Abstract: A magneto-optical storage medium includes: a reproduction magnetic layer exhibiting in-plane magnetization at room temperature and changing to perpendicular magnetization at a critical temperature or higher; first and second in-plane magnetized layers with Curie temperatures in a proximity of the critical temperature and exhibiting mutually opposite magnetic polarities; and a recording magnetic layer fabricated from a perpendicularly magnetized film, the reproduction magnetic layer, the first and second in-plane magnetized layers, and the recording magnetic layer being sequentially deposited, wherein the reproduction magnetic layer is exchange-coupled with the first and second in-plane magnetized layers at least at room temperature.

Abstract: In the present invention, in a pre-recorded information recording region on an optical disk capable of recording in both a land and a groove, a first address region is displaced off a second address region along the length of the track. Address information is stored by a first pit string P1 following a groove G1 in the first address region and by a second pit string P2 following a groove G2 in the second address region. The first pit string P1 and the second pit string P2 are adapted so that the gaps between pits constituting those strings in accordance with address information are equal to, or less than, the width of the pits measured in a radial direction of the disk. Thus, the present invention offers an optical disk and a recording/reproducing device which effect a stable tracking control.

Abstract: The magneto-optical storage medium includes: a reproduction layer exhibiting in-plane magnetization at room temperature and changing to perpendicular magnetization above a transition temperature Tp1; a first in-plane magnetized layer disposed adjacent the reproduction layer and constituted by an in-plane magnetized film having a Curie temperature Tc2 around the transition temperature Tp1; a storage layer constituted by a perpendicularly magnetized film for storing information; and at least one supplementary reproduction section, interposed between the storage layer and the first in-plane magnetized layer, constituted by a first supplementary reproduction layer and a second in-plane magnetized layer, the first supplementary reproduction layer exhibiting in-plane magnetization at room temperature and changing to perpendicular magnetization above a transition temperature Tp3, the second in-plane magnetized layer being disposed adjacent the first supplementary reproduction layer and constituted by an in-pla

Abstract: An optical recording medium includes a substrate having groove and land areas, in which address pits having substantially the same depth and which are formed deeper than the groove area are provided. By thus forming the address pits deeper than the groove area, address information can be reproduced accurately, and the optical recording medium can readily be manufactured by making the address pits which are respectively formed in the groove and land areas to have substantially the same depth.

Abstract: A magneto-optical recording medium includes at least: a reproducing magnetic layer composed at least of Gd and Co showing an in-plane magnetization state at room temperature and a transition to a perpendicular magnetization state at temperatures of not lower than a critical temperature; and a recording magnetic layer formed of a perpendicular magnetization film, the reproducing magnetic layer and the recording magnetic layer being magneto-statically coupled at least in the vicinity of the critical temperature, the reproducing magnetic layer containing at least either Tb or Dy so as to increase the total magnetization at a temperature at which a perpendicular magnetic anisotropy constant and a diamagnetic field energy are equal to each other.

Abstract: An optical recording medium includes a substrate having groove and land areas, in which address pits having substantially the same depth and which are formed deeper than the groove area are provided. By thus forming the address pits deeper than the groove area, address information can be reproduced accurately, and the optical recording medium can readily be manufactured by making the address pits which are respectively formed in the groove and land areas to have substantially the same depth.

Abstract: An optical read/write apparatus causes a read/write light beam from illuminating means to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers. In this case, the optical read/write apparatus operates so that data is read/written from/into a second data storage layer after fully recording a recordable area of a first data storage layer. Thus, light can be shone with uniform intensity across the substantially entire recordable area of the second data storage layer without using a complex read/write system even under such conditions that the transmittance to light of the first data storage layer in the recordable area may vary depending on whether any data is recorded in the recordable area.

Abstract: A magneto-optical recording medium includes at least a first magnetic layer, a second magnetic layer and a third magnetic layer which are layered in this order, the first magnetic layer being formed of a perpendicularly magnetized film having a relatively small wall coercivity and a relatively large wall mobility compared with the third magnetic layer in the vicinity of a predetermined temperature, and the magneto-optical recording medium satisfies conditions

Abstract: A magneto-optical recording medium is provided with at least: a recording layer, made of a perpendicular magnetization film, in which magnetized information is recorded in the form of a perpendicular direction of magnetization; a magnetic flux generating layer, made of a perpendicular magnetization film, which is exchange-coupled with the recording layer; and a read-out layer, having a perpendicular magnetization at a predetermined temperature or higher temperatures than the predetermined temperature, which copies the magnetized information of the recording layer by magneto-static coupling with the magnetic flux generating layer and the recording layer, wherein the magnetic flux generating layer is a magnetic film having a lower Curie temperature than that of the recording layer and having a larger total magnetization than that of the recording layer at a temperature at which the read-out layer has a perpendicular magnetization.

Abstract: A magneto-optical recording medium according to the present invention includes a reproducing layer having in-plane magnetization at room temperature and shifting to have perpendicular magnetization at temperatures at and above a critical temperature, a first in-plane magnetized layer having a Curie temperature in the vicinity of the critical temperature, a second in-plane magnetized layer having a Curie temperature higher than that of the first in-plane magnetized layer, and a recording layer made of a perpendicularly magnetized film, provided in that order.

