Patent EP0046341A1 successfully refreshed from Google Patents.
EP0046341A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Signal reproducing apparatus having head tracking control
Assignee: Sony Corp
•
Filing: 1981-07-22
•
Granted: —
•
Expires: 2001-07-22
Abstract
Abstract A video tape recording/reproducing apparatus for reproducing video signals recorded in successive parallel tracks on a magnetic tape, includes a magnetic head movable in a direction generally along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing signals recorded therein, and a bi-morph leaf for mounting the head and being operative to deflect the head in a direction transverse to the direction along the tracks. During the scanning operation, the bi-morph leaf is supplied with a dithering signal for wobbling the head transversely with respect to the longitudinal direction of the record tracks, a tracking error signal to correct deviations of the head trace from the tracks to be scanned and a slant compensation signal to correct any inclination tracking error of the head. During the non-scanning operation, a jump signal is supplied to the bi-morph leaf for deflecting the head to accurately scan the beginning of the tracks. The present invention also includes a sample and hold circuit and a comparator circuit for producing a polarity signal corresponding to the direction of any deviation between the scanning trace of the head and the track then being scanned thereby, at the beginning end of the scanned track, and an UP/DOWN counter for producing and storing a control signal and for supplying the control signal to the bi-morph leaf so as to control the latter to deflect the head to accurately scan the beginning ends of the tracks, the counter being controlled by the comparator circuit to change the value of the stored control signal by an incremental amount by counting either UP or DOWN during each scan in accordance with the direction of the deviation at the beginning ends of the tracks.
Inventors
- 👤 Hitoshi Sakamoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 21:05
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/58; G11B5/584; G11B5/588
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
211 words
Apparatus for reproducing information signals recorded in successive parallel tracks on a record medium, comprising at least one transducer adapted for movement along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing the signals recorded therein; and a transducer deflecting device for deflecting said at least one transducer in a direction transverse to the direction along the tracks; characterized by a polarity detecting circuit (34, 35, 36, 37) for detecting the direction of any deviation between the scanning trace of said at least one transducer (1) and the track then being scanned thereby at the beginning end (S) of said scanned track; and an updating circuit (38, 39) for producing and storing a control signal in response to said polarity detecting circuit (34, 35, 36, 37) and for supplying said control signal to said transducer deflecting device (2) so as to control the latter (2) to deflect said at least one transducer (1) to accurately scan the beginning ends (S) of said tracks, said updating circuit (38, 39) being controlled. by said polarity detecting circuit (34, 35, 36, 37) to change the value of said stored control signal by an incremental amount in accordance with the detected direction of said deviation.
Claim 2
Dependent Claim
211 words
Apparatus for reproducing information signals recorded in successive parallel tracks on a record medium, comprising at least one transducer adapted for movement along each of the tracks in a scanning path from a beginning end to a concluding end thereof for reproducing the signals recorded therein; and a transducer deflecting device for deflecting said at least one transducer in a direction transverse to the direction along the tracks; characterized by a polarity detecting circuit (34, 35, 36, 37) for detecting the direction of any deviation between the scanning trace of said at least one transducer (1) and the track then being scanned thereby at the beginning end (S) of said scanned track; and an updating circuit (38, 39) for producing and storing a control signal in response to said polarity detecting circuit (34, 35, 36, 37) and for supplying said control signal to said transducer deflecting device (2) so as to control the latter (2) to deflect said at least one transducer (1) to accurately scan the beginning ends (S) of said tracks, said updating circuit (38, 39) being controlled. by said polarity detecting circuit (34, 35, 36, 37) to change the value of said stored control signal by an incremental amount in accordance with the detected direction of said deviation.
Claim 3
Dependent Claim
76 words
Apparatus according to claim 1; further characterized in that said polarity detecting circuit (34, 35, 36, 37) includes a comparator circuit (37) for comparing a tracking error signal (e) corresponding to said deviation between the scanning trace of said at least one transducer (1) and the track then being scanned thereby at the beginning end (S) of said scanned track, with a reference signal, for producing a polarity signal corresponding to the direction of said deviation.
