US3851959A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for controlling a motion picture projector, especially a projector for teaching machines
Assignee: Individual
•
Filing: 1973-03-15
•
Granted: 1974-12-03
•
Expires: 1993-03-15
Abstract
Abstract A method and device for controlling a motion picture projector by signals, a first signal being derived from the rotation of a drive motor and a second signal from control marks on the film. In the case of projectors having a claw transport system and a sectored rotating shutter a first signal is derived from the rotation of the said shutter, whilst a second signal is produced, not only in the case of the said projectors but also in the case of other types of projectors, by control marks on the film and appropriate sensing elements. Reliable stopping of the film at a specific frame can thus be achieved, as can troublefree and automatic switching-off of the film transport drive at the end of the film.
Inventors
- 👤 G Kreutze
- 👤 M Moessner
- 👤 G Obstfelder
- 👤 G Soehring
- 👤 V Pfirrman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:03
CPC Classifications
G; G03; G03B; G03B31/00; G03B31/06; G09; G09B; G09B5/00; G09B5/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
264 words
A method of controlling a film projector for use in a teaching machine, which further includes a tape recorder, the tape of which having signals recorded thereon for initiation or stopping the movement of a film in said projector, on said film there being provided with designations associated with the frames of said film, said designations being formed as optical marks which indicate each frame whether being a frame of a motion picture scene or being a frame for still picture presentation only; said projector including a cam which rotates together with a sectored shutter and actuates a claw for moving the film, and an additional actuating element by means of which the claw is prevented from engaging the film for movement or is released for film transport, the operation of said actuating element being controlled by signals derived from the rotation of the sectored shutter and from the movement of the film wherein the first of said signals (a) being produced by means of an illuminated slot in the sectored shutter and at least one photoelectric component located in the circular path in which the slot moves as the sectored shutter rotates and the second of said signals (b) being produced by means of said optical marks on the film and at least one further photoelectric component associated therewith, when an initial or stop signal from the tape recorder is fed to the projector the occurring of said signals (a) and (b) being detected and only when said signals (a) and (b) coincide a control signal activates to initiate or stop film movement.
Claim 2
Independent Claim
264 words
A method of controlling a film projector for use in a teaching machine, which further includes a tape recorder, the tape of which having signals recorded thereon for initiation or stopping the movement of a film in said projector, on said film there being provided with designations associated with the frames of said film, said designations being formed as optical marks which indicate each frame whether being a frame of a motion picture scene or being a frame for still picture presentation only; said projector including a cam which rotates together with a sectored shutter and actuates a claw for moving the film, and an additional actuating element by means of which the claw is prevented from engaging the film for movement or is released for film transport, the operation of said actuating element being controlled by signals derived from the rotation of the sectored shutter and from the movement of the film wherein the first of said signals (a) being produced by means of an illuminated slot in the sectored shutter and at least one photoelectric component located in the circular path in which the slot moves as the sectored shutter rotates and the second of said signals (b) being produced by means of said optical marks on the film and at least one further photoelectric component associated therewith, when an initial or stop signal from the tape recorder is fed to the projector the occurring of said signals (a) and (b) being detected and only when said signals (a) and (b) coincide a control signal activates to initiate or stop film movement.
Claim 3
Dependent Claim
241 words
A teaching machine which comprises in combination: a film projector having a sectored rotating shutter; a tape recorder; a tape playably mounted on said recorder, said tape having signals recorded thereon for starting or stopping the movement of a film in said projector, said film including optical marks which designate each frame of a movie film or a still picture; said projector including a cam which rotates together with a sectored shutter and actuates a claw for moving the film, and an additional actuating element by means of which the claw is prevented from engaging the film for movement or, is released for film transport, the operation of said actuating element being controlled by signals derived from the rotation of the sectored shutter and from the movement of the film wherein the first of said signals (a) being produced by means of an illuminated slot in the sectored shutter and at least one photoelectric component located in the circular path in which the slot moves as the sectored shutter rotates and the second of said signals (b) being produced by means of said optical marks on the film and at least one further photoelectric component associated therewith, when an initial or stop signal from the tape recorder is fed to the projector the occurring of said signals (a) and (b) being detected and only when said signals (a) and (b) coincide a control signal activates to initiate or stop film movement.
Claim 4
Dependent Claim
241 words
A teaching machine which comprises in combination: a film projector having a sectored rotating shutter; a tape recorder; a tape playably mounted on said recorder, said tape having signals recorded thereon for starting or stopping the movement of a film in said projector, said film including optical marks which designate each frame of a movie film or a still picture; said projector including a cam which rotates together with a sectored shutter and actuates a claw for moving the film, and an additional actuating element by means of which the claw is prevented from engaging the film for movement or, is released for film transport, the operation of said actuating element being controlled by signals derived from the rotation of the sectored shutter and from the movement of the film wherein the first of said signals (a) being produced by means of an illuminated slot in the sectored shutter and at least one photoelectric component located in the circular path in which the slot moves as the sectored shutter rotates and the second of said signals (b) being produced by means of said optical marks on the film and at least one further photoelectric component associated therewith, when an initial or stop signal from the tape recorder is fed to the projector the occurring of said signals (a) and (b) being detected and only when said signals (a) and (b) coincide a control signal activates to initiate or stop film movement.
Claim 5
Dependent Claim
35 words
A teaching machine as described in claim 2 wherein each end of said film is provided with a transparent section extending in the longitudinal direction of the film in the form of a transparent leader.
Claim 6
Dependent Claim
68 words
A teaching machine as set forth in claim 2 wherein a coincidence gate is provided for the signals (a and b) derived from the rotation of the sectored rotating shutter and from the designation on the film, by means of which coincidence gate the members which move the film can be controlled, via actuating devices, only if the signals (a and b) occur in a predetermined time pattern.
Claim 7
Dependent Claim
18 words
A teaching machine as set forth in claim 4 wherein the coincidence gate used is an impulse counter.
Claim 8
Dependent Claim
106 words
A teaching machine as in claim 2 wherein said first signal (a) is produced by means of an illuminated slot in the sectored rotating shutter And at least one photoelectric component located in the circular path in which the slot moves as the sectored shutter rotates, and a second signal b being produced by means of illuminated optical marks on the film and at least one further photoelectric component associated therewith, the claw only being disengaged from or brought into engagement with the perforation in the film by the said additional actuating element which is activated when the first and second signals (a and b) coincide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |