Patent EP0396362A2 successfully refreshed from Google Patents.
EP0396362A2
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EP
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Helical scan type playback apparatus for video data recorded on magnetic tape
Assignee: Victor Company of Japan Ltd
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Filing: 1990-04-27
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Granted: —
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Expires: 2010-04-27
Abstract
Abstract There is disclosed a helical scan type playback apparatus comprising a plurality of magnetic heads (1a,1b), a position signal generation element for generating a signal indicative of each position of these magnetic heads, and a switching element (S1) for video signals played back by the plurality of magnetic heads in response to the position signal (105) from the generation element, particularly a playback apparatus for information recorded on a video tape in which the phase of a low frequency band color signal is altered every track of a video tape on the basis of a predetermined rule, thereby allowing spectra of color signals not to overlap with each other between adjacent tracks. This playback apparatus comprises an element (4) for storing the position signal after a first predetermined time has passed from the time when a vertical synchronizing signal (101) of the video signal is received, and a readout element for reading out the position signal stored in the storage element (4) after a second predetermined time has passed from the time when the vertical synchronizing signal is received, and outputting it.
Inventors
- 👤 Yasuomi Namiki
- 👤 Masaru Tanaka
- 👤 Yoshio Tokuyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 09:29
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; H; H04; H04N; H04N5/00; H04N5/76; H04N5/78; H04N5/782; G11B15/00; G11B15/02; G11B15/12; G11B15/14; H04N9/00; H04N9/79; H04N9/80; H04N9/82; H04N9/83; H04N9/84
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
A helical scan type magnetic playback apparatus comprising a plurality of magnetic heads, position signal generator means for generating a position signal indicative of each position of the plurality of magnetic heads, and switching means responsive to the position signal from said position signal generator means to switch video signals played back or reproduced by said plurality of magnetic heads, said apparatus comprising first means responsive to a vertical synchronizing signal of said video signal to store said position signal after a first predetermined time has passed from reception of said vertical synchronizing signal, and second means responsive to said vertical synchronizing signal to read said position signal stored in said first means after a second predetermined time longer than said first predetermined time has passed from reception of said vertical synchronizing signal and output it.
Claim 2
Dependent Claim
136 words
A helical scan type magnetic playback apparatus comprising a plurality of magnetic heads, position signal generator means for generating a position signal indicative of each position of the plurality of magnetic heads, and switching means responsive to the position signal from said position signal generator means to switch video signals played back or reproduced by said plurality of magnetic heads, said apparatus comprising first means responsive to a vertical synchronizing signal of said video signal to store said position signal after a first predetermined time has passed from reception of said vertical synchronizing signal, and second means responsive to said vertical synchronizing signal to read said position signal stored in said first means after a second predetermined time longer than said first predetermined time has passed from reception of said vertical synchronizing signal and output it.
Claim 3
Dependent Claim
191 words
An apparatus as set forth in claim 1, and a video tape recorder in which the phase of a low frequency band color signal is altered every track of a video tape on the basis of a predetermined rule, thereby allowing spectra of color signals not to overlap with each other between adjacent tracks, characterized by the provision of a color phase processing control signal generator circuit adapted to receive a drum flip-flop signal of which state varies in dependency upon changes in a rotational phase of a drum for playing back or reproducing a signal from a tape wound onto the outer circumference thereof and a synchronizing signal included in the video signal to output a modified drum flip-flop signal adjusted so that its state varies at a predetermined timing with respect to the synchronizing signal as a color phase processing control signal for designating the direction of alteration of a low frequency band color phase, and a phase alteration circuit for altering a low frequency band color phase on the basis of a predetermined rule in accordance with an output from the color phase processing control signal generator circuit.
Claim 4
Dependent Claim
41 words
A video tape recorder as set forth in claim 2, wherein said video signal is a recording video signal, and said phase alteration circuit serves to alter the low frequency band color phase at the time of recording said video signal.
Claim 5
Dependent Claim
44 words
A video tape recorder as set forth in claim 2, wherein said video signal is a playback video signal, and said phase alteration circuit serves to alter the low frequency band color phase at the time of playing back or reproducing the video signal.
Claim 6
Dependent Claim
73 words
A video tape recorder as set forth in claim 2, which further comprises a plurality of video playback heads, a head switching circuit for switching outputs from these heads to deliver a switched one to a video playback circuit, and a delay circuit for delaying said drum flip-flop signal by a predetermined time, thus to deliver an output from said delay circuit to said head switching circuit as a head switching control signal.
Claim 7
Dependent Claim
140 words
An apparatus as set forth in claim 1, and a video tape recorder in which the phase of a low frequency band color signal is altered every track of a video tape on the basis of a predetermined rule, thereby allowing spectra of color signals not to overlap with each other between adjacent tracks, characterized by the provision of sense means for sensing an error of the phase of a low frequency band color signal produced at the time of playback by a shift between the switching point of a predetermined rule at the time of recording and the switching point of a predetermined rule at the time of playback, and control correction means for correcting the phase of a playback low frequency color signal in dependency upon a sense signal of a phase error outputted from the sense means.
Claim 8
Dependent Claim
51 words
A video tape recorder as set forth in claim 6, wherein said control correction means comprises timing means for setting a fixed period related to the vertical synchronizing signal obtained from a playback video signal, and gate means for taking out said phase error sense signal only for a fixed period.
Claim 9
Dependent Claim
118 words
A video tape recorder as set forth in claim 7, which further comprises a plurality of video playback head, a head switching circuit for switching outputs from these heads to a switched output to the video playback circuit, and a head switching control circuit for delivering, to said head switching circuit, as a head switching control signal, a modified flip-flop signal adjusted so that the state change point of a drum flip-flop signal of which state varies in dependency upon changes in the phase of rotation of the drum for playing back or reproducing a signal from said tape wound onto the outer circumference thereof is shifted up to the position after the range of a fixed period.
Claim 10
Dependent Claim
68 words
A video tape recorder as set forth in claim 8, wherein said gate means serves to take out only a first phase error within a fixed period, and said control correction means serves to correct a playback color phase in accordance with a predetermined rule from the time point when said error sense signal is produced to the time point when said head switching control signal is produced.
References Cited (Backward Citations)
No citation records indexed.
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