US4757406A
Expired / Lapsed
US
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High capacity disk drive
Assignee: QED INTELLECTUAL PROPERTY SERVICES Ltd
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Filing: 1985-09-13
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Granted: 1988-07-12
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Expires: 2005-09-13
Abstract
Abstract A method of and apparatus for generating and protecting hard sector pulses using the read/write heads of the disk drive without using any external transducers is disclosed. Each track of the disk is pre-formatted with a pattern of a burst of data followed by a short erased gap repeated around the track once per sector. The data bursts are converted to digital pulses which are used to trigger a monostable as long as the read/write heads are positioned over data. The lack of an output signal from the monostable is used to detect the erased gaps. At the end of the erased gap, a sector marker pulse is generated. Various protection signals are also generated. The high capacity hard sectored computer disk drive system disclosed herein utilizes a hard disk which rotates at a speed of approximately 2750 r.p.m. The data received from the host computer for storage on the hard disk is converted to 2,7 RLL coding prior to being written onto the disk. The disk drive system has a formatted data storage capacity in excess of 10 megabytes per disk, using both sides of the disk.
Inventors
- 👤 Alec D. Stewart
- 👤 David Shanks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:53
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G11; G11B; G11B19/00; G11B19/02; G11B19/04; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/30; G11B5/00; G11B5/012; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G06F3/0668; G06F3/0671; G06F3/0673
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
123 words
A method of generating hard sector marker pulses for use in conjunction with a micro-hard disk drive system, comprising the steps of; pre-initializing each concentric track on at least one hard-disk with a plurality of data signals separated by erased gaps; reading said plurality of data signals and erased gaps using the read/write head of said disk drive; converting said read plurality of data signals to digital pulses; triggering a monostable using said digital pulses in order to provide an output signal during the time said read/write head senses the presence of said data signals; and generating a sector marker pulse upon again receiving an output signal from said monostable after it has ceased to produce an output signal for a predetermined time.
Claim 2
Independent Claim
123 words
A method of generating hard sector marker pulses for use in conjunction with a micro-hard disk drive system, comprising the steps of; pre-initializing each concentric track on at least one hard-disk with a plurality of data signals separated by erased gaps; reading said plurality of data signals and erased gaps using the read/write head of said disk drive; converting said read plurality of data signals to digital pulses; triggering a monostable using said digital pulses in order to provide an output signal during the time said read/write head senses the presence of said data signals; and generating a sector marker pulse upon again receiving an output signal from said monostable after it has ceased to produce an output signal for a predetermined time.
Claim 3
Dependent Claim
18 words
The method of claim 1, wherein said plurality of data signals and erased gaps are equal in number.
Claim 4
Dependent Claim
25 words
The method of claim 1, wherein said plurality of data signals and erased gaps are equal to the number of sectors contained on each track.
Claim 5
Dependent Claim
27 words
The method of claim 1, wherein one of said plurality of erased gaps is of a longer duration than the rest of the plurality of erased gaps.
Claim 6
Dependent Claim
27 words
The method of claim 1, wherein each of said plurality of data signals occurs for a longer time period than each of said plurality of erased gaps.
Claim 7
Dependent Claim
20 words
The method of claim 1, wherein said monostable times out a predetermined time after it ceases receiving said digital pulses.
Claim 8
Dependent Claim
22 words
The method of claim 6, wherein said predetermined time is less than the duration of one of said plurality of erased gaps.
Claim 9
Dependent Claim
41 words
The method of claim 4, further including the step of generating an index pulse upon the retriggering of said monostable after it has ceased to produce an output signal for a period of time corresponding to said longer duration erased gap.
Claim 10
Dependent Claim
72 words
The method of claim 1, further including the steps of: generating a plurality of clock pulses; counting said plurality of clock pulses starting from the generation of said sector marker pulse; producing a first clock signal a predetermined time after the generation of said sector marker pulse; and generating a write protect signal upon the production of said first clock signal such that the next erased gap is prevented from being overwritten.
Claim 11
Dependent Claim
32 words
The method of claim 9, wherein said write protect signal serves to prevent the read/write head from writing data on said hard disk until the generation of the next sector marker pulse.
Claim 12
Dependent Claim
26 words
The method of claim 1, further including the step of writing data on said hard disk in accordance with the location of said pre-initialized data signals.
Claim 13
Dependent Claim
63 words
The method of claim 9, further including the steps of: producing a second clock signal a second predetermined time after the generation of said sector marker pulse; and generating a missing data enable signal upon the production of said second clock signal such that said step of generating said sector marker pulse occurs only after the generation of said missing data enable signal.
Claim 14
Dependent Claim
20 words
The method of claim 12, wherein said first clock signal is produced a predetermined time before said second clock signal.
Claim 15
Dependent Claim
22 words
The method of claim 12, wherein said first and second clock signals are terminated upon the generation of a sector marker pulse.
Claim 16
Dependent Claim
147 words
Apparatus for generating hard sector pulses for use in conjunction with a micro-hard disk drive system, comprising: at least one micro-hard disk having a plurality of concentric tracks, each of said concentric tracks having a plurality of data signals of predetermined duration separated by a like plurality of erased gaps; transducer means for reading information from and writing information to said hard disk; converter means connected to said transducer means for converting said plurality of data signals to a plurality of digital pulses; switching means connected to said converter means for producing an output signal during at least the time said transducer means is reading each of said plurality of data signals; and decoding means for generating a sector marker pulse upon again receiving an output signal from said switching means after said switching means has ceased to produce an output signal for a predetermined time period.
