US3557320A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reproduction of a still picture from a video tape recording by combined drop-out zone sensing
Assignee: Individual
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Filing: 1967-08-08
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Granted: 1971-01-19
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Expires: 1987-08-08
Abstract
Abstract A tape containing a sequence of television picture signals recorded in parallel tracks at normal recording speed, is scanned while at slow motion speed. The tape is stopped when the crossover dropout zone is immediately followed or preceded by an additional dropout zone. The additional dropout zone results from simultaneous tracking of two neighboring tracks and the space between, due to the reduced tape advance speed. This criterion is evaluated by generating a pulse whose amplitude is proportional to the width of the combined dropout zone. When this pulse reaches a maximum maximum amplitude, a switching circuit stops the tape transport. A timing circuit restarts the transport after an adjustable time interval.
Inventors
- 👤 Jurgen Hopf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:27
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/78; H04N5/782; H04N5/783
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
229 words
A system for reproducing a still picture from a sequence of pictures recorded, by means of rotating recording means, on a signal carrier means having mutually parallel tracks and intertrack spaces between said tracks, while said signal carrier means was advanced past said recording means at normal recording speed, comprising, in combination, means for advancing said signal carrier means at a predetermined speed, greatly reduced relative to said recording speed; rotating scanning means sequentially scanning said parallel tracks while said signal carrier means is being advanced at said greatly reduced speed, thus generating a scanned signal having a crossover dropout zone resulting from crossover from one track to the subsequent track, and additional dropout zones resulting from simultaneous tracking of portions of two neighboring tracks and the corresponding intertrack space; width measuring means operatively associated with said scanning means for furnishing a width signal having a width signal characteristic corresponding to the width of said dropout zones; signal generating means for generating a stop signal when said width signal characteristic exceeds a determined value, thus indicating the presence of a combined dropout zone resulting from the immediate sequence in time of one of said crossover dropout zones and one of said additional dropout zones; and switching means responsive to said stop signal and adapted to stop the advance of said signal storage means upon receipt of said stop signal.
Claim 2
Independent Claim
229 words
A system for reproducing a still picture from a sequence of pictures recorded, by means of rotating recording means, on a signal carrier means having mutually parallel tracks and intertrack spaces between said tracks, while said signal carrier means was advanced past said recording means at normal recording speed, comprising, in combination, means for advancing said signal carrier means at a predetermined speed, greatly reduced relative to said recording speed; rotating scanning means sequentially scanning said parallel tracks while said signal carrier means is being advanced at said greatly reduced speed, thus generating a scanned signal having a crossover dropout zone resulting from crossover from one track to the subsequent track, and additional dropout zones resulting from simultaneous tracking of portions of two neighboring tracks and the corresponding intertrack space; width measuring means operatively associated with said scanning means for furnishing a width signal having a width signal characteristic corresponding to the width of said dropout zones; signal generating means for generating a stop signal when said width signal characteristic exceeds a determined value, thus indicating the presence of a combined dropout zone resulting from the immediate sequence in time of one of said crossover dropout zones and one of said additional dropout zones; and switching means responsive to said stop signal and adapted to stop the advance of said signal storage means upon receipt of said stop signal.
Claim 3
Dependent Claim
26 words
A invention as set forth in claim 1, wherein said signal carrier means comprise a magnetic tape and said rotating scanning means comprise a magnetic head.
Claim 4
Dependent Claim
60 words
A system as set forth in claim 1, whErein said switching means comprise a trigger circuit having a predetermined threshold value equal to the amplitude of said stop signal; and a relay adapted to stop said tap advance upon energization of said relay; and wherein said trigger circuit is adapted to energize said relay when said stop signal is received.
Claim 5
Dependent Claim
33 words
A system as set forth in claim 1, also comprising means for restarting said tape transport after a predetermined still picture time period in order to avoid excessive wear of the scanned track.
Claim 6
Dependent Claim
43 words
A system as set forth in claim 1, wherein said signal generating means comprise means for generating a pulse having an amplitude proportional to the width of said combined dropout zone and wherein said stop signal comprises said pulse at its maximum amplitude.
Claim 7
Dependent Claim
66 words
A system as set forth in claim 5, wherein said means for generating a signal having an amplitude proportional to the width of said combined dropout zone comprise means for generating a pulse having a width proportional to the width of said dropout zone; and means for integrating said pulse, thus generating said signal having an amplitude proportional to the width of said combined dropout zone.
Claim 8
Dependent Claim
55 words
A system as set forth in claim 6, wherein said means for generating a pulse having a width proportional to the width of said combined dropout zone comprises a limiter stage; and a rectifier and low pass filter stage also including a switching transistor, adapted to generate a pulse having a steep rise and fall.
Claim 9
Dependent Claim
25 words
A system as set forth in claim 5, also comprising means for compensating for differences in the width of crossover dropout zones for different equipment.
Claim 10
Dependent Claim
159 words
A system as set forth in claim 8, wherein said compensating means comprise subtraction means adapted to subtract predetermined fixed subtraction value from said pulse thus generating a decreased amplitude pulse; negative peak rectifier means adapted to generate a negative direct current signal proportional to the amplitude of said decreased amplitude pulse; positive peak rectifier means adapted to generate a positive direct current signal proportional to the amplitude of said pulse, wherein the discharge time constant of said positive peak rectifier means is larger than the interval between said pulses, but substantially smaller than the discharge time constant of said negative peak rectifier means; and an adder circuit for adding said negative direct current signal and said positive direct current signal and generating an adder output signal, said adder output attaining its maximum value corresponding to the value of said stop signal only when said pulse has an amplitude corresponding to the maximum width of the combined dropout zone.
Claim 11
Dependent Claim
35 words
A system as set forth in claim 9, wherein said positive peak rectifier discharge time constant is approximately equal to .1 seconds and said negative peak rectifier time constant is approximately equal to 10 seconds.
Claim 12
Dependent Claim
38 words
A system as set forth in claim 10, wherein said restarting means comprise an electronic timing switch having a selectable delay time and adapted to generate a tape transport restart signal at the end of said delay time.
Claim 13
Dependent Claim
75 words
A system as set forth in claim 10, also comprising additional time delay means responsive to said tape transport restart signal and adapted to generate a disconnect signal for a predetermined disconnect time delay following said tape transport restart signal; and means for disconnecting said adder means from said switching means for the duration of said disconnect signal, thus preventing the tape transport from restopping at the same location as for the previous still picture.
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) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |