US3643036A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for detecting a position error in the step-by-step movements of magnetic heads
Assignee: Victor Company of Japan Ltd
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Filing: 1970-01-26
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Granted: 1972-02-15
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Expires: 1990-01-26
Abstract
Abstract A system for detecting an error in the step-by-step movements of magnetic heads for a recording and reproducing apparatus using a rotary magnetic medium. A plurality of magnetic heads are alternately moved intermittently in a predetermined cycle over the rotary magnetic medium, from its marginal portion to its central portion and return, for example. The recording or reproducing is a continuous video signal recorded on a number of concentric circular tracks. The magnetic heads are moved in stepby-step motion. The recording magnetic head remains stationary over the rotating medium, each field or each frame of the video signal being recorded in one of the circular tracks. The inventive system enables a ready detection, and it indicates and corrects an error in the step-by-step movements of the magnetic heads.
Inventors
- 👤 Seiichi Takashima
- 👤 Takatoshi Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:51
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/78; H04N5/781
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
190 words
A system for controlling the step-by-step movements of magnetic heads comprising a rotary magnetic medium, a plurality of magnetic heads maintained in contact with said magnetic medium, means for rotating said magnetic medium at a predetermined rate, means comprising said plurality of magnetic heads for recording and reproducing a signal in a plurality of concentric tracks formed on said magnetic medium, means for alternately moving said plurality of magnetic heads over a radius of said magnetic medium in intermittent step-by-step movements, said system continuously recording signals on said medium with one of said heads recording while the other of said heads is stepping, motion detecting means for confirming the physical occurrence of said stepping motion, each stationary period in said step-by-step movement including a portion when one of said plurality of magnetic heads overlaps a stationary portion of the other magnetic head, and means responsive to the detection of an error by said motion-detecting means in the operation of said means for alternately moving said plurality of magnetic heads in intermittent step-by-step movements for detecting the absence of overlapping portions in said detection signals and actuating an error informing deviCe.
Claim 2
Independent Claim
190 words
A system for controlling the step-by-step movements of magnetic heads comprising a rotary magnetic medium, a plurality of magnetic heads maintained in contact with said magnetic medium, means for rotating said magnetic medium at a predetermined rate, means comprising said plurality of magnetic heads for recording and reproducing a signal in a plurality of concentric tracks formed on said magnetic medium, means for alternately moving said plurality of magnetic heads over a radius of said magnetic medium in intermittent step-by-step movements, said system continuously recording signals on said medium with one of said heads recording while the other of said heads is stepping, motion detecting means for confirming the physical occurrence of said stepping motion, each stationary period in said step-by-step movement including a portion when one of said plurality of magnetic heads overlaps a stationary portion of the other magnetic head, and means responsive to the detection of an error by said motion-detecting means in the operation of said means for alternately moving said plurality of magnetic heads in intermittent step-by-step movements for detecting the absence of overlapping portions in said detection signals and actuating an error informing deviCe.
Claim 3
Dependent Claim
20 words
A system as defined in claim 1 in which said error informing device comprises a sensory signal error indication device.
Claim 4
Dependent Claim
81 words
A system as defined in claim 1 further comprising intermittent step-by-step movement error correction means comprising quick return means for returning each of said plurality of magnetic heads to its step-by-step movement initiation position, means for detecting the step-by-step movement initiation position of each of said plurality of magnetic heads, and means for controlling said means for alternately moving said plurality of magnetic heads in intermittent step-by-step movements with a detection output signal of said step-by-step movement initiation position detection means.
Claim 5
Dependent Claim
74 words
A system as defined in claim 1 in which there are two of said plurality of magnetic heads and said means for alternately moving said two magnetic heads in intermittent step-by-step movements consists of two units, each of said units comprising a pulse motor, a feed screw connected to the rotary shaft of said pulse motor, and a head supporting member mounting one of said two magnetic heads and threadably engaging said feed screw.
Claim 6
Dependent Claim
122 words
A system as defined in claim 4 wherein said step-by-step motion error detection means comprises first detection means for detecting a rotational angular position of said feed screw of one of said units and producing a first detection signal, second detection means for detecting a rotational angular position of said feed screw of the other unit and producing a second detection signal, and an AND gate circuit to which said first detection signal and said second detection signal are connected, said AND gate circuit producing an output signal during the period while said two detection signals are simultaneously produced, and said AND gate circuit does not produce an output signal during the period while said two detection signals are not produced simultaneously.
Claim 7
Independent Claim
269 words
A system for detecting an error in the step-by-step movements of magnetic heads associated with a rotary magnetic medium, means comprising a plurality of magnetic heads maintained in contact with said magnetic medium, means for rotating said magnetic medium at a predetermined rate, means comprising said plurality of magnetic heads for recording and reproducing a signal in a plurality of tracks formed on said magnetic medium, means for alternately moving said plurality of magnetic heads over a path along the radius of said magnetic medium, said movement being in intermittent step-by-step movements, each stationary period in said step-by-step movements including an interval during which one of said plurality of magnetic heads overlaps a stationary portion of the other magnetic head, means for switching a continuous recording signal to supply the recording signal to alternate ones of said magnetic heads during the time while the operating one of said magnetic heads remains stationary, means for selecting and switching signals reproduced by alternate ones of said magnetic heads to produce a continuous signal, means for detecting the positions where said magnetic heads remain stationary and for producing detection signals indicative of said stationary position, an AND gate circuit means to which said detection signals are applied, said AND gate circuit producing an output signal during the period while said detection signals are simultaneously produced and producing no output signal during the period while said detection signals are not produced simultaneously, and means for detecting the absence of overlapping portions in one of said detection signals and said output signal of said AND gate circuit, and means for actuating an error-indicating device.
Claim 8
Independent Claim
269 words
A system for detecting an error in the step-by-step movements of magnetic heads associated with a rotary magnetic medium, means comprising a plurality of magnetic heads maintained in contact with said magnetic medium, means for rotating said magnetic medium at a predetermined rate, means comprising said plurality of magnetic heads for recording and reproducing a signal in a plurality of tracks formed on said magnetic medium, means for alternately moving said plurality of magnetic heads over a path along the radius of said magnetic medium, said movement being in intermittent step-by-step movements, each stationary period in said step-by-step movements including an interval during which one of said plurality of magnetic heads overlaps a stationary portion of the other magnetic head, means for switching a continuous recording signal to supply the recording signal to alternate ones of said magnetic heads during the time while the operating one of said magnetic heads remains stationary, means for selecting and switching signals reproduced by alternate ones of said magnetic heads to produce a continuous signal, means for detecting the positions where said magnetic heads remain stationary and for producing detection signals indicative of said stationary position, an AND gate circuit means to which said detection signals are applied, said AND gate circuit producing an output signal during the period while said detection signals are simultaneously produced and producing no output signal during the period while said detection signals are not produced simultaneously, and means for detecting the absence of overlapping portions in one of said detection signals and said output signal of said AND gate circuit, and means for actuating an error-indicating device.
Claim 9
Dependent Claim
69 words
A system as defined in claim 6 in which there are two of said magnetic heads, and said means for alternately moving said two magnetic heads in intermittent step-by-step movements comprising two units each having a pulse motor, a feed screw connected to the rotary shaft of said pulse motor, and a head suppoRting member individually mounting one of said two magnetic heads and threadably engaging said feed screw.
Claim 10
Dependent Claim
17 words
A system as defined in claim 6 in which said error-indicating device comprises an error indication lamp.
Claim 11
Dependent Claim
17 words
A system as defined in claim 6 in which said error-indicating device comprises an error warning buzzer.
Claim 12
Dependent Claim
22 words
A system as defined in claim 6 in which said error-indicating device comprises an error indication lamp and an error warning buzzer.
Claim 13
Dependent Claim
52 words
A system as defined in claim 6 further comprising intermittent step-by-step movement error correction means comprising quick return means for returning each of said magnetic heads to its initial position, means for detecting the initial position of each of said magnetic heads, and a quick return switch controlling said quick return means.
References Cited (Backward Citations)
US3548095A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-14 | 1975-08-16 | 1976-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-14 | 1979-08-16 | 1980-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-14 | 1983-08-16 | 1984-02-15 | $7700.00 | Window Closed / Lapsed |