Abstract: A magneto-optical recording medium wherein an initializing layer is covered with a resin layer for dissipating heat from the initializing layer thereby to prevent signal degradation at high recording power and thus excellent in-record/reproduce repetition times, and the initializing layer is compositionally modulated thereby to broaden allowable ranges for the recording/reproducing light intensity and for the external magnetic field, besides the composition of a first or a second magnetic layer is controlled thereby to enhance recording sensitivity, and the exchange-coupling force between the first and second magnetic layers or the magnetic field strengthe to reverse the magnetization of the first magnetic layer is controlled thereby to enhance the recording/reproducing characteristics.

Abstract: An optical disc comprises two facing disc units, at least one of which has a recording layer formed on its surface facing to the other disc unit. The disc units are bonded together by a layer of adhesive which may be a room-temperature curing thermosetting adhesive having a glass transition temperature higher than the upper limit of the range of temperatures of environments in which the disc may be used. Alternatively, the adhesive may be a room-temperature curing two-pack epoxy adhesive which comprises a bisphenol epoxy resin base agent and a modified aliphatic polyamine curing agent, and which has a viscosity of 100-1000 cps, a pot life of one hour or more, a cure shrinkage of 1.0% or less, a water absorption, after curing, of 0.2% or less, and a Shore hardness, after curing, of 80-90.

Abstract: A magneto-optic recording system uses a unit recording medium having on a substrate a first magnetic layer whose Curie temperature is low and also having on the first magnetic layer a second magnetic layer whose Curie temperature is high. The system heats a spot on the medium with a heating device. The system may employ two such unit recording media, each having the second magnetic layer magnetized in one direction. The two unit recording media are superposed on each other and formed integrally so as to obtain a magneto-optic recording medium in which the amount of information recorded and the recording speed are doubled. In addition, a light-emitting device and a magnetic field generator are added to the magneto-optic recording medium to obtain a compact magneto-optic recording system with a low level of power consumption.

Abstract: The present invention provides a phosphonic diester derivative of the formula: ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are the same or different and they each represent a hydrogen atom, a lower alkyl group, a halogen atom, a cyano group, a hydroxyl group, or a lower alkoxy group optionally having a halogen atom, a phenyl group or a hydroxypiperidino group as a substituent; R.sup.4 represents a hydrogen atom, a lower alkoxy group, a halogen atom, or a lower alkyl group optionally having a halogen atom or a cyano group as a substituent; and R.sup.5 and R.sup.6 are the same or different and they each represent a hydrogen atom or a lower alkyl group.The derivative of the present invention has excellent hypolipidemic, vasodepressor and hypoglycemic activities and is useful as therapeutic and preventive agents for hyperlipidemic diseases, hypertension and diabetes.

Abstract: This invention relates to a multi-layer magneto-optic recording medium having an information recording layer and an initializing layer that can be overwritten by light modulation, and in which adjacent layers, including auxiliary layers provided for more efficient transfer from the initializing layer to the recording layer, are coupled by an exchange force. This structure enables high-density, high-speed recording of audio information, visual information, and computer data.

Abstract: The invention provides a phosphonic diester derivative of the formula: ##STR1## wherein the variables are as defined in the specification. The derivative of the invention has excellent hypolipidemic and hypoglycemic activities and little side effects and hence is useful as therapeutic and prophylactic agents for hyperlipidemic diseases and diabetes and as a therapeutic agent for cataract.

Abstract: A unit recording medium, having on a substrate a first magnetic layer whose Curie temperature is low and also having on the first magnetic layer a second magnetic layer whose Curie temperature is high, is heated by a heating device. After two such unit recording media each having the second magnetic layer magnetized in one direction are fabricated, and the fabricated two unit recording media are superposed on each other and formed integrally so as to obtain a magneto-optic recording recording medium in which the amount of information recorded and the recording speed are doubled. In addition, a light-emitting device and a magnetic field generator are added to the magneto-optic recording medium to obtain a compact magneto-optic recording system with a low level of power consumption.

Abstract: A magneto-optical recording medium allowing both direct overwriting by light power modulation and superresolutive reproduction, and a recording/reproduction method therefor are provided. The magneto-optical recording medium includes six magnetic layers of which adjacent layers are coupled by an exchange force thereof, the first magnetic layer being made of a rare earth-transition metal alloy or a ferromagnetic material containing a magnetic transition metal, the second to sixth magnetic layers being each composed of a rare earth-transition metal alloy. Each of the magnetic layers has a predetermined Curie temperature, and the respective transition metal sub-lattice magnetization directions of the first to third magnetic layers (including the magnetization direction of the first layer) are aligned in one direction at room temperature while at the same time those of the fourth to sixth magnetic layers are aligned in one direction at room temperature.

Abstract: An optical disk adapted to resist moisture absorption, warping and static charge is disclosed. The disk includes an SiO.sub.2 film coating over at least a portion of a disk substrate. Additionally, an optical disk having a magnetic film protected by a fluorocarbon polymer is disclosed. Either of such disks can be used individually or, alternatively, they can be used in a laminated structure having two disks laminated in a face-to-face relationship. The laminated structure can be covered with SiO.sub.2 film.

Abstract: A magnetic thin film memory is provided including a plurality of magnetic thin film memory elements each adapted to record information on the basis of the direction of magnetization of a magnetic thin film thereof, the magnetic thin film memory elements being each composed of at least the magnetic thin film and a switching element. With such a constitution the magnetic thin film memory can be reduced in size while a sufficiently large signal can be obtained with a substantially improved SN ratio. A method for recording and reproduction information using the magnetic thin film memory is also provided. In another aspect, the present invention provides a magnetic thin film memory element including at least two kinds of magnetic layer, and a nonmagnetic layer which is interposed between the magnetic layers wherein the two kinds of magnetic layers are stacked so as to be coupled to each other by an exchange interaction through the nonmagnetic layer.

