US3696981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film position and break detector
Assignee: Link Flight Simulation Corp
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Filing: 1968-09-05
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Granted: 1972-10-10
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Expires: 1988-09-05
Abstract
Abstract The disclosed exemplification of the present invention is a film position and break detector for use with a motion picture projector and the like. An opaque magnetic material in the form of a strip extends along each longitudinal edge of the film and preferably contains information relating to film speed. A portion of one strip is removed at the beginning end of the film and a portion of the other strip is removed at the finish end of the film leaving transparent portions of the film exposed. A pair of light sources are mounted on one side of the prescribed path of film travel and are positioned to illuminate a respective magnetic strip. A pair of light sensing diodes are mounted on the opposite side of the prescribed path of film travel and are positioned to be illuminated from a corresponding light source in the absence of any magnetic strip interposed therebetween. A circuit is responsive to the conduction of one light sensing diode to actuate the film translating mechanism of the projector to drive the film in one direction and is responsive to the conduction of the other light sensing diode to actuate the translating mechanism to drive the film in the opposite direction. The circuit is further responsive to the conduction of both light sensing diodes to de-energize the film translating mechanism.
Inventors
- 👤 Kenneth Levy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 17:01
CPC Classifications
G; G09; G09B; G09B9/00; G09B9/02; G09B9/08; G09B9/30; G09B9/304; G03; G03B; G03B19/00; G03B19/18; G03B21/00; G03B21/14; G03B21/32; G03B21/42
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
181 words
In combination with a film drive mechanism for translating a film in two opposite directions, a pair of opaque strips disposed on respective opposite longitudinal edges of the film, a first said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminating one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film and disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips therebetween, and logic means responsive to the illuminating of only one of said light sensors for actuating the film drive mechanism to translate the film in a corresponding direction and to the illumination of both of said light sensors for deenergizing the film drive mechanism.
Claim 2
Dependent Claim
181 words
In combination with a film drive mechanism for translating a film in two opposite directions, a pair of opaque strips disposed on respective opposite longitudinal edges of the film, a first said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminating one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film and disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips therebetween, and logic means responsive to the illuminating of only one of said light sensors for actuating the film drive mechanism to translate the film in a corresponding direction and to the illumination of both of said light sensors for deenergizing the film drive mechanism.
Claim 3
Dependent Claim
207 words
In combination with a film drive mechanism for translating a film in two opposite directions, a pair of opaque strips formed of magnetic material capable of having information recorded thereon indicative of film speed and position and disposed on respective opposite longitudinal edges of the film, a first of said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminating one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips therebetween, first means responsive to the illumination of one of said light sensors for actuating the film drive mechanism to translate the film in one direction, and second means responsive to the illumination of the other of said light sensors for actuating the film drive mechanism to translate the film in an opposite direction.
Claim 4
Dependent Claim
207 words
In combination with a film drive mechanism for translating a film in two opposite directions, a pair of opaque strips formed of magnetic material capable of having information recorded thereon indicative of film speed and position and disposed on respective opposite longitudinal edges of the film, a first of said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminating one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips therebetween, first means responsive to the illumination of one of said light sensors for actuating the film drive mechanism to translate the film in one direction, and second means responsive to the illumination of the other of said light sensors for actuating the film drive mechanism to translate the film in an opposite direction.
Claim 5
Dependent Claim
223 words
In combination with a film drive mechanism for translating a film in two opposite directions, a pair of opaque strips disposed on respective opposite longitudinal edges of the film, a first of said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminAting one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film and disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips therebetween, first means responsive to the illumination of one of said light sensors for actuating the film drive mechanism to translate the film in one direction, and second means responsive to the illumination of the other of said light sensors for actuating the film drive mechanism to translate the film in an opposite direction, said first and said second means each including means for energizing the film drive mechanism only for a predetermined time period following interruption of the illumination of each of said light sensors.
Claim 6
Dependent Claim
223 words
In combination with a film drive mechanism for translating a film in two opposite directions, a pair of opaque strips disposed on respective opposite longitudinal edges of the film, a first of said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminAting one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film and disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips therebetween, first means responsive to the illumination of one of said light sensors for actuating the film drive mechanism to translate the film in one direction, and second means responsive to the illumination of the other of said light sensors for actuating the film drive mechanism to translate the film in an opposite direction, said first and said second means each including means for energizing the film drive mechanism only for a predetermined time period following interruption of the illumination of each of said light sensors.
