Abstract: A non-magnetic intermediate layer for intercepting magnetic exchange interaction is provided between a recording layer and a reproducing layer which are composed of a magnetic thin film with perpendicular magnetization. At this time, the reproducing layer is formed so that when an external magnetic field is applied thereto in reproducing information, its magnetization direction is arranged in the direction of the external magnetic field in a first temperature range, and when a light beam for reproduction is projected thereto and the reproducing layer is in a second temperature, the magnetization direction is arranged in the direction of a leakage magnetic flux generated from the recording layer, and is again arranged in the direction of the external magnetic field in a third temperature range. As a result, a rise and a fall of a reproducing signal detected from the reproducing layer can be made sharp, thereby achieving recording and reproducing at high density.

Abstract: A magneto-optical recording medium has at least a substrate, a first magnetic layer, a second magnetic layer, and a first interface layer provided between the first and second magnetic layers. The first magnetic layer exhibits a perpendicular magnetic anisotropy from room temperature to a Curie temperature thereof. The second magnetic layer has a coercive force lower than A: that of the first magnetic layer at room temperature, has a Curie temperature higher than that of the first magnetic layer, and exhibits a perpendicular magnetic anisotropy from room temperature to a Curie temperature of the second magnetic layer. The first interface layer is made of at least one rare-earth metal and has a thickness of several atoms. With this arrangement, it is possible (1) to carry out light modulation overwriting with respect to the magneto-optical recording medium, (2) to carry out initialization without an initializing magnetic field, and (3) to stabilize recording bits.

Abstract: If the Curie points of the first magnetic layer, second magnetic layer, third magnetic layer and fourth magnetic layer of alloys of rare-earth metal and transition metal as ferrimagnetic materials showing perpendicular magnetization from room temperature to their Curie points are indicated as Tc1, Tc2, Tc3 and Tc4, respectively, the Curie points and room temperature are related by: room temperature<Tc3<Tc4<Tc1<Tc2. If the sublattice magnetization of transition metal is indicated as .alpha. and the sublattice magnetization of rare-earth metal is .beta., .alpha. is stronger than .beta. in the second magnetic layer at temperatures between Tc1 and Tc2, and .beta. is stronger than .alpha. in the fourth magnetic layer at temperatures between room temperature and Tc4.

Abstract: A magneto-optical recording medium is arranged so that (1) a first transparent dielectric layer, (2) a reproduction layer showing in-plane magnetization at room temperature while showing perpendicular magnetization in response to temperature rise, (3) a second transparent dielectric layer, (4) a recording layer made of perpendicular magnetization film; and (5) a protective layer are laminated on a substrate in this order. The reproduction layer has a thickness of 5 nm to 30 nm, the second transparent dielectric layer has a thickness of 6 nm to 40 nm, and the recording layer has a thickness of 20 nm to 80 nm. It is possible to separately reproduce individual recording bit even when one or more adjacent recording bits exist within the diameter of the light beam converged onto a target recording bit. This is because the information of a recording magnetic domain of a portion showing in-plane magnetization is masked.

Abstract: An optical probe element for focusing light from a light source into micro light of a diameter not larger than the diffraction limit, includes a light transmitting flat substrate and an optical probe formed on one of the surfaces of the flat substrate. The optical probe has a substantially conical light transmitting projection, and a reflective film which covers the conical surface of the projection so that the tip of the projection is exposed. The optical probe element enables the optical probe to be formed on the flat substrate using a semiconductor processing technique, thereby achieving efficient mass production of a standardized optical probe element. Thus, a recording and reproduction apparatus using the optical probe element is efficiently mass-produced.

Abstract: A magneto-optical recording medium has a transparent substrate, a first magnetic layer, first intermediate layer, a second magnetic layer, and a third magnetic layer provided in this order. The first magnetic layer has an in-plane magnetization at room temperature, while a transition from the in-plane magnetization to a perpendicular magnetization occurs to the first magnetic layer with a temperature rise. The first intermediate layer is made of a non-magnetic substance. The second magnetic layer is a film having a perpendicular magnetization. The third magnetic layer is a film having a perpendicular magnetization, has a coercive force smaller than that of the second magnetic layer at room temperature, and has a Curie temperature higher than that of the second magnetic layer.

