US5490124A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Write and erase assembly for magneto-optic drive apparatus
Assignee: HP Inc
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Filing: 1994-08-02
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Granted: 1996-02-06
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Expires: 2014-08-02
Abstract
Abstract A write-erase magnet assembly for a data storage device including: a permanent magnet having a longitudinal axis and having a first longitudinally extending face portion with a first polarity and a second longitudinally extending face portion with a second polarity opposite the first polarity for alternately producing write and erase magnetic bias fields on an adjacently positioned data storage medium; a magnet support assembly for rotatably supporting the permanent magnet; a magnetic detent fixedly positioned relative to the longitudinal axis of the permanent magnet for magnetically producing a biasing torque on the magnet tending to orient the closer of the first and second face portions of the permanent magnet in adjacent relationship with the detent. A coil for applying flipping torque and braking torque for an eddy current rotation dampening assembly are also disclosed.
Inventors
- 👤 Thomas C. Oliver
- 👤 David P. Jones
- 👤 Leslie G. Christie
- 👤 Mark E. Wanger
- 👤 Thomas E. Berg
- 👤 Melvin C. Crane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:11
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/1055; G11B11/10556; G11B11/10558; G11B11/1056; G11B33/00; G11B33/14
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
118 words
A method of switching write and erase magnetic bias fields applied to a data storage medium using a permanent magnet having a first magnetic field orientation in a first rotation position associated with a writing operation and a second magnetic field orientation in a second rotation position associated with an erasing operation comprising the steps of: a) applying a flipping torque to rotate the permanent magnet from the first rotation position to the second rotation position; b) during all periods when the permanent magnet is not in the first or second rotation positions, passively applying torque thereto with a stationary magnetic detent so as to urge said permanent magnet towards one of said first and second rotation positions.
Claim 2
Independent Claim
118 words
A method of switching write and erase magnetic bias fields applied to a data storage medium using a permanent magnet having a first magnetic field orientation in a first rotation position associated with a writing operation and a second magnetic field orientation in a second rotation position associated with an erasing operation comprising the steps of: a) applying a flipping torque to rotate the permanent magnet from the first rotation position to the second rotation position; b) during all periods when the permanent magnet is not in the first or second rotation positions, passively applying torque thereto with a stationary magnetic detent so as to urge said permanent magnet towards one of said first and second rotation positions.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein the step of applying a flipping torque comprises energizing an electric coil only during periods when said flipping torque is to be applied.
Claim 4
Dependent Claim
22 words
The method of claim 2 comprising the further step of applying a braking torque on the permanent magnet with the electric coil.
Claim 5
Dependent Claim
24 words
The method of claim 3 comprising the further step of applying a braking torque on the permanent magnet through the use of eddy currents.
Claim 6
Dependent Claim
45 words
The method of claim 4 wherein the step of applying a braking torque on the permanent magnet through the use of eddy currents comprises using eddy currents produced in the coil and eddy currents produced in a frame member which rotationally supports the permanent magnet.
Claim 7
Dependent Claim
55 words
The method of claim 5 comprising the further steps of: a) continuously sensing the relative rotated position of the permanent magnet and generating a sensing signal representative thereof; and b) performing the steps of applying a flipping torque and applying a braking torque with the electric coil at predetermined times dependent upon said sensing signal.
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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) | 1999-02-05 | 1999-08-07 | 2000-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-02-05 | 2003-08-07 | 2004-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-02-05 | 2007-08-07 | 2008-02-06 | $7700.00 | Window Closed / Lapsed |