US4009949A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Threading and synchronization system for sound motion picture projector
Assignee: Bell and Howell Co
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Filing: 1975-10-30
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Granted: 1977-03-01
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Expires: 1995-10-30
Abstract
Abstract For a sound motion picture projector, an automatic threading and image-sound synchronization system is provided without added moving components. During threading the system establishes for image-sound synchronization the correct image-to-sound spacing of a film having the sound longitudinally spaced along the film from the related image.
Inventors
- 👤 Arthur E. Nupnau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:20
CPC Classifications
G; G03; G03B; G03B1/00; G03B1/56; G03B1/58; G03B31/00; G03B31/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
209 words
In a motion picture projector having a projection station, a sound station, a fixed film guide surface for guiding film along a film path connecting the projection station and the sound station, a leading sprocket for feeding film along the film path to said projection station, and a trailing sprocket for feeding film from said sound station, a sound and image synchronization system comprising: a film threading path defining block fixed intermediate said projection station and said sound station relative to said fixed film guide surface to define a fixed threading path for guiding film from said projection station toward said sound station during film threading and film projection; a throat recess formed in the surface of said block opposite said fixed film guide surface past which said film is move for threading and relative to which said film pulses during transport to and through said sound station toward said trailing sprocket; and a pulsation smoothing portion formed on said surface of said block proximate said throat recess in the direction in which said film is moved along said block during threading and against which said film is moved to isolate intermittent film movement as said film is transported from said projection station toward said sound station during projection.
Claim 2
Dependent Claim
209 words
In a motion picture projector having a projection station, a sound station, a fixed film guide surface for guiding film along a film path connecting the projection station and the sound station, a leading sprocket for feeding film along the film path to said projection station, and a trailing sprocket for feeding film from said sound station, a sound and image synchronization system comprising: a film threading path defining block fixed intermediate said projection station and said sound station relative to said fixed film guide surface to define a fixed threading path for guiding film from said projection station toward said sound station during film threading and film projection; a throat recess formed in the surface of said block opposite said fixed film guide surface past which said film is move for threading and relative to which said film pulses during transport to and through said sound station toward said trailing sprocket; and a pulsation smoothing portion formed on said surface of said block proximate said throat recess in the direction in which said film is moved along said block during threading and against which said film is moved to isolate intermittent film movement as said film is transported from said projection station toward said sound station during projection.
Claim 3
Dependent Claim
54 words
A sound and image synchronization system for a motion picture projector as in claim 1 wherein said film path between said projection station and said gate is configured to accept during threading a length of film equal to frame-to-sound linear separation along said film whereby said image and sound are synchronized during film projection.
Claim 4
Dependent Claim
133 words
A sound and image synchronization system for a motion picture projector as in claim 1 wherein said projector includes a loop former and the said sound station includes a relatively movable transducer and pressure pad defining a gate, and said system comprises; gate control means coupled to said loop former for opening and closing said gate in synchronism with positioning of said loop former, said gate control means opening said sound station gate for unrestrained movement of film therethrough during a film threading sequence and for closing said gate during a projection sequence to restrain film movement through said gate to form a pulsating loop in said throat recess and over said pulsating said smoothing portion to isolate intermittent film movement through said projection station from constant film movement through said sound station.
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) | 1980-02-29 | 1980-08-30 | 1981-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-29 | 1984-08-30 | 1985-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-29 | 1988-08-30 | 1989-03-01 | $7700.00 | Window Closed / Lapsed |