Hitachi, Ltd.

501 Hitachi, Ltd.

Masaaki Imamura

Yoshiki Kato

Jun Fumioka

Yasushi Ito

Yutaka Ito

Masatoshi Wakagi

Takayuki Nakakawaji

Masanobu Hanazono

Fumio Nakano

Kunihiro Tamahashi

Katsumi Tamura

Akira Sato

Shigeki Komatsuzaki

Kenzo Masuda

Motoo Akagi

Mitsuyoshi Shoji

Fuminori Ishikawa

Eiichi Takasuna

An electrophotographic photoreceptor comprising a photoconductive layer comprising a photoconductor, a support for the photoconductive layer and a surface layer formed on the photoconductive layer and comprising a curable resin film and an inorganic insulator pieces having a size larger than the film thickness of the curable resin film. In order to prevent the image blurring of an a-Si:H photoreceptor, on the outermost surface of the photoreceptor was formed a surface layer having a structure in which inorganic insulator pieces have protruded from the curable resin film. Since the curable resin is of high resistance and shows no quality change by corona irradiation, and besides the protruding inorganic insulator pieces prevent the abrasion of the resin, the surface layer having a long life and excellent humidity resistance, durability for corona irradiation and abrasion resistance can be realized. Further, by covering the surface layer with a fluorine-containing lubricant, the surface layer having a low friction coefficient and excellent cleaning characteristics is obtained, and besides the resin constituting the surface layer absorbs little moisture. As a result, it becomes possible to use the a-Si:H photoreceptors without a heater. Also, the surface layer of the present invention can be removed and then re-formed.

Electrophotographic photoreceptor with protruding inorganic insulator

A method of producing a magnetic disk by lapping a magnetic disk medium, comprising the steps of:

Method of producing magnetic disk

In a magnetic recording medium in which a thin film of a magnetic material is disposed on a surface of a base of a non-magnetic material directly or through an undercoated film, powder of a material substantially the same as that of the non-magnetic base or an undercoated film is disposed directly beneath the magnetic thin film to form dispersed projections on the surface of the magnetic recording medium. Thus, the product has surface projections, and its magnetic thin film has a generally uniform thickness and uniform magnetic properties.

Magnetic recording medium having a thin film magnetic layer formed over

Lapping member and lapping tape

Fillers are mixed into a resin solution used to form a resin layer on the substrate of a magnetic disk. Therefore, the distance from the boundary between the resin layer and magnetic film to the filler top as well as the distance from the surface of the magnetic film to the top of the filler in the magnetic film are freely adjustable by appropriately setting the particle size of mixed fillers, thickness of the resin layer and thickness of magnetic film independently or in combination. Thus, the magnetic disk can be designed with a considerably improved freedom.

Magnetic disk and method of manufacturing same

A method of producing a magnetic disk by lapping a magnetic disk medium, comprising the steps of: preparing a lapping tape having an abrasive particle layer provided with abrasive particle clusters and chip pockets formed between adjacent two clusters, each of said clusters having abrasive particles of Al.sub.2 O.sub.3 or SiC and abrasive particles of diamond, lapping the surface of said magnetic disk medium by using the thus prepared lapping tape.

Growing community of inventors

Odawara, Japan

Masaaki Imamura