Sharp Kabushiki Kaisha Corporation

Ippei Suzuki

Akira Takahashi

Naoyasu Iketani

Yoshiteru Murakami

Go Mori

Michinobu Mieda

Junji Hirokane

Shinya Hirata

A magneto-optical recording medium comprising a reproducing magnetic layer having a magnetic layer which is in an in-plane magnetization state at room temperature but shifts to a perpendicular magnetization state as temperature rises, a dielectric layer and a recording magnetic layer having a magnetic layer which exhibits a perpendicular magnetization, sequentially from a photo-receptive side, the recording medium being further comprising a metal layer between the reproducing magnetic layer and the dielectric layer.

Magneto-optical recording medium and process for producing the same

An optical disk is provided with a recording layer, and with an optical coupling layer on a light-incident side of the recording layer. An optical recording and reproducing device and method include an objective lens and a hemispherical lens, which converge a light beam from a light source and project the light beam onto the optical disk. The hemispherical lens is provided in close proximity to the optical coupling layer, in a position such that an interval therebetween is not more than the wavelength of the light produced by the light source. The light beam converged by the objective lens and the hemispherical lens is coupled with the optical coupling layer while substantially maintaining a direction of propagation in which it was propagating while inside the hemispherical lens.

Optical recording and reproducing method optical recording and reproducing device, and optical recording medium

An optical disk of the present invention includes a transparent dielectric film formed on a light incident side of the disk on an opposite side of an optical recording film so as to sandwich the transparent substrate therebetween, for suppressing bimetallic effects caused by a difference in thermal expansion between an optical recording film formed on an optical recording surface and the transparent substrate, whereby changes in tilt against temperature changes can be suppressed. Further, by an optimal selection of a reflectance of the transparent dielectric film, unwanted reflection due to multi-interference can be reduced at the same time.

Optical recording disk capable of suppressing bimetallic effects caused

A magneto-optical recording medium with a reproducing layer that exhibits in-plane magnetization at room temperature and that comes to exhibit perpendicular magnetization as temperature rises. The second shielding layer is used to block the magnetization of record bits other than a record bit to be reproduced from being copied on a signal reproducing area in the reproducing layer. Consequently, even in the case of high-density record bits in the recording layer, only the magnetization of the record bit to be reproduced is copied on the reproducing layer. Therefore, the application of the magneto-optical recording medium makes it possible to produce superior reproducing signals even in the case where the records bits with high density are formed on the recording layer.

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Tenri, Japan

Ippei Suzuki