US4054912A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film scanner with compensation for film shrinkage
Assignee: Rank Cintel Ltd
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Filing: 1976-04-09
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Granted: 1977-10-18
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Expires: 1996-04-09
Abstract
Abstract The invention is concerned with a means of compensating for film shrinkage in a continuous film motion telecine apparatus. A measure of the film shrinkage is obtained by deriving a signal representing the angular speed of a roller in non-slipping contact with the film, the film being driven at a constant frame rate by, for example, a smooth capstan servo-controlled to maintain the constant frame rate. The roller whose angular speed is measured may be the drive capstan itself or a separate roller. The signal so derived is dependent on the film shrinkage and thus is used to automatically control a registration adjusting means to compensate for such shrinkage.
Inventors
- 👤 John David Millward
- 👤 John Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:37
CPC Classifications
H; H04; H04N; H04N3/00; H04N3/36; H04N3/38
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
63 words
In a continuous film motion telecine apparatus, means for deriving a signal representing the angular speed of a roller in non-slipping contact with the film when the film is being driven at a constant frame rate, the value of such signal being dependent upon film shrinkage, and means using said signal to automatically control a registration adjusting means to compensate for such shrinkage.
Claim 2
Dependent Claim
63 words
In a continuous film motion telecine apparatus, means for deriving a signal representing the angular speed of a roller in non-slipping contact with the film when the film is being driven at a constant frame rate, the value of such signal being dependent upon film shrinkage, and means using said signal to automatically control a registration adjusting means to compensate for such shrinkage.
Claim 3
Dependent Claim
17 words
A telecine apparatus according to claim 1, wherein the roller is a drive capstan for the film.
Claim 4
Dependent Claim
69 words
A telecine apparatus according to claim 1, wherein the means for deriving a signal comprises means for generating pulses at a frequency proportional to the angular speed of the roller, means for counting the pulses so generated, means for counting film sprocket holes, means for storing the pulse count when a predetermined sprocket hole count is reached, and means for forming an analogue signal representative of the stored count.
Claim 5
Dependent Claim
79 words
A telecine apparatus according to claim 1, wherein the means for deriving a signal comprises means for generating first pulses at a frequency proportional to the angular speed of the roller, means for counting the pulses so generated, a source of reference pulses of constant frequency, means for counting the reference pulses, means for storing the reference pulse count when a predetermined first pulse count is reached, and means for forming an analogue signal representative of the stored count.
Claim 6
Dependent Claim
31 words
A telecine apparatus according to claim 23, further comprising means for comparing said signal with a reference value corresponding to unshrunk film to provide a correction signal for controlling the adjustment.
Claim 7
Dependent Claim
31 words
A telecine apparatus according to claim 4, further comprising means for comparing said signal with a reference value corresponding to unshrunk film to provide a correction signal for controlling the adjustment.
Claim 8
Dependent Claim
21 words
A telecine apparatus according to claim 1 wherein the adjusting means adjusts the vertical deflection waveform of the telecine raster-producing circuits.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-17 | 1981-04-18 | 1981-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-17 | 1985-04-18 | 1985-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-17 | 1989-04-18 | 1989-10-18 | $7700.00 | Window Closed / Lapsed |