US4424539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic disk-control track read through envelope
Assignee: International Business Machines Corp
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Filing: 1981-12-23
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Granted: 1984-01-03
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Expires: 2001-12-23
Abstract
Abstract Control information for a flexible magnetic disk storage assembly is recorded on the periphery of the disk in a region not used for recording data. The control information is read through the protective cover or envelope which encloses the disk by means of a magnetic transducer such as a four track audio cassette head which bears against the envelope. By recording index and sector pulses as part of the control information, hard sectoring can be inexpensively and accurately achieved. A recorded fixed frequency control signal can be read and used as part of the feedback loop in a phase locked oscillator used to control a d.c. motor driving the spindle. The control information can also include servo tracks which assist in registering the data transducer directly over data tracks on media which has changed its dimensions.
Inventors
- 👤 Steven D. Keidl
- 👤 Karl A. Shidler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:21
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/02; G11B19/12; G11B19/20; G11B19/28; G11B21/00; G11B21/02; G11B21/10; G11B21/106; G11B23/00; G11B23/30; G11B23/36; G11B23/38; G11B23/42; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/32; G11B2220/00; G11B2220/20; G11B2220/25; G11B2220/2508; G11B2220/2512
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
69 words
In a magnetic disk assembly including a flexible disk having a magnetic recording coating on at least one surface thereof and positioned within a disk carrier having an aperture therein for permitting a magnetic transducer to coact with said coating, the improvement comprising: at least one magnetic storage track at a location which is not accessible through said aperture, said storage track containing control information readable through said carrier.
Claim 2
Dependent Claim
69 words
In a magnetic disk assembly including a flexible disk having a magnetic recording coating on at least one surface thereof and positioned within a disk carrier having an aperture therein for permitting a magnetic transducer to coact with said coating, the improvement comprising: at least one magnetic storage track at a location which is not accessible through said aperture, said storage track containing control information readable through said carrier.
Claim 3
Dependent Claim
21 words
A device according to claim 1 wherein, said disc carrier is a flexible, rectangular envelope having walls of substantially uniform thickness.
Claim 4
Dependent Claim
31 words
A device according to claim 2 wherein, said aperture is a slot through both surfaces of said envelope positioned radially in a direction perpendicular to one edge of said rectangular envelope.
Claim 5
Dependent Claim
41 words
A device according to claim 3 wherein, said magnetic storage track not accessible through said aperture is located a radial distance from the center of said disk which is greater than the radial distance to the outmost end of said aperture.
Claim 6
Dependent Claim
24 words
A device according to claim 4 wherein, said control information includes a plurality of pulses which provide an indication of rotational velocity when read.
Claim 7
Dependent Claim
14 words
A device according to claim 4 wherein, said control information contains an index signal.
Claim 8
Dependent Claim
17 words
A device according to claim 4 wherein, said control information includes a plurality of sector locating pulses.
Claim 9
Dependent Claim
14 words
A device according to claim 4 wherein, said control information includes track servo information.
Claim 10
Dependent Claim
72 words
In a magnetic disk drive system for use with a flexible disk positioned within a carrier, a disk drive device for rotation of said disk within said carrier, first transducer means for coaction with said disk through an aperture in said carrier, to read and/or write data to or from said disk, the improvement comprising: second transducer means positioned to read control information from said disk through the wall of said carrier.
Claim 11
Dependent Claim
72 words
In a magnetic disk drive system for use with a flexible disk positioned within a carrier, a disk drive device for rotation of said disk within said carrier, first transducer means for coaction with said disk through an aperture in said carrier, to read and/or write data to or from said disk, the improvement comprising: second transducer means positioned to read control information from said disk through the wall of said carrier.
Claim 12
Dependent Claim
45 words
A device according to claim 9 wherein said disk drive device includes an electric motor, speed control means for said electric motor, and first circuit means connecting said second transducer to said speed control means to regulate the rotational velocity of said disk drive device.
Claim 13
Dependent Claim
60 words
A device according to claim 9 wherein said disk drive device includes control signal generating means for developing an index signal indicating a predetermined angular position of an associated flexible disk, and second circuit means connecting said second transducer to said control signal generating means to develop said index signal in response to control information recorded on an associated disk.
Claim 14
Dependent Claim
57 words
A device according to claim 9 wherein, said disk drive device includes control signal generating means for developing a sector signal indicating the sector positioned under said first transducer, and third circuit means connecting said second transducer to said control signal generating means to develop said sector signal in response to control information recorded on said disk.
Claim 15
Dependent Claim
62 words
A device according to claim 9 wherein, said disk drive device includes control signal generating means for developing a track servo signal indicating the relative displacement of said second transducer from a track, and fourth circuit means connecting said second transducer to said control signal generating means to develop said track servo signal in response to control information recorded on said disk.
Claim 16
Dependent Claim
59 words
A device according to claim 10 wherein, said disk drive device includes control signal generating means for developing an index signal indicating a predetermined angular position of an associated flexible disk, and second circuit means connecting said second transducer to said control signal generating means to develop said index signal in response to control information recorded on said disk.
Claim 17
Dependent Claim
57 words
A device according to claim 10 wherein, said disk drive device includes control signal generating means for developing a sector signal indicating the sector positioned under said first transducer, and third circuit means connecting said second transducer to said control signal generating means to develop said sector signal in response to control information recorded on said disk.
Claim 18
Dependent Claim
143 words
In combination, a magnetic disk drive system and a magnetic disk assembly, said magnetic disk assembly comprising; a flexible disk having a magnetic recording coating on at least one surface thereof to accommodate a plurality of data recording tracks and a control track, a disk carrier enclosing said disk, a first aperture in said enclosure to accommodate engagement with a drive means, a second aperture in said enclosure to permit a magnetic transducer to coact with said coating in the region of said data recording tracks, and said magnetic disk drive system comprising; a disk drive device for rotating said disk within said carrier, first transducer means for coaction with said disk through said second aperture in the region of said data recording tracks, and second transducer means for coaction with said disk through said carrier in the region of said control track.
Claim 19
Dependent Claim
143 words
In combination, a magnetic disk drive system and a magnetic disk assembly, said magnetic disk assembly comprising; a flexible disk having a magnetic recording coating on at least one surface thereof to accommodate a plurality of data recording tracks and a control track, a disk carrier enclosing said disk, a first aperture in said enclosure to accommodate engagement with a drive means, a second aperture in said enclosure to permit a magnetic transducer to coact with said coating in the region of said data recording tracks, and said magnetic disk drive system comprising; a disk drive device for rotating said disk within said carrier, first transducer means for coaction with said disk through said second aperture in the region of said data recording tracks, and second transducer means for coaction with said disk through said carrier in the region of said control track.
Claim 20
Dependent Claim
20 words
The combination of claim 16 wherein, said disk carrier is a flexible rectangular envelope having walls of substantially uniform thickness.
Claim 21
Dependent Claim
42 words
The combination of claim 17 wherein, said first aperture is a circular hole centered in said envelope and said second aperture is a slot through both surfaces of said envelope positioned radially in a direction perpendicular to one edge of said envelope.
Claim 22
Dependent Claim
35 words
The combination of claim 18 wherein, said control track is located a radial distance from the center of said disk which is greater than the radial distance to the outmost end of said second aperture.
Claim 23
Dependent Claim
22 words
The combination of claim 19 wherein said control track contains a recorded signal which provides an indication of rotational velocity when read.
Claim 24
Dependent Claim
14 words
The combination of claim 19 wherein, said control track contains a recorded index signal.
Claim 25
Dependent Claim
27 words
The combination of claim 19 wherein said control track contains a recorded signal which provides an indication of the sector under said first transducer means when read.
Claim 26
Dependent Claim
31 words
The combination of claim 19 wherein, said control track contains recorded track servo signals to provide an indication of the displacement of said second transducer from said control track when read.
Claim 27
Dependent Claim
57 words
The combination of claim 16 wherein, said disk drive device includes an electric motor, speed control means for said electric motor, and first circuit means connecting said second transducer to said speed control means to regulate the rotational velocity of said disk in response to the output signal from said second transducer developed from the control track.
Claim 28
Dependent Claim
60 words
The combination of claim 16 wherein, said disk drive device includes control signal generating means for developing an index signal indicating a predetermined angular position of an associated flexible disk, and second circuit means connecting said second transducer to said control signal generating means to develop said index signal in response to a control signal recorded on said control track.
Claim 29
Dependent Claim
56 words
The combination of claim 16 wherein, said disk drive device includes control signal generating means for developing a sector signal indicating the sector positioned under said first transducer, and third circuit means connecting said second transducer to said control signal generating means to develop said sector signal in response to control information recorded on said disk.
Claim 30
Dependent Claim
61 words
The combination of claim 16 wherein, said disk drive device includes control signal generating means for developing a track servo signal indicating the relative displacement of said second transducer from a track, and fourth circuit means connecting said second transducer to said control signal generating means to develop said track servo signal in response to control information recorded on said disk.
Claim 31
Dependent Claim
56 words
The combination of claim 24 further including control signal generating means for developing an index signal indicating a predetermined angular position of an associated flexible disk, and second circuit means connecting said second transducer to said control signal generating means to develop said index signal in response to a control signal recorded on said control track.
Claim 32
Dependent Claim
52 words
The combination of claim 24 further including control signal generating means for developing a sector signal indicating the sector positioned under said first transducer, and third circuit means connecting said second transducer to said control signal generating means to develop said sector signal in response to control information recorded on said disk.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-02 | 1987-07-04 | 1988-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-02 | 1991-07-04 | 1992-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-02 | 1995-07-04 | 1996-01-03 | $7700.00 | Window Closed / Lapsed |