Seiko Epson Corporation

Akira Aoyama

Mamoru Sugimoto

Tatsuya Shimoda

Satoshi Nebashi

Satoshi Shimokawato

Shin Funada

Shigeru Kogure

Nobuhiko Kano

Shinobu Kunida

An optical recording medium having at least one aluminum nitride and silicon nitride composite dielectric layer is provided. The amount of aluminum nitride in the dielectric layer, x, is more than zero and less than or equal to about 95 mol %. The amount of silicon nitride in the layer is represented as (100-x) and is equal to or greater than about 5 and less than 100 mol %. The refractive index of the composite dielectric layer is between about 1.70 and 2.15. The composite dielectric layer is sandwiched between a transparent support such as a plastic transparent support and an optical recording layer adapted to be irradiated by laser light in order to read, write or erase information in order to protect the recording layer.

Optical recording medium and method of preparing same

A magnetic recording film and a magneto-optic recording system utilizing films. The film includes light and heavy rare earth elements and transition metal elements. The system can include dielectric layers and low magnetic coercivity layers in addition to the recording layer.

Magneto-optic recording systems

A magnetic thin film recording layer comprised primarily of a light rare earth element and a transition metal element is disclosed. Other elements are optionally included in the film. The film has an easy axis of magnetization perpendicular with respect to the surface of the film. Magneto-optic recording systems using such films are also disclosed.

A magneto-optic recording medium including a transparent substrate and a non-oxide dielectric layer formed thereon is provided. The dielectric layer includes a first dielectric material of the type which exhibits cracks running in a generally radial direction when deposited on a surface and which is designated dielectric Group A and a second dielectric material which exhibits cracks running in a generally tangential direction when deposited on a surface and which is designated dielectric Group B. The dielectric layer may be separate layers or a mixture of the two dielectric materials.

Optical recording medium

An optical recording medium having two adhered substrates one of which has a magneto-optic recording layer thereon and the other of which has at least one dielectric layer thereon so as to improve stability and weatherability. The dielectric layer is a transparent oxide, a nitride or a mixture of an oxide and a nitride and has a thickness between about 30.ANG. and 10 .mu.m. In an especially preferred embodiment, neither substrate is provided with any layers in either the internal area or the circumferential area of a disk and the substrates themselves are exposed and adhered together with adhesive.

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Nagano-ken, Japan

Akira Aoyama