US3879114A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound film camera with damping circuit
Assignee: Agfa Gevaert AG
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Filing: 1974-06-27
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Granted: 1975-04-22
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Expires: 1994-06-27
Abstract
Abstract The camera has a circuit including an amplifier for amplifying audio signals prior to recording same with a recording head on the sound track of the film. Since the motor transporting the film needs a predetermined time to come up to speed, a damping circuit including a field-effect transistor and an RC timing circuit is provided at the input of the amplifier to reduce the signal at the input when the camera is first put into operation and then slowly to increase this signal until it is at full strength when the motor is up to speed.
Inventors
- 👤 Volkmar Stenzenberger
- 👤 Eduard Wagensonner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:56
CPC Classifications
G; G03; G03B; G03B31/00; G03B31/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
101 words
In a motion picture camera having film, a sound track on said film, transport means for transporting said film along a predetermined path, said transport means requiring a determined start-up time for reaching a determined operating speed from a stopped condition, and transfer means for transferring audio signals furnished to said motion picture camera to said sound track: damping means connected to said transfer means for damping said audio signals during said determined start-up time, said damping means further comprises timing means for furnishing a timing signal varying as a predetermined function of time following said start-up of said transport means.
Claim 2
Dependent Claim
101 words
In a motion picture camera having film, a sound track on said film, transport means for transporting said film along a predetermined path, said transport means requiring a determined start-up time for reaching a determined operating speed from a stopped condition, and transfer means for transferring audio signals furnished to said motion picture camera to said sound track: damping means connected to said transfer means for damping said audio signals during said determined start-up time, said damping means further comprises timing means for furnishing a timing signal varying as a predetermined function of time following said start-up of said transport means.
Claim 3
Dependent Claim
101 words
In a motion picture camera having film, a sound track on said film, transport means for transporting said film along a predetermined path, said transport means requiring a determined start-up time for reaching a determined operating speed from a stopped condition, and transfer means for transferring audio signals furnished to said motion picture camera to said sound track: damping means connected to said transfer means for damping said audio signals during said determined start-up time, said damping means further comprises timing means for furnishing a timing signal varying as a predetermined function of time following said start-up of said transport means.
Claim 4
Dependent Claim
101 words
In a motion picture camera having film, a sound track on said film, transport means for transporting said film along a predetermined path, said transport means requiring a determined start-up time for reaching a determined operating speed from a stopped condition, and transfer means for transferring audio signals furnished to said motion picture camera to said sound track: damping means connected to said transfer means for damping said audio signals during said determined start-up time, said damping means further comprises timing means for furnishing a timing signal varying as a predetermined function of time following said start-up of said transport means.
Claim 5
Dependent Claim
51 words
A motion picture camera as set forth in claim 1, wherein said damping means further comprises a semiconductor element having a control electrode connected to said timing means and an output circuit connected to said transfer means, the resistance of said output circuit varying as a function of said timing signal.
Claim 6
Dependent Claim
64 words
A motion picture camera as set forth in claim 2, wherein said motion picture camera further comprises a battery; wherein said semiconductor element is a field-effect transistor; and wherein said timing means comprise an RC timing circuit including at least one capacitor and one resistor, and switch means for connecting said RC timing circuit to said battery upon activation of said motion picture camera.
Claim 7
Dependent Claim
102 words
A motion picture camera as set forth in claim 3, wherein said transfer means include a recording head at a first predetermined location along said predetermined path of said film; wherein said motion picture camera further comprises an aperture at A second predetermined location along said predetermined path of said film, said second predetermined location preceding said first predetermined location by a predetermined distance in the direction of film transport; and wherein said RC timing circuit has a time constant substantially equal to the time required for a point on said film for travel from said first to said second predetermined location.
Claim 8
Dependent Claim
61 words
A motion picture camera as set forth in claim 4, wherein said motion picture camera further comprises a high-frequency oscillator; wherein said transfer means comprise an amplifier and means for connecting the output of said amplifier to the output of said high-frequency oscillator and to said recording head; and wherein said field-effect transistor is connected to the input of said amplifier.
Claim 9
Dependent Claim
44 words
A motion picture camera as set forth in claim 1, further comprising microphone means associated with said motion picture camera for transducing sound waves impinging thereon into corresponding electrical audio signals; and connecting means for connecting said microphone means to said motion picture camera.
References Cited (Backward Citations)
US3649109A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |