Patent US3789138A successfully refreshed from Google Patents.
US3789138A
Expired / Lapsed
US
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Device for gaining random access to video signal information for use in video tape recorders
Assignee: Hitachi Ltd
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Filing: 1971-06-18
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Granted: 1974-01-29
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Expires: 1991-06-18
Abstract
Abstract In a video tape recorder for recording video signal information of television scenes, pictures and various documents frame by frame on one or more tracks on a magnetic tape and selectively reproducing a desired video signal, a means for gaining random access to the desired video signal. The video signal information is recorded in blocks each consisting of many tracks noted above and each being spaced from another to define a blank portion without any information recorded between adjacent blocks. In addition to the video signal information, block identifying signals are recorded on the magnetic tape. For the reproduction of a desired static picture, random access to the desired frame is made by first running the magnetic tape by a fast feed or fast rewind drive until a block including the desired track or tracks is detected from the block identifying signals and then by feeding the tape either intermittently or continuously at a low speed until the position of the track of the desired frame is reached.
Inventors
- 👤 T Terada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:00
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/005; G11B27/00; G11B27/02; G11B27/022; G11B27/024; G11B27/10; G11B27/19; G11B27/28; G11B27/32; G11B27/322
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
285 words
A device for gaining random access to video signal information for use with a helical scan type video tape recorder utilizing a magnetic tape which carries video signal information of a large number of picture frames, wherein the information of each frame is recorded as one or two recording tracks on said magnetic tape, all of said recording tracks being divided into a plurality of blocks each including a number of said recording tracks, and the positions of the leading ends of said blocks being detectable by block address signals recorded at the leading parts of said blocks and said frames being detectable by frame address signals recorded at the position of each frame, respectively, said device comprising: first driving means for driving the magnetic tape for fast winding and rewinding; second driving means for driving the magnetic tape in a stepped manner; detecting means for detecting the lead end of a selected one of said blocks by identifying said block address signals, said selected one block including a specific recording track on which the video signal information of a desired picture frame is recorded; first control means responsive to said detecting means for operating said first driving means and stopping the same upon detection of the leading end of said selected one block, second control means responsive to said detecting means for operating said second driving means upon the detection of the leading end of said selected one block and stopping the same upon detection of said specific recording track; and third control means for operating a reproducing rotary magnetic head upon the detection of said specific recording track to achieve a still reproduction of the video signal information of said desired picture frame.
Claim 2
Independent Claim
285 words
A device for gaining random access to video signal information for use with a helical scan type video tape recorder utilizing a magnetic tape which carries video signal information of a large number of picture frames, wherein the information of each frame is recorded as one or two recording tracks on said magnetic tape, all of said recording tracks being divided into a plurality of blocks each including a number of said recording tracks, and the positions of the leading ends of said blocks being detectable by block address signals recorded at the leading parts of said blocks and said frames being detectable by frame address signals recorded at the position of each frame, respectively, said device comprising: first driving means for driving the magnetic tape for fast winding and rewinding; second driving means for driving the magnetic tape in a stepped manner; detecting means for detecting the lead end of a selected one of said blocks by identifying said block address signals, said selected one block including a specific recording track on which the video signal information of a desired picture frame is recorded; first control means responsive to said detecting means for operating said first driving means and stopping the same upon detection of the leading end of said selected one block, second control means responsive to said detecting means for operating said second driving means upon the detection of the leading end of said selected one block and stopping the same upon detection of said specific recording track; and third control means for operating a reproducing rotary magnetic head upon the detection of said specific recording track to achieve a still reproduction of the video signal information of said desired picture frame.
Claim 3
Dependent Claim
55 words
A device according to claim 1 wherein each of said block address signals includes a plurality of pulses recorded on said magnetic tape in a row in the driving direction of said tape and the leading end of each of said blocks is identified upon detection of at least a predetermined number of said pulses.
Claim 4
Dependent Claim
26 words
A device according to claim 1 wherein said blocks are disposed on the magnetic tape with a predetermined space between each adjacent two of said blocks.
Claim 5
Dependent Claim
53 words
A device according to claim 1 wherein each of said block address signals includes a specific low frequency component indicative of the leading end of said each block and the leading end of said each block is detected by means of a band-pass filter which is adaptable to detect said specific frequency component.
Claim 6
Dependent Claim
39 words
A device according to claim 1 wherein each of said block address signals includes a block identIfying signal and a leading end indicating signal respectively recorded as different tracks spaced from the recording tracks of the video signal information.
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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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |