Patent ID: 7110218

Claim:
A magnetic disk apparatus comprising a magnetic recording media, a motor to drive the magnetic recording media, a magnetic head to read from and write onto the magnetic recording media, and a mechanism for positioning the magnetic head, wherein at least one inductive head is mounted as the magnetic head, said inductive head comprising a lower magnetic core formed on a substrate, a magnetic pole tip layer formed on the lower magnetic core wherein said magnetic pole tip layer comprises three layers of magnetic layer/non-magnetic layer/magnetic layer, an upper magnetic core coupled in its front end to the magnetic pole tip layer, coupled in its rear end to the lower magnetic core, having a width of the front end smaller than that of the rear end, and having at least partially a shape gradually reducing the width from the rear end to the front end, coils disposed between the upper magnetic core and the lower magnetic core, and an insulating layer formed between the coils and the upper magnetic core or the lower magnetic core, wherein the distance between the upper magnetic core and the lower magnetic core in a rear end region away from an air bearing surface in a region connecting the magnetic pole tip layer to said upper magnetic core is shorter than the distance between the top surface of said magnetic pole tip layer in the air bearing surface and said lower magnetic core, and wherein a width of the front end of the upper magnetic core is larger than that of a rear end of the magnetic pole tip layer, a width of the magnetic pole tip layer of said magnetic head in the air bearing surface is not more than 0.5 μm, a saturation magnetic flux density of the magnetic layer consisting of the magnetic pole tip layer is not less than 1.6 T, and a coercivity of the magnetic recording media is 317 to 634 kA/m (4.0 to 8.0 kOe), and said three layers of magnetic layer/non-magnetic layer/magnetic layer of said magnetic pole tip layer have the same shape as viewed from top, and have an angle of extension of 5° to 45°.