second frame, and retiming picture information derived from the scanning so that signals corresponding to the field scans are separated by the normal field blanking interval.
Claim 14
Independent Claim
262 words
A method of producing a television video signal from a motion pciture film comprising the steps of: scanning a first frame of the film with a flying spot scanner to produce first and second successive fields, said scanning including delaying the initiation of the first field scan by an amount not greater than a normal blanking interval between fields, and causing initiation of a second field scan during a time interval following the first scan which is less than a normal blanking interval, whereby the first and second fields are separated by a time interval shorter than the normal blanking interval, scanning a second frame of the film with the flying spot scanner to produce first and second fields, said scanning of the second frame including delaying the initiation of the first field scan of the second frame by an amount not greater than a normal blanking interval, and causing initiation of the second field scan of the second frame during a time interval following the first frame which is less than a normal blanking interval, so that there is a time interval between the second field scan of the first frame and the first field scan of the second frame which is no longer than a normal blanking interval, moving the film one frame during the longer time interval between the second field scan of the first frame and the first field scan of the second frame, and retiming picture information derived from the scanning so that signals corresponding to the field scans are separated by the normal field blanking interval.
References Cited (Backward Citations)
GB1232133A
Cited
DE2062644A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |