EP0174714A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Magnetic transducer head structure and method of use
Assignee: Irwin Magnetic Systems Inc
•
Filing: 1985-06-12
•
Granted: —
•
Expires: 2005-06-12
Abstract
Abstract A magnetic core structure (18) for transducer heads (10), generalty of the type used in magnetic recording, for data for storage purposes, which, although of single-gap form provides operational characteristics similar to those typically found in multi-gap heads. It is thus suitable for use in a bi-directional media transport although having only a single read/write gap. The core structure (18) includes a full-width pole piece (20) on one side of the gap, and a partial-width pole piece (28) on the opposite side of the gap; additionally, the core structure includes separate magnetic return shunt pieces (26, 30) which are disposed on opposite sides of the partial-width pole piece (28) and extend into communication with the opposite pole piece (20). During writing, the full-width core structure is energized, producing a magnetic circuit which includes both the partial width pole and the shunt pieces. During reading, signals are taken only from flux present in the partial-width pole. Thus, the "write" width is wider than the "read" width.
Inventors
- 👤 Michael Loren Bolt
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 09:01
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/245; G11B5/2452; G11B5/33
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
203 words
A magnetic core structure (18) for a transducer head (10) characterised by a magnetic circuit formed from magnetic material defining at least two separate paths for magnetic flux and having a gap (24) where magentic flux in the circuit may access a magnetic data-storage media, the circuit including a first magnetic pole structure (22) at one side of the gap, and a second magnetic pole structure (20) at the other side of the gap; the first pole structure comprising at least a main former (28) (defining, with the second pole structure, a first magnetic flux path) and a subsidiary former (26, 30) (defining, with the second pole structure, a second magnetic flux path), the formers being magnetically isolated from eachother in the region of the gap, and the main former having a thickness at the gap which is less than that of the second pole structure at the gap, the subsidiary former extending from the gap into magnetic communication with the second pole structure at a point spaced from the gap to provide a parallel magnetic return; and the nain former having an intermediate portion (shunted by and separated from the subsidiary former) defining an electromagnetic coil-accessing location along the first magnetic path.
Claim 2
Dependent Claim
203 words
A magnetic core structure (18) for a transducer head (10) characterised by a magnetic circuit formed from magnetic material defining at least two separate paths for magnetic flux and having a gap (24) where magentic flux in the circuit may access a magnetic data-storage media, the circuit including a first magnetic pole structure (22) at one side of the gap, and a second magnetic pole structure (20) at the other side of the gap; the first pole structure comprising at least a main former (28) (defining, with the second pole structure, a first magnetic flux path) and a subsidiary former (26, 30) (defining, with the second pole structure, a second magnetic flux path), the formers being magnetically isolated from eachother in the region of the gap, and the main former having a thickness at the gap which is less than that of the second pole structure at the gap, the subsidiary former extending from the gap into magnetic communication with the second pole structure at a point spaced from the gap to provide a parallel magnetic return; and the nain former having an intermediate portion (shunted by and separated from the subsidiary former) defining an electromagnetic coil-accessing location along the first magnetic path.
Claim 3
Dependent Claim
39 words
A magnetic core structure as claimed in Claim 1, in which the first pole structure includes a second subsidiary former (30), the two subsidiary formers (26, 30) being disposed on either side of the main former at the gap.
Claim 4
Dependent Claim
38 words
A magnetic core structure as claimed in Claim 1 or Claim 2 in which each of the pole structures (20, 22) at the gap (24) have generally the same overall width (measured in a direction along the gap).
Claim 5
Dependent Claim
34 words
A magnetic core structure as claimed in any one of Claims 1 to 3 in which the first magnetic path length is longer than the other, or any of the other, magnetic path lengths.
Claim 6
Dependent Claim
57 words
A magnetic core structure as claimed in any one of Claims 1 to 4 in which the subsidiary former (26, 30), or at least one of them, extends laterally of and out of superposition with respect to the main former (23) (in a direction parallel to the gap) at least in the area of the intermediate portion.
Claim 7
Dependent Claim
42 words
A magnetic core structure as claimed in any one of the preceding claims in which the main former (28) and the subsidiary former or formers (26, 30) extend into magnetic communication with the second pole structure (20) at a common junction area.
Claim 8
Dependent Claim
22 words
A magnetic core structure as claimed in Claim 6 in which the common junction area is located generally opposite the gap (24).
Claim 9
Dependent Claim
48 words
A magnetic core structure as claimed in any one of the preceding claims in which the main former (28) is provided with an electromagnetic write or read coil (40) at the coil accessing location and the second pole structure is provided with a read or write coil (36).
Claim 10
Independent Claim
145 words
A method of reading and writing magnetic flux transitions on magnetically-recordable media characterised by transporting the recording media past a single-gap transducer head (10) in a recording pass; recording flux transitions on the media during the recording pass by using a first portion (20; 28) of a magnetic core structure (which structure defines the two opposite sides of the gap (24)), the first portion defining a predetermined first partof the overall length of the gap; transporting the recording media past the transducer head in a reproducing pass; and, during the reproducing pass, reproducing the flux transitions previously recorded on the media by using a second portion (20; 26, 30) of the magnetic core structure, the second portion of the core structure defining a predetermined second part of the overall length of the gap; the first and second parts being different lengths of the transducing gap.
Claim 11
Independent Claim
145 words
A method of reading and writing magnetic flux transitions on magnetically-recordable media characterised by transporting the recording media past a single-gap transducer head (10) in a recording pass; recording flux transitions on the media during the recording pass by using a first portion (20; 28) of a magnetic core structure (which structure defines the two opposite sides of the gap (24)), the first portion defining a predetermined first partof the overall length of the gap; transporting the recording media past the transducer head in a reproducing pass; and, during the reproducing pass, reproducing the flux transitions previously recorded on the media by using a second portion (20; 26, 30) of the magnetic core structure, the second portion of the core structure defining a predetermined second part of the overall length of the gap; the first and second parts being different lengths of the transducing gap.
Claim 12
Dependent Claim
78 words
A method of reading and writing magnetic flux transitions as claimed in Claim 9, in which the first and second parts of the transducing gap (24) are made available by using a magnetic core structure comprising several formers (26, 28, 30) to define the two opposite sides of the gap and selecting a different former or formers (28) for use as a read gap from the former or formers (26, 30) selected for use as a write gap.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.