Claim 17
Dependent Claim
147 words
Apparatus for generating hard sector pulses for use in conjunction with a micro-hard disk drive system, comprising: at least one micro-hard disk having a plurality of concentric tracks, each of said concentric tracks having a plurality of data signals of predetermined duration separated by a like plurality of erased gaps; transducer means for reading information from and writing information to said hard disk; converter means connected to said transducer means for converting said plurality of data signals to a plurality of digital pulses; switching means connected to said converter means for producing an output signal during at least the time said transducer means is reading each of said plurality of data signals; and decoding means for generating a sector marker pulse upon again receiving an output signal from said switching means after said switching means has ceased to produce an output signal for a predetermined time period.
Claim 18
Dependent Claim
25 words
The apparatus of claim 15, wherein said plurality of data signals and erased gaps are equal to the number of sectors contained on each track.
Claim 19
Dependent Claim
16 words
The apparatus of claim 15, wherein said plurality of erased gaps are of equal time duration.
Claim 20
Dependent Claim
29 words
The apparatus of claim 15, wherein one of said plurality of erased gaps is of a predetermined longer time duration that the rest of the plurality of erased gaps.
Claim 21
Dependent Claim
27 words
The apparatus of claim 15, wherein each of said plurality of data signals is of a longer time duration than each of said plurality of erased gaps.
Claim 22
Dependent Claim
21 words
The apparatus of claim 15, wherein said switching means switches off a predetermined time after it ceases receiving said digital pulses.
Claim 23
Dependent Claim
29 words
The apparatus of claim 20, wherein said predetermined time after which said switching means switches off is less than the duration of one of said plurality of erased gaps.
Claim 24
Dependent Claim
40 words
The apparatus of claim 18, wherein said decoding means generates an index pulse upon again receiving an output signal from said switching means after said switching means has ceased to produce an output signal for said predetermined longer time duration.
Claim 25
Dependent Claim
76 words
The apparatus of claim 15, further comprising: means for generating a plurality of clock pulses; counter means counting said plurality of clock pulses beginning from the generation of said sector marker pulses and for producing a first clock signal a predetermined time after the generation of said sector marker pulse; and said decoding means receives said first clock signal and generates a write protect signal such that the next erased gap is prevented from being overwritten.
Claim 26
Dependent Claim
31 words
The apparatus of claim 23, wherein said write protect signal serves to protect said transducer from writing data on said hard disk until the generation of the next sector marker pulse.
Claim 27
Dependent Claim
62 words
The apparatus of claim 23, further comprising: said counter means producing a second clock signal a second predetermined time after the generation of said sector marker pulse; and said decoding means generates a missing data enable signal upon receiving said second clock signal such that said generation of said sector marker pulse occurs only after the generation of said missing data signal.
Claim 28
Dependent Claim
20 words
The apparatus of claim 25, wherein said first clock signal is produced a predetermined time before said second clock signal.
Claim 29
Dependent Claim
23 words
The apparatus of claim 25, wherein said counter means is reset upon the generation of said sector marker pulse by said decoding means.
Claim 30
Dependent Claim
14 words
The apparatus of claim 15, wherein said switching means comprises a retriggerable monostable device.
Claim 31
Dependent Claim
20 words
The apparatus of claim 15, wherein said converter means comprises a pulse detector integral to said hard disk drive system.
Claim 32
Dependent Claim
26 words
The apparatus of claim 25, wherein said means for generating a plurality of clock pulses comprises a write oscillator integral to said hard disk drive system.
Claim 33
Dependent Claim
201 words
A high capacity disk drive system for operating a hard sectored micro-hard disk, said disk drive comprising: at least one micro-hard disk having a plurality of concentric tracks each of said concentric tracks having a plurality of data signals of like predetermined duration separated by a like plurality of erased gaps; means for rotatably supporting said micro-hard disk; means for rotating said micro-hard disk; transducer means for writing digital information on and reading digital information from said micro-hard disk in 2,7 RLL coding format so that said at least one micro-hard disk has at least 10 MB of formatted digital information stored thereon; positioning means for moving said transducer means between the tracks on said micro-hard disk; converter means connected to said transducer means for converting said plurality of data signals to a plurality of digital pulses; switching means connected to said converter means for producing an output signal during at least the time said transducer means is reading each of said plurality of data signals; and decoding means for generating a sector marker pulse upon again receiving an output signal from said switching means after said switching means has ceased to produce an output signal for a predetermined time period.
Claim 34
Dependent Claim
201 words
A high capacity disk drive system for operating a hard sectored micro-hard disk, said disk drive comprising: at least one micro-hard disk having a plurality of concentric tracks each of said concentric tracks having a plurality of data signals of like predetermined duration separated by a like plurality of erased gaps; means for rotatably supporting said micro-hard disk; means for rotating said micro-hard disk; transducer means for writing digital information on and reading digital information from said micro-hard disk in 2,7 RLL coding format so that said at least one micro-hard disk has at least 10 MB of formatted digital information stored thereon; positioning means for moving said transducer means between the tracks on said micro-hard disk; converter means connected to said transducer means for converting said plurality of data signals to a plurality of digital pulses; switching means connected to said converter means for producing an output signal during at least the time said transducer means is reading each of said plurality of data signals; and decoding means for generating a sector marker pulse upon again receiving an output signal from said switching means after said switching means has ceased to produce an output signal for a predetermined time period.
Claim 35
Dependent Claim
24 words
The disk drive system of claim 31, wherein said means for rotating said micro-hard disk rotates said micro-hard disk at 2750+10% and -5% r.p.m.
References Cited (Backward Citations)
US4366512A
Cited
US4345280A
Cited
US4484176A
Cited
US4568988A
Cited
US4568988B1
Cited
US4554598A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-12 | 1992-01-11 | 1992-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-12 | 1996-01-11 | 1996-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-12 | 2000-01-11 | 2000-07-12 | $7700.00 | Window Closed / Lapsed |