US4037258A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Read/write apparatus for magnetic recorders
Assignee: Xerox Corp
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Filing: 1976-02-02
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Granted: 1977-07-19
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Expires: 1996-02-02
Abstract
Abstract A read/write apparatus for magnetic recorders including a decoder for converting input digital control and data signals into a plurality of select signals, a voltage source switchably connected to the read/write heads of the apparatus such that individual select lines are enabled for determining which recording head is actuated for writing on a chosen magnetic medium, what orientation of magnetic flux will be written, and what magnitude of flux will be written. Also, the select lines operate, when the voltage source is disabled, to condition the heads to allow read-out of data recorded on the magnetic media, and to select which head is to perform this read-out. Also included in the recorder is a signal redigitizer to digitize data read from the magnetic media, and erase means for reducing edge and transient effects on the magnetic media.
Inventors
- 👤 Srinivasan V. Chari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:49
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/02; G11B15/12; G11B15/125
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
185 words
In a read/write apparatus for magnetic recorders including a magnetic recording and reproducing head having at least one winding for converting electric signals into magnetic flux variations that may be recorded on a magnetic recording medium movable relative to said head and for converting said magnetic flux variations so recorded back into electric signals, the improvement comprising: control means for generating a signal to be recorded, said control means including a digital decoder capable of numeric base transformations and having a plurality of inputs for receiving function control and data input signals and plurality of outputs normally at a first voltage state, wherein a predetermined number of said outputs will assume a second voltage state in response to the particular function control and data input signals applied at its inputs; and write means for generating said electric signals, said write means including a voltage source coupled to said head and capable of being applied across said winding when at least a predetermined one of said outputs is at its second voltage state, whereby current of a predetermined magnitude is made to flow through said winding.
Claim 2
Dependent Claim
185 words
In a read/write apparatus for magnetic recorders including a magnetic recording and reproducing head having at least one winding for converting electric signals into magnetic flux variations that may be recorded on a magnetic recording medium movable relative to said head and for converting said magnetic flux variations so recorded back into electric signals, the improvement comprising: control means for generating a signal to be recorded, said control means including a digital decoder capable of numeric base transformations and having a plurality of inputs for receiving function control and data input signals and plurality of outputs normally at a first voltage state, wherein a predetermined number of said outputs will assume a second voltage state in response to the particular function control and data input signals applied at its inputs; and write means for generating said electric signals, said write means including a voltage source coupled to said head and capable of being applied across said winding when at least a predetermined one of said outputs is at its second voltage state, whereby current of a predetermined magnitude is made to flow through said winding.
Claim 3
Dependent Claim
12 words
The read/write apparatus of claim 1, wherein said predetermined number is one.
Claim 4
Dependent Claim
57 words
The read/write apparatus of claim 1, wherein current of a first magnitude is made to flow through said winding when said predetermined one output is at its second voltage state, and current of a second magnitude is made to flow through said winding when a predetermined other one of said outputs is at its second voltage state.
Claim 5
Dependent Claim
49 words
The read/write apparatus of claim 1, further comprising read means for reading electrical signals converted by said head from magnetic flux variations recorded on said magnetic recording medium, wherein said digital decoder includes means for disconnecting said voltage source from across said winding during operation of said read means.
Claim 6
Dependent Claim
177 words
The read/write apparatus of claim 1 wherein: said head comprises first and second windings connected together at a centertap point, said first winding being adapted to record magnetic flux variations in a first direction on said magnetic recording medium and alternatively to reproduce electrical signals when sensing magnetic flux variations so written in said first direction, and said second winding being adapted to record magnetic flux variations in a second direction on said magnetic recording medium and alternatively to reproduce electrical signals when sensing magnetic flux variations so written in said second direction; said voltage source is capable of being applied across said first winding when at least a predetermined one of said outputs is at its second voltage state whereby current of a predetermined magnitude is made to flow through said first winding; and said voltage source is capable of being applied across said second winding when at least a predetermined other one of said outputs is at its second voltage state whereby current of a predetermined magnitude is made to flow through said second winding.
Claim 7
Dependent Claim
60 words
The read/write apparatus of claim 5, wherein current of a first magnitude is made to flow through said first winding when said predetermined one output is at its second voltage state, and current of a second magnitude is made to flow through said first winding when a predetermined still other one of said outputs is at its second voltage state.
Claim 8
Dependent Claim
60 words
The read/write apparatus of claim 6, wherein current of said first magnitude is made to flow through said second winding when said predetermined other one output is at its second voltage state, and current of second magnitude is made to flow through said second winding when a predetermined yet other one of said outputs is at its second voltage state.
Claim 9
Dependent Claim
12 words
The read/write apparatus of claim 7, wherein said predetermined number is one.
Claim 10
Dependent Claim
72 words
The read/write apparatus of claim 8, further comprising a second magnetic recording and reproducing head having first and second windings, wherein said decoder outputs are divided into a first group associated with a write operation and a second group associated with a read operation, each output of said first group when at its second voltage state causing a specific magnitude of current to applied through a specific winding of a specific head.
Claim 11
Dependent Claim
17 words
The read/write apparatus of claim 9, wherein said second voltage state of said outputs is ground potential.
Claim 12
Dependent Claim
84 words
The apparatus of claim 10, further comprising an erase head associated with each magnetic recording and reproducing head, each erase head being physically located such that it is exposed to the same path or track on the medium as was exposed to its associated magnetic recording and reproducing head, each erase head acting to erase edge effects including magnetic flux transients on said medium, while leaving intact the desired magnetic flux variations placed on the medium by the associated magnetic recording and reproducing head.
Claim 13
Dependent Claim
60 words
The apparatus of claim 11, further comprising delay means for delaying the turn-on and turn-off time of said erase head to compensate for the position of the erase head with respect to the magnetic recording and reproducing head so that erasure is synchronized to begin at a point on the magnetic medium where recording was begun by said recording head.
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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) | 1980-07-18 | 1981-01-17 | 1981-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-18 | 1985-01-17 | 1985-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-18 | 1989-01-17 | 1989-07-19 | $7700.00 | Window Closed / Lapsed |