US3573357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Skip-field recorder with electronically controlled stop action capability
Assignee: General Electric Co
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Filing: 1968-04-24
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Granted: 1971-04-06
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Expires: 1988-04-24
Abstract
Abstract A system for providing from a helical scan skip-field magnetic tape recorder composite video having iterative portions corresponding to a single frame to enable such frames to be displayed as stable still pictures on a monitor. With the magnetic tape stationary, the video signals developed from a pair of heads spaced apart by 180* plus the arc corresponding to linear tape travel in the time of one field are combined and every other sync pulse is advanced in relation to the video signal such that corresponding portions of video in successive identical fields is in the same time relationship to its synchronizing pulse.
Inventors
- 👤 Francis G Toce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:15
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/78; H04N5/782; H04N5/783
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
373 words
In a helical scan skip-field system for recording and reproducing a video signal, said system including an elongated magnetic storage medium capable of being moved in the direction of elongation thereof along a helical path about a circular drum, a pair of heads, one of said heads scanning across said medium transverse to the direction of movement of said medium so as to record every other field of the video signal in successive tracks on said medium when said system is operated in a recording mode, both of said heads scanning across said medium transverse to the direction of movement of said medium so as to play back the recorded video signal, said one of said heads being located at one end of a diameter of the circle of revolution of said heads and the other of said heads being located near the other end of said diameter displaced in a direction opposite to the direction of rotation of said heads by an arc corresponding to longitudinal displacement of the medium occurring during presentation of one field, apparatus for developing a train of vertical synchronizing pulses for use in connection with the video signal repetitively reproduced by said heads from a single one of said tracks on said medium when said medium is stationary, comprising: means including a first magnetic member on the arm of a rotor in alignment with said one head and moving in rotational synchronism therewith for developing a first train of pulses at one-half vertical synchronization rate, each pulse of said first train occurring at initiation of scanning of said single one of said tracks by said one of said heads; means including a second magnetic member on the arm of said rotor in alignment with said other head and moving in rotational synchronism therewith for developing a second train of pulses at one-half vertical synchronization rate, each pulse of said second train occurring after a predetermined delay following initiation of scanning of said track by the other of said head; and means including a coil adjacent said circle of revolution and responsive to said first and second magnetic members for interlacing the pulses of said first and second pulse trains into a single train of vertical synchronizing pulses.
Claim 2
Dependent Claim
373 words
In a helical scan skip-field system for recording and reproducing a video signal, said system including an elongated magnetic storage medium capable of being moved in the direction of elongation thereof along a helical path about a circular drum, a pair of heads, one of said heads scanning across said medium transverse to the direction of movement of said medium so as to record every other field of the video signal in successive tracks on said medium when said system is operated in a recording mode, both of said heads scanning across said medium transverse to the direction of movement of said medium so as to play back the recorded video signal, said one of said heads being located at one end of a diameter of the circle of revolution of said heads and the other of said heads being located near the other end of said diameter displaced in a direction opposite to the direction of rotation of said heads by an arc corresponding to longitudinal displacement of the medium occurring during presentation of one field, apparatus for developing a train of vertical synchronizing pulses for use in connection with the video signal repetitively reproduced by said heads from a single one of said tracks on said medium when said medium is stationary, comprising: means including a first magnetic member on the arm of a rotor in alignment with said one head and moving in rotational synchronism therewith for developing a first train of pulses at one-half vertical synchronization rate, each pulse of said first train occurring at initiation of scanning of said single one of said tracks by said one of said heads; means including a second magnetic member on the arm of said rotor in alignment with said other head and moving in rotational synchronism therewith for developing a second train of pulses at one-half vertical synchronization rate, each pulse of said second train occurring after a predetermined delay following initiation of scanning of said track by the other of said head; and means including a coil adjacent said circle of revolution and responsive to said first and second magnetic members for interlacing the pulses of said first and second pulse trains into a single train of vertical synchronizing pulses.
Claim 3
Dependent Claim
316 words
In a helical scan skip-field system for recording and reproducing a video signal, said system including an elongated magnetic storage medium capable of being moved in the direction of elongation thereof along a helical path about a circular drum, a pair of heads, one of said heads scanning across said medium transverse to the direction of movement of said medium so as to record every other field of the video signal in successive tracks on said medium when said medium is operated in a recording mode, both of said heads scanning across said medium transverse to the direction of movement of said medium so as to play back the recorded video signal, said one of said heads being located at one end of a diameter of the circle of revolution of said heads and the other of said heads being located near the other end of said diameter displaced in a direction opposite to the direction of rotation of said heads by an arc corresponding to longitudinal displacement of the medium occurring during presentation of one field, apparatus for developing a train of vertical synchronizing pulses for use in connection with the video signal repetitively reproduced by said heads from s single one of said tracks on Said medium when said medium is stationary, comprising: means responsive to rotation of said heads for deriving a first train of pulses occurring at the field rate of said video signals; means responsive to rotation of said heads for deriving a second train of pulses occurring at the field rate of said video signal, each pulse of said second train being delayed by a predetermined interval with respect to the respective pulses of said first train; and means responsive to said means for deriving said first and second pulse trains for interlacing pulses alternatively from said first and second pulse trains into a resultant train of vertical synchronizing pulses.
Claim 4
Dependent Claim
316 words
In a helical scan skip-field system for recording and reproducing a video signal, said system including an elongated magnetic storage medium capable of being moved in the direction of elongation thereof along a helical path about a circular drum, a pair of heads, one of said heads scanning across said medium transverse to the direction of movement of said medium so as to record every other field of the video signal in successive tracks on said medium when said medium is operated in a recording mode, both of said heads scanning across said medium transverse to the direction of movement of said medium so as to play back the recorded video signal, said one of said heads being located at one end of a diameter of the circle of revolution of said heads and the other of said heads being located near the other end of said diameter displaced in a direction opposite to the direction of rotation of said heads by an arc corresponding to longitudinal displacement of the medium occurring during presentation of one field, apparatus for developing a train of vertical synchronizing pulses for use in connection with the video signal repetitively reproduced by said heads from s single one of said tracks on Said medium when said medium is stationary, comprising: means responsive to rotation of said heads for deriving a first train of pulses occurring at the field rate of said video signals; means responsive to rotation of said heads for deriving a second train of pulses occurring at the field rate of said video signal, each pulse of said second train being delayed by a predetermined interval with respect to the respective pulses of said first train; and means responsive to said means for deriving said first and second pulse trains for interlacing pulses alternatively from said first and second pulse trains into a resultant train of vertical synchronizing pulses.
Claim 5
Dependent Claim
119 words
The apparatus of claim 2 in which said means for interlacing pulses alternately from said first and second pulse trains includes first and second gating means, means coupled to each of said first and second gating means for alternately rendering said first and second gating means conductive at a rate equal to the vertical synchronization rate and for sufficient duration such that each conduction interval of said first and second gating means overlaps the interval of conduction of a single pulse in said first and second pulse trains respectively, and means coupled jointly to the outputs of said first and second gating means for combining output pulses from said first and second gating means into a single pulse train.
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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |