Patent EP0012912A1 successfully refreshed from Google Patents.
← Back to Patent Explorer
EP0012912A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Thin film magnetic transducers

Assignee: International Business Machines Corp
•
Filing: 1979-12-10
•
Granted: —
•
Expires: 1999-12-10
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A thin film magnetic transducer for reading and writing a track on a magnetic recording medium consists of layers deposited on a deposition surface of a non-magnetic substrate (20) which has an air bearing surface (ABS) at right angles to the deposition surface. Two of the layers (14, 15) are of magnetic material to form a yoke (13) with a pole tip region having a transducing gap (18) at the air bearing surface(ABS), and with a back region. A read/write coil (10a to 10h) is coupled to the back region. <??>The pole tip region has a width approximating to track width and a length (D) of approximately 5/d where d is the recording density on the recording medium in order to minimise signals from adjacent tracks and maximise read resolution. <??>The thickness and width of the layers (14, 15) in the back region are greater than those dimensions in the pole tip region, the increase in width being provided by a taper. The width of the back region is greater than the width of the pole tip region, the wider back region tapering to join the pole tip region. Also the thickness of the back region magnetic layers (14,15) is at least 60% greater than the thickness of the pole tip region. The back region is designed taking into account saturation to provide an efficient write operation.

Inventors

  • 👤 Robert Edward Jones Jr.
  • 👤 Walther Nystrom

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-23 20:48
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3109; G11B5/313; G11B5/3116

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 217 words
A thin film magnetic transducer of the kind that can be used for both reading and writing with respect to a track on a magnetic recording medium and that is formed of layers built up by deposition on a deposition surface of a non-magnetic substrate (20), an air bearing surface (ABS) being provided at right angles to the deposition surface, the deposited layers including two layers of magnetic material (14, 15) defining a yoke (13) with a pole tip region (P), with a transducing gap (18) at the air bearing surface (ABS), and a back region (B) and a read/write coil (10) in coupling juxtaposition relative to the back region (B) characterised in that (a) the layers (14, 15) at the pole tip region (P), for a distance (D) from the air bearing surface (ABS) parallel to the deposition surface, are of width (W) parallel to both surfaces and (b) the thickness and width of the layers (14, 15) in the back region (B) are greater than those dimensions of the layers on the pole tip region, the increase in width being accommodate by a taper of angle 0 whereby, in the unitary deposited structure, reading definition is provided by the polo tip region (P) and resistance to writing saturation is provided by the back region (B).
Claim 2
Dependent Claim 217 words
A thin film magnetic transducer of the kind that can be used for both reading and writing with respect to a track on a magnetic recording medium and that is formed of layers built up by deposition on a deposition surface of a non-magnetic substrate (20), an air bearing surface (ABS) being provided at right angles to the deposition surface, the deposited layers including two layers of magnetic material (14, 15) defining a yoke (13) with a pole tip region (P), with a transducing gap (18) at the air bearing surface (ABS), and a back region (B) and a read/write coil (10) in coupling juxtaposition relative to the back region (B) characterised in that (a) the layers (14, 15) at the pole tip region (P), for a distance (D) from the air bearing surface (ABS) parallel to the deposition surface, are of width (W) parallel to both surfaces and (b) the thickness and width of the layers (14, 15) in the back region (B) are greater than those dimensions of the layers on the pole tip region, the increase in width being accommodate by a taper of angle 0 whereby, in the unitary deposited structure, reading definition is provided by the polo tip region (P) and resistance to writing saturation is provided by the back region (B).
Claim 3
Dependent Claim 32 words
A transducer as claimed in claim 1, characterised in that the length (D) of the pole tip region (P) is approximately 5/d where d is the recording density on the recording medium.
Claim 4
Dependent Claim 41 words
A transducer as claimed in claim 1 or claim 2, characterised in that the length (D) of the pole tip region (P) is between 12 and 18 microns when the recording density or the medium is 400 flux charges per millimetre.
Claim 5
Dependent Claim 42 words
A transducer as claimed in any one of the preceding claims characterised in that the thickness of the back region (B) magnetic layers (14, 15) is at least 60% greater than the thickness of the pole tip region (P) layers (14, 15).
Claim 6
Dependent Claim 27 words
A transducer as claimed in any one of the preceding claims characterised in that the back region (B) tapers by an angle 0 between 30° and 60°.
Claim 7
Dependent Claim 40 words
A transducer as claimed in any one of the preceding claims characterised in that the two magnetic layers (14, 15) are parallel (to X) to form transducing gap (18) and then diverge (X to Y) to the back region (B).

References Cited (Backward Citations)

US3700827A Cited
US4016601A Cited
US4078300A Cited

USPTO Annuity & Maintenance Windows

Maintenance schedule is calculated for granted US utility patents.

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag