Patent ID: 6195233
Filing Date: 2001-02-27
Classification: G11B

Abstract:
A perpendicular thin-film magnetic head comprising a magnetic core having a main magnetic pole and a return path of a high magnetic permeability to be magnetically coupled to said main magnetic pole, and a coil surrounded by said magnetic core, for accomplishing writing and reading when in use with a perpendicular double-layered magnetic recording medium having a highly permeable layer and a perpendicular recording layer laminated on a substrate in a named order, given that an inner circumferential length of said magnetic core surrounding said coil is Lc, a distance from a medium opposing face of said perpendicular thin-film magnetic head to a recording-layer side face of said highly permeable layer of said recording medium is S, an interval between said main magnetic pole and said return path at a position of said medium opposing face is Lb, a film thickness in a vicinity of said medium opposing face of said main magnetic pole is Tm, an average value of a density of a magnetic flux (unit: T (tesla)) generated toward said highly permeable layer from a distal end portion of said main magnetic pole, needed for sufficiently magnetizing said perpendicular recording layer, is Bav and an effective magnetic permeability of said magnetic core is .mu., wherein Lc, S, Lb and Tm are determined in such a manner that a magnetomotive force I needed for recording, expressed by a following equation (1), in a range of equal to or less than 0.1 A.multidot.T: ##EQU20##wherein Log is a natural logarithm, L=Lc+2S+Lb, and variables in said equation (2) are expressed in SI units.