Hitachi, Ltd.

Shinya Matsuoka

Takaaki Shirakura

Masaki Ohura

Takao Nakamura

Hiroyuki Suzuki

Yoshihiro Shiroishi

Kazumasa Takagi

Makoto Sano

Kenji Furusawa

Tokuumi Fukazawa

Sadao Hishiyama

Tomoyuki Ohno

Hiroyuki Kataoka

Kenzo Susa

Hiroshi Yashiki

Nobuya Sekiyama

Noriyoshi Goda

Keiko Nakano

Tatsuo Kawaide

Masanori Arayashiki

Yoshihiro Shiraisi

The present invention relates to a magnetic disk unit of a high memory capacity wherein a magnetic head and a magnetic disk with a lubricant layer formed on the surface thereof are allowed to perform a relative motion in a mutually contacted state to write and read out information of a high recording density, and the invention is also concerned with the shape and material of the magnetic head suitable for a continual sliding motion of the head on the magnetic disk surface, as well as the lubricant layer formed on the disk surface. According to the present invention, the magnetic head, which has a slider surface of a predetermined curvature, is supported by an arm through a spring and is pushed onto the magnetic disk surface with the lubricant layer formed thereon, then with rotation of the magnetic disk, the lubricant layer liquefies and information is recorded or read out in a contacted state of the head and the disk. The distance between the magnetic head and the disk surface can be shortened to a great extent and the recording density of the magnetic disk can be increased remarkably, thereby permitting a larger capacity of the magnetic disk unit.

Frictionally sliding head magnet disk apparatus

The present invention relates to a high-density magnetic recording medium (or 'media' as it is sometimes called) for a recording/reproduction system (such as thosed used in computer disk drives) and, more particularly, to a magnetic recording medium having a plurality of magnetic recording layers such that the uppermost layer is comparatively thinner and more densely structured than the lower magnetic recording layers. The present magnetic recording medium comprises a non-magnetic plated substrate, a non-magnetic underlying layer laminated on the plated substrate, a plurality of magnetic alloy layers including the uppermost layer laminated onto the underlying layer, a non-magnetic covering layer laminated onto the uppermost layer, and a lubricating layer formed onto the non-magnetic covering layer. The present invention improves the corrosion resistance of an alloy-type magnetic recording medium while maintaining or exceeding the recording/reproducing characteristics of such media, all at a desirable cost of production.

Magnetic recording medium and method of producing same

A magnetic recording medium having high recording density and being capable of obtaining excellent over-write characteristics by having a magnetic layer including Co and Ni as its principal components on a non-magnetic substrate, the Ni content of the magnetic layer is greater at portions closer to the surface of the magnetic layer in the direction of its thickness; the Ni content at portions closer to the surface of the magnetic layer is 20.about.50 at %; and the portion closer to the surface of the magnetic layer has at least one element selected from the group consisting of Zr, Ti, Pt, Ru, Ta, Rh, V, Nb, Cr and Pd.

Magnetic recording medium

A magnetic disk medium in which texture working is performed on surfaces of a substrate or on surfaces of subbing films provided on the substrate to attain circumferential worked-traces so that the contact start stop area thereof is different from the recording/reproducing area thereof in roughness of the worked surfaces.

Magnetic disk medium with circumferentially textured surfaces and varied

A magnetic recording medium having a magnetic film formed on a substrate directly or through an underlayer from an alloy containing Co as a principal component. The central line average surface roughness Ra and maximum surface roughness Rmax of the magnetic film in a direction perpendicular to the direction of magnetic recording are selected so as to fall within the ranges of 1 nm.ltoreq.Ra.ltoreq.20 nm and Rmax.ltoreq.25 Ra, respectively, and the in-plane magnetic anisotropy energy Ku of the magnetic film is selected to fall within the range of 0.ltoreq.Ku.ltoreq.8.times.10.sup.5 erg/cm.sup.3. Thus, it is possible to minimize the value of modulation which represents the degree of variation of read output on the same circumference of a magnetic disk. It is also possible to reduce the noise generated in read and write operations by forming the magnetic film so as have no crystallographic orientation.

Magnetic recording medium and process for producing the same

Growing community of inventors

Odawara, Japan

Shinya Matsuoka