US4491884A
Expired / Lapsed
US
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Method of monitoring head alignment in a magnetic data storage device
Assignee: Verbatim Corp
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Filing: 1983-03-01
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Granted: 1985-01-01
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Expires: 2003-03-01
Abstract
Abstract A method for monitoring the alignment of the read-write head of a magnetic media data storage device comprising the steps of: establishing an elasped time window during which the read-write head should pass through a predetermined position if the head alignment has not drifted; checking to determine if the actual time at which the read-write head passes through said position actually falls within said window; and providing a pair of signals for indication of alignment or misalignment.
Inventors
- 👤 Kevin J. Carey
- 👤 Brian Hanlon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:28
CPC Classifications
G; G11; G11B; G11B33/00; G11B33/10; G11B21/00; G11B21/02; G11B21/10; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/5526; G11B5/553; G11B5/5534
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
211 words
A method for monitoring alignment of a read-write transducer head with respect to the tracks of data in a storage device having magnetic storage of data on magnetic recording media wherein the method comprises the steps of: a. activating a first timing means for measuring a fixed interval of time simultaneously with the initiation of the movement of the read-write head from its resting position; b. activating a second timing means for measuring a fixed interval of time at the instant in time when said first means for measuring a fixed interval of time has completed its respective time interval; c. sensing the instant in time when the read-write head has moved to a predetermined position a distance away from said resting position by utilizing a means for position sensing; and d. checking the status of said second timing means for measuring a fixed interval of time at the instant the read-write head has moved to said predetermined position and, if said second means for measuring a fixed interval of time has not yet been actuated, or if said second means for measuring a fixed interval of time has been activated and has completed the timing of its respective time interval, producing a signal signifying potential misalignment of the read-write head.
Claim 2
Independent Claim
211 words
A method for monitoring alignment of a read-write transducer head with respect to the tracks of data in a storage device having magnetic storage of data on magnetic recording media wherein the method comprises the steps of: a. activating a first timing means for measuring a fixed interval of time simultaneously with the initiation of the movement of the read-write head from its resting position; b. activating a second timing means for measuring a fixed interval of time at the instant in time when said first means for measuring a fixed interval of time has completed its respective time interval; c. sensing the instant in time when the read-write head has moved to a predetermined position a distance away from said resting position by utilizing a means for position sensing; and d. checking the status of said second timing means for measuring a fixed interval of time at the instant the read-write head has moved to said predetermined position and, if said second means for measuring a fixed interval of time has not yet been actuated, or if said second means for measuring a fixed interval of time has been activated and has completed the timing of its respective time interval, producing a signal signifying potential misalignment of the read-write head.
Claim 3
Dependent Claim
25 words
The method of claim 1, further comprising the step of exciting an indicator in response to said signal signifying potential misalignment of the read-write head.
Claim 4
Dependent Claim
13 words
The method of claim 2, wherein said indicator comprises a light emitting diode.
Claim 5
Dependent Claim
45 words
The method of claim 1, further comprising generating a signal signifying correct alignment of the read-write head when said signal signifying potential misalignment is absent, and further comprising the exciting of an indicator in response to said signal signifying correct alignment of the read-write head.
Claim 6
Dependent Claim
13 words
A method of claim 4 wherein said indicator comprises a light emitting diode.
Claim 7
Dependent Claim
32 words
The method of claim 1 wherein said first means for measuring a fixed interval of time, and said second means for measuring a fixed interval of time each comprise a monostable multivibrator.
Claim 8
Dependent Claim
73 words
The method of claim 1 wherein said checking of the status of said second means for measuring a fixed interval of time at the instant the read-write head has moved to said predetermined position is accomplished by use of a bistable multivibrator with its data input connected to the output of said second means for measuring a fixed interval of time, and with its clock input connected to said means for position sensing.
Claim 9
Independent Claim
75 words
A method for monitoring alignment of a read-write head in a data storage device comprising comparing the actual time required for the head to move from its resting position to a predetermined position, with a predetermined value for that time period, and producing a signal if said actual time required for the head to so move is different from said predetermined value for that time period by an amount of time exceeding a predetermined limit.
Claim 10
Independent Claim
75 words
A method for monitoring alignment of a read-write head in a data storage device comprising comparing the actual time required for the head to move from its resting position to a predetermined position, with a predetermined value for that time period, and producing a signal if said actual time required for the head to so move is different from said predetermined value for that time period by an amount of time exceeding a predetermined limit.
References Cited (Backward Citations)
US3670316A
Cited
US4136365A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-01 | 1988-07-02 | 1989-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-01 | 1992-07-02 | 1993-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-01 | 1996-07-02 | 1997-01-01 | $7700.00 | Window Closed / Lapsed |