US4044387A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic head switching system
Assignee: Unisys Corp
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Filing: 1975-09-02
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Granted: 1977-08-23
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Expires: 1995-09-02
Abstract
Abstract A switching system for use with magnetic heads and providing protection for the read or write circuits while the other is being used and further substantially reducing any losses or distortion in the read signal when the circuit is switched to the read mode.
Inventors
- 👤 Lee A. Watkins
- 👤 Larry M. Jacob
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:41
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/02; G11B15/12; G11B5/00; G11B5/02
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
187 words
A combined magnetic recording and reading system for recording data on and reading data from a magnetic recording medium, said system comprising: a read/write head capable of recording data on the magnetic recording medium responsive to electrical signals and for generating electrical signals responsive to reading data from the recording medium; a write driver circuit for generating electrical signals for causing the read/write head to record data on the medium; a read circuit for processing electric signals generated by the read/write head reading recorded data from the medium; a first switching circuit connecting the write driver circuit to the read/write head; a second switching circuit connecting the read circuit to the read/write head; switching means in the first and second switching circuits; and means for energizing said switching means operable to open the switching means in the first switching circuit while the read/write head is reading data and for opening the switching means in the second switching circuit when the read/write head is recording data thereby to prevent the electrical signals of the read circuit and write driver circuit from being transmitted through the other switching circuit.
Claim 2
Dependent Claim
187 words
A combined magnetic recording and reading system for recording data on and reading data from a magnetic recording medium, said system comprising: a read/write head capable of recording data on the magnetic recording medium responsive to electrical signals and for generating electrical signals responsive to reading data from the recording medium; a write driver circuit for generating electrical signals for causing the read/write head to record data on the medium; a read circuit for processing electric signals generated by the read/write head reading recorded data from the medium; a first switching circuit connecting the write driver circuit to the read/write head; a second switching circuit connecting the read circuit to the read/write head; switching means in the first and second switching circuits; and means for energizing said switching means operable to open the switching means in the first switching circuit while the read/write head is reading data and for opening the switching means in the second switching circuit when the read/write head is recording data thereby to prevent the electrical signals of the read circuit and write driver circuit from being transmitted through the other switching circuit.
Claim 3
Dependent Claim
34 words
A combined magnetic recording and reading system as defined in claim 7 wherein said switching means comprises diodes with means to back bias said diodes to prevent current flow through the associated switching circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-22 | 1981-02-21 | 1981-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-22 | 1985-02-21 | 1985-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-22 | 1989-02-21 | 1989-08-23 | $7700.00 | Window Closed / Lapsed |