US 2004/0070869 A1Published application

Perpendicular magnetic recording system

AssigneeHitachi, Ltd.

InventorsYasutaka Nishida, Hisashi Takano, Masafumi Mochizuki

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Abstract

To make a soft magnetic underlayer of a double layered perpendicular magnetic recording medium thinner than heretofore while avoiding saturation. Assuming that Tb1 is the thickness of the soft magnetic underlayer of the double layered perpendicular magnetic recording medium, BS2 the saturation flux density of the same, Tm the thickness of a magnetic recording head's main pole 1 along a track direction in the vicinity of its floating surface, TWW the track width of the same, and BS1 the saturation flux density of the same, then Tb1<(BS1×Tm×TWW)/2(BS2×(Tm+TWW)) is satisfied.

Claims6

Dependent claims

A perpendicular magnetic recording system comprising:

a perpendicular magnetic recording medium having a soft magnetic underlayer and
a magnetic head having a magnetic recording head and a magnetic read head,
wherein said magnetic read head comprises an upper shield, a lower shield and a read element provided between said upper shield and said lower shield,
wherein said magnetic recording head comprises a main pole for recording a magnetization reversal on said perpendicular magnetic recording medium,
the perpendicular magnetic recording system satisfying
Tb1<(Bs1×Tm×Tww)/2(Bs2×(Tm+Tww)),
wherein Tb1 is the thickness of said soft magnetic underlayer, Bs2 is the saturation flux density of the same, Tm is the thickness of said main pole along a track direction in the vicinity of its floating surface, Tww is the track width of the same, and Bs1 is the saturation flux density of the same.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/677,302Filed 3 Oct 2003
Priority: JP 2000-05191728 Feb 2000
Published: 15 Apr 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

G11B 5/1278
Structure or manufacture of heads, e.g. inductive: specially adapted for magnetisations perpendicular to the surface of the record carrier
G11B 5/00
Recording by magnetisation or demagnetisation of a record carrier
G11B 5/667
The record carriers consisting of several layers: including a soft magnetic layer
G11B 5/7368
Base layers , i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a…:…

Family

Application09/785,417Continuation · filed 20 Feb 2001
Application10/677,302Continuation · filed 3 Oct 2003
US 2001/0017746 A1Published application
US 6,657,813 B2Related patent
US 7,088,548 B2Related patent
US 2004/0070869 A1This patent

From the US filing history. Foreign family members aren’t listed.

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