Patent US4514772A successfully refreshed from Google Patents.
US4514772A
Expired / Lapsed
US
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Apparatus for reading/writing data on magnetic disc
Assignee: Individual
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Filing: 1983-02-09
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Granted: 1985-04-30
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Expires: 2003-02-09
Abstract
Abstract Apparatus for incrementally positioning a magnetic transducer read/write head for recording data magnetically upon a single rotating magnetic recording media in the form of a disc wherein the read/write head is moved such that the read/write head gap travels along a locus which is parallel to but displaced from a radial disposed in an orthogonal plane extending from the axis of rotation of the disc.
Inventors
- 👤 Gill Cantwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:42
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/012
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
155 words
Apparatus for reading/writing data on a single flexible rotatable magnetic disc comprising: (A) first means for magnetically reading/writing data on said disc including a tunnel erase head including a read/write head gap and erase gaps, said read/write head gap being separated from said erase gaps by a first pre-determined distance; (B) second means for moving said first means along a linear path parallel to a radial disposed in an orthogonal plane extending from the axis of rotation of said disc; (C) said linear path being displaced from said radial by a distance equal to one half of said first pre-determined distance; and (D) said second means positioning said first means in incremental steps along said linear path at a ratio of: ##EQU5## where R=the distance between the axis of rotation of the disc and the center of the data track under consideration, and A=1/2 the distance between the read/write head gap and the erase gaps.
Claim 2
Dependent Claim
155 words
Apparatus for reading/writing data on a single flexible rotatable magnetic disc comprising: (A) first means for magnetically reading/writing data on said disc including a tunnel erase head including a read/write head gap and erase gaps, said read/write head gap being separated from said erase gaps by a first pre-determined distance; (B) second means for moving said first means along a linear path parallel to a radial disposed in an orthogonal plane extending from the axis of rotation of said disc; (C) said linear path being displaced from said radial by a distance equal to one half of said first pre-determined distance; and (D) said second means positioning said first means in incremental steps along said linear path at a ratio of: ##EQU5## where R=the distance between the axis of rotation of the disc and the center of the data track under consideration, and A=1/2 the distance between the read/write head gap and the erase gaps.
Claim 3
Dependent Claim
69 words
Apparatus as defined in claim 1 wherein the angle of the magnetic transitions representative of data recorded on said disc with respect to a matching radial is equal to: ∠B=ARCSINE(A/R) wherein B=the angle of the magnetic transitions, R=the distance between the axis of rotation of the disc and the center of the data track under consideration, and A=1/2 the distance between the read/write head gap and the erase gaps.
Claim 4
Dependent Claim
98 words
Apparatus for reading/writing data on a single flexible rotatable magnetic disc comprising: (A) first means for magnetically reading/writing along a linear path parallel to a radial disposed in an orthogonal plane extending from the axis of rotation of said disc, said linear path being displaced from said radial by an amount substantially equal to 0.018 inches, said second means positioning said first means in incremental steps along said linear path at a ratio of: ##EQU6## where R=the distance between the axis of rotation of the disc and the center of the data track under consideration, and A=0.018 inches.
Claim 5
Dependent Claim
98 words
Apparatus for reading/writing data on a single flexible rotatable magnetic disc comprising: (A) first means for magnetically reading/writing along a linear path parallel to a radial disposed in an orthogonal plane extending from the axis of rotation of said disc, said linear path being displaced from said radial by an amount substantially equal to 0.018 inches, said second means positioning said first means in incremental steps along said linear path at a ratio of: ##EQU6## where R=the distance between the axis of rotation of the disc and the center of the data track under consideration, and A=0.018 inches.
Claim 6
Dependent Claim
59 words
Apparatus as defined in claim 3 wherein the angle of the magnetic transitions representative of data recorded on said disc with respect to a matching radial is equal to: ∠B=ARCSINE(A/R) wherein B=the angle of the magnetic transitions, R=the distance between the axis of rotation of the disc and the center of the data track under consideration, and A=0.018 inches.
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) | 1988-04-29 | 1988-10-29 | 1989-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-29 | 1992-10-29 | 1993-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-29 | 1996-10-29 | 1997-04-30 | $7700.00 | Window Closed / Lapsed |