US4928186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording method and magnetic head
Assignee: Fujifilm Holdings Corp
•
Filing: 1987-08-31
•
Granted: 1990-05-22
•
Expires: 2007-08-31
Abstract
Abstract In a magnetic recording/reproducing apparatus, desired information is recorded on a main track of a magnetic disk using a magnetic head. Other information is recorded on a guard band which is adjacent to the main track using another magnetic head. Each of the magnetic heads has a magnetic layer, an insulator layer, and a conductor layer formed of thin films. The heads are adjacent to each other in the widthwise direction of the track with a predetermined relative azimuth angle between them in which is greater than 0 DEG and no greater than 45 DEG . The magnetic head for the main track is applied with an optimum recording current. The magnetic head for the guard band is applied with a recording current so that its magnetomotive force is within the range of 40% to 80% of the magnetomotive force of the magnetic head for the main track.
Inventors
- 👤 Takashi Matsumoto
- 👤 Masamichi Sato
- 👤 Satoshi Yoshida
- 👤 Yoshiaki Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:29
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/012; G11B5/127; G11B5/29; G11B5/31; G11B5/3103; G11B5/48; G11B5/488; G11B5/4893
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
84 words
A magnetic recording method comprising the steps of: recording first information on a main track of a magnetic disk using a first magnetic head with an adequate recording current; and recording second information on a guard band adjacent to said recording main track using a second magnetic head having a predetermined non-zero azimuth angle relative to said first magnetic head with a magnetomotive force set within a range of 40% to 80% of a magnetomotive force of said magnetic head for said main track.
Claim 2
Dependent Claim
84 words
A magnetic recording method comprising the steps of: recording first information on a main track of a magnetic disk using a first magnetic head with an adequate recording current; and recording second information on a guard band adjacent to said recording main track using a second magnetic head having a predetermined non-zero azimuth angle relative to said first magnetic head with a magnetomotive force set within a range of 40% to 80% of a magnetomotive force of said magnetic head for said main track.
Claim 3
Dependent Claim
79 words
A magnetic recording method as claimed in claim 1, wherein said first and second information is recorded by a composite thin film magnetic head, said composite thin film magnetic head comprising: said first magnetic head for recording said first information; and said second magnetic head for recording said second information; wherein each of said first and second magnetic heads are thin film magnetic heads comprising a magnetic layer, an insulator layer, and a conductor layer formed of thin films.
Claim 4
Dependent Claim
47 words
A magnetic recording method as claimed in claim 2, wherein said first and second magnetic heads are disposed adjacent to each other in a widthwise direction of the track and have a relative azimuth angle between them which is greater than 0° and no greater than 45°.
Claim 5
Dependent Claim
23 words
A magnetic recording method according to claim 3, wherein said relative azimuth angle is no less than 25° and no greater than 45°.
Claim 6
Dependent Claim
67 words
A magnetic recording method as claimed in claim 1, wherein a magnetic head comprising a first head chip and a second head chip having different azimuth angles disposed on the same plane of a head base plate is used, said head base plate is slanted, and said first information is recorded by said first head chip and said second information is recorded by said second head chip.
Claim 7
Dependent Claim
18 words
A magnetic recording method according to claim 1, wherein said range of magnetomotive force is 40% to 50%.
Claim 8
Dependent Claim
27 words
A magnetic recording method according to claim 1, wherein said main track is recorded with video signals and said guard band is recorded with time-compressed audio signals.
Claim 9
Dependent Claim
126 words
A composite thin film magnetic head comprising: a first magnetic head for recording and reproducing first information on a main track of a magnetic disk; and a second magnetic head for recording and reproducing second information on a guard band adjacent to said main track; wherein each of said first and second magnetic heads are thin film magnetic heads comprising a magnetic layer, an insulator layer, and a conductive layer formed of thin films, and said first and second magnetic heads are disposed adjacent to each other in a widthwise direction of the track and have a non-zero relative azimuth angle, said second magnetic head having a magnetomotive force set within a range of 40% to 80% of a magnetomotive force of said first magnetic head.
Claim 10
Dependent Claim
126 words
A composite thin film magnetic head comprising: a first magnetic head for recording and reproducing first information on a main track of a magnetic disk; and a second magnetic head for recording and reproducing second information on a guard band adjacent to said main track; wherein each of said first and second magnetic heads are thin film magnetic heads comprising a magnetic layer, an insulator layer, and a conductive layer formed of thin films, and said first and second magnetic heads are disposed adjacent to each other in a widthwise direction of the track and have a non-zero relative azimuth angle, said second magnetic head having a magnetomotive force set within a range of 40% to 80% of a magnetomotive force of said first magnetic head.
Claim 11
Dependent Claim
35 words
A composite thin film magnetic head as claimed in claim 8, wherein the relative azimuth angle between said first magnetic head and said second magnetic head is greater than 0° and no greater than 45°.
References Cited (Backward Citations)
US3611417A
Cited
US4318146A
Cited
GB2115598A
Cited
US4533961A
Cited
US4758903A
Cited
JPS61129701A
Cited
JPS61153803A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-21 | 1993-11-20 | 1994-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-21 | 1997-11-20 | 1998-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-21 | 2001-11-20 | 2002-05-22 | $7700.00 | Window Closed / Lapsed |