US5325244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording data storage system
Assignee: HGST Japan Ltd
•
Filing: 1992-02-28
•
Granted: 1994-06-28
•
Expires: 2012-02-28
Abstract
Abstract A magnetic recording data storage system includes a magnetic recording medium having pits formed therein, the pits defining recording tracks on the magnetic recording medium and being arranged in a staggered manner relative to respective center lines of the recording tracks, a magnetic head including an inductive element for recording data on the recording tracks and a magnetoresistive element for reproducing data from the recording tracks, one of (1) a unit for magnetically producing a signal from the pits, and (2) an optical unit for optically producing a signal from the pits, the optical unit including a laser for illuminating the pits, servo means for positioning the head on the recording tracks based on the signal produced from the pits, the servo means including a dual-stage actuator including a rough movement portion and a fine movement portion.
Inventors
- 👤 Hisashi Takano
- 👤 Kyo Akagi
- 👤 Mikio Suzuki
- 👤 Yoshibumi Matsuda
- 👤 Takeshi Nakao
- 👤 Yoshinori Miyamura
- 👤 Fumio Kugiya
- 👤 Masaaki Futamoto
- 👤 Hideki Sawaguchi
- 👤 Nobuyuki Inaba
- 👤 Takayuki Munemoto
- 👤 Kenji Mori
- 👤 Hirotsugu Fukuoka
- 👤 Tokuho Takagaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:15
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3967; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/5552; G11B5/58; G11B5/596; G11B5/59677; G11B5/60; G11B5/6005; G11B5/74
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
135 words
A magnetic recording data storage system comprising: a magnetic recording medium having pits formed therein, the pits defining recording tracks on the magnetic recording medium and being arranged in a staggered manner relative to respective center lines of the recording tracks; a magnetic head including an inductive element for recording data on the recording tracks and a magnetoresistive element for reproducing data from the recording tracks; one of (1) means for magnetically producing a signal from the pits, and (2) optical means for optically producing a signal from the pits, the optical means including a laser for illuminating the pits; servo means for positioning the head on the recording tracks based on the signal produced from the pits, the servo means including a dual-stage actuator including a rough movement portion and a fine movement portion.
Claim 2
Dependent Claim
135 words
A magnetic recording data storage system comprising: a magnetic recording medium having pits formed therein, the pits defining recording tracks on the magnetic recording medium and being arranged in a staggered manner relative to respective center lines of the recording tracks; a magnetic head including an inductive element for recording data on the recording tracks and a magnetoresistive element for reproducing data from the recording tracks; one of (1) means for magnetically producing a signal from the pits, and (2) optical means for optically producing a signal from the pits, the optical means including a laser for illuminating the pits; servo means for positioning the head on the recording tracks based on the signal produced from the pits, the servo means including a dual-stage actuator including a rough movement portion and a fine movement portion.
Claim 3
Dependent Claim
21 words
A system according to claim 1, wherein the system includes the optical means for optically producing a signal from the pits.
Claim 4
Dependent Claim
49 words
A system according to claim 2, wherein at least 1000 pits are formed in the magnetic recording medium along a circumference of the magnetic recording medium at each of the recording tracks, and wherein each of the pits is one of 3 microns square and 3 microns in diameter.
Claim 5
Dependent Claim
23 words
A system according to claim 1, wherein the magnetic recording medium has a storage capacity of at least 1.2 gigabits per square inch.
Claim 6
Dependent Claim
20 words
A system according to claim 1, wherein the magnetic head has a track width of not more than 2.5 microns.
Claim 7
Dependent Claim
25 words
A system according to claim 5, wherein the inductive element includes a magnetic material having a saturation magnetic flux density of at least 2.0 T.
Claim 8
Dependent Claim
57 words
A system according to claim 5, wherein the magnetoresistive element is one of a shunt biasing type magnetoresistive element and a soft film biasing type magnetoresistive element, and includes a magnetoresistive film and a magnetic film disposed on top of at least a portion of the magnetoresistive film for causing an exchange coupling with the magnetoresistive film.
Claim 9
Dependent Claim
60 words
A system according to claim 5, wherein the magnetic head further includes a slider supporting the inductive element and the magnetoresistive element, and wherein the slider is provided with a pair of rails that slide on the magnetic recording medium, and a groove is provided in a central portion of each of the rails extending in a direction perpendicular thereto.
Claim 10
Dependent Claim
25 words
A system according to claim 1, wherein the magnetic recording medium is one of a longitudinal magnetic recording medium and a perpendicular magnetic recording medium.
Claim 11
Dependent Claim
46 words
A system according to claim 1, wherein the magnetic head further includes a slider supporting the inductive element and the magnetoresistive element, wherein the system includes the optical means for optically producing a signal from the pits, and wherein the laser is mounted on the slider.
Claim 12
Dependent Claim
33 words
A system according to claim 1, wherein the rough movement portion of the dual-stage actuator includes an electric motor, and wherein the fine movement portion of the dual-stage actuator includes a piezoelectric element.
Claim 13
Dependent Claim
23 words
A system according to claim 1, further comprising a class 4 partial response equalizer for processing an output signal of the magnetoresistive element.
References Cited (Backward Citations)
US4639906A
Cited
US4633451A
Cited
JPS5996571A
Cited
US4547824A
Cited
JPS6319951A
Cited
JPS6319950A
Cited
US4816939A
Cited
US4858040A
Cited
US4961123A
Cited
US5189578A
Cited
US5067039A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-27 | 1997-12-27 | 1998-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-27 | 2001-12-27 | 2002-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-27 | 2005-12-27 | 2006-06-28 | $7700.00 | Window Closed / Lapsed |