JPS6341125B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a perpendicular magnetization recording head, which eliminates the influence on the main magnetic pole from other bits written on the medium, and also directs the magnetic flux from the bit to be read to the surrounding bits. The present invention relates to a perpendicular magnetization recording head having a structure that prevents perpendicular magnetization from escaping.

Conventionally, in the perpendicular magnetization recording method, as shown in FIG. , an auxiliary magnetic pole 4 having a winding 3 for generating a magnetic field for writing across the medium 1;
has been established. By excitation of this auxiliary magnetic pole 4,
Information is written on the medium 1 by the main magnetic pole 2, and the same main magnetic pole 2 is also used to read the information. There is also a method of writing/reading information to/from the medium 1 by excitation of the main magnetic pole wound around the main magnetic pole 2, as shown in FIG. 1B.

When reading perpendicular magnetization using this method, as shown in Figure 2, the magnetic flux that enters the main magnetic pole 2 from bit a to be read flows into the adjacent bit, and the magnetic flux that reaches the winding part is Therefore, there was a drawback that the readout output was small.

The purpose of the present invention is to provide a perpendicular magnetization recording head in which the readout output is increased by increasing the amount of magnetic flux coming to the readout winding without letting the magnetic flux emitted from the bit being read out to the surrounding bits. There is something to do.

A feature of the present invention is to achieve the above-mentioned object by providing a magnetic layer for shielding on the surface of the perpendicular magnetic recording head facing the medium, excluding the main pole portion.

The present invention will be explained below using the drawings.

FIG. 3 shows one of the perpendicular magnetization recording heads according to the present invention.
A sectional view for explaining an example is shown.

In the figure, a permalloy film 7 is provided perpendicularly on a ferrite 6 in a direction perpendicular to a perpendicular recording medium 5 which has anisotropy in a direction perpendicular to the film surface, and is located close to the ferrite 6 surface with a fairly large radius. Winding 8
(The winding 8 is sized so that a uniform magnetic field is applied to the permalloy film 7 of the main pole.) A main magnetic pole 7 is provided on the surface of the head having such a structure that faces the medium 5.
A magnetic layer for shielding, for example, a permalloy film 9, which is tapered as shown in the figure except for the surface, is deposited.
Further, as the perpendicular magnetization medium 5, a substrate 10 of Al etc.
A permalloy film (Ni--Fe) 11 is provided between the magnetic film 5 made of Co--Cr. Naho 12 is made of glass.

The thickness of the permalloy film 9 for shielding is 0.5 μm or more, which is less than the thickness of the CoCr film 5 which is a perpendicular magnetization film. The bits other than bit a that are read by the permalloy film 9 for shielding are the permalloy film 9.
Since the magnetic flux from the read bit a is sufficiently absorbed into the permalloy film 7 of the main magnetic pole and does not escape to the surrounding bits,
Read efficiency is increased. Furthermore, since there is no influence from surrounding bits, the S/N ratio can be reduced, making reading possible in high-density recording.

FIG. 4 shows a cross-sectional view of another embodiment of the perpendicular magnetization recording head according to the present invention. The difference from FIG. 2 is that the shield layer 12 is located near the tip of the main pole 7 on the surface facing the medium 5. However, the winding 8 is further away from the surface facing the medium 5.
At this time, care must be taken to ensure that the ferrite 6 serving as the back yoke and this shield layer 12 do not form a magnetically closed circuit.

As another embodiment of the present invention, as shown in FIG. It is also possible to implement the method using the auxiliary magnetic pole excitation method.

The present invention has been described above with reference to the embodiments. According to the present invention, a permalloy layer is provided for shielding on the surface of the medium except for the main magnetic pole portion of the perpendicular magnetization recording head. It is possible to provide a perpendicular magnetization recording head that eliminates the influence of bits on the main magnetic pole and prevents magnetic flux from the bit to be read from escaping to surrounding bits.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view for explaining the perpendicular magnetization recording method, A is auxiliary magnetic pole excitation, B is main pole excitation, Figure 2 is an explanatory diagram of conventional perpendicular magnetization readout, and Figures 3 and 4 are 1 is a cross-sectional view for explaining one embodiment of a perpendicular magnetization recording head according to the present invention. In the figure, 5 is a medium, 6 is a ferrite, 7 is a permalloy film, 8 is a winding wire, 9 and 12 are permalloy films for shielding, 10 is a substrate, 11 is a permalloy film, and 12 is glass.

Claims (1)

[Claims] 1. In a magnetic head for perpendicular magnetization that records magnetization using magnetic flux from a main pole placed perpendicularly to a perpendicular recording medium, a magnetic layer for shielding is provided on the surface facing the medium, excluding the main magnetic pole part. A perpendicular magnetization recording head characterized by being provided with.