Abstract: A magneto-optical recording medium comprising a recording magnetic layer made of a perpendicularly magnetized film and a multilayer reproducing film, wherein the multilayer reproducing film has two reproducing magnetic layers which are in a in-plane magnetized state at room temperature and shift to a perpendicularly magnetized state with a rise in temperature and an in-panel magnetized layer disposed between the two reproducing magnetic layers, which is in an in-plane magnetized state from room temperature to a Curie temperature and has a lower Curie temperature than the recording magnetic layer and the reproducing magnetic layers.

Abstract: A reproducing layer having perpendicular magnetization in a single layer, an in-plane magnetic layer, and a recording layer having perpendicular magnetization are formed in this order. When the reproducing layer, the in-plane magnetic layer, and the recording layer have the Curie temperatures of Tc1, Tc2, and Tc3, these values satisfy conditions of Tc2<Tc1 and Tc2<Tc3. The reproducing layer has in-plane magnetization due to an exchange coupling with the in-plane magnetic layer at lower than Tc2. At Tc2 or higher, magnetization information is expanded and transferred from the recording layer to the reproducing layer, so that the reproducing layer has single-domain perpendicular magnetization.

Abstract: There are provided a magneto-optical disk, a super-resolution magneto-optical disk and a domain wall moving magneto-optical disk whose cross-talk, cross-write and cross-erasure are suppressed and whose recording density is improved. A recording magnetic layer formed on a land is shut off magnetically from the recording magnetic layer formed on a groove and thermal diffusion in the track direction is suppressed, by selectively oxidizing a magnetic layer formed on a side wall between the land and the groove.

Abstract: A recording and reproducing device of the present invention is provided to achieve the object of realizing stable and desirable recording and reproducing of information by suppressing fluttering of an optical disk by way of suppressing pressure fluctuation which is caused, for example, when an objective lens or an optical pickup with the objective lens is moved. The object is attained by a transparent stabilizer, provided between a disk and an optical pickup, which is moved with the optical pickup, and a slider which is provided to face the transparent stabilizer with the disk in between. The slider is supported to oscillate, and the surface of the slider facing the disk is flat. During rotation of the disk, the slider moves to balance the air pressure between the transparent stabilizer and the disk with that between the slider and the disk.

Abstract: A disc-like recording medium provided with a disc substrate having a hole at its center and a circular information recording area at its surface that is concentric with the hole, and a hub that is fitted to the hole, wherein the disc substrate has a relief portion thereon for position alignment of the hub.

Abstract: A magneto-optical recording medium includes at least a first magnetic layer, a second magnetic layer and a third magnetic layer which are layered in this order, the first magnetic layer being formed of a perpendicularly magnetized film having a relatively small wall coercivity and a relatively large wall mobility compared with the third magnetic layer in the vicinity of a predetermined temperature, and the magneto-optical recording medium satisfies conditions Tc2<Tcomp1<Tc1 and Tc2<Tcomp1<Tc3 where Tcomp1 is a compensation temperature of the first magnetic layer, Tc1, Tc2 and Tc3 are Curie temperatures of the first, second and third magnetic layers, respectively.

Abstract: A magneto-optical recording medium includes at least a first magnetic layer, a second magnetic layer, a third magnetic layer, a non-magnetic intermediate layer and a fourth magnetic layer which are layered in this order, the first magnetic layer being formed of a perpendicularly magnetized film having a relatively small wall coercivity and a relatively large wall mobility compared with the third magnetic layer in the vicinity of a predetermined temperature, the second magnetic layer being formed of a magnetic film whose Curie temperature is lower than the Curie temperatures of the first magnetic layer and third magnetic layer, the fourth magnetic layer being a perpendicularly magnetized film with a uniform magnetization direction and forming a region having a uniform magnetization direction in the first magnetic layer by magnetostatic coupling with the first magnetic layer when the second magnetic layer is heated to a predetermined temperature or a higher temperature.

Abstract: A magneto-optical storage medium includes: a reproduction layer exhibiting an in-plane magnetization state at room temperature and changing to a perpendicular magnetization state at a transition temperature Tp1; a supplementary reproduction layer exhibiting an in-plane magnetization state at room temperature and changing to a perpendicular magnetization state at a transition temperature Tp2; a non-magnetic intermediate layer; and a storage layer made of a perpendicular magnetization film, the layers being deposited in this order, the magneto-optical storage medium being arranged so as to satisfy: Tp1<Tp2 This arrangement enables the magneto-optical storage medium to amplify the magnetic information stored in the storage layer and duplicate it to the reproduction layer, and signals whose cycle is equal to, or below, diffraction limits of light to be reproduced from the storage layer without reducing the amplitude.

Abstract: In the present invention, in a pre-recorded information recording region on an optical disk capable of recording in both a land and a groove, a first address region is displaced off a second address region along the length of the track. Address information is stored by a first pit string P1 following a groove G1 in the first address region and by a second pit string P2 following a groove G2 in the second address region. The first pit string P1 and the second pit string P2 are adapted so that the gaps between pits constituting those strings in accordance with address information are equal to, or less than, the width of the pits measured in a radial direction of the disk. Thus, the present invention offers an optical disk and a recording/reproducing device which effect a stable tracking control.

Abstract: A squeeze type pump that transfers slurry via an elastic tube by squeezing the elastic tube with pairs of rollers to elastically deform the tube by moving each pair of squeezing rollers. The elastic tube has an outer diameter, an inner diameter, and a thickness. A ratio of the inner diameter to the outer diameter is set within a range of 0.56 to 0.72, and the thickness is set within a range of 23 to 35 mm.