摘要:
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. With such an arrangement, an external magnetic field for initializing the reproducing layer and an external magnetic field for reproduction-use can be omitted, thereby preventing a recording device from becoming large in size, as well as enhancing the recording density of the recording layer.
摘要:
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. Therefore, track pitches can be made narrower so as to increase recording density of the magnetic recording medium. Further, since crosstalk from adjoining tracks is eliminated, a high S/N can be achieved.
摘要:
A magneto-optical recording medium is composed of a base which has a property that a light can be transmitted therethrough, a readout layer formed on the base, which has in-plane magnetization at room temperature, whereas, a transition occurs from in-plane magnetization to perpendicular magnetization as the temperature thereof is raised and a recording layer formed on the readout layer for recording information magneto-optically. A recording and reproducing method and the optical head are designed for the magneto-optical recording medium. By the recording and reproducing method using the optical head, information recorded at high density can be reproduced.
摘要:
A magneto-optical recording disk includes a recording layer for recording information as a mark and a reproduction layer, laminated with the recording layer, to which magnetization direction of the recording layer is transferred at high temperatures, wherein the reproduction layer and the recording layer are magnetostatically coupled and are not exchange-coupled. The information is read out by using a temperature distribution generated by a light beam for reproduction. The recording layer has, on a side thereof to which the reproduction layer is not provided, a supplementary back layer of a soft magnetic material composed of ferromagnetic material. The magneto-optical disk is designed to generate good CNR and thereby improves recording density even when a short mark is reproduced.
摘要:
Featured is a recording and reproducing method of a magneto-optical recording medium including a recording layer for recording thereon information magneto-optically and a readout layer which has in-plane magnetization at room temperature and where a transition occurs from in-plane magnetization to perpendicular magnetization as temperature raises. The method includes projecting a light beam onto such a magneto-optical recording medium so as to form a perpendicularly magnetized area in the readout layer by duplication of the magnetization of said recording layer to the area. In further embodiments, the recording medium further includes an intermediate layer made of non-magnetic film formed between the readout and recording layers and the readout and recording layers are composed of rare-earth transition metal alloys such as TbFeCo (recoding layer) readout layer, made of GdFeCo (readout layer).
摘要:
Featured is a recording and reproducing method for recording and reproducing information on and from a recording medium. The medium includes a base having a property that a light can be transmitted therethrough, a readout layer formed on the base, which has an in-plane magnetization at room temperature, whereas, a transition occurs from in-plane magnetization to perpendicular magnetization as temperature rises and a recording layer formed on said readout layer for recording thereon information magneto-optically. A groove for guiding a light beam is formed on a readout layer side of the base and a groove width is set substantially equal to a land width formed between grooves. The recording layer on the grooves and the recording layer on lands are used in recording and reproducing information. Further a light beam is incident on a converging lens of an optical head, the light beam having a larger diameter &ohgr; than an aperture &agr; of the converging lens for converging the light beam on a predetermined position of the magneto-optical recording medium.
摘要:
A magneto-optical memory medium according to the present invention comprises a reproducing layer, which has in-plane magnetization at room temperature and perpendicular magnetization when heated to above a predetermined temperature by a reproducing light beam; a recording layer, which is magnetostatically coupled to the reproducing layer; and an in-plane magnetized layer, provided adjacent to the recording layer, which has a Curie temperature at the above-mentioned predetermined temperature. In this medium, at temperatures below the predetermined temperature, signals recorded at high density in the recording layer are masked, and the above-mentioned magnetostatic coupling is suppressed, by magnetic masking by the in-plane magnetized layer. At temperatures above the predetermined temperature, however, within a domain forming part of the in-plane magnetized layer, the recording layer and the reproducing layer are magnetostatically coupled, and a recording bit of the recording layer is copied and expanded to a magnetic domain in the reproducing layer. Accordingly, with this medium, by reproducing from an expanded magnetic domain of the reproducing layer, even information from recording bits recorded at high density can be reproduced with high signal quality.
摘要:
A magneto-optical memory medium according to the present invention comprises a reproducing layer, which has in-plane magnetization at room temperature and perpendicular magnetization when heated to above a predetermined temperature by a reproducing light beam; a recording layer, which is magnetostatically coupled to the reproducing layer; and an in-plane magnetized layer, provided adjacent to the recording layer, which has a Curie temperature at the above-mentioned predetermined temperature. In this medium, at temperatures below the predetermined temperature, signals recorded at high density in the recording layer are masked, and the above-mentioned magnetostatic coupling is suppressed, by magnetic masking by the in-plane magnetized layer. At temperatures above the predetermined temperature, however, within a domain forming part of the in-plane magnetized layer, the recording layer and the reproducing layer are magnetostatically coupled, and a recording bit of the recording layer is copied and expanded to a magnetic domain in the reproducing layer. Accordingly, with this medium, by reproducing from an expanded magnetic domain of the reproducing layer, even information from recording bits recorded at high density can be reproduced with high signal quality.
摘要:
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. Therefore, track pitches can be made narrower so as to increase recording density of the magnetic recording medium. Further, since crosstalk from adjoining tracks is eliminated, a high S/N can be achieved.
摘要:
A magnetic recording and reproducing apparatus using a recording medium made of a ferrimagnetic material, comprises a magnetic head for magnetically recording information on a recording area of a selected information recording track on a recording medium having a plurality of tracks and for magnetically reproducing the information from the recording medium, the magnetic head has a width larger than that of the width of the selected information recording track of the recording medium. For recording, light beams are radiated from a first light source on the recording area of the selected information recording track upon which recording is to be performed tracks to raise the temperature of the irradiated area to approximately a Curie temperature so as to allow recording only on that area. For reproduction, light beams are radiated from another light source onto areas on both sides of on a second area of the recording medium, located on both sides of the selected information recording track, to raise the temperature of the second irradiated areas to approximately a magnetic compensation temperature so as to allow reproduction only from the desired track, thus preventing crosstalk from the side tracks.