Claim 4
Dependent Claim
103 words
Apparatus according to claim 2; in which said information signals include horizontal synchronizing signals; and in which said apparatus further includes a circuit for producing a dithering signal, and a tracking error detecting circuit for producing said tracking error signal, said tracking error detecting circuit including an envelope detecting circuit for producing an amplitude-modulation component from said signals reproduced by said at least one transducer, a sampling circuit for sampling said amplitude-modulation component at the occurrence of each horizontal synchronizing signal, and a synchronous detection circuit for synchronously detecting the sampled amplitude-modulation component with said dithering signal to produce said tracking error signal.
Claim 5
Dependent Claim
27 words
Apparatus according to claim 3; further characterized in that said polarity detecting circuit includes a sample and hold circuit (34, 36) for sampling said tracking error signal
Claim 6
Dependent Claim
60 words
(e), and a sampling signal generator circuit (35) for supplying a sampling signal (m) to said sample and hold circuit (34, 36) to cause the latter to sample and hold said tracking error signal (e) at the beginning ends (S) of the tracks and to then transmit the sampled and held tracking error signal (e) to said comparator circuit (37).
Claim 7
Dependent Claim
60 words
(e), and a sampling signal generator circuit (35) for supplying a sampling signal (m) to said sample and hold circuit (34, 36) to cause the latter to sample and hold said tracking error signal (e) at the beginning ends (S) of the tracks and to then transmit the sampled and held tracking error signal (e) to said comparator circuit (37).
Claim 8
Dependent Claim
46 words
Apparatus according to claim 1; further characterized in that said updating circuit (38, 39) includes an UP/DOWN counter circuit (38) for producing and storing said control signal by counting either UP or DOWN by said incremental amount in accordance with the detected direction of said deviation.
Claim 9
Dependent Claim
141 words
Apparatus according to claim 5; in which said information signals include vertical synchronizing signals; and further characterized in that said polarity detecting circuit (34, 35, 36, 37) includes a comparator circuit (37) for comparing a tracking error signal (e) corresponding to said deviation between the scanning trace of said at least one transducer (1) and the track then being scanned thereby at the beginning end (S) of said scanned track, with a reference signal, for producing a polarity signal corresponding to the direction of said deviation; and in that said UP/DOWN counter circuit (38) includes an UP/DOWN control input (U/D) supplied with said polarity signal for controlling said counter circuit (38) to count either UPor DOWN by said incremental amount in accordance with the detected direction of said deviation, and a clock input (CK) supplied with said vertical synchronizing signals (VD).
Claim 10
Dependent Claim
86 words
Apparatus according to claim 5; in which said stored control signal from said counter circuit (38) is in digital form; and further characterized in that said updating circuit (38, 39) further includes a digital-to-analog converting circuit (39) for converting said control signal in digital form to analog form and for supplying said analog control signal to said transducer deflecting device (2) so as to control the latter (2) to deflect said at least one transducer (1) to accurately scan the beginning ends (S) of said tracks.
Claim 11
Dependent Claim
56 words
Apparatus according to claim 5; in which said information signals include vertical synchronizing signals; and further characterized by a gating device (32) controlled by said vertical synchronizing signals (VD) to transmit said stored control signal to said transducer deflecting device (2) during the time when said at least one transducer (1) is not scanning said tracks.
Claim 12
Dependent Claim
129 words
Apparatus according to claim 8; in which said record medium is longitudinally advanced at a recording speed during a recording operation and at a reproducing speed during a reproducing operation; said apparatus further includes a jump signal forming circuit for producing a jump signal to eliminate phase errors between said at least one transducer and the beginning ends of the tracks to be scanned thereby when said reproducing speed is different from said recording speed; and further characterized by an adder (31) for adding said jump signal to said stored control signal and for supplying an added output to said gating device (32) which transmits said added output to said transducer deflecting device (2) during the time when said at least one transducer (1) is not scanning said tracks.
Claim 13
Dependent Claim
52 words
Apparatus according to claim 1; further characterized in that said updating circuit includes a charge pump circuit for producing and storing said control signal and for changing the value of said stored control signal by either adding or sub- tracing said incremental amount in accordance with the detected direction of said deviation.
References Cited (Backward Citations)
FR2345035A1
Cited
DE2738210A1
Cited
FR2401574A1
Cited
FR2418516A1
Cited
GB2018491A
Cited
GB2030346A
Cited
FR2444989A1
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.