Abstract: In an oil-operated tensioner, oil from s reservoir formed in the tensioner housing passes through a check valve to a chamber behind a spring-urged plunger, which protrudes from the housing to maintain tension in a chain or belt. Instead of the usual press-fit cup for closing the opening of the reservoir, a flat or convex cover plate is fixed to the housing for closing the opening in the reservoir.

Abstract: A MR element which has a basically three-layered structure wherein the first and the second magnetic layer sandwich the nonmagnetic layer or of a basically five-layered structure wherein nonmagnetic layers are sandwiched between the first and second magnetic layers and between the second and third magnetic layers, respectively. The MR element of such arrangement offers a surprisingly large MR ratio under application of a sufficiently low magnetic field despite such a simple arrangement thereof.

Abstract: The invention provides a phosphonic diester derivative of the general formula ##STR1## The phosphonic diester derivative of the invention has hypoglycemic and hypolipidemic activities, for instance, and is of value as an antidiabetic or anti-hyperlipidemic agent.

Abstract: A magneto-optic recording medium has a cartridge provided with a magnetization direction indicating portion for indicating the direction of magnetization of a second magnetic layer. Alternatively, the direction of magnetization of the second magnetic layer is recorded in advance in the first magnetic layer. The direction of magnetization of the second magnetic layer indicated or recorded is detected and recognized. A magnetic field oriented in an opposite direction to the direction of magnetization detected is imparted to the magneto-optic recording medium. Alternatively, predetermined information is recorded in the first magnetic layer, the direction of magnetization of the second magnetic layer is detected on the basis of a signal reproducing that information, and the direction of a magnetic field to be applied to the magneto-optic recording medium is set on the basis of the direction of magnetization thus detected.

Abstract: A magnetic thin film memory device having information recorded in a magnetic thin film thereof by the direction of magnetization, and adapted to reproduce the recorded information on the basis of the voltage generated as a result of the change of the magnetization direction due to the extraordinary Hall effect, magnetoresistance effect or the like.A magnetic thin film memory device in which a magnetic thin film is formed of ferrimagnetic substance having perpendicular magnetic anisotropy, and producing extraordinary Hall effect in the composition of RE rich and having the minimum saturation field which enables recording in a small magnetic field and is hard to be influenced by temperatures.

Abstract: A magnetic thin film memory wherein the memory is composed of magnetic thin films with a layer of a higher coercive force and a layer of a lower coercive force via a nonmagnetic layer laminated repetitively, or magnetic thin films having the easy magnetization axis which lies between the perpendicular and the horizontal directions of the magnetic thin film, and information is recorded on the layer of a lower coercive force, or information is recorded by changing the direction of the magnetization by means of a magnetic field applied by two recording lines which cross the magnetic thin film, thereby to obtain a sufficient amplitude of reproduction signal even when the size of the memory is reduced.

Abstract: An information storage system for recording and reproducing information by use of irradiating light on a medium capable of overwriting information is provided. The information storage system is capable of recording information even if the light intensity is varied so as to enhance reliability. The intensity of the light at the time of overwriting is modulated, the more intense light intensity being P.sub.H and the less intense light intensity being P.sub.L. The system includes a mechanism to keep relationship of P.sub.H +.alpha.P.sub.L equal to a constant (.alpha. being a constant depending on the recording conditions). The laser drive circuit is so adjusted that P.sub.H and P.sub.L always provide an optimal condition even if P.sub.H and/or P.sub.L vary. Thus recording can always be performed under optimal conditions to enhance the reliability of the information storage system to expand the power margin of a recording medium and to increase the percentage yield of information medium.

Abstract: An optical disc comprises two facing disc units, at least one of which has a recording layer formed on its surface facing to the other disc unit. The disc units are bonded together by a layer of adhesive which may be a room-temperature curing thermosetting adhesive having a glass transition temperature higher than the upper limit of the range of temperatures of environments in which the disc may be used. Alternatively, the adhesive may be a room-temperature curing two-pack epoxy adhesive which comprises a bisphenol epoxy resin base agent and a modified aliphatic polyamine curing agent, and which has a viscosity of 100-1000 cps, a pot life of one hour or more, a cure shrinkage of 1.0% or less, a water absorption, after curing, of 0.2% or less, and a Shore hardness, after curing, of 80-90.

Abstract: Methods and apparatuses are disclosed for improving accuracy of recording and reproducing information onto and from a magneto-optic recording information medium. In the first method, a width of a mark formed by a relatively low intensity light beam between two kinds of light beam intensities used for recording information is made larger than a sum of a track land width and the maximum track offset of the light beam, thereby the mark formed by the relatively low intensity light beam covers the track land portion in its full width. In the first apparatus, a reflected light beam from the magneto-optic recording information medium is split into a reflected beam for information reproducing and a reflected beam for tracking and focusing servos at the reproducing, thereby the apparatus can remove part being affected by the track groove portion from the reflected light beam for information reproducing.

Abstract: A magneto-optical disk comprising a substrate, a dielectric film made of aluminum germanium nitride disposed on the substrate and a magnetic film disposed on the dielectric film. The magnetic-optical disk has increased Kerr rotational angle, while having excellent corrosion resistivity and high performance with respect to the CNR ratio.