Abstract: A magneto-optical recording medium is composed of a reproducing layer, a recording layer, and an initializing layer, which are laminated in this order. The reproducing layer is provided so that a light beam is projected thereon so as to reproduce information. The recording layer is provided so that information is recorded therein and the information is copied to the reproducing layer at a readout temperature. The initializing layer is provided so that the reproducing layer is initialized at room temperature. Non-magnetic layers are provided between the reproducing layer and the recording layer and between the recording layer and the initializing layer, respectively, so that such two layers are not exchange-coupled each other. The recording layer has a compensation temperature of room temperature, while the initializing layer has a compensation temperature of the readout temperature, which is achieved by temperature rise caused by the projection of the light beam.

Abstract: A magneto-optic memory device includes a transparent dielectric film of a non-oxygen containing nitride material deposited by sputtering on a substrate such as glass, a rare-earth/transition metal alloy recording medium deposited by sputtering on the dielectric film and a reflecting film deposited over the recording medium with or without an intervening transparent dielectric film of non-oxygen containing nitride material. This arrangement prevents the recording medium from being oxidized, and stablizes coercive force characteristics and information recording characteristics of the recording medium.

Abstract: A magneto-optic memory device which comprises a recording medium deposited by sputtering on a substrate such as glass, a transparent dielectric film formed on the recording medium, and a reflecting film deposited on the transparent dielectric film. This arrangement prevents the recording medium from being oxidized, and stabilizes coercive force characteristics and information recording characteristics of the recording medium.

Abstract: A magneto-optical recording medium has an exchange-coupled triplilayer film wherein a readout layer which has in-plane magnetization at room temperature, and in which a transition occurs from in-plane magnetization to perpendicular magnetization when temperature thereof is raised above T.sub.1, an intermediate layer which has perpendicular magnetization at room temperature, the perpendicular magnetization being maintained from room temperature to Curie temperature T.sub.3, and a recording layer which has perpendicular magnetization at room temperature, the perpendicular magnetization been maintained from room temperature to Curie temperature T.sub.2 which are laminated in this order, and the temperatures T.sub.1, T.sub.2 and T.sub.3 satisfy the following inequality: T.sub.1 <T.sub.3 <T.sub.2.

Abstract: A magneto-optical recording medium including a base; a readout layer formed on the base; a recording layer formed on the readout layer; and an auxiliary recording layer formed on the recording layer, each of the readout layer, recording layer and auxiliary recording layer being made of an alloy of rare-earth metal and transition metal showing ferrimagnetism.

Abstract: A magneto-optical recording medium includes a first magnetic layer and a second magnetic layer being laminated. When information is to be recorded on the first magnetic layer, first, a magnetization direction in the second magnetic layer is arranged in one direction with an application of an initialization magnetic field. Then, an intensity modulated light beam is projected while applying thereto a recording magnetic field so as to change the magnetization direction in the second magnetic layer. Thereafter, the magnetization direction in the second magnetic layer is copied to the first magnetic layer, thereby recording information. The first magnetic layer has a magnetization in an intermediate direction between a perpendicular direction and an in-plane direction at room temperature, while has a perpendicular magnetization at above a predetermined temperature.

Abstract: A magneto-optical disk provided with a record layer having a recording magnetic domain where data are recorded, an auxiliary reproduction layer for transferring the record data in the record layer to a reproduction layer by generating a floating magnetic field corresponding to the data in the record layer, and the reproduction layer from which the data are read out through irradiation of a light beam, which are sequentially layered while interposing non-magnetic intermediate layers therebetween. The stable magnetic domain width in the auxiliary reproduction layer is shorter than the recording magnetic domain width at room temperature and extends as the temperature rises and becomes longer at or above a first temperature. The stable magnetic domain width in the reproduction layer is longer than the recording magnetic domain width at room temperature and lessens as the temperature rises and becomes shorter at or above a second temperature which is lower than the first temperature.

Abstract: In an optical disk, since a header section has only one recording section for address information, the capacity of memory where a user can freely record data is increased. In an optical disk drive, four laser beams have a fixed positional relation. Based on the address information of a header section read out by at least one of the laser beams and the positional relation among the laser beams, the address information of tracks being scanned by the other laser beams is obtained. It is therefore possible to accurately record or reproduce information on the optical disk.

Abstract: Grooves and lands are provided to a magneto-optical disk so as to be alternately arranged, and recording bit strings are formed on the grooves and lands respectively so that information is recorded. Moreover, pit rows are formed on boundary sections between the adjoining grooves and lands so that address information of a recording/reproducing track is recorded, and the pit rows are formed every other boundary section. When the grooves and the lands are scanned as the recording/reproducing track by a light, an address of the recording/reproducing track is read out from the pit rows, and successively, discrimination is made whether the recording/reproducing track which is scanned by an optical spot is the groove or the land. This prevents crosstalk which causes inclusion of address information in the next pit rows, thereby, making it possible to obtain accurate address information.

Abstract: A magneto-optical recording medium with a first, second, and third magnetic layers which are laminated on a substrate. The first magnetic layer has a perpendicular magnetization in a temperature range between room temperature and its Curie temperature. The second magnetic layer has an in-plane magnetization at room temperature, and has a perpendicular magnetization at or above a temperature falling within a range between room temperature and its Curie temperature. The third magnetic layer has an in-plane magnetization at room temperature, and has a perpendicular magnetization at or above a temperature falling within a range between room temperature and the temperature at which a transition occurs in the second magnetic layer from the in-plane magnetization to the perpendicular magnetization.

Abstract: A recording layer including a recording magnetic domain for recording thereon information is formed. A reproducing layer for reproducing information by projecting thereto a light beam is formed on the recording layer. A non-magnetic intermediate layer for intercepting a magnetic exchange coupling force exerted between the recording layer and the reproducing layer is formed between the recording layer and the reproducing layer. The reproducing layer is arranged such that the width of the stable magnetic domain on the reproducing layer at room temperature is larger than the width of the recording magnetic domain in the recording layer. At a reproducing temperature by the light beam, the width of the stable magnetic domain becomes smaller than the width of the recording magnetic domain, and the information is copied by the leakage magnetic flux of the recording magnetic domain.

Abstract: A magnetic recording medium having a recording layer made up of a ferrimagnetic material whose compensation temperature is included within room temperatures and an information recording-reproduction method using the magnetic recording medium. During recording, while a light beam is projected on the recording layer so as to raise the temperature of a recording portion, information is recorded by applying a signal magnetic field from a magnetic head. During reproduction, while a light beam is projected on a reproducing portion of the recording layer so as to raise the temperature thereof, information is reproduced by detecting leakage flux from the reproducing portion by the magnetic head. Thus, during reproduction, no magnetic flux is generated from other portions of the recording layer not irradiated by the light beam. With the arrangement, crosstalk due to leakage flux from adjoining tracks not irradiated by the optical beam can be eliminated.

Abstract: A magneto-optical recording medium including a base; a readout layer formed on the base; a recording layer formed on the readout layer; and an auxiliary recording layer formed on the recording layer, each of the readout layer, recording layer and auxiliary recording layer being made of an alloy of rare-earth metal and transition metal showing ferrimagnetism.

Abstract: An intermediate layer is formed between a memory layer and a writing layer. The intermediate layer shows in-plane magnetization at room temperature, and perpendicular magnetization within a temperature range within which the coercive force of the memory layer is lower than that of the writing layer. The Curie point of the intermediate layer is lower than that of the memory layer. Like a conventional method, light-intensity modulation overwriting is performed by irradiating laser light whose intensity has been modulated between high level and low level while applying a recording magnetic field after performing an initialization. Even when there are variations in the raised temperature by the irradiation of laser light of high level, it is possible to perform stable overwriting with light-intensity modulation by satisfactorily restraining the exchange forces between the intermediate layer and the writing layer from causing coupling.