Claim 7
Dependent Claim
249 words
In combination with a film drive mechanism for translating a film in two opposite directions which is connected to a source of control voltage having a polarity and magnitude determining the direction and speed respectively of film travel, a pair of opaque strips disposed on respective opposite longitudinal edges of the film, a first of said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminating one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film and disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips there-between, first means responsive to the illumination of one of said light sensors for actuating the film drive mechanism to translate the film in one direction, and second means responsive to the illumination of the other of said light sensors for actuating the film drive mechanism to translate the film in an opposite direction, said first and said second means each including means for disconnecting said source of control voltage from said film drive mechanism in response to the illumination of said one and said other light sensor respectively.
Claim 8
Dependent Claim
249 words
In combination with a film drive mechanism for translating a film in two opposite directions which is connected to a source of control voltage having a polarity and magnitude determining the direction and speed respectively of film travel, a pair of opaque strips disposed on respective opposite longitudinal edges of the film, a first of said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminating one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film and disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips there-between, first means responsive to the illumination of one of said light sensors for actuating the film drive mechanism to translate the film in one direction, and second means responsive to the illumination of the other of said light sensors for actuating the film drive mechanism to translate the film in an opposite direction, said first and said second means each including means for disconnecting said source of control voltage from said film drive mechanism in response to the illumination of said one and said other light sensor respectively.
Claim 9
Dependent Claim
186 words
In combination with a film drive mechanism for translating a film in two opposite directions, a pair of opaque strips disposed on respective opposite longitudinal edges of the film, a first of said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminating one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film and disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips therebetween, first means responsive to the illumination of one of said light sensors for actuating the film drive mechanism to translate the film in an opposite direction, and detector further comprising means responsive to the simultaneous illumination of both of said light sensors for de-energizing the film drive mechanism.
Claim 10
Dependent Claim
186 words
In combination with a film drive mechanism for translating a film in two opposite directions, a pair of opaque strips disposed on respective opposite longitudinal edges of the film, a first of said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminating one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film and disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips therebetween, first means responsive to the illumination of one of said light sensors for actuating the film drive mechanism to translate the film in an opposite direction, and detector further comprising means responsive to the simultaneous illumination of both of said light sensors for de-energizing the film drive mechanism.
Claim 11
Dependent Claim
245 words
In combination with a film drive mechanism for translating a film in two opposite directions, a pair of opaque strips disposed on respective opposite longitudinal edges of the film, a first of said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminating one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film and disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips therebetween, first means responsive to the illumination of one of said light sensors for actuating the film drive mechanism to translate the film in one direction, and second means responsive to the illumination of the other of said light sensors for actuating the film drive mechanism to translate the film in an opposite direction, each of said light sensors being formed of a photosensitive diode, each of said first and said second means including a time constant circuit connected in series with a respective one of said diodes across a source of voltage and switching means connected to said time constant circuit for actuating the film drive mechanism.
Claim 12
Dependent Claim
245 words
In combination with a film drive mechanism for translating a film in two opposite directions, a pair of opaque strips disposed on respective opposite longitudinal edges of the film, a first of said strips extending from one end of the film to a spaced distance from the other end of the film, a second of said strips extending from said other end of the film to a spaced distance from said one end of the film, a film position detector comprising a pair of light sources disposed for illuminating one side of respective edges of the film, a pair of light sensors mounted on the other side of respective edges of the film and disposed for being illuminated from a respective one of said light sources in the absence of a respective one of said opaque strips therebetween, first means responsive to the illumination of one of said light sensors for actuating the film drive mechanism to translate the film in one direction, and second means responsive to the illumination of the other of said light sensors for actuating the film drive mechanism to translate the film in an opposite direction, each of said light sensors being formed of a photosensitive diode, each of said first and said second means including a time constant circuit connected in series with a respective one of said diodes across a source of voltage and switching means connected to said time constant circuit for actuating the film drive mechanism.
References Cited (Backward Citations)
US1950692A
Cited
US